transmission FORD MONDEO 1993 Service Manual PDF

24Ford specify the use of their STAR (Self-
Test Automatic Readout) tester; most Ford
dealers should have such equipment, and the
staff trained to use it effectively. The only
alternatives are as follows:
(a) To obtain one of those proprietary readers
which can interpret EEC-IV three-digit
codes - at present, such readers are too
expensive for the DIY enthusiast, but are
becoming more popular with smaller
specialist garages.
(b) To use an analogue voltmeter, whereby
the stored codes are displayed as sweeps
of the voltmeter needle. This option limits
the operator to a read-out of any codes
stored - ie, there is no control of sensors
and/or actuators - but can still be useful in
pinpointing the faulty part of the engine
management system. The display is
interpreted as follows. Each code
(whether fault code or
command/separator) is marked by a
three-to-four second pause - code “538”
would therefore be shown as long (3 to
4 seconds) pause, five fast sweeps of the
needle, slight (1 second) pause, three fast
sweeps, slight pause, eight fast sweeps,
long pause.
(c) Owners without access to such
equipment must take the vehicle to a Ford
dealer, or to an expert who has similar
equipment and the skill to use it.
25Because of the variations in the design of
fault code readers, it is not possible to give
exact details of the sequence of tests; the
manufacturer’s instructions must be followed,
in conjunction with the codes given below.
The following ten paragraphs outline the
procedure to be followed using a version of
the Ford STAR tester, to illustrate the general
principles, as well as notes to guide the owner
using only a voltmeter.
26The vehicle must be prepared by applying
the handbrake, switching off the air
conditioning (where fitted) and any other
electrical loads (lights, heated rear window,
etc), then selecting neutral (manual
transmission) or the “P” position (automatic
transmission). Where the engine is required to
be running, it must be fully warmed-up to
normal operating temperature before the test
is started. Using any adaptors required,
connect the fault code reader to the system
via the (triangular, three-pin) self-test
connector on the right-hand end of the engine
compartment bulkhead (see illustration). If a
voltmeter is being used, connect its positive
lead to the battery positive terminal, and its
negative lead to the self-test connector’s
output terminal, pin 17. Have a pen and paper
ready to write down the codes displayed.
27Set the tester in operation. For the Ford
STAR tester, a display check will be carried
out and the test mode requirements must be
entered. If a voltmeter is being used, connect
a spare length of wire to earth the self-test
connector’s input terminal, pin 48. Be very
careful to ensure that you earth the correctterminal - the one with the white/green wire.
The first part of the test starts, with the
ignition switched on, but with the engine off.
On pressing the “Mem/test” button, the tester
displays “TEST” and the ready code “000”,
followed by a command code “010” - the
accelerator pedal must be fully depressed
within 10 seconds of the command code
appearing, or fault codes “576” or “577” will
appear when they are called up later. If a
voltmeter is being used, code “000” will not
appear (except perhaps as a flicker of the
needle) and “010” will appear as a single
sweep - to ensure correct interpretation of the
display, watch carefully for the interval
between the end of one code and the
beginning of the next, otherwise you will
become confused and misinterpret the read-
out.
28The tester will then display the codes for
any faults in the system at the time of the test.
Each code is repeated once; if no faults are
present, code “111” will be displayed. If a
voltmeter is being used, the pause between
repetitions will vary according to the
equipment in use and the number of faults in
the system, but was found to be
approximately 3 to 4 seconds - it may be
necessary to start again, and to repeat the
read-out until you are familiar with what you
are seeing.
29Next the tester will display code “010”
(now acting as a separator), followed by the
codes for any faults stored in the ECU’s
memory; if no faults were stored, code “111”
will be displayed.
30When prompted by the tester, the
operator must next depress the accelerator
pedal fully; the tester then checks several
actuators. Further test modes include a
“wiggle test” facility, whereby the operator
can check the various connectors as
described in paragraph 19 above (in this case,
any fault will be logged and the appropriate
code will be displayed), a facility for recalling
codes displayed, and a means for clearing the
ECU’s memory at the end of the test
procedure when any faults have been
rectified.
31The next step when using the Ford STAR
tester is to conduct a test with the engine
running. With the tester set in operation (see
paragraph 26 above) the engine is started and
allowed to idle. On pressing the “Mem/test”
button, the tester displays “TEST”, followed
by one of two codes, as follows.
32If warning code “998” appears, followed
by the appropriate fault code, switch off and
check as indicated the coolant temperature
sensor, the intake air temperature sensor, the
air mass meter, the throttle potentiometer
and/or their related circuits, then restart the
test procedure.
33If command code “020” appears, carry
out the following procedure within ten
seconds:
(a) Depress the brake pedal fully.
(b) Turn the steering to full-lock (either way)and centre it again, to produce a signal
from the power steering pressure switch -
if no signal is sent, fault code “521” will
be displayed.
(c) If automatic transmission is fitted, switch
the overdrive cancel button on and off,
then do the same for the
“Economy/Sport” mode switch.
(d) Wait for separator code “010” to be
displayed, then within 10 seconds,
depress the accelerator pedal fully,
increasing engine speed rapidly above
3000 rpm - release the pedal.
34Any faults found in the system will be
logged and displayed. Each code is repeated
once; if no faults are present, code “111” will
be displayed.
35When the codes have been displayed for
all faults logged, the ECU enters its “Service
Adjustment Programme”, as follows:
(a) The programme lasts for 2 minutes.
(b) The idle speed control valve is
deactivated, and the idle speed is set to
its pre-programmed (unregulated) value. If
the appropriate equipment is connected,
the base idle speed can be checked
(note, however, that it is not adjustable).
(c) The ignition timing can be checked if a
timing light is connected (note, however,
that it is not adjustable).
(d) Pressing the accelerator pedal fully at any
time during this period will execute a
cylinder balance test. Each injector in turn
is switched off, and the corresponding
decrease in engine speed is logged -
code “090” will be displayed if the test is
successful.
(e) At the end of the 2 minutes, the
completion of the programme is shown
by the engine speed briefly rising, then
returning to normal idling speed as
the idle speed control valve is
reactivated.
36As with the engine-off test, further test
modes include a “wiggle test” facility,
whereby the operator can check the various
connectors as described in paragraph 19
above (in this case, any fault will be logged
and the appropriate code will be displayed), a
facility for recalling codes displayed, and a
means for clearing the ECU’s memory at the
end of the test procedure when any faults
have been rectified. If equipment other than
the Ford STAR tester is used, the ECU’s
memory can be cleared by disconnecting the
battery - if this is not done, the code will
reappear with any other codes in the event of
subsequent trouble, but remember that other
systems with memory (such as the clock and
audio equipment) will also be affected. Should
it become necessary to disconnect the
battery during work on any other part of the
vehicle, first check to see if any fault codes
have been logged.
37Given overleaf are the possible codes,
their meanings, and where relevant, the action
to be taken as a result of a code being
displayed.
Emissions control systems 6•7
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Code Meaning Action327 EGR system exhaust gas pressure
differential sensor or solenoid valve Check components (Section 6 of this Chapter)
328 EGR system solenoid valve Check component (Section 6 of this Chapter)
332 EGR valve not opening Check component (Section 6 of this Chapter)
334 EGR system solenoid valve Check component (Section 6 of this Chapter)335 EGR system exhaust gas pressure
differential sensor Check component (Section 6 of this Chapter)
336 Exhaust gas pressure too high Check system (Section 6 of this Chapter)337 EGR system exhaust gas pressure
differential sensor or solenoid valve Check components (Section 6 of this Chapter)
338, 339 Coolant temperature sensor Carry out system test (see below)
341 Service connector earthed Unplug connector and repeat test - reconnect on completion
411 Engine speed too low during test Check for air leaks, then repeat test
412 Engine speed too high during test Check for air leaks, then repeat test
413 to 416 Idle speed control valve Check component (Chapter 4, Section 16)
452 Vehicle speed sensor Check component (Section 4 of this Chapter)
511, 512 ECU memory Check whether battery was disconnected, then check fuse 11 - if fault still
exists, renew ECU (Section 6 of this Chapter)
513 ECU reference voltage Carry out system test (see below)
519, 521 Power steering pressure switch not Check component is fitted and connected, then repeat test - if fault still
operated during test exists, carry out system test (see below)
522, 523 Selector lever position sensor Check component (Chapter 7, Part B)
536 Brake on/off switch not activated
during test Repeat test
538 Operator error during test Repeat test
539 Air conditioning switched on during test Switch off and repeat test
542, 543 Fuel pump circuit Carry out system test (see below)
551 Idle speed control valve circuit Carry out system test (see below)
552 Pulse-air system circuit Carry out system test (see below)
556 Fuel pump circuit Check fuel pump relay - if fault still exists, carry out system test (see below)
558 EGR system solenoid valve circuit Carry out system test (see below)
563 Radiator (high-speed) electric
cooling fan relay and/or circuit Carry out system test (see below)564 Radiator electric cooling fan relay
and/or circuit Carry out system test (see below)
565 Charcoal canister-purge solenoid valve Check component (Section 5 of this Chapter)573 Radiator electric cooling fan relay
and/or circuit Carry out system test (see below)
574 Radiator (high-speed) electric
cooling fan relay and/or circuit Carry out system test (see below)575 Fuel pump and/or fuel cut-off
switch circuits Carry out system test (see below)
576, 577 Accelerator pedal not depressed fully during
test procedure - automatic transmission
kickdown not activated Repeat test
621 Automatic transmission shift solenoid 1 circuit Refer to Chapter 7, Part B
622 Automatic transmission shift solenoid 2 circuit Refer to Chapter 7, Part B
624 Automatic transmission electronic
pressure control solenoid Refer to Chapter 7, Part B
625 Automatic transmission electronic
pressure control solenoid circuit Refer to Chapter 7, Part B
629 Automatic transmission torque
converter clutch solenoid Refer to Chapter 7, Part B
634 Selector lever position sensor circuit Check component (Chapter 7, Part B)
635, 637 Automatic transmission fluid temperature sensor Refer to Chapter 7, Part B
639 Automatic transmission speed sensor Refer to Chapter 7, Part B
645 Automatic transmission 1st speed Refer to Chapter 7, Part B
646 Automatic transmission 2nd speed Refer to Chapter 7, Part B
647 Automatic transmission 3rd speed Refer to Chapter 7, Part B
648 Automatic transmission 4th speed Refer to Chapter 7, Part B
653 Automatic transmission overdrive
cancel button and “Economy/Sport”
mode switch not operated during test Repeat test
998 Warning code Check fault(s) indicated by subsequent code(s)
Emissions control systems 6•9
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Ignition timing and base idle
speed check
Note:The following procedure is a check only,
essentially of the ECU. Both the ignition timing
and the base idle speed are controlled by the
ECU. The ignition timing is not adjustable at
all; the base idle speed is set in production,
and should not be altered.
38If the fault code read-out (with any checks
resulting from it) has not eliminated the fault,
the next step is to check the ECU’s control of
the ignition timing and the base idle speed.
This task requires the use of a Ford STAR
tester (a proprietary fault code reader can be
used only if it is capable of inducing the ECU
to enter its “Service Adjustment Programme”),
coupled with an accurate tachometer and a
good-quality timing light. Without this
equipment, the task is not possible; the
vehicle must be taken to a Ford dealer for
attention.
39To make the check, apply the handbrake,
switch off the air conditioning (where fitted)
and any other electrical loads (lights, heated
rear window, etc), then select neutral (manual
transmission) or the “P” position (automatic
transmission). Start the engine, and warm it
up to normal operating temperature. The
radiator electric cooling fan must be running
continuously while the check is made; this
should be activated by the ECU, when
prompted by the tester. Switch off the engine,
and connect the test equipment as directed
by the manufacturer - refer to paragraph 26
above for details of STAR tester connection.
40Raise and support the front of the vehicle
securely, and remove the auxiliary drivebelt
cover (see Chapter 1). Emphasise the two
pairs of notches in the inner and outer rims of
the crankshaft pulley, using white paint. Note
that an ignition timing reference mark is not
provided on the pulley - in the normal
direction of crankshaft rotation (clockwise,
seen from the right-hand side of the vehicle)
the first pair of notches are irrelevant to the
vehicles covered in this manual, while the
second pair indicate Top Dead Centre (TDC)
when aligned with the rear edge of the raised
mark on the sump; when checking the ignition
timing, therefore, the (rear edge of the) sumpmark should appear just before the TDC
notches (see Part A of Chapter 2, Section 4,
for further information if required).
41Start the engine and allow it to idle. Work
through the engine-running test procedure
until the ECU enters its “Service Adjustment
Programme” - see paragraph 35 above.
42Use the timing light to check that the
timing marks appear approximately as
outlined above at idle speed. Do not spend
too much time on this check; if the timing
appears to be incorrect, the system may have
a fault, and a full system test must be carried
out (see below) to establish its cause.
43Using the tachometer, check that the
base idle speed is as given in the
Specifications Section of Chapter 4.
44If the recorded speed differs significantly
from the specified value, check for air leaks,
as described in the preliminary checks
(paragraphs 15 to 18 above), or any other
faults which might cause the discrepancy.
45The base idle speed is set in production
by means of an air bypass screw (located in
the front right-hand corner of the throttle
housing) which controls the amount of air that
is allowed to pass through a bypass passage,
past the throttle valve when it is fully closed in
the idle position; the screw is then sealed with
a white tamperproof plug (see illustration). In
service, the idle speed is controlled by the
ECU, which has the ability to compensate for
engine wear, build-up of dirt in the throttle
housing, and other factors which might
require changes in idle speed. The air bypass
screw setting should not, therefore, be
altered. If any alterations are made, a blue
tamperproof plug must be fitted, and the
engine should be allowed to idle for at least
five minutes on completion, so that the ECU
can re-learn its idle values.
46When both checks have been made and
the “Service Adjustment Programme” is
completed, follow the tester instructions to
return to the fault code read-out, and
establish whether the fault has been cured or
not.
Basic check of ignition system
47If the checks so far have not eliminated
the fault, the next step is to carry out a basic
check of the ignition system components,
using an engine analyser with an oscilloscope
- without such equipment, the only tests
possible are to remove and check each spark
plug in turn, to check the spark plug (HT) lead
connections and resistances, and to check
the connections and resistances of the
ignition coil. Refer to the relevant Sections of
Chapters 1 and 5.
Basic check of fuel system
48If the checks so far have not eliminated
the fault, the next step is to carry out a basic
check of the fuel system components.
49Assuming that the preliminary checks
have established that the fuel pump is
operating correctly, that the fuel filter isunlikely to be blocked, and also that there are
no leaks in the system, the next step is to
check the fuel pressure (see Chapter 4). If this
is correct, check the injectors (see Chapter 4)
and the Positive Crankcase Ventilation system
(see Chapter 1).
System test
50The final element of the Ford testing
procedure is to carry out a system test, using
a break-out box - this is a device that is
connected between the ECU and its electrical
connector, so that the individual circuits
indicated by the fault code read-out can be
tested while connected to the system, if
necessary with the engine running. In the case
of many of the system’s components, this
enables their output voltages to be measured
- a more accurate means of testing.
51In addition to the break-out box and the
adaptors required to connect it, several items
of specialist equipment are needed to
complete these tests. This puts them quite
beyond the scope of many smaller dealers, let
alone the DIY owner; the vehicle should be
taken to a Ford dealer for attention.
Note:This Section is concerned principally
with the sensors which give the ECU the
information it needs to control the various
engine management sub-systems - for further
details of those systems and their other
components, refer to the relevant Chapter of
this manual.
General
ECU (Electronic Control Unit)
1This component is the heart of the entire
engine management system, controlling the
fuel injection, ignition and emissions control
systems. It also controls sub-systems such as
the radiator cooling fan, air conditioning and
automatic transmission, where appropriate.
Refer to Section 2 of this Chapter for an
illustration of how it works.
Air mass meter
2This uses a “hot-wire” system, sending the
ECU a constantly-varying (analogue) voltage
signal corresponding to the mass of air
passing into the engine. Since air mass varies
with temperature (cold air being denser than
warm), measuring air mass provides the ECU
with a very accurate means of determining the
correct amount of fuel required to achieve the
ideal air/fuel mixture ratio.
Crankshaft speed/position sensor
3This is an inductive pulse generator bolted
(in a separate bracket) to the cylinder
block/crankcase, to scan the ridges between
36 holes machined in the inboard (right-hand)
face of the flywheel/driveplate. As each ridge
4 Information sensors -
general information, testing,
removal and refitting
6•10 Emissions control systems
3.45 Throttle housing air bypass screw is
sealed on production with a white
tamperproof plug (arrowed)
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passes the sensor tip, a signal is generated,
which is used by the ECU to determine engine
speed.
4The ridge between the 35th and 36th holes
(corresponding to 90° BTDC) is missing - this
step in the incoming signals is used by the
ECU to determine crankshaft (ie, piston)
position.
Camshaft position sensor
5This is bolted to the rear left-hand end of
the cylinder head, to register with a lobe on
the inlet camshaft. It functions in the same
way as the crankshaft speed/position sensor,
producing a series of pulses (corresponding
to No 1 cylinder at 46° ATDC); this gives the
ECU a reference point, to enable it to
determine the firing order, and operate the
injectors in the appropriate sequence.
Coolant temperature sensor
6This component, which is screwed into the
top of the thermostat housing, is an NTC
(Negative Temperature Coefficient) thermistor
- that is, a semi-conductor whose electrical
resistance decreases as its temperature
increases. It provides the ECU with a
constantly-varying (analogue) voltage signal,
corresponding to the temperature of the
engine coolant. This is used to refine the
calculations made by the ECU, when
determining the correct amount of fuel
required to achieve the ideal air/fuel mixture
ratio.
Intake air temperature sensor
7This component, which is screwed into the
underside of the air intake resonator, is also an
NTC thermistor - see the previous paragraph -
providing the ECU with a signal corresponding
to the temperature of air passing into the
engine. This is used to refine the calculations
made by the ECU, when determining the
correct amount of fuel required to achieve the
ideal air/fuel mixture ratio.
Throttle potentiometer
8This is mounted on the end of the throttle
valve spindle, to provide the ECU with a
constantly-varying (analogue) voltage signal
corresponding to the throttle opening. This
allows the ECU to register the driver’s input
when determining the amount of fuel required
by the engine.
Vehicle speed sensor
9This component is a Hall-effect generator,
mounted on the transmission’s speedometer
drive. It supplies the ECU with a series of
pulses corresponding to the vehicle’s road
speed, enabling the ECU to control features
such as the fuel shut-off on the overrun, and
to provide information for the trip computer,
adaptive damping and cruise control systems
(where fitted).
Power steering pressure switch
10This is a pressure-operated switch,
screwed into the power steering system’shigh-pressure pipe. Its contacts are normally
closed, opening when the system reaches the
specified pressure - on receiving this signal,
the ECU increases the idle speed, to
compensate for the additional load on the
engine.
Exhaust gas pressure differential
sensor
11This component measures the difference
in pressure of the exhaust gases across a
venturi (restriction) in the Exhaust Gas
Recirculation (EGR) system’s pipe, and sends
the ECU a voltage signal corresponding to the
pressure difference.
Oxygen sensor
12The oxygen sensor in the exhaust system
provides the ECU with constant feedback -
“closed-loop” control - which enables it to
adjust the mixture to provide the best possible
conditions for the catalytic converter to
operate.
13The sensor has a built-in heating element
which is controlled by the ECU, in order to
bring the sensor’s tip to an efficient operating
temperature as rapidly as possible. The
sensor’s tip is sensitive to oxygen, and sends
the ECU a varying voltage depending on the
amount of oxygen in the exhaust gases. If the
intake air/fuel mixture is too rich, the exhaust
gases are low in oxygen, so the sensor sends
a low-voltage signal, the voltage rising as the
mixture weakens and the amount of oxygen in
the exhaust gases rises. Peak conversion
efficiency of all major pollutants occurs if the
intake air/fuel mixture is maintained at the
chemically-correct ratio for the complete
combustion of petrol, of 14.7 parts (by weight)
of air to 1 part of fuel (the “stoichiometric”
ratio). The sensor output voltage alters sharply
around this point, the ECU using the signal
change as a reference point, and correcting
the air/fuel mixture by altering the fuel injector
pulse width.
Air conditioning system
14Two pressure-operated switches and the
compressor clutch solenoid are connected to
the ECU, to enable it to determine how the
system is operating. The ECU can increase
idle speed or switch off the system, as
necessary, so that normal vehicle operation
and driveability are not impaired. See Chapter
3 for further details, but note that diagnosis
and repair should be left to a dealer service
department or air conditioning specialist.
Automatic transmission
15In addition to the driver’s controls, the
transmission has a speed sensor, a fluid
temperature sensor (built into the solenoid
valve unit), and a selector lever position
sensor. All of these are connected to the ECU,
to enable it to control the transmission
through the solenoid valve unit. See Part B of
Chapter 7 for further details.
Testing
ECU (Electronic Control Unit)
16 Do notattempt to “test” the ECU with any
kind of equipment. If it is thought to be faulty,
take the vehicle to a Ford dealer for the entire
electronic control system to be checked using
the proper diagnostic equipment. Only if all
other possibilities have been eliminated should
the ECU be considered at fault, and replaced.
Air mass meter
17Testing of this component is beyond the
scope of the DIY mechanic, and should be left
to a Ford dealer.
Crankshaft speed/position sensor
18Unplug the electrical connector from the
sensor.
19Using an ohmmeter, measure the
resistance between the sensor terminals.
Compare this reading to the one listed in the
Specifications Section at the beginning of this
Chapter. If the indicated resistance is not
within the specified range, renew the sensor.
20Plug in the sensor’s electrical connector
on completion.
Camshaft position sensor
21The procedure is as described in
paragraphs 18 to 20 above.
Coolant temperature sensor
22Refer to Chapter 3.
Intake air temperature sensor
23Unplug the electrical connector from the
sensor.
24Using an ohmmeter, measure the
resistance between the sensor terminals.
Depending on the temperature of the sensor
tip, the resistance measured will vary, but it
should be within the broad limits given in the
Specifications Section of this Chapter. If the
sensor’s temperature is varied - by placing it
in a freezer for a while, or by warming it gently
- its resistance should alter accordingly.
25If the results obtained show the sensor to
be faulty, renew it.
Throttle potentiometer
26Remove the plenum chamber (see
Chapter 4) and unplug the potentiometer’s
electrical connector.
27Using an ohmmeter, measure the
resistance between the unit’s terminals - first
between the centre terminal and one of the
outer two, then from the centre to the
remaining outer terminal. The resistance
should be within the limits given in the
Specifications Section of this Chapter, and
should alter smoothlyas the throttle valve is
moved from the fully-closed (idle speed)
position to fully open and back again.
28If the resistance measured is significantly
different from the specified value, if there are
any breaks in continuity, or if the reading
fluctuates erratically as the throttle is
operated, the potentiometer is faulty, and
must be renewed.
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(a) Apply petroleum jelly or clean engine oil
to the sensor’s sealing O-ring.
(b) Locate the sensor fully in the cylinder
head, and wipe off any surplus lubricant
before securing it.
(c) Tighten the screw to the specified torque
wrench setting.
Coolant temperature sensor
48Refer to Chapter 3, Section 6.
Intake air temperature sensor
49Remove the air mass meter and resonator
(refer to Chapter 4) to gain access to the
sensor (see illustration).
50Releasing its clip, unplug the sensor’s
electrical connector, then unscrew the sensor
from the resonator.
51Refitting is the reverse of the removal
procedure. Tighten the sensor to the specified
torque wrench setting; if it is overtightened, its
tapered thread may crack the resonator.
Throttle potentiometer
52Remove the plenum chamber (see
Chapter 4). Releasing its wire clip, unplug the
large electrical connector (next to the fuel
pressure regulator).
53Releasing its wire clip, unplug the
potentiometer’s electrical connector. Remove
the retaining screws, and withdraw the unit
from the throttle housing (see illustration). Do
notforce the sensor’s centre to rotate past itsnormal operating sweep; the unit will be
seriously damaged.
54Refitting is the reverse of the removal
procedure, noting the following points:
(a) Ensure that the potentiometer is correctly
orientated, by locating its centre on the D-
shaped throttle shaft (throttle closed), and
aligning the potentiometer body so that
the bolts pass easily into the throttle
housing.
(b) Tighten the screws evenly and securely
(but do not overtighten them, or the
potentiometer body will be cracked).
Vehicle speed sensor
55The sensor is mounted at the base of the
speedometer drive cable, and is removed with
the speedometer drive pinion (see
illustration). Refer to the relevant Section of
Chapter 7, Part A or B, as applicable.
Power steering pressure switch
56Releasing its clip, unplug the switch’s
electrical connector, then unscrew the switch
(see illustration). Place a wad of rag
underneath, to catch any spilt fluid. If a
sealing washer is fitted, renew it if it is worn or
damaged.
57Refitting is the reverse of the removal
procedure; tighten the switch securely, then
top-up the fluid reservoir (see Chapter 1) to
replace any fluid lost from the system, and
bleed out any trapped air (see Chapter 10,
Section 33).
Exhaust gas pressure differential
sensor
Note:See also Section 6, illustration 6.21.
58If better access is required, remove the
resonator (see Chapter 4).
59Releasing its wire clip, unplug the
sensor’s electrical connector. Remove the
two retaining screws, withdraw the unit from
the bulkhead mounting bracket, then
disconnect the two vacuum hoses. Note that
the hoses are of different sizes, to ensure that
they cannot be mixed up on reconnection.
60Check the condition of both hoses, and
renew them if necessary (see Chapter 1).
61Refitting is the reverse of the removal
procedure. Ensure that the hoses are securely
connected to the correct unions.
Oxygen sensor
Note:The sensor is delicate, and will not work
if it is dropped or knocked, if its power supply
is disrupted, or if any cleaning materials are
used on it.
62Release the sensor’s electrical connector
from its bracket on the engine/transmission
front mounting, and unplug it to disconnect
the sensor (see illustration).
63Raising and supporting the front of the
vehicle if required to remove the sensor from
underneath, unscrew the sensor from the
exhaust system front downpipe; collect the
sealing washer (where fitted).
64On refitting, clean the sealing washer
Emissions control systems 6•13
6
4.56 Power steering pressure switch is
screwed into pipe at right-hand rear end of
engine4.62 Oxygen sensor is screwed into
exhaust system front downpipe . . .
4.49 Intake air temperature sensor
(arrowed) is screwed into underside of air
intake resonator4.53 Throttle potentiometer is secured by
two screws (arrowed)
4.55 Vehicle speed sensor “A”, with its
electrical connector “B”
4.45 Camshaft position sensor is located
at left-hand rear end of cylinder head
procarmanuals.com

15Locate the steering column shaft on the
flexible coupling, swivel the clamp plate
round, then insert the bolt and tighten to the
specified torque.
16Refit the driver’s side lower trim panel.
17Refit the steering column upper and lower
shrouds.
18Reconnect the battery negative lead.
Removal
1Disconnect the battery negative (earth) lead
(refer to Chapter 5, Section 1).
2Turn the steering wheel so that the front
wheels are in the straight-ahead position.
Remove the ignition key, then turn the
steering wheel slightly as necessary until the
steering lock engages.
3Unscrew the clamp plate bolt securing the
steering column shaft to the flexible coupling.
Swivel the clamp plate around, and disengage
it from the flexible coupling stub.
4Carefully prise the rubber boot from the
bulkhead, and withdraw it into the passenger
compartment. Take care not to damage the
sealing lip of the boot.
5Using an Allen key, unscrew the clamp bolt
securing the flexible coupling to the pinion
shaft on the steering gear, and withdraw the
coupling from inside the vehicle.
Refitting
6Refitting is a reversal of the removal
procedure, but tighten the clamp bolts to the
specified torque. Make sure that the rubber
boot engages correctly in the bulkhead and
on the flexible coupling.
Removal
1Remove the steering column flexible
coupling as described in Section 29.
2Apply the handbrake, then jack up the frontof the vehicle and support it on axle stands.
Remove both front wheels.
3Working beneath the vehicle, unbolt the
rear engine mounting from the transmission
and underbody.
4Extract the split pins from the track rod end
balljoint nuts, then unscrew the nuts, and
detach the rods from the arms on the steering
knuckles using a conventional balljoint
removal tool. Take care not to damage the
balljoint seals.
5Position a suitable container beneath the
steering gear, then unscrew the union nuts
securing the power steering fluid supply,
return, and cooler lines to the steering gear.
Identify the lines for position, then unbolt the
clamps, disconnect the lines, and allow the
fluid to drain into the container. Cover the
apertures in the steering gear and also the
ends of the fluid pipes, to prevent the ingress
of dust and dirt into the hydraulic circuit.
6Unscrew and remove the steering gear
mounting bolts. The bolts are located on top
of the steering gear, and are difficult to reach.
Ideally, the special U-shaped Ford spanner
should be used, but it is just possible to reach
them with a normal spanner (see illustration).
7Withdraw the steering gear through the
wheel arch.
Refitting
8If the steering gear is being replaced with a
new one, the new unit will be supplied
together with union nuts already fitted. The
new nuts must only be used with new feed
and return lines - otherwise, they must be
removed and discarded. If the original lines
and union nuts are being used, the Teflon
rings on the union nuts must be renewed. To
do this, the rings must be expanded
individually onto a fitting adaptor (see
illustration), then located in the grooves of
the union nuts.
9Locate the steering gear on the subframe,
and insert the two mounting bolts. Tighten the
bolts to the specified torque (see illustration).
Note that, if the special Ford tool is being
used, the bottom of the tool must be turned
anti-clockwise in order to tighten the
mounting bolts.10Remove the covers from the apertures on
the steering gear, then reconnect the fluid
lines and tighten the union nuts to the
specified torque. Refit the clamps and tighten
the bolts.
11Refit the track rod end balljoints to the
steering knuckles, and tighten the nuts to the
specified torque. Check that the split pin
holes are aligned; if necessary, turn the nuts
to the nearest alignment, making sure that the
torque wrench setting is still within the
specified range. Insert new split pins, and
bend them back to secure.
12Refit the rear engine mounting to the
transmission and underbody, and tighten the
bolts to the specified torque.
13Refit the front wheels, and lower the
vehicle to the ground.
14Refit the steering column flexible coupling
with reference to Section 29.
15Bleed the power steering hydraulic
system as described in Section 33.
16Have the front wheel alignment checked,
and if necessary adjusted, at the earliest
opportunity (refer to Section 36).Removal
1Disconnect the battery negative (earth) lead
(refer to Chapter 5, Section 1).
2Working inside the vehicle, unscrew the
clamp plate bolt securing the steering column
shaft to the flexible coupling. Swivel the clamp
plate around, and disengage it from the
flexible coupling stub.
3Apply the handbrake, then jack up the front
of the vehicle and support it on axle stands.
Remove both wheels.
4On manual transmission models,
disconnect the gearchange linkage and
support rods from the transmission, as
described in Chapter 7, Part A.
5Remove the exhaust downpipe complete,
as described in Chapter 4.
6Remove the cover from under the radiator
by unscrewing the screws and releasing the
clips.
31 Power steering gear
(left-hand-drive models with
ABS) - removal and refitting
30 Power steering gear (all except
left-hand-drive models with
ABS) - removal and refitting
29 Steering column flexible
coupling - removal and refitting
10•20 Suspension and steering systems
30.6 U-shaped Ford spanner for
unscrewing the steering gear mounting
bolts
30.8 Using an adaptor to fit the Teflon
rings to the union nuts
1 Adaptor 2 Teflon ring 3 Union nut
4 Groove location for the Teflon ring
30.9 Tightening the steering gear
mounting bolts using the U-shaped
spanner (arrowed)
procarmanuals.com

7Support the radiator in its raised position,
by inserting split pins through the small holes
in the radiator mounting extensions which
protrude through the upper mountings (see
illustration).
8Unbolt and remove the radiator lower
mounting brackets.
9Where applicable, unscrew the bolts
securing the air conditioning accumulator to
the subframe.
10Working beneath the vehicle, unbolt the
engine rear mounting from the transmission
and underbody.
11Unscrew the front engine mounting-to-
cylinder block bolts, and also the through-
bolt.
12Extract the split pins from the track rod
end balljoint nuts, then unscrew the nuts, and
detach the rods from the arms on the steering
knuckles using a conventional balljoint
removal tool. Take care not to damage the
balljoint seals.
13Working on each side in turn, unscrew the
mounting nuts, and remove the anti-roll bar
links from the front suspension struts. Note
that, on models fitted with ABS, the ABS
sensor wiring support brackets are located
beneath the nuts.
14Working on each side in turn, note which
way round the front suspension lower arm
balljoint clamp bolt is fitted, then unscrew and
remove it from the knuckle assembly. Lever
the balljoint down from the knuckle - if it is
tight, prise the joint open carefully using a
large flat-bladed tool. Take care not to
damage the balljoint seal during the
separation procedure.
15Support the weight of the front subframe
assembly on two trolley jacks (or two scissor
jacks).
16Unscrew and remove the subframe
mounting bolts, then lower the subframe
sufficiently to gain access to the power
steering fluid pipes on top of the steering
gear. Note that the front subframe mountingbolts are gold in colour - the rear ones are
silver.
17Position a suitable container beneath the
steering gear, then unscrew the union nuts
securing the power steering fluid supply,
return, and cooler lines to the steering gear.
Identify the lines for position, then unbolt the
clamps, disconnect the lines, and allow the
fluid to drain into the container. Cover the
apertures in the steering gear and also the
ends of the fluid pipes, to prevent the ingress
of dust and dirt into the hydraulic circuit.
18Lower the subframe, together with the
power steering gear, to the ground.
19Unscrew the mounting bolts and remove
the power steering gear from the subframe.
20Using a suitable Allen key, unscrew the
clamp bolt securing the flexible coupling to
the pinion shaft on the steering gear, and
withdraw the coupling.
21Refer to Section 30, paragraph 8 for
details of renewing the Teflon rings.Refitting
22Refit the flexible coupling to the pinion
shaft on the steering gear, then insert and
tighten the clamp bolt using an Allen key.
23Locate the power steering gear on the
subframe, then insert the mounting bolts and
tighten to the specified torque.
24Raise the subframe until it is possible to
refit the fluid lines. Tighten the union nuts and
clamps.
25Raise the subframe, making sure that the
alignment holes are in line with the holes in
the underbody. At the same time, make sure
that the flexible coupling locates correctly on
the steering column. Ford technicians use a
special tool to ensure that the subframe is
correctly aligned - refer to Chapter 2 for more
details of the alignment procedure. With the
subframe aligned, insert and tighten the
mounting bolts to the specified torque. Note
that the front mounting bolts are gold in
colour - the rear bolts are silver.
26Working on each side in turn, refit the
front suspension lower arm balljoint to the
knuckle assembly, and insert the clamp bolt
with its head facing forwards. Refit the nut
and tighten to the specified torque.
27Working on each side in turn, refit the
anti-roll bar links and tighten the mounting
nuts to the specified torque. On models fitted
with ABS, don’t forget to locate the wheel
sensor wiring support brackets beneath the
nuts.
28Refit the track rod end balljoints to the
steering knuckles, and tighten the nuts to the
specified torque. Check if the split pin holes
are aligned, and if necessary turn the nuts to
the nearest alignment, making sure that the
torque wrench setting is still within the
specified range. Insert new split pins, and
bend them back to secure.
29Refit and tighten the engine front
mounting bolts.
30Refit the engine rear mounting and tighten
the bolts.31Where applicable, insert and tighten the
air conditioning accumulator bolts.
32Refit the radiator lower mounting brackets
and tighten the bolts.
33Remove the split pins supporting the
radiator in its raised position.
34Refit the cover under the radiator.
35Refit the exhaust downpipe as described
in Chapter 4.
36On manual transmission models,
reconnect the gearchange linkage and
support rods.
37Refit the front wheels, and lower the
vehicle to the ground.
38Working inside the vehicle, reconnect the
steering column clamp plate, then insert the
bolt and tighten to the specified torque.
39Reconnect the battery negative lead.
40Bleed the power steering hydraulic
system as described in Section 33.
41Have the front wheel alignment checked,
and if necessary adjusted, at the earliest
opportunity (refer to Section 36).
1Remove the track rod end and its locknut
from the track rod, as described in Section 35.
Make sure that a note is made of the exact
position of the track rod end on the track rod,
in order to retain the front wheel alignment
setting on refitting.
2Release the outer retaining clip and inner
plastic clamp band, and disconnect the gaiter
from the steering gear housing.
3Disconnect the breather from the gaiter,
then slide the gaiter off the track rod.
4Scrape off all grease from the old gaiter,
and apply to the track rod inner joint. Wipe
clean the seating areas on the steering gear
housing and track rod.
5Slide the new gaiter onto the track rod and
steering gear housing, and reconnect the
breather.
6Fit a new inner plastic clamp band and
outer retaining clip.
7Refit the track rod end as described in
Section 35.
8Have the front wheel alignment checked,
and if necessary adjusted, at the earliest
opportunity (refer to Section 36).
1Following any operation in which the power
steering fluid lines have been disconnected,
the power steering system must be bled, to
remove any trapped air.
2With the front wheels in the straight-ahead
position, check the power steering fluid level
in the reservoir and, if low, add fresh fluid until
it reaches the “MAX” or “MAX COLD” mark.
Pour the fluid slowly, to prevent air bubbles
forming, and use only the specified fluid (refer
to Chapter 1 Specifications).
33 Power steering hydraulic
system - bleeding
32 Power steering gear rubber
gaiters - renewal
Suspension and steering systems 10•21
10
31.7 Method of supporting the radiator in
its raised position
1 Radiator upper mounting extension
2 Small hole
3 Pin or split pin inserted through hole
procarmanuals.com

Mix up a little filler on a clean piece of card
or board - measure the hardener carefully
(follow the maker’s instructions on the pack),
otherwise the filler will set too rapidly or too
slowly. Using the applicator, apply the filler
paste to the prepared area; draw the
applicator across the surface of the filler to
achieve the correct contour and to level the
surface. As soon as a contour that
approximates to the correct one is achieved,
stop working the paste - if you carry on too
long, the paste will become sticky and begin
to “pick-up” on the applicator. Continue to
add thin layers of filler paste at 20-minute
intervals, until the level of the filler is just
proud of the surrounding bodywork.
Once the filler has hardened, the excess
can be removed using a metal plane or file.
From then on, progressively-finer grades of
abrasive paper should be used, starting with a
40-grade production paper, and finishing with
a 400-grade wet-and-dry paper. Always wrap
the abrasive paper around a flat rubber, cork,
or wooden block - otherwise the surface of
the filler will not be completely flat. During the
smoothing of the filler surface, the wet-and-
dry paper should be periodically rinsed in
water. This will ensure that a very smooth
finish is imparted to the filler at the final stage.
At this stage, the “dent” should be
surrounded by a ring of bare metal, which in
turn should be encircled by the finely
“feathered” edge of the good paintwork.
Rinse the repair area with clean water, until all
of the dust produced by the rubbing-down
operation has gone.
Spray the whole area with a light coat of
primer - this will show up any imperfections in
the surface of the filler. Repair these
imperfections with fresh filler paste or
bodystopper, and once more smooth the
surface with abrasive paper. Repeat this
spray-and-repair procedure until you are
satisfied that the surface of the filler, and the
feathered edge of the paintwork, are perfect.
Clean the repair area with clean water, and
allow to dry fully.
The repair area is now ready for final
spraying. Paint spraying must be carried out
in a warm, dry, windless and dust-free
atmosphere. This condition can be created
artificially if you have access to a large indoor
working area, but if you are forced to work in
the open, you will have to pick your day very
carefully. If you are working indoors, dousing
the floor in the work area with water will help
to settle the dust which would otherwise be in
the atmosphere. If the repair area is confined
to one body panel, mask off the surrounding
panels; this will help to minimise the effects ofa slight mis-match in paint colours. Bodywork
fittings (eg chrome strips, door handles etc)
will also need to be masked off. Use genuine
masking tape, and several thicknesses of
newspaper, for the masking operations.
Before commencing to spray, agitate the
aerosol can thoroughly, then spray a test area
(an old tin, or similar) until the technique is
mastered. Cover the repair area with a thick
coat of primer; the thickness should be built
up using several thin layers of paint, rather
than one thick one. Using 400-grade wet-and-
dry paper, rub down the surface of the primer
until it is really smooth. While doing this, the
work area should be thoroughly doused with
water, and the wet-and-dry paper periodically
rinsed in water. Allow to dry before spraying
on more paint.
Spray on the top coat, again building up the
thickness by using several thin layers of paint.
Start spraying at one edge of the repair area,
and then, using a side-to-side motion, work
until the whole repair area and about 2 inches
of the surrounding original paintwork is
covered. Remove all masking material 10 to
15 minutes after spraying on the final coat of
paint.
Allow the new paint at least two weeks to
harden, then, using a paintwork renovator, or
a very fine cutting paste, blend the edges of
the paint into the existing paintwork. Finally,
apply wax polish.
Plastic components
With the use of more and more plastic body
components by the vehicle manufacturers (eg
bumpers. spoilers, and in some cases major
body panels), rectification of more serious
damage to such items has become a matter
of either entrusting repair work to a specialist
in this field, or renewing complete
components. Repair of such damage by the
DIY owner is not really feasible, owing to the
cost of the equipment and materials required
for effecting such repairs. The basic technique
involves making a groove along the line of the
crack in the plastic, using a rotary burr in a
power drill. The damaged part is then welded
back together, using a hot-air gun to heat up
and fuse a plastic filler rod into the groove.
Any excess plastic is then removed, and the
area rubbed down to a smooth finish. It is
important that a filler rod of the correct plastic
is used, as body components can be made of
a variety of different types (eg polycarbonate,
ABS, polypropylene).
Damage of a less serious nature (abrasions,
minor cracks etc) can be repaired by the DIY
owner using a two-part epoxy filler repair
material. Once mixed in equal proportions,
this is used in similar fashion to the bodywork
filler used on metal panels. The filler is usually
cured in twenty to thirty minutes, ready for
sanding and painting.
If the owner is renewing a complete
component himself, or if he has repaired it
with epoxy filler, he will be left with theproblem of finding a suitable paint for finishing
which is compatible with the type of plastic
used. At one time, the use of a universal paint
was not possible, owing to the complex range
of plastics encountered in body component
applications. Standard paints, generally
speaking, will not bond to plastic or rubber
satisfactorily. However, it is now possible to
obtain a plastic body parts finishing kit which
consists of a pre-primer treatment, a primer
and coloured top coat. Full instructions are
normally supplied with a kit, but basically, the
method of use is to first apply the pre-primer
to the component concerned, and allow it to
dry for up to 30 minutes. Then the primer is
applied, and left to dry for about an hour
before finally applying the special-coloured
top coat. The result is a correctly-coloured
component, where the paint will flex with the
plastic or rubber, a property that standard
paint does not normally posses.
Where serious damage has occurred, or
large areas need renewal due to neglect, it
means that complete new panels will need
welding-in; this is best left to professionals. If
the damage is due to impact, it will also be
necessary to check completely the alignment
of the bodyshell; this can only be carried out
accurately by a Ford dealer, using special jigs.
If the body is left misaligned, it is primarily
dangerous, as the car will not handle properly,
and secondly, uneven stresses will be
imposed on the steering, suspension and
possibly transmission, causing abnormal wear
or complete failure, particularly to items such
as the tyres.
Removal
Front bumper
1Apply the handbrake, jack up the front of
the vehicle and support it on axle stands.
2Where applicable, remove the foglights
from the front bumper (Chapter 12).
3Where applicable, disconnect the tubing
from the headlight washer jets.
4Unscrew the screws securing the wheel
arch liners to the front bumper (see
illustration).
5Unscrew the bumper mounting nuts, and
withdraw the bumper forwards from the
vehicle, at the same time disconnecting the
guides from the side pins (see illustrations).
Rear bumper
6Chock the front wheels, jack up the rear of
the vehicle and support it on axle stands.
6 Bumpers - removal and refitting
5 Major body damage - repair
11•4 Bodywork and fittings
If bodystopper is used, it can
be mixed with cellulose
thinners, to form a really thin
paste which is ideal for filling
small holes.
procarmanuals.com

compartment, but on Estate models, it is on
the right-hand side.
Some models are fitted with a headlight
levelling system, which is controlled by a knob
on the facia. On position “0”, the headlights
are in their base position, and on position “5”,
the headlights are in their maximum inclined
angle.
It should be noted that, when portions of
the electrical system are serviced, the cable
should be disconnected from the battery
negative terminal, to prevent electrical shorts
and fires.
Caution: When disconnecting the
battery for work described in the
following Sections, refer to
Chapter 5, Section 1.
Note:Refer to the precautions given in
“Safety first!” and in Section 1 of this Chapter
before starting work. The following tests relate
to testing of the main electrical circuits, and
should not be used to test delicate electronic
circuits (such as engine management systems,
anti-lock braking systems, etc), particularly
where an electronic control module is used.
Also refer to the precautions given in Chapter
5, Section 1.
General
1A typical electrical circuit consists of an
electrical component, any switches, relays,
motors, fuses, fusible links or circuit breakers
related to that component, and the wiring and
connectors which link the component to both
the battery and the chassis. To help to
pinpoint a problem in an electrical circuit,
wiring diagrams are included at the end of this
manual.
2Before attempting to diagnose an electrical
fault, first study the appropriate wiring
diagram, to obtain a complete understanding
of the components included in the particular
circuit concerned. The possible sources of a
fault can be narrowed down by noting if other
components related to the circuit are
operating properly. If several components or
circuits fail at one time, the problem is likely to
be related to a shared fuse or earth
connection.
3Electrical problems usually stem from
simple causes, such as loose or corroded
connections, a faulty earth connection, a
blown fuse, a melted fusible link, or a faulty
relay (refer to Section 3 for details of testing
relays). Visually inspect the condition of all
fuses, wires and connections in a problem
circuit before testing the components. Use
the wiring diagrams to determine which
terminal connections will need to be checked
in order to pinpoint the trouble-spot.
4The basic tools required for electrical fault-
finding include a circuit tester or voltmeter (a
12-volt bulb with a set of test leads can alsobe used for certain tests); an ohmmeter (to
measure resistance and check for continuity);
a battery and set of test leads; and a jumper
wire, preferably with a circuit breaker or fuse
incorporated, which can be used to bypass
suspect wires or electrical components.
Before attempting to locate a problem with
test instruments, use the wiring diagram to
determine where to make the connections.
5To find the source of an intermittent wiring
fault (usually due to a poor or dirty
connection, or damaged wiring insulation), a
“wiggle” test can be performed on the wiring.
This involves wiggling the wiring by hand to
see if the fault occurs as the wiring is moved.
It should be possible to narrow down the
source of the fault to a particular section of
wiring. This method of testing can be used in
conjunction with any of the tests described in
the following sub-Sections.
6Apart from problems due to poor
connections, two basic types of fault can
occur in an electrical circuit - open-circuit, or
short-circuit.
7Open-circuit faults are caused by a break
somewhere in the circuit, which prevents
current from flowing. An open-circuit fault will
prevent a component from working.
8Short-circuit faults are caused by a “short”
somewhere in the circuit, which allows the
current flowing in the circuit to “escape” along
an alternative route, usually to earth. Short-
circuit faults are normally caused by a
breakdown in wiring insulation, which allows a
feed wire to touch either another wire, or an
earthed component such as the bodyshell. A
short-circuit fault will normally cause the
relevant circuit fuse to blow.
Finding an open-circuit
9To check for an open-circuit, connect one
lead of a circuit tester or the negative lead of a
voltmeter either to the battery negative
terminal or to a known good earth.
10Connect the other lead to a connector in
the circuit being tested, preferably nearest to
the battery or fuse. At this point, battery
voltage should be present, unless the lead
from the battery or the fuse itself is faulty
(bearing in mind that some circuits are live
only when the ignition switch is moved to a
particular position).
11Switch on the circuit, then connect the
tester lead to the connector nearest the circuit
switch on the component side.
12If voltage is present (indicated either by
the tester bulb lighting or a voltmeter reading,
as applicable), this means that the section of
the circuit between the relevant connector
and the switch is problem-free.
13Continue to check the remainder of the
circuit in the same fashion.
14When a point is reached at which no
voltage is present, the problem must lie
between that point and the previous test point
with voltage. Most problems can be traced to
a broken, corroded or loose connection.
Finding a short-circuit
15To check for a short-circuit, first
disconnect the load(s) from the circuit (loads
are the components which draw current from
a circuit, such as bulbs, motors, heating
elements, etc).
16Remove the relevant fuse from the circuit,
and connect a circuit tester or voltmeter to the
fuse connections.
17Switch on the circuit, bearing in mind that
some circuits are live only when the ignition
switch is moved to a particular position.
18If voltage is present (indicated either by
the tester bulb lighting or a voltmeter reading,
as applicable), this means that there is a
short-circuit.
19If no voltage is present during this test,
but the fuse still blows with the load(s)
reconnected, this indicates an internal fault in
the load(s).
Finding an earth fault
20The battery negative terminal is
connected to “earth” - the metal of the
engine/transmission unit and the vehicle body
- and many systems are wired so that they
only receive a positive feed, the current
returning via the metal of the car body. This
means that the component mounting and the
body form part of that circuit. Loose or
corroded mountings can therefore cause a
range of electrical faults, ranging from total
failure of a circuit, to a puzzling partial failure.
In particular, lights may shine dimly (especially
when another circuit sharing the same earth
point is in operation), motors (eg wiper motors
or the radiator cooling fan motor) may run
slowly, and the operation of one circuit may
have an apparently-unrelated effect on
another. Note that on many vehicles, earth
straps are used between certain components,
such as the engine/transmission and the
body, usually where there is no metal-to-
metal contact between components, due to
flexible rubber mountings, etc.
21To check whether a component is
properly earthed, disconnect the battery (refer
to Chapter 5, Section 1) and connect one lead
of an ohmmeter to a known good earth point.
Connect the other lead to the wire or earth
connection being tested. The resistance
reading should be zero; if not, check the
connection as follows.
22If an earth connection is thought to be
faulty, dismantle the connection, and clean
both the bodyshell and the wire terminal (or
the component earth connection mating
surface) back to bare metal. Be careful to
remove all traces of dirt and corrosion, then
use a knife to trim away any paint, so that a
clean metal-to-metal joint is made. On
reassembly, tighten the joint fasteners
securely; if a wire terminal is being refitted,
use serrated washers between the terminal
and the bodyshell, to ensure a clean and
secure connection. When the connection is
2 Electrical fault finding -
general information
12•4 Body electrical system
procarmanuals.com

remade, prevent the onset of corrosion in the
future by applying a coat of petroleum jelly or
silicone-based grease, or by spraying on (at
regular intervals) a proprietary ignition sealer
such as Holts Damp Start, or a water-
dispersant lubricant such as Holts Wet Start.
Note:It is important to note that the ignition
switch and the appropriate electrical circuit
must always be switched off before any of the
fuses (or relays) are removed and renewed. In
the event of the fuse/relay unit having to be
removed, the battery earth lead must be
disconnected. When reconnecting the battery,
reference should be made to Chapter 5.
1Fuses are designed to break a circuit when
a predetermined current is reached, in order
to protect components and wiring which
could be damaged by excessive current flow.
Any excessive current flow will be due to a
fault in the circuit, usually a short-circuit (see
Section 2). The main fusebox, which also
carries some relays, is located inside the
vehicle below the facia panel on the
passenger’s side, and is accessed by a lever
behind the glovebox (see illustration).
2A central timer module is located on the
bottom of the main fusebox. This module
contains the time control elements for the
heated rear window, interior lights and
intermittent wiper operation. The module also
activates a warning buzzer/chime when the
vehicle is left with the lights switched on, or if
a vehicle fitted with automatic transmission is
not parked in position “P”.
3The auxiliary fusebox is located on the front
left-hand side of the engine compartment,
and is accessed by unclipping and removing
the cover. The auxiliary fusebox also contains
some relays (see illustration). Each circuit is
identified by numbers on the main fusebox
and on the inside of the auxiliary fusebox
cover. Reference to the fuse chart in the
Specifications at the start of this Chapter will
indicate the circuits protected by each fuse.
Plastic tweezers are attached to the main
fusebox and to the inside face of the auxiliary
fuse and block cover, to remove and fit the
fuses and relays.
4To remove a fuse, use the tweezers
provided to pull it out of the holder. Slide the
fuse sideways from the tweezers. The wire
within the fuse is clearly visible, and it will be
broken if the fuse is blown (see illustration).
5Always renew a fuse with one of an
identical rating. Never substitute a fuse of a
higher rating, or make temporary repairs using
wire or metal foil; more serious damage, or
even fire, could result. The fuse rating is
stamped on top of the fuse. Never renew a
fuse more than once without tracing the
source of the trouble.
6Spare fuses of various current ratings areprovided in the cover of the auxiliary fusebox.
Note that if the vehicle is to be laid up for a
long period, fuse 34 in the main fusebox
should be removed, to prevent the ancillary
electrical components from discharging the
battery.
7Relays are electrically-operated switches,
which are used in certain circuits. The various
relays can be removed from their respective
locations by carefully pulling them from the
sockets. Each relay in the fuseboxes has a
plastic bar on its upper surface to enable the
use of the tweezers. The locations and
3 Fuses, relays and timer
module- testing and renewal
Body electrical system 12•5
12
3.4 The fuses can be checked visually to
determine if they are blown
3.1 Main fusebox layout
1 Fuse/relay removal tweezers 2 Diode 3 Multi-plug connections
3.3 Auxiliary fusebox layout
1 Fuses 1 to 3 3 Relays R2, R5 and R6 5 Relay sockets for relays R1 and R4
2 Fuses 4 to 8, 11 to 14 4 Relays R7 to R11 6 Diode
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