fuses JAGUAR XJ6 1994 2.G Electrical Diagnostic Manual

lw Automatic Transmission (AJ16)
SYSTEM VOLTAGE MALFUNCTION - P 1794
The TCM monitors the supply voltage and will log this fault if the voltage is less than 10.5V when the engine speed is
greaterthan 1600rpm. This fault code is unlikelyto becaused by afault within theTCM and assuch thevehicle harness
and fuses etc. should be completely tested before the TCM is condemned.
Possible causes:
. Blown fuses.
. Faulty harness wiring /connections.
Effects:
Transmission default settings adopted.
. MIL illuminated.
Transmission warning lamp illuminated.
. Maximum fluid pressure available.
. Limp home mode applied.
Remedy:
Examine fuse F14 in LH heelboard fuse-box. Renew (if necessary) after determining cause of rupture.
. Repair or renew harness / connector.
KICK-DOWN SWITCH SYSTEM - P 1796
The diagnostic check on the mode switch input is a plausibility check which is performed continuously while in oper- ation. A fault is determined when kickdown is seen when the throttle angle is less than 50%. However a fault will only
be logged if the output speed is greater than 256 rpm. No fault is logged if there is already a throttle signal fault. The
kickdown switch is located on the floor under the accelerator pedal and is operated when the throttle is fully open (ap- prox 90%). It is a normally open switch with one contact permanently to ground and the other is a signal to the TCM.
The signal wire is routed through the bulkhead harness and the gearbox harness to the TCM.
LHD
(FCO19) PIN 2 GROUND PIN 1 KD
SIGNAL
RHD
(CA074) PIN 2 GROUND PIN 1 KD
SIGNAL
Possible causes
. Faulty harness wiring /connections.
. Faulty switch (or switch adjustment).
Effects:
No kickdown facility.
Remedy:
. Repair or renew harness /connector.
. Re-adjust or renew switch.
0
0
0
Q
Issue 1 August 1994 24 X300 EDM

Automatic Transmission (V12) - Powertrain
System Voltage Malfunction - P1794
Function:
Battery voltage monitor.
Possible causes:
. Faulty harness wiring /connection.
. Blown fuses.
Effects:
. MIL illuminated.
. Second gear selected permanently ie ‘Limp Home’ mode.
Remedy:
Repair or renew harness I connector.
. Examine fuse F14 and F5 in LH and RH heelboard fuse-boxes respectively.
. Renew (if necessary) after determining cause of rupture.
P5 5
P53
1
I -3---+-2 YR
System supply voltage -fault code PI794
J86 - 1 753 Fig. 1
- Note: * +12V present only when ignition switched ON
X300 EDM ~.
25 Issue 1 August 1994

Brakes
12.4 SYSTEM FAULT INDICATION
Fault Indication:
ABS MIL lamp is still illuminated after ignition switch on and instrument pack self test.
h:
Possible causes
Fuses blown.
Faulty wheel speed sensor or harness.
Faulty wiring.
Faulty ABS
/ TC CM.
It is likely that theTC MIL lamp and Traction OFF lamp will also illuminate on vehicles with traction control fitted.
Fault Diagnosis
On the first ignition cycle after afault has been sucessfully diagnosed and corrected the vehicle must bedriven to a speed above 20kph (12.5 mile/ h) before warning lamps will extinguish. If lamps remain on after this exer- cise repeat fault diagnosis.
. Check fuses (F7) in battery feed lines and (F16) in ignition line. Battery fuses are located in the left and right hand
. Unbolt 28 way multi-plug connector from ABS / TC CM.
. Measure resistance across each wheel speed sensor.
No - Unplug sensor flying lead and re-measure sensor resistance.
N&:
heelboard fuse boxes. The ignition supply fuse is located in the left hand heelboard fuse box.
Is value measured 1 10052, f 50%?
Rear sensor connectors are located beneath the rear seat. Seat must be removed to gain access to connector.
Forward sensor connectors are located adjacent to the hood catch bracket.
Is value now within range?
Yes
- Examine harness between ABS I TC CM and sensor.
No - Renew sensor.
= Check continuity to ground from ABS 1 TC CM harness connections 13 and 14. If value is much greater than 0.152
renew harness.
. With the ignition switch ON, measure voltage between ABS /TC CM harness connection 14 and connections 1 and 2 respectively. If value is not approximately equivalent to battery voltage renew harness.
. With the ignition switch ON, measure voltage between ABSITC CM harness connections14 and 15. If value is not
approximately equivalent to battery voltage renew harness.
Renew ABS /TC CM if fault is not located during the above procedures.
fault Indication:
ABS MIL lamp illuminates at 20 kph.
m:
Possible Causes
Fuses blown.
Faulty hydraulic module pump
/ motor unit or circuitry.
Faulty ABS
/ TC CM.
Fault Diagnosis
Check fuses.
. Disconnect pump / motor unit and measure resistance across two pin connector. Measured value should be in the
. Unbolt 28-way connector from ABS /TC CM and measure voltage between harness connections1 and 14. If value
. Renew ABS 1 TC CM if fault is not located during the above procedures.
It is IikelythattheTCMILlampandTraction OFFlampwill also illuminateonvehicleswithtractioncontrolfitted.
region of 0.852. Renew unit if excessive resistance or short circuit is recorded.
is not approximately equal to battery volts renew harness.
Issue 1 August 1994 X300 EDM

Brakes
Fault Indication:
0 ABS MIL lamp illuminates on 'pull-away' or during driving
U:
Possible Causes
Faulty sensor or wiring.
Faulty rotor or wheel bearing installation giving inconsistent signals to
ABS / TC CM.
Fault Diagnosis
Check sensor installation for:
Security of sensor lead fixing bolt.
Damage to sensor lead.
Possible damage to rotor.
Excessive play in wheel bearing.
Intermittent faults caused by poor harness connection or damage.
It is IikelythattheTC MIL lamp andTraction OFF lamp will also illuminate on vehicles with traction control fitted.
Fault Indication:
TC MIL lamp only is still illuminated after ignition switch on and instrument pack self test.
Possible Causes - Faulty throttle position actuator.
Faulty actuator potentiometer.
Faulty wiring.
Fault Diagnosis
Disconnect flying lead to actuator motor bi-pin connector and measure motor resistance, reading should be approxi- mately 1.6Q. Renew actuator if value is excessive or short circuit.
Disconnect actuator potentiometer and measure resistance across pins 1 and 3, reading should be approximately 6.4kQ. Renew actuator if value indicates open or short circuit. If value is correct, operate accelerator pedal while
measuring resistance between pins 1 and 2, readings should vary in accordance with pedal travel.
. With the ignition switch ON, measure voltage across harness connections to potentiometer pins 1 and 3, reading
should be
5V+ 0.5V. If a voltage below 4.5 Vis recorded ensure that supply fuses are intact and all connections secure
before renewing harness.
m: Examine ABS MIL lamp at ignition switch-on. If lamp illuminates briefly, then goes out the supply fuses will
be intact. If lamp does not illuminate at all supply fuses may be blown, or MIL lamp may be faulty.
. Check continuity between harness connection to potentiometer pin 2 and pin 26 of 28-way multi-pug connector to
ABS I TC CM.
Fault Indication:
TC MIL lamp only is still illuminated 8 seconds after ignition switch on.
Possible Causes
Faulty harness or TCS switch.
Fault Diagnosis
= Check pin 18 of 28 way multi-plug connector is not shorted to ground.
X300 EDM 7 Issue 1 August 1994

Electrical rl
15.4.8 DlAG NOSTIC SUB-ROU T1 NES
0
The following information details possible fault conditions, causes and remedies. Detail test procedures for compo-
nents are covered in 'PIN-POINT TESTS' (Sub-Section 15.4.9).
Fault:
Possible causes:
Remedy:
Fault: Possible causes:
Remedy:
0
Fault:
Possible causes:
Remedy:
Fault:
Possible causes:
Remedy: Driver's
seat adjustment inoperative
1.
2.
3. Mechanical mechanism fault.
1.
2.
3.
No power supply to SCM.
Wiring harness or connectors faulty.
Check fuses
in 'A' post base fuse boxes.
Check harness and connectors between
SCM -fuse box,
SCM
-switch pack and SCM - motors.
Identify and repair mechanical faults.
Seat positional adjustment restricted
1.
2. Motor faulty.
3. Switch faulty.
4. Mechanical mechanism fault.
5. SCM faulty.
1.
2. Renew motor.
3. Renew switch pack.
4.
5. SCM faulty.
Harness
wiring or connector fault.
Examine wiring and connectors between SCM
- switch
pack and SCM
- motors.
Identify and repair mechanical faults.
Seat lumbar pump only inoperative
1.
2.
3. Motor faulty.
4. Switch faulty.
5. Mechanical mechanism
fault.
1.
2.
3. Renew motor.
4. Renew switch.
5. No
power supply to SCM.
Harness wiring or connector fault.
Check fuses in
'A' post base fuse boxes.
Examine wiring and connectors between SCM
- switch
pack and SCM
- motors.
Identify and repair mechanical faults.
Seat heaters only inoperative
1.
2.
3. Heater element faulty.
4. Heater thermostat faulty.
5. Heater switch faulty.
6. Body processor signal fault.
1.
2.
3.
4. Renew faulty switch.
5.
No power supply to SCM.
Wiring harness or connectors faulty.
Check fuses in
'A' post base fuse boxes.
Examine harness and connectors between SCM
- heater
circuit and SCM
- BPU.
Locate and renew faulty heater and thermostat unit.
Refer to BPU fault diagnosis.
X300 EDM 15.4 - 17 Issue 1 August 1994

Electrical IT
Fault:
Possible causes:
Remedy:
Fault: Possible causes:
Remedy:
Fault:
Possible causes:
Remedy:
Fault:
Possible causes:
Remedy:
Fault:
Possible causes:
Remedy: Steering
column positional adjustment inoperative
1. No power supply.
2. Wiring harness or connector fault.
3. Switch faulty.
4. Mechanical failure.
1. 2. Examine harness and connectors between S 1 CM -
3. Renew switch.
4.
Check fuses in 'A' post base fuse boxes.
fuse,
S I C CM - joy-stick switch and SI C CM - motors.
Identify and repair mechanical faults.
Steering column positional adjustment restricted
1. Wiring harness or connector fault.
2. Motor faulty.
3. Switch faulty.
4.
1.
2. Renew faulty motor.
3. Renew faulty switch.
4.
M echa n ica I mechanism fa i I u re.
Examine harness and connectors between
S 1 C CM -
motors and SI C CM and switch.
Identify and repair mechanical faults.
Rear view mirror positional adjustment inoperative or restricted
1. No power supply.
2.
3. Motor faulty.
4. Switch faulty.
5. Mechanical mechanism failure.
1.
2.
3. Renew faulty motor.
4. Renew faulty switch.
5.
Wiring harness or connector fault.
Check fuses in
'A' post base fuse boxes.
Examine harness and connectors between
S 1 C CM -
motors and SI C CM and switch.
Identify and repair mechanical faults.
Recall / Memory set facility inoperative or incorrect
1. Wiring harness or connector fault.
2. Potentiometers out of range or faulty.
3. Switches faulty.
1. Examine harness and connectors between SCM, S I C
CM and switches.
2. PDU only to check.
3. Renew faulty switches.
Exit \Entry facility inoperative or incorrect
1. Wiring harness or connector fault.
2. Potentiometers out of range or faulty.
3. Switch faulty.
1. Examine harness and connectors between SCM, S 1 C
CM and switches.
2.. PDU only to check.
3. Renew faulty switches. ~
Issue 1 August 1994 15.4 - 18 X300 EDM

15.4.9 PIN-POINT TESTS
The following tests give detailed information on component fault diagnosis. Refer to sub-section 15.4.9.16 for key to
schematic diagrams.
1. Seat power supply
a.
b.
Check fuses F3, F4, F9 and F12 in RH and fuse F6 in LH 'A' post base fuse boxes are
intact.
If blown determine reason for failure and renew.
Unplug harness connector from SCM and check for battery supply voltage to ground,
at pins 4,6,7 & 12 (B1 connector) and pin 11 (82 connector) with ignition on. If supply
is not recorded on all pins switch off ignition and check harness wiring continuity from
'A' post base fuse boxes to faulty lines as follows:
Connector B1
Pin 4 -fuse F 3, RH fuse box
Pin
6 -fuse F 4, RH fuse box
Pin
7 -fuse F 6, LH fuse box
Pin
12 -fuse F 9, RH fuse box
Connector 82
Pin 11 -fuse F12, RH fuse box
1 I
J86 - 1867
Fig. 1 SCM power supplies
Issue 1 August 1994 15.4 - 19 X300 EDM