air condition JAGUAR X308 1998 2.G Owner's Manual
[x] Cancel search | Manufacturer: JAGUAR, Model Year: 1998, Model line: X308, Model: JAGUAR X308 1998 2.GPages: 2490, PDF Size: 69.81 MB
Page 368 of 2490

Rear Disc Brake - Brake CaliperVehicles W
ith: Standard Brakes
Re
mo
val and Installation
Remov
a
l
WA
RNING: BRAKE DUST, IF INHALED CAN DAMAGE YOUR
HEALTH. ALWAYS REMOVE BRAKE DUST USING A VACUUM
BRUSH. DO NOT USE A COMPRESSED-AIR LINE TO DISPERSE BRAKE DUST INTO THE ATMOSPHERE.
• CAUTIONS:
Replacement of nuts and bolts: Various thread-locking de vices are used on nuts and bolts throughout the vehicle.
These devices restrict the number of times a nut or bolt can be used. See section 100-00 for information.
Remove brake fluid spilla ge immediately from paint work, with clean water.
The brake pad adhesive backing must not be reused, therefore always install new brake pads, irrespective of the
condition of the original pads when replacing a brake caliper. Always replace brake pads as an axle set.
Sp
ecial Tool(s)
Brake Pedal
H
old Tool
JDS 9013
1. Op
en luggage compartment lid and fit suitable paintwork
protection equipment.
2. Raise vehicle on a four-post lift.
3. Raise rear of vehicl e and support on stan ds. See Section 100-
02.
4. Remove rear wheel. See Section 204-04.
5. NOTE
: Th
e following three pictorial procedures must be
carried-out to minimize brake fl uid loss when disconnecting the
brake hose.
Open Left-Hand-Front and Left-H and-Rear caliper bleed nipples.
Connect a
bleed tube and co
ntainer to the calipers.
Op
en bleed nipples.
6. Depress and hold down brak e pedal at the specified
measurement using the special tool.
1. Position tool between brake pedal and seat frame.
2. Turn the tool wheel unti l the brake pedal is held
60mm down from its released position.
Page 376 of 2490

Rear Disc
Brake - Brake DiscVe
hicles With: Standard Brakes
Remo
val and Installation
Remov
a
l
• WAR
N
INGS:
BRAKE DISCS MUST ALWAYS BE REPLACED IN PAIRS.
BRAKE DUST, IF INHALED CAN DAMAGE YOUR HEALTH. ALWAYS REMOVE BRAKE DUST USING A VACUUM BRUSH.
DO NOT USE A COMPRESSED-AIR LINE TO DI SPERSE BRAKE DUST INTO THE ATMOSPHERE.
CAUTION: Replacement of nuts and bolts: Various thread-locking devices are used on nuts and bolts throughout the
vehicle. These devices restrict the number of times a nut or bolt can be used. See section 100-00 for information.
1. Op
en engine compartment and fit
paint work protection covers
to fenders.
2. Raise rear of vehicle and support on stands. Refer to section
100-02.
3. Remove rear wheels. Refer to section 204-04.
4. CAUTIO
N: Remove brake flui
d spillage immediately from
paint work, with clean water.
Loosen brake fluid reservoir-cap.
Position a cloth around the reser
voir to collect any fluid
spillage.
5. CAUT
ION: Tie caliper housing aside. Do not allow the
caliper housing to hang on the hydraulic hose, as this will
damage the hose.
Remove caliper housing from caliper carrier.
1. Remove anti-rattle spring.
2. Remove dust covers.
3. Remove guide pins.
4. Remove housing from carrier.
Tie
caliper housing aside.
6.
CAUTIO
N: Always install new brake pads, irrespective of
the condition of the original pads, when renewing a brake disc.
• NOTE: The inner brake pad is fitted with a clip which secures
the pad into the caliper piston.
Page 380 of 2490

Rear Disc
Brake - Brake DiscVehicl
es With: High Performance Brakes
Remo
val and Installation
Remov
a
l
1.
WAR N
INGS:
BRAKE DISCS MUST ALWAYS BE REPLACED IN PAIRS.
BRAKE DUST, IF INHALED CAN DAMAGE YOUR HEALTH.
ALWAYS REMOVE BRAKE DUST USING A VACUUM BRUSH. DO
NOT USE A COMPRESSED-AIR LINE TO DISPERSE BRAKE DUST
INTO THE ATMOSPHERE.
• CAUTIONS:
Replacement of nuts and bolts: Various thread-locking
devices are used on nuts and bolts throughout the vehicle. These
devices restrict the number of ti mes a nut or bolt can be used.
See section 100-00 for information.
The Brembo caliper is aligned to the brake disc when it is
first installed to the vehicle, therefore, care must be taken not to
disturb this alignment. When removing the caliper; remove the
bolts that secure the anchor brac ket to the hub carrier only. DO
NOT loosen any other caliper bolts.
Open engine compartment and fit paint work protection covers
to fenders.
2. Ra
ise rear of vehicle and support
on stands. Refer to section
100-02.
3. Remove rear wheels. Refer to section 204-04.
4. CAUTIO
N: Remove brake flui
d spillage immediately from
paint work, with clean water.
Loosen brake fluid reservoir-cap.
Position a cloth around the reser
voir to collect any fluid
spillage.
5. CAUTIO
N: Always install new brake pads, irrespective of
the condition of the original pads, when renewing brake discs.
Remove brake pads from caliper. 1. Withdraw pins from caliper.
2. Remove anti-rattle spring.
3. Discard brake pads.
Page 436 of 2490

Pinpoint tests
W
S
S circuit: short
circuit to power
WSS f
ailure
C1
175Left -hand re
ar wheel speed
sensor (WSS) circuit failure
W S
S circuit: open
circuit
WS
S circuit: short
circuit to ground
W S
S circuit: short
circuit to power
WSS f
ailure
F
or l
eft-hand rear WSS test
s. GO to Pinpoint Test E.
C1267Modulat or valv
e failure
Supply volt
ages
to valve
solenoids or sensors out of range
Fo
r power and ground tests. GO to Pinpoint Test
A.
B1342CAN co
mmunication circuit
failure
CAN :
open circuit fault
CAN:
short circuit to
ground
CAN :
short circuit to
power
Fo
r CAN tests. GO to Pinpoint Test
F.
B1676Supply volt
age out of range
Supply voltage:
too
low
Supply volt age:
too
high
Check fo
r DTCs indicating a charging system fault.
Rectify as necesssary.
PI
NPOINT TEST A : MODULE
POWER AND GROUND SUPPLIES
TES
T
CONDITIONS
D E
TAILS/RESULTS/ACTIONS
A
1
: CHECK THE POWER SUPPLY FUSES
Make sure the igniti
on is turned off. 1
Chec
k fuses 04, 16 and 18 of the engine compartment junction box.
2
Are th
e fus
es in good condition?
Yes GO to A2
.
No
Install a new f
use as
necessary. Check the syst em for normal operation. If the fuse fails again,
check the circuit for a short circuit to ground. Refer to the electrical guides.
A2: CHECK THE PERMANENT
POWER SUPPLY (1) TO THE MODULE
Disc
onnect the ABS module connector, LF27.
1
Measure the voltage between LF
2
7, pin 09 (NR) and ground.
2
Is the vol
t
age greater than 10 volts?
Yes GO to A3
.
No Re
pair the circuit between the engine compartment
junction box, fuse 16, and LF27 pin 09. Refer to
the electrical guides. Clear the DTC, check for normal operation.
A3: CHECK THE PERMANENT
POWER SUPPLY (2) TO THE MODULE
Meas
ure t
he voltage between LF27, pin 25 (NW) and ground.
1
Is the vol
t
age greater than 10 volts?
Yes GO to A4
.
No
Re
pair the circuit between the engine compartment ju
nction box, fuse 18, and LF27 pin 25. Refer to
the electrical guides. Clear the DTC, check for normal operation.
A4: CHECK
THE IGNITION POWER SUPPLY TO THE MODULE
Make sure the ignition is on. 1
Measure the
voltage between LF 2
7, pin 20 (WU) and ground.
2
Is the vol
t
age greater than 10 volts?
Yes GO to A5
.
No Re
pair the circuit between the engine compartment ju
nction box, fuse 04, and LF27 pin 20. Refer to
the electrical guides. Clear the DTC, check for normal operation.
A5: CHECK
THE GROUND SUPPLY TO THE MODULE
Page 437 of 2490

Make sure the ignition is turned off. 1
Meas
ure the resistances between LF27,
pins 08 and 24 (B) and ground.
2
Are
the resistances less than 5 ohms?
Yes The power and ground supplies to the module are ok . Recheck the DTCs for codes indicating a fault
elsewhere.
No Repair the high resistance circui t. Refer to the electrical guides. Clear the DTC, check for normal
operation.
PINPOINT TE
ST B : CHECK THE RIGHT-HAND FRONT WSS AND CIRCUITS
•
NOTE: Check connectors and pins for damage/corrosion
(see visual inspection).
•
NOTE: Check the WSS ring condition, whee
l bearing etc. Before beginning pinpoint test s refer to the visual inspection.
TE
ST
CONDITIONS
D
ETAILS/RESULTS/ACTIONS
B1: CHECK
THE WSS OUTPUT
Disc
onnect the ABS sensor connector, FR01.
1
Connec
t a multimeter set
to read alternating curr ent volts (AC volts) between pins 1 and 2 of the
sensor.
2
Spin
the wheel by hand and check the meter display.
3
Doe
s the sensor generate a voltage?
Yes GO to B2
.
No
If the WSS ring is in good condition, install a new WSS.
REFER to: Front Wheel Speed Sensor
(20
6-09 Anti-Lock Control, Removal and Installation).
B2:
CHECK THE WSS SIGNAL CIRCUIT CONTINUITY
Make sure the ignition is off. 1
Di
sconnect the ABS module connector, LF27.
2
Meas
ure the resistance between LF27
, pin 03 (Y) and FR01, pin 02 (Y).
3
I
s the resistance less than 5 ohms?
Yes GO to B3
.
No
Repair the high resistance circui t. This circuit includes intermediate connector, LF02. Refer to the
electrical guides. Clear the DTC, check for normal operation.
B3:
CHECK THE WSS RETURN CIRCUIT CONTINUITY
Meas
ure the resistance between LF27
, pin 04 (G) and FR01, pin 01 (G).
1
I
s the resistance less than 5 ohms?
Yes The WSS and circuits are OK. Check for DTCs indicating a possible module failure.
No Repair the high resistance circui t. This circuit includes intermediate connector, LF02. Refer to the
electrical guides. Clear the DTC, check for normal operation.
P
INPOINT TEST C : CHECK THE LEFT-HAND FRONT WSS AND CIRCUITS
•
NOTE: Check connectors and pins for damage/corrosion
(see visual inspection).
•
NOTE: Check the WSS ring condition, whee
l bearing etc. Before beginning pinpoint test s refer to the visual inspection.
TE
ST
CONDITIONS
D
ETAILS/RESULTS/ACTIONS
C1
: CHECK THE WSS OUTPUT
Disc
onnect the ABS sensor connector, FL01.
1
Connec
t a multimeter set
to read alternating curr ent volts (AC volts) between pins 1 and 2 of the
sensor.
2
Spin
the wheel by hand and check the meter display.
3
Doe
s the sensor generate a voltage?
Yes GO to C2
.
No
If the WSS ring is in good condition, install a new WSS.
REFER to: Front Wheel Speed Sensor
(20
6-09 Anti-Lock Control, Removal and Installation).
C2
: CHECK THE WSS SIGNAL CIRCUIT CONTINUITY
Page 438 of 2490

Make sure the ignition is off. 1
Disc
onnect the ABS module connector, LF27.
2
M
e
asure the resistance between LF27, pin 17 (W) and FL01, pin 02 (W).
3
I
s
the resistance less than 5 ohms?
Yes GO to C3
.
No
Re
pair the high resistance circui
t. This circuit includes intermed iate connector, LF02. Refer to the
electrical guides. Clear the DTC, check for normal operation.
C3: CH
ECK THE WSS RETURN CIRCUIT CONTINUITY
Measure
the resistance between LF27, pin 18 (R) and FL01, pin 01 (R).
1
Is
the resistance less than 5 ohms?
Yes The WSS and circuits are OK. Check for DTCs indicating a possible module failure.
No Repair the high resistance circui t. This circuit includes intermediate connector, LF01. Refer to the
electrical guides. Clear the DTC, check for normal operation.
PI
NPOINT TEST D : CHECK THE RIGH
T-HAND REAR WSS AND CIRCUITS
•
NOTE: Check connectors and pins for damage/corrosion
(see visual inspection).
• NO
TE: Check the WSS ring condition, whee
l bearing etc. Before beginning pinpoint test s refer to the visual inspection.
TES
T
CONDITIONS
D E
TAILS/RESULTS/ACTIONS
D1: CHECK
THE WSS OUTPUT
Disc
onne
ct the ABS sensor connector, RA02.
1
Connec
t
a multimeter set
to read alternating curr ent volts (AC volts) between pins 1 and 2 of the
sensor.
2
Spin
the wheel by hand and check the meter display.
3
Doe
s
the sensor generate a voltage?
Yes GO to D2
.
No
If
the WSS ring is in good condition, install a new WSS.
REFER to: Rear Wheel Speed Sensor
(206-0
9 Anti-Lock Control, Removal and Installation).
D
2
: CHECK THE WSS SIGNAL CIRCUIT CONTINUITY
Make sure the ignition is off. 1
Disc
onnect the ABS module connector, LF27.
2
Measure t
he resistance between LF27
, pin 07 (O) and RA02, pin 01 (O).
3
Is
the resistance less than 5 ohms?
Yes GO to D3
.
No Re
pair the high resistance circui
t. This circuit includes intermed iate connector, LA02. Refer to the
electrical guides. Clear the DTC, check for normal operation.
D3:
CHECK THE WSS RETURN CIRCUIT CONTINUITY
Meas
ure t
he resistance between LF27
, pin 06 (Y) and RA02, pin 02 (Y).
1
Is
the resistance less than 5 ohms?
Yes The WSS and circuits are OK. Check for DTCs indicating a possible module failure.
No Repair the high resistance circui t. This circuit includes intermediate connector, CA09. Refer to the
electrical guides. Clear the DTC, check for normal operation.
PI
NPOINT TEST E : CHECK THE LEFT-HAND REAR WSS AND CIRCUITS
•
NOTE: Check connectors and pins for damage/corrosion
(see visual inspection).
• NO
TE: Check the WSS ring condition, whee
l bearing etc. Before beginning pinpoint test s refer to the visual inspection.
TES
T
CONDITIONS
D E
TAILS/RESULTS/ACTIONS
E1
: CHECK THE W
SS OUTPUT
Disc
onne
ct the ABS sensor connector, LA02.
1
Connec
t
a multimeter set
to read alternating curr ent volts (AC volts) between pins 1 and 2 of the
sensor.
2
Page 439 of 2490

Spin
the wheel by hand and check the meter display.
3
Doe
s the sensor generate a voltage?
Yes GO to E2
.
No
If the WSS ring is in good condition, install a new WSS.
REFER to: Rear Wheel Speed Sensor
(20
6-09 Anti-Lock Control, Removal and Installation).
E2
: CHECK THE WSS SIGNAL CIRCUIT CONTINUITY
Make sure the ignition is off. 1
Di
sconnect the ABS module connector, LF27.
2
Meas
ure the resistance between LF27
, pin 21 (U) and LA02, pin 01 (U).
3
I
s the resistance less than 5 ohms?
Yes GO to E3
.
No
Repair the high resistance circui t. This circuit includes intermediate connector, LA02. Refer to the
electrical guides. Clear the DTC, check for normal operation.
E3
: CHECK THE WSS RETURN CIRCUIT CONTINUITY
Meas
ure the resistance between LF27
, pin 22 (U) and LA02, pin 02 (U).
1
I
s the resistance less than 5 ohms?
Yes The WSS and circuits are OK. Check for DTCs indicating a possible module failure.
No Repair the high resistance circui t. This circuit includes intermediate connector, CA29. Refer to the
electrical guides. Clear the DTC, check for normal operation.
P
INPOINT TEST F : CONT
ROLLER AREA NETWORK (CAN) INTEGRITY TEST
TE
ST
CONDITIONS
D
ETAILS/RESULTS/ACTIONS
F
1: CHECK THE NETWORK INTEGRITY
FROM THE DIAGNOSTIC SOCKET
M
easure the resistance between pins 06 (Y) and 14 (G) of the diagnostic socket.
1
I
s the resistance 60 ohms?
Yes The CAN system is OK. Check for DTCs indicating a fault elsewhere.
No Check the CAN system for open an d short circuits. Refer to the electrical guides. Clear the DTC,
check for normal operation.
Page 462 of 2490

Fo
r additional information, REFER to the
Electrical Checks and Tests in this section.
Steering control
module
(SCM) defective.
CHECK
the SCM and INSTALL a new SCM as
necessary.
Power steeri ng f
luid
delivery pressure or flow too low.
CHECK
the power stee
ring pressure. For
additional information, REFER to the Power Steering Pressure Test in this section.
INSTALL a ne
w power steering pump as
necessary. For additi onal information,
REFER to Section 211
-0 2
Power Steering
.
Internal steering gear
leakage.
CHECK
the power stee
ring pressure. For
additional information, REFER to the Power Steering Pressure Test in this section.
INSTALL a ne
w steering
gear as necessary.
For additional information,
REFER to Section 211
-0 2
Power Steering
.
Steeri
ng operati
on is very
heavy when driving, but when stationary
manoeuvring is good
Steering transducer open earl
y.
CHECK
steering transducer and INSTALL a
new steering transducer as necessary.
Carry out th
e electrical checks and tests.
For additional information, REFER to the
Electrical Checks and Tests in this section.
Steering transducer open
early,
steering control
module (SCM) fault.
CHECK
SCM and INSTALL a new SCM as
necessary.
Steering transducer open
earl
y, speedo signal error.
CHECK
speedo
circui
t. For additional
information, REFER to the wiring diagrams.
Steeri ng operati
on is very
light when driving, but when
stationary manoeuvring is good
Steering transducer not
o
pen, (no power steering
fluid flow).
CHECK
the power steering fluid condition.
For additional information, REFER to the
Power Steering Fluid condition check in this section.
Steering transducer not o
pen, steering control
module (SCM) fault.
CHECK
the SCM and INSTALL a new SCM as
necessary.
Carry out th
e electrical checks and tests.
For additional information, REFER to the
Electrical Checks and Tests in this section.
Steering transducer not
o
pen, speedo signal error.
CHECK
the speedo circ
uit. For additional
information, REFER to the wiring diagrams.
CHECK
the power steering
fluid low pressure pipe for restricted flow.
INSTALL a ne
w power steering fluid low
pressure pipe.
S t
eering heavy operation
during rapid manoeuvring
Ai r i
n power steering
system.
CHECK for an air l
eak into the power
steering system and re pair as necessary.
BLEED the
power steering system. For
additional information,
REFER to Power Steering System Bleeding
- in t hi
s section.
Fluid loss at the power
steering pump shaft seal.
CHECK the power steer
ing pump for signs o
f steering fl
ui
d loss.
INST
ALL a ne
w power steering pump as
necessary. For additi onal information,
REFER to Section 211
-0 2
Power Steering
.
Power steeri
ng f
luid
delivery pressure or flow too low.
CHECK the power steer
ing pump for signs o
f steering fl
ui
d loss.
CHECK
the power stee
ring pressure. For
additional information, REFER to the Power Steering Pressure Test in this section.
INSTALL a ne
w power steering pump as
necessary. For additi onal information,
REFER to Section 211
-02
Power Steering
.
Lower steeri
ng col
umn
interference.
CHECK
the steering co
lumn is free from
interference from the en gine harness, sound
proofing or the floor covering.
Incorrect steering geometry. CHE
CK the front wheel alignment. For
additional information,
REFER to Section 204
-00 Sus
pension
Sy
ste
m
- General
Information
.
CHECK
the power stee
ring pressure. For
Page 464 of 2490

Vibrati
on
Power steeri
ng
pump noisy
Low power steer i
ng fluid.
CHECK
steering system for s
igns of steering fluid
loss.
BLEE D the
power steering system. For additional
information,
REFER to Section 211
-0 0
Steering System
-
Ge n
eral
Informati
o
n
.
Power steeri
ng pump wor
n or
otherwise defective.
CHECK for leaks. R
EPAIR as necessary.
CHECK
the power steering pressure. For additional
information, REFER to th e Power Steering Pressure
Test in this section.
INST ALL a ne
w power steering pump as necessary.
For additional information,
REFER to Section 211
-0 2
Power Steering
.
Wh
in
e type noise
Aerated flui
d.
BLEE
D the
power steering system. For additional
information,
REFER to Power Steering System Bleeding
- in t h
is
section.
Power steering pump.
CHECK for leaks. R
EPAIR as necessary.
INSTALL a ne
w power steering pump as necessary.
For additional information,
REFER to Section 211
-0 2
Power Steering
.
No
i
se during
steering gear movement
Low power steer i
ng fluid.
CHECK
steering system for s
igns of steering fluid
loss.
BLEE D the
power steering system. For additional
information,
REFER to Section 211
-0 0
Steering System
-
Ge n
eral
Informati
o
n
.
Water co
n
tamination to the
power steering fluid.
DR AIN
the power steering system.
BLEE
D the
power steering system. For additional
information,
REFER to Section 211
-00
Steering System
-
Gen
eral
Informati
o
n
.
Cavi
tation due to restricted
po
wer steering feed hose.
CHECK
and reposition power
steering feed hoses and
INSTALL new hoses as necessary.
Continu o
us noise
Low power steer i
ng fluid.
CHECK
steering system for s
igns of steering fluid
loss.
BLEE D the
power steering system. For additional
information,
REFER to Section 211
-0 0
Steering System
-
Ge n
eral
Informati
o
n
.
Power steeri
ng pump dri
ve
loose.
CHECK
power steering coupli
ng and power steering
pump.
IN ST
ALL a new power steering coupling or power
steering pump as nece ssary. For additional
information,
REFER to Section 211
-0 2
Power Steering
.
Incorre
ct
accessory drive belt
tension or accessory drive belt glazed.
CHECK acc
essory drive belt condition and INSTALL a
new accessory drive belt as necessary. For additional
information,
REFER to Section 303
-0 5 Ac
cessory Drive
.
Power steeri
ng pump dri
ve
pulley loose.
CHECK
and TIGHTEN the power steering pump drive
pulley retaining bolts as necessary. For additional
information, REFER to Section 303
-03A En
gine
Coo
ling / 30 3-03
B Supercharger Cooling
.
Power steeri
ng pump
r
etaining bolts loose.
CHECK
the power steering pump retaining bolts and
TIGHTEN as necessary.
Power steering hose/pipe in c
ontact with the vehicles
body.
CHECK
and reposition powe
r steering hoses/pipes,
INSTALL new hoses/pipes as necessary.
Power steeri ng hose
r
estricted/twisted.
CHECK
and reposition powe
r steering hose, replace
hose as necessary.
Conditi
on
Possibl
e Sources
Actio
n
Loose/worn tie-
ro
ds.
INST
ALL a new tie-r
od end. For additional
information,
Page 522 of 2490

diverter val
ve (if fitted) and oil filter.
Main
bearings
which are grooved in the upper positions and plain in
the lower positions. They are manufactured from
aluminium / tin material.
A c
rankshaft with under
cuts and rolled fillets for extra strength.
Fracture
-split connecting rods in sintered-forged steel.
Brackets
bolted to the front of
the cylinder
block are used to mo unt all accessories.
A sin
gle, seven ribbed vee belt
drives the accessories.
An au
tomatic belt tensioner for the front accessory drive,
incorporating a wear indicator.
An advanced en
gine management system inco
rporating electronic throttle control.
The un
it meets the requirements of the CARB OBDII USA legislation.
Ancillary Systems
The an
ci
llary systems, driven by the engine, each have a
detailed Description and Operation along with Diagnostic
Procedures, and Removal and Installation instructions ; refer to the following sections of this manual:
Power Steeri
ng Pump - Section 211-02
Ai
r Conditioning Compressor - Sectio
n 412-03
Engine
C
ooling Pump - Section 303-03
Generator
- Sectio
n 414-02
The drive belt, idler pulley and automatic tensioner are described in Section 303-05.
The engine starting system is described in Section 303-06.
En
gine Management and Emission Control System
Engine Control Modu
le (ECM)
Engine
management and exhaust emissions are controlled by the ECM, which has the
following main functions:
Fu
el injection
Idle
s
peed
Ignition Ev
aporative loss system
Engine
cooling fans Clim
ate control compressor clutch demand
The microprocessor within the ECM receiv es signals from various sensors and other modules and uses a pre-determined
program to compute engine management functions.
Adaptive functions are incorporated in the ECM to cater for co ntinuous adjustments to its computations to suit prevailing
conditions. Because the system also controls emissions to suit all modes, neither CO levels nor idle speed require service
attention or adjustment, except if an error should occur.
On Board Diagnostics are controlled by the ECM with the continuous monitoring of incoming signals and the subsequent
verification against what the module expects to 'see'. Should a si gnal be incorrect or missing, the ECM will substitute a fixed
value to provide the 'limp home mode' and alert the driver of the problem. Fixed values may be adopted for:
Transmission oil
temperature
Mechanica
l
guar
d position
Throttle blade angle Camshaft position
Inta
k
e air temperature
Diagnostic trouble codes (DTC), including OBD II codes, are stored in the ECM memo ry and can be read by an appropriate
retrieval tool.
Should either the ECM or TCM fa il, ensure that the control housing cooling fan is operating correctly. Failure of the cooling
fan MUST be rectified before renewing a control module and details of a fa n failure should accompany a returned control
module.