check engine light NISSAN PULSAR 1987 Owner's Manual
[x] Cancel search | Manufacturer: NISSAN, Model Year: 1987, Model line: PULSAR, Model: NISSAN PULSAR 1987Pages: 238, PDF Size: 28.91 MB
Page 98 of 238
Fuel and Engine Management
(8) Remove the bolts retaining the intermediate
exhaust pipe to the rear of the catalytic converter,
remove the bolt securing the exhaust mounting to the
underbody and slightly lower the intermediate exhaust
pipe. Support the intermediate pipe to prevent the
tailpipe fouling the lower bumper panel.
(9) Remove the bolts retaining the stabilizer bar
mounting brackets to the underbody and allow the
stabilizer bar to drop.
(10) Remove the bolts retaining the exhaust heat
shield to the underbody, located at the front of the
fuel tank. (11) Remove the handbrake cable mounting
bracket retaining nuts and remove the mounting
brackets from the mounting studs. (12) Remove the fuel tank retaining bolts and
maneuver the fuel tank from the vehicle. Installation is a reversal of the removal procedure
with attention to the following points:
(1) When installing the fuel tank, ensure that the
fuel pump wiring harness is directed through the
aperture in the floor. (2) Install the stabilizer bar mounting
bracket
bolts and tighten to the specified torque. Refer to the
Rear Suspension section.
(3) Using a new gasket, install the intermediate
exhaust pipe to the catalyti c converter ensuring that
the earth wire terminal is installed and tighten the
bolts securely. (4) Connect the fuel filler neck hose, the fuel
check valve hose and the breat her hose ensuring that
they are secured firmly. (5) Tighten the fuel tank drain plug to the
specified torque. (6) Connect the fuel hoses to the fuel pump,
using the marks made during removal to ensure
correct installation. (7) Install the fuel pump wiring harness and the
rubber grommet to the fuel pump cover plate. Install
the cover plate and tighten the retaining bolts se-
curely.
(8) Connect the fuel pump wiring connector
securely. (9) Check for fuel leaks as previously described.
6. AIR FLOW COMPONENTS
NOTE: Before proceeding with any of the
operations in this section, refer to the Ser-
vice Precautions and Procedures heading.
AIR CLEANER ASSEMBLY
To Renew Element
The procedure for renewing the air cleaner ele-
ment is covered in the Engine Tune-up section.
To Remove and Install — 1.8 Liter Engine
(1) Disconnect the negative battery terminal.
(2) Release the air intake hose retaining clamps,
disconnect the hose from the air cleaner upper
housing and the throttle body and remove the hose. (3) Remove the screw securing the air cleaner
intake duct to the front panel mounting bracket. (4) Remove the hexagon head screws retaining
the air cleaner mounting bracket to the right hand
inner mudguard and remove the air cleaner from the
engine compartment. (5) Release the upper housing retaining clips,
separate the upper housing from the lower housing
and remove the element. (6) Remove the air cleaner intake duct retaining
screw and disconnect the duct from the lower air
cleaner housing. (7) If necessary, remove the bolts securing the
mounting bracket to the ai r cleaner lower housing and
separate the mounting bracket from the housing. (8) Thoroughly clean the upper and lower hous-
ings in cleaning solvent and check for cracks, splits or
damage that would allow unfiltered air to enter the
engine. Renew any components as necessary.
Installation is a reversal of the removal procedure
with attention to the following points:
(1) Ensure that the r ubber insulators are in-
Dismantled view of the ai r cleaner assembly. 1.8 liter
engine.
Page 99 of 238
Fuel and Engine Management 99
stalled on each side of the air cleaner mounting
bracket when installing the mounting bolts.
(2) If renewing the element, ensure that the
specified element is installed and is correctly seated in
the air cleaner housing. (3) Ensure that the air intake hose clamps are
tightened securely.
To Remove and Install — 1.6 Liter Engine
(1) Disconnect the negative battery terminal.
(2) Remove the nuts and washers retaining the
air cleaner to the throttle body assembly. (3) Release the top cover retaining clips and
remove the top cover and the air cleaner element.
Remove the air cleaner retainer from the throttle body
bolts. (4) Disconnect the engine vent hose from the air
cleaner support clamp. (5) Slightly raise the air cleaner and tilt it
towards the windscreen. Disc onnect the engine vent
hose and the temperature sensor vacuum hose from
the underside of the air cleaner. (6) Remove the air cleaner housing from the
engine.
Dismantled view of the air cleaner.
(7) Thoroughly clean the air cleaner housing and
top cover and check for cracks or damage that would
allow unfiltered air to enter the engine. Renew any
components as necessary.
Installation is a reversal of the removal procedure
with attention to the following points:
(1) Inspect the air cleaner base gasket. Renew if
necessary. (2) Connect the engine vent hose and the tem-
perature sensor vacuum hose. (3) Install the air cleaner ensuring that the hot air
inlet tube is located correc tly between the exhaust heat
shield and the air cleaner housing. (4) When installing the top cover retaining nuts,
hand tighten only. THROTTLE BODY ASSEMBLY
To Remove and Install — 1.8 Liter Engine
(1)
Disconnect the negative battery terminal.
(2) Release the air intake hose clamp and dis-
connect the air intake hose from the throttle body. (3) Unclip the actuating rod from the throttle
lever using a small screwdriver under the ball socket if
necessary.
(4) Mark the throttle body vacuum hoses with
quick drying paint or similar and disconnect the hoses
from the throttle body. Disconnect the engine vent
hose from the throttle body. (5) Disconnect the wiring connectors from the
throttle position sensor and the IAC valve.
(6) Remove the retaining nuts and withdraw the
throttle body and gasket.
View of the throttle body and actuating rod. The rod
length must be set so that dimension A - 8—9 mm for
automatic transaxle models and 3—4 mm for manual
transaxle models.
View of the throttle body and associated components.
Page 101 of 238
Fuel and Engine Management 101
Location of the idle air control (IAC) valve. Inset shows the terminal identification.
(b) Check for a binding throttle cable, throttle
shaft or throttle position sensor. (c) Check the coolant temperature sensor resis-
tance as described later in this section. (d) Ensure that the battery terminals and the
engine earth terminals are clean and secure.
(e) Check the operation of the Park/Neutral
switch and the transaxle as described in the Automatic
Transaxle section under the Neutral Safety Switch
heading. (f) Check the spark plug gaps as described in the
Engine Tune-up section.
(g) Check the base idle speed adjustment.
(h) Check the fuel pressure and check the system
for leaks as described previously.
(I) Check the alternator voltage output as de-
scribed in the Electrical System section to ensure that
it is between 9-17 volts.
(j) Remove the IAC valve and check the bore in
the throttle body for dirt or damage.
(7) Stop the engine, switch the ignition On and
connect a jumper lead between terminals A and B on
the diagnostic link connector. (8) Disconnect the wiring connector from the
IAC valve.
(9) Check for voltage at each of the terminals on
the IAC valve wiring connector using a test lamp. If the test lamp flashes at each terminal, correct
operation of the wiring and control unit is indicated.
check for faulty IAC valve terminals. If no fault is
found renew the IAC valve.
If the test lamp is a steady light at one or more
terminals, proceed to operation (10).
If the test lamp does not flash at one or more of
the terminals proceed as follows:
(a) Check the circuit with no voltage for shorts
and for continuity between the IAC valve and the
control unit. Repair or renew the wiring harness as
necessary.
(b) Measure the resistance across the IAC valve
terminals A and B, and across terminals C and D. The resistance should be more than 30 ohms.
If the resistance is not as specified, renew the IAC
valve.
If the resistance is as specified, check for faulty
wiring connector terminals on the IAC valve and the
control unit. If no fault is found, renew the control
unit
(10) Switch the ignition Oft' and disconnect the
control unit wiring connectors. (11) Switch the ignition On and check the IAC
connector with the test lamp again. If the light is stilt
steady on one or more terminals there is a short
circuit to voltage in the wiring harness. Repair or
renew as necessary. (12) If the light is not on, check for faulty IAC
valve terminals. If no fault is found renew the IAC
valve.
To Remove and Install
(1) Disconnect the negative battery terminal.
(2) On 1.6 liter engines, remove the air cleaner
assembly as previously described. (3) Disconnect the wiring connector from the
IAC valve. (4) Remove the IAC valve retaining screws and
withdraw the IAC valve and O ring.
View of the IAC valve removed from the throttle body
assembly. 1.6 liter engine.
(5) Clean the IAC sealing surfaces to ensure
proper operation.
Installation is a reversal of the removal procedure
with attention to the following points:
(1) When installing a new IAC valve ensure that
the part number is correct as the valve is not
interchangeable between the 1.8 and 1.6 liter engines.
(2) Measure the length of the pintle extension as
shown in the illustration. If necessary push the pintle
in by exerting firm thum b pressure with a slight
rocking motion.
NOTE: Installing (he IAC valve with the
pintle protruding too far can damage the
valve.
Page 102 of 238
\(V2 Fuel and Engine Management
View of the IAC valve removed from the engine. Dimension A must not exceed 28 mm.
(3) Lubricate the IAC valve O ring with engine
oil and install the IAC valve. Tighten the retaining
screws securely.
(4). Install the IAC valve wiring connector and
the negative battery terminal.
(5) On 1.6 liter engines, install the air cleaner
assembly as previously described. (6) Run the engine until normal operating tem-
perature and idle speed are attained.
NOTE: Several minutes may elapse before
the normal idle speed is attained.
(7) Hold the throttle open at approximately
3 000 rpm for 10 seconds to reset the IAC valve.
MANIFOLD ABSOLUTE PRESSURE (MAP)
SENSOR
To Test - Codes 33 and 34
NOTE: The following test procedure
assumes that fault codes 33 or 34 have
been
displayed during the self diagnosis test
pro-
cedure. If no codes have been displayed
but
the operation of the MAP sensor is suspect,
begin the test procedure at operation (15).
(1) Erase the self diagnosis code memory as
previously described.
(2) Start and run the engine at idle speed for 60
seconds or until the ECM warning lamp lights.
(3) Stop the engine, switch the ignition On and
connect a jumper lead between terminals A and B on
the diagnostic link connector. Note any fault codes
displayed. If code 34 is displayed, remove the jumper lead
from the diagnostic link connector, erase the self
diagnosis codes and proceed to operation (7).
If code 33 is displayed, remove the jumper lead
from the diagnostic link connector, erase the self
diagnosis code memory and proceed to operation (4).
If no codes are displayed, but codes 33 or 34
were
displayed when the self diagnosis test procedure was
originally performed, an intermittent fault is indi-
cated. Proceed as follows:
(a) Check for faulty wiring connections. Check
that all wiring connectors are clean and secure. (b) Check that all earth wires are secure.
(c) Check the vacuum hose to the MAP sensor
for deterioration or restriction.
(4) Disconnect the wiring connector from the
MAP sensor. (5) Start and run the engine at idle speed for 60
seconds or until the ECM warning lamp lights. (6) Stop the engine, switch the ignition On and
connect a jumper lead between terminals A and B on
the diagnostic link connector. Note any fault codes
displayed.
If code 33 is displayed, measure the voltage at
the
MAP sensor wiring connector terminal B with a
voltmeter to earth. Renew the control unit if the
voltage is less than 1 volt.
If the voltage is more than 1 volt, check the
wiring
harness for a short to voltage between terminal B and
the control unit wiring connector terminal Cll.
Repair or renew the wiring harness as necessary.
If code 34 is displayed, proceed as follows:
(a) Check for a restricted or leaking MAP sensor
vacuum hose.
(b) Check the wiring harness for continuity and
shorts between terminals A on the MAP sensor
connector and terminal A11 on the control unit wiring
connector. Repair or renew the wiring harness as
necessary.
If no faults are indicated in the above two checks,
proceed to operation (15).
(7) Disconnect the wiring connector from the
MAP sensor and connect a jumper lead between
terminals B and C on the wiring connector. (8) Start and run the engine at idle speed for 60
seconds or until the ECM warning lamp lights. (9) Stop the engine, switch the ignition On and
connect a jumper lead between terminals A and B on
the diagnostic link connector. Note any fault codes
displayed.
If code 33 is displayed, proceed to operation (15).
If code 34 is displayed, proceed as follows.
Location of the MAP sensor. Inset shows the terminal
identification.
Page 106 of 238
106 Fuel and Engine Management
on the pickup coil wiring connector. The resistance
should be 500-1 500 ohms.
If the resistance is not as specified in either of the
above tests, renew the pickup coil.
(4) Remove the retaining spring from the dis-
tributor drive coupling.
(5) Using a pin punch, remove the drive pin
from the shaft. (6) Remove the drive coupling, washer, tang
washer and thrust spring from the shaft. (7) Remove the rotor and sh aft from the distrib-
utor housing. (8) Remove the retainer from the distributor
housing and withdraw the pickup coil. (9) Remove the retaining sc rews and remove the
control module from the distributor body. (10) Carefully lever the stationary pole from the
housing using a suitable screwdriver. Assembly is a reversal of the dismantling proce-
dure with attention to the following points:
(1) Ensure that the mating surfaces of the dis-
tributor housing and the control module are clean.
(2) Apply a silicone heat sink compound to the
surfaces between the control module and the distrib-
utor housing.
IGNITION COIL
To Test
(1) Disconnect the grey wiring connector and the
black wiring connector from the ignition coil in that
order. (2) Measure the resistance between coil terminal
I and the coil body. There should be a high resistance. (3) Measure the resistance between coil termi-
nals 2 and 4. There should be a low resistance. (4) Measure the resistance between coil terminal
3 and the high tension termin al. The resistance should
be other than infinity.
If any of the tests indicate a fault, renew the
ignition coil.
To Remove and Install
(1) Disconnect the negative battery terminal.
(2) Disconnect the grey wiring connector and the
black wiring connector from the ignition coil in that
order. Disconnect the high tension lead. (3) Remove the coil mounting bracket retaining
bolts and remove the coil and bracket from the
engine. Installation is a reversal of the removal procedure.
ELECTRONIC SPARK TIMING
To Test - Code 42
(1) Erase the self diagnosis code memory as
previously described. (2) Start and run the engine at idle speed for 60
seconds or until the ECM warning lamp lights.
(3) Stop the engine, switch the ignition On and
connect a jumper lead between terminals A and B on
the diagnostic link connector . Note any fault codes
displayed. If code 42 is displayed, proceed to operation (4).
If code 42 is not displayed, but was displayed
when the self diagnosis test procedure was originally
performed, an intermittent fault is indicated. Proceed
as follows:
(a) Check for faulty wiri ng connections. Check
that all wiring connectors are clean and secure.
(b) Check that all earth wires are secure.
(4) With the ignition switched Off, disconnect
the control unit wiring connectors. (5) With the ignition switched On, measure the
resistance between the contro l unit wiring connector
terminal D4 and a good earthing point. The resistance
should be less than 500 ohms.
If the ohmmeter reading is as specified, check the
wiring harness between the distributor 4 pin wiring
connector terminal D and the control unit wiring
connector terminal D4 for continuity. Repair or
renew the wiring harness as necessary. Also ensure
that the distributor 4 pin wiring connector is making
good contact when connected to the distributor.
If no fault can be found, renew the ignition
control module.
If the resistance is as specified proceed as follows.
(6) With the lead of a test lamp connected to the
positive battery terminal, backprobe the control unit
wiring connector terminal D5.
If the test lamp does not light, proceed to
operation (7).
If the test lamp lights, disconnect the 4 pin wiring
connector from the distributor. If the test lamp
remains illuminated check the wiring harness between
the distributor 4 pin wiring connector terminal B and
the control unit wiring connector terminal D5 for
shorts to earth. Repair or renew the wiring harness as
necessary. If the test lamp extinguishes, renew the
ignition system control module.
(7) Connect an ohmmeter between the control
Installed view of the ignition coil showing the coil
terminal identification.
Page 107 of 238
Fuel and Engine Management 107
unit wiring connector terminal D4 and a good earth-
ing point.
(8) With the lead of a test lamp connected to the
positive battery terminal, backprobe the control unit
wiring connector terminal D5. As the test lamp probe
touches the terminal, the ohmmeter reading should
change from less than 500 ohms to over 5 000 ohms.
If the ohmmeter reading is not as specified,
proceed to operation (9).
If the ohmmeter reading is as specified, switch the
ignition Off and install the control unit wiring connec-
tors. Run the engine for 60 seconds or until the ECM
warning lamp lights and check for fault codes.
If code 42 is displayed renew the control unit.
If code 42 is not displayed, check the wiring
harness for continuity or sh orts between the control
unit wiring connector terminals D4 and D5 and the
distributor 4 pin wiring connector terminals D and B.
(9) Disconnect the 4 pin wiring connector from
the distributor.
(10) Check for continuity between the control
unit wiring connector termin al D4 and a good earth-
ing point. There should be no continuity.
If the continuity is not as specified, check the
wiring harness between the distributor 4 pin wiring
connector terminal D and the control unit wiring
connector terminal D4 for shorts to earth. Repair or
renew the wiring harness as necessary.
If the continuity is as specified, check the wiring
harness between the distributor 4 pin wiring connec-
tor terminal B and the control unit wiring connector
terminal D5 for continuity. Repair or renew the
wiring harness as necessary. If no fault is found, renew
the ignition system control module.
CONTROL UNIT
To Test Input Circuits — Code 55
(1) Switch the ignition On with the engine
stopped and note the ECM warning lamp. (2) If a steady light is showing, proceed to
operation (3). If code 55 is displayed, proceed as follows:
(a) Switch the ignition Off and disconnect the
wiring connector from the control unit.
(b) Switch the ignition On and measure the
voltage at the wiring connector on terminals C10,
C I 1 , C12, C13 and A9. Disregard terminal C12 on
1.6 liter engines. (c) If there is voltage at any of the terminals
tested above, a faulty wi ring harness is indicated.
Repair the short circuit to voltage and return to
operation (1). (d) If there is no voltage at any of the terminals
tested, a faulty control unit is indicated. Renew the
control unit and return to operation ( 1 ) . (3) Connect a jumper lead between terminals A
and B on the diagnostic link connector and note if
code 55 is displayed.
If code 55 is displayed, an intermittent fault is
indicated. Switch Off the engine, erase the self diag-
nosis codes and run the engine for 2 minutes. Return
to operation (1 ) and repeat the test procedures.
If code 55 continues to return, renew the control
unit.
To Remove and Install
(1) Disconnect the negative battery terminal.
(2) Slide the passengers front seat to the rear-
most position and working under the seat, disconnect
the control unit wiring connectors. (3) Disengage the plastic control unit cover from
the mounting plate and remove the control unit from
the vehicle. (4) If necessary, remove the screws retaining the
Mem-Cal cover to the control unit.
(5) Release the Mem-Cal unit retaining clips,
grasp the Mem-Cal unit at each end and remove it
from the control unit. Installation is a reversal of the removal procedure
with attention to the following points:
(1) When installing the Mem-Cal unit, align the
notches in the Mem-Cal with those in the control unit
and push on each end of the Mem-Cal unit. Do not
push on the middle section of the Mem-Cal unit.
View of the control unit with the Mem-Cal unit re-
moved.
Page 109 of 238
Fuel and Engine Management 109
Diagram showing the identification of the relay and the relay connector terminals.
To Test Relay Circuits
(1) Remove the relevant relay as previously
described and connect the ne gative battery terminal.
(2) Connect a test lamp to earth and probe the
fuel pump relay connector terminal C or the EGI relay
connector terminal A. With the ignition switched On
the test lamp should light. If the test lamp does not light check the fuel pump
fuse and the wiring harness for continuity between the
ignition switch and the fuel pump relay connector
terminal C or EGI rela y connector terminal A.
(3) With the ignition remaining switched On,
connect the test lamp between the fuel pump relay
connector terminals C and B or the EGI relay
connector terminals A and B.
If the test lamp does not light, repair the open
circuit between terminal B and earth.
(4) When checking the EGI relay circuit, pro-
ceed to operation (9).
When checking the fuel pu mp relay circuit pro-
ceed as follows.
(5) Probe the relay connector terminal A with a
test lamp to earth. Switch the ignition On and note the
test lamp.
If the test lamp lights for 2 seconds, proceed to
step (7).
If the test lamp does not light as specified, proceed
as follows.
(6) Switch the ignition Off and backprobe the
control unit wiring connector terminal A1 with a test
lamp to earth. With the ignition switched On the test
lamp should light as previously described.
If the test lamp does not light as described, renew
the control unit.
If the test lamp does light as described, locate the
open circuit or short in the wiring harness between the
control unit wiring connector terminal Al and the
relay connector terminal A. Repair or renew the
wiring harness as necessary.
(7) With the ignition switched Off connect a
jumper lead between the relay connector terminals C
and D. (8) Switch the ignition On and listen for the
operation of the fuel pump. It should be possible to
feel vibrations in the fuel return hose. If the fuel pump is operating, the fuel pump relay
circuit can be considered serviceable.
If the fuel pump is not operating, check the wiring
harness for continuity between the fuel pump wiring
harness connector, the fuel pump relay connector
terminal D and earth. If no fault can be found, renew
the fuel pump.
(9) Probe the relay connector terminal C with a
test lamp to earth. The test lamp should light.
If the test lamp does not light, locate the open
circuit between the battery and terminal C. Check the
fusible link which is located third from the front in the
fusible link connecting block.
(10) Connect a jumper lead between the relay
connector terminals C and D and backprobe the
control unit wiring connector terminal A6 with a test
lamp to earth.
If the test lamp lights, the EGI relay circuit can be
considered serviceable.
If the test lamp does not light locate the open
circuit between the contro l unit wiring connector
terminal A6 and the relay connector terminal D.
Repair or renew the wiring harness as necessary.
COOLANT TEMPERATURE SENSOR
To Test — Codes 14 and 15
(1) Erase the self diagnosis code memory as
previously described. (2) Start and run the engine at idle speed for 60
seconds or until the ECM warning lamp lights.
(3) Stop the engine, switch the ignition On and
connect a jumper lead between terminals A and B on
the diagnostic link connect or. Note any fault codes
displayed. If codes 14 or 15 are displayed, proceed to
operation (4).
If codes 14 or 15 are not displayed, but were
displayed when the self diagnosis test procedure was
View showing the location of the coolant temperature
sensor. 1.6 liter engine.
Page 110 of 238
110 Fuel and Engine Management
originally performed, an intermittent fault is indi-
cated. Proceed as follows:
(a) Check for faulty wiri ng connections. Check
that all wiring connectors are clean and secure. (b) Check that all earth wires are secure.
(4) Disconnect the wiring connector from the
coolant temperature sensor. (5) With the ignition switched On, measure the
voltage across the terminals on the coolant tempera-
ture sensor wiring connector. The voltage should be
4-6 volts.
If the voltage is below 4 volts, proceed to opera-
tion (9).
If the voltage is as specified, proceed as follows.
(6) Remove the coolant temperature sensor
from the vehicle. (7) Connect an ohmmeter to the coolant temper-
ature sensor terminals. (8) Immerse the meta1 end of the coolant
tem-
perature sensor in a 50/50 mixture of glycol and iced
water at a temperature of 0 deg C. The resistance
should be 6 000 ohms. Slowly heat the mixture and measure the resis-
tance of the coolant temperature sensor at the follow-
ing temperatures. Compare the results with the spec-
ified values:
0 d e g C ................................................. 6 000 ohms
20 deg C .................................................. 2 500 ohms
30 deg C .................................................. 1 800 ohms
40 deg C.................................................. 1 200 ohms
70 deg C .......................................................450 ohms
90 degC .......................................................250 ohms
100 deg C.....................................................190 ohms
110 deg C.....................................................110 ohms
If the resistances obtained are not as specified at
any of the given temperatures, renew the coolant
temperature sensor and retest for fault codes.
(9) Disconnect the control unit wiring connec-
tors.
(10) Check the wiring harness for shorts and
continuity between the coolant temperature sensor
wiring connector terminals and the control unit wiring
connector terminals C10 and D2. Repair or renew the
wiring harness as necessary.
Also check the control unit terminals for damage.
If no fault is found, renew the control unit and
retest for fault codes.
To Remove and Install
(1) Disconnect the negative battery terminal.
(2) Disconnect the wiring connector from the
coolant temperature sensor.
(3) Drain the coolant as described in the Cooling
and Heating Systems section to a level below the
sensor.
(4) Unscrew the sensor from the thermostat
housing. Installation is a reversal of the removal procedure
with attention to the following points;
(1) Apply Loctite 675 or a similar conductive
sealer to the threads of th e sensor. Tighten the sensor
to the specified torque.
(2) Fill the cooling system with the correct
mixture of water and inhibitor as described in the
Cooling and Heating Systems section. (3) Ensure that the wiring connector is clean and
secure.
THROTTLE POSITION SENSOR
To Test - Codes 21 and 22
NOTE: The following test procedure as-
sumes that fault codes 21 or 22 have been
displayed during the se lf diagnosis test pro-
cedure. If no codes have been displayed but
the operation of the throttle position sensor
is suspect, begin the test procedure at oper-
ation (24).
(1) Erase the self diagnosis code memory as
previously described.
(2) Start and run the engine at idle speed for 60
seconds or until the ECM warning lamp lights. If the engine will not start, disconnect the throttle
position sensor wiring co nnector and proceed to
operation (8). .
(3) With the engine id ling, quickly increase the
engine speed to 3 000 rpm and return to idle.
If the ECM warning lamp remains illuminated,
proceed to operation (4).
If the ECM warning lamp extinguishes, an inter-
mittent fault is indicated. Proceed as follows:
(a) Check for faulty wiri ng connections. Check
that all wiring connectors are clean and secure. (b) Check that all earth wires are secure.
(4) Stop the engine, switch the ignition On and
connect a jumper lead between terminals A and B on
the diagnostic link connect or. Note any fault codes
displayed.
If codes 21 or 22 are displayed, proceed as
follows.
(5) Remove the jumper lead from the diagnostic
link connector. (6) Erase the self diagnosis codes as previously
described. (7) Disconnect the wiring connector from the
throttle position sensor. If code 22 was displayed in operation (4), proceed
to operation (13).
If code 21 was displayed in operation (4), proceed
as follows.
(8) Start and run the engine at idle speed for 2
minutes or until the ECM warning lamp lights. If the
engine will not start, pr oceed to operation (11).
(9) Stop the engine, switch the ignition On and
connect a jumper lead between terminals A and B on
Page 111 of 238
Fuel and Engine Management 111
Location of the throttle position sensor. Inset shows the terminal identification.
the diagnostic link connector. Note any fault codes
displayed.
If code 21 is displayed, proceed to operation (11).
If code 22 is displayed, proceed as follows.
(10) Connect the lead of a test lamp to the
positive battery terminal and insert the probe into
terminal B on the throttle position sensor wiring
connector.
If the test lamp lights, pr oceed to operation (24).
If the test lamp does not light, check the wiring
harness between the throt tle position sensor wiring
connector terminal B and the control unit wiring
connector terminal D2 fo r continuity. Repair or
renew the wiring harness as necessary and retest for
fault codes.
(11) With the ignition switched Off, disconnect
the control unit wiring connectors. (12) With the ignition switched On, measure the
voltage at terminal C13 on the control unit wiring
connector.
If the voltage is less than 1 volt, check the wiring
harness for shorts between the throttle position sensor
wiring connector terminals C and A and the control
unit wiring connector terminals C13 and C14. Repair
or renew the wiring harness as necessary. If no fault
can be found, renew the control unit.
(13) Start and run the engine at idle speed.
(14) Connect a jumper lead across terminals A
and C on the throttle position sensor wiring connec-
tor. (15) Stop the engine, switch the ignition On and
connect a jumper lead between terminals A and B on
the diagnostic link connector . Note any fault codes
displayed. If codes 21 and 22 are displayed, proceed to
operation (24).
If code 22 only is displayed, proceed as follows.
(16) Remove the jumper lead from the throttle
position sensor wiring connector. (17) Measure the voltage across the throttle posi- tion sensor wiring connector terminals A and B.
If the voltage is below 4 volts, proceed to opera-
tion (20).
If the voltage is 4-6 volts, proceed as follows:
(18) With the ignition switched Off, disconnect
the control unit wiring connectors.
(19) Check the wiring harness between the con-
trol unit wiring connector terminal C13 and the
throttle position sensor wiring connector terminal C
for continuity and shorts. Repair or renew the wiring
harness as necessary and retest for fault codes. If no fault is found, renew the control unit and
retest for fault codes.
(20) Disconnect the wiring connector from the
MAP sensor. (21) Measure the voltage across the throttle posi-
tion sensor wiring connector terminals A and B.
If the voltage is 4 - 6 volts, renew the MAP sensor.
If the voltage is below 4 volts, proceed as follows.
(22) With the ignition switched Off, disconnect
the control unit wiring connectors. (23) Check the wiring harness between the con-
trol unit wiring connecto r terminal C14 and the
throttle position sensor wiring connector terminal A
for continuity and shorts. Repair or renew the wiring
harness as necessary and retest for fault codes. If no fault is found, renew the control unit and
retest for fault codes.
(24) With the ignition switched On, measure the
voltage at the control unit wiring connector terminal
C13.
If the voltage is 0.2-1.2 volts, proceed to opera-
tion (27).
If the voltage is 1.2-2.5 volts, proceed to opera-
tion (25).
If the voltage is over 2.5 volts, proceed as follows:
(a) Disconnect the wiring connector from the
throttle position sensor. (b) Measure the voltage at the control unit
wiring connector terminal C13. If the voltage is less than 1 volt, check the wiring
harness for continuity between the throttle position
sensor terminal B and the control unit wiring connec-
tor terminal D2. If the wiring harness is satisfactory,
renew the throttle position sensor.
(25) Check the base idle sp eed and adjust if
necessary as previously described. (26) With the ignition switched On, measure the
voltage at the control unit wiring connector terminal
C13. The voltage should be 0.2-1.2 volts. If the voltage is not as specified, renew the throttle
position sensor.
If the voltage is as specified, proceed as follows.
(27) With the ignition switched On, measure the
voltage at the control unit wiring connector terminal
C13 as the throttle is steadily opened to the wide open
throttle position. The voltage should increase steadily
with no sudden variations.
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112 Fuel and Engine Management
If the voltage does not increase as specified, renew
the throttle position sensor.
If the voltage is as specified, proceed as follows.
(28) With the ignition switched On and the
throttle valve held fully open, measure the voltage at
control unit wiring connector terminal C13. The
voltage should be above 4 volts.
If the voltage is below 4 volts, renew the throttle
position sensor.
To Remove and Install
(1) Disconnect the negative battery terminal.
(2) On 1.6 liter engines, remove the air cleaner
assembly as previously described. (3) Disconnect the throttle position sensor wir-
ing connector. (4) Remove the throttle position sensor retain-
ing screws and remove the throttle position sensor
from the throttle body. Installation is a reversal of the removal procedure
with attention to the following points:
(1) Ensure that the throttle valve is in the fully
closed position. (2) Tighten the retaining screws securely and
install the wiring connector.
View of the throttle positi on sensor removed from the
throttle body assembly.
MANIFOLD AIR TEMPERATURE (MAT)
SENSOR - 1.8 LITRE ENGINE
To Test - Codes 23 and 25
(1) Erase the self diagnosis code memory as
previously described.
(2) Start and run the engine for 2 minutes or
until the ECM warning lamp lights. (3) Stop the engine, switch the ignition On and
connect a jumper lead between terminals A and B on
the diagnostic link connector . Note any fault codes
displayed. If codes 23 or 25 are displayed, proceed to
operation (4).
If codes 23 or 25 are not displayed but were
displayed when the self diagnosis test procedure was
originally performed, an intermittent fault is indi-
cated. Proceed as follows:
(a) Check for faulty wiri ng connections. Check
that all wiring connectors are clean and secure. (b) Check that all earth wires are secure.
(4) Disconnect the wiring connector from the
MAT sensor. (5) With the ignition switched On, measure the
voltage across the terminals on the MAT sensor wiring
connector. The voltage s hould be 4-6 volts.
If the voltage is below 4 volts, proceed to opera-
tion (9).
If the voltage is as specified, proceed as follows.
(6) Remove the MAT sensor from the engine.
(7) Connect an ohmmeter to the MAT sensor
terminals. (8) Immerse the metal end of the MAT sensor in
a container of iced water at a temperature of 4 deg C.
The resistance should be 7 500 ohms. Slowly heat the water and measure the resistance
of the MAT sensor at the following temperatures.
Compare the results with the specified values:
20 deg C .................................................. 3 400 ohms
38 deg C....................................................1 800 ohms
70 degC ...................................................... 450 ohms
100 deg C.................................................... 185 ohms
If the resistances obtained are not close to the
specified figures at any of the given temperatures,
renew the MAT sensor and retest for fault codes.
(9) Disconnect the control unit wiring connec-
tors. (10) Check the wiring harness between the MAT
sensor wiring connector and the control unit wiring
connector terminals C12 and A11 for shorts and
continuity. Also check the control unit terminals for
damage. Repair or renew the wiring harness as necessary.
If no fault is found, renew the control unit and
retest for fault codes.
To Remove and Install
(1) Disconnect the negative battery terminal.
Installed view of the MAT sensor. 1.8 liter engine.