wiring JAGUAR XJ6 1994 2.G Electrical Diagnostic Manual

Automatic Transmission (V12) Powertrain
Shift Malfunction (Max- Adapt) - PO780
Function:
Transmission internal operation monitoring.
Possible causes:
. Mechanical wear 1 failure.
Effects:
. Harsher shifts.
Remedy:
. Refer to VSM, Section 8.2.
Transmission Component Slipping - PI 739
Function:
Transmission internal operation monitoring.
Possible causes:
Faulty harness wiring /connection.
. Fuse blown.
. Faulty torque converter clutch.
Mechanical wear.
Effects:
. MIL lamp illuminated.
. Harsh shifts.
Remedy:
. Repair or renew harness 1 connector.
Renew fuse F14 in LH heelboard fuse-box on determining reason for rupture.
Refer to VSM, Section 8.2.
0
0
Issue 1 August 1994 20 X300 EDM

Automatic Transmission (V12) Powertrain
Torque Reduction Signal Malfunction - P1780
Function:
ECM signal monitor.
Connections: TCM PI Harness ECM
CC048/007 P1063/008 P1044/006
Possible causes:
. Faulty harness wiring /connection.
. Faulty ECM signal.
Effects:
. Harsh gearshifts.
Remedy:
. Repair or renew harness / connector.
Examine ECM fault diagnosis (refer to EDM, section 5.2).
Transmission
warning lamp illuminated.
Engine Torque Signal Malfunction - P1781
Function:
ECM signal monitor.
Connections: TCM PI Harness
CC048/0 12 P1063/007
ECM
P1044/005
Possible causes:
. Faulty harness wiring /connection.
. Faulty ECM signal.
Effects:
. Transmission warning lamp illuminated.
. Harsh gearshifts.
Remedy:
Repair or renew harness / connector.
Examine ECM fault diagnosis (refer
to EDM, section 5.2).
X300 EDM 21 Issue 1 August 1994

Powertrain Automatic Transmission (V12)
Traction Control Active Input - PI 782
Function:
ABS signal monitor.
Connections: TCM Connector
CCO48/023 FCOO7/041
Connector Connector
FCOO5/025 LHD LSOO3/017 LHD
FCOO6/040 RHD RS003/00D RHD Connector
FCO57/008
ABS / TC CM
LSO27/003 LHD
RS027/003 RHD
Possible
causes:
8 Faulty harness wiring / connection.
8 Faulty signal from ABS / TC CM.
Effects:
8 No 'shift inhibit' during traction control.
Remedy:
8 Repair or renew harness / connector. - Examine ABS / TC CM fault diagnosis (refer to EDM Section 14). Connector
FCO57/002
P2:
1
Traction
control active -fault code PI782
-
'03
14
JE6 1751
Issue 1 August 1994 X300 EDM 23

I' Automatic Transmission (V12) Powertrain
PI Harness
Pl063/00 1
Throttle Position Signal Fault - P1791
Function:
Throttle position signal monitor.
Connections: TCM
CC04810 1 1
Possible causes:
Faulty harness wiring 1 connection.
Faulty ECM signal.
Effects:
9 MIL illuminated.
Fixed shift points, giving harsh shifts.
Remedy:
Repair or renew harness 1 connector.
Examine ECM fault diagnosis (refer to EDM, Section 5.2).
ECM
PI 104/004
P' 1
1
Throttle position -fault code P1791
7-1 GN
Fia. 1
W4
8
J86 ~ 1752
X300 EDM Issue 1 August 1994 24

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

I:.
Powertrain Automatic Transmission (V12) w
Kickdown Switch System - P1796
Function:
Switch operation monitor.
Connection: TCM Connector
CCO48/024 FCOO7/009
Possible causes:
8 Faulty harness wiring /connection.
8 Faulty switch (or switch adjustment).
Effects:
No kickdown facility.
Remedy:
8 Repair or renew harness / connector.
Re-adjust or renew switch. Switch
in
CA074/001 RHD
FCO19/001 LHD
Ground
CA074/002 RHD
FCO 191002 LH D
Kickdown switch -fault code PI796
Fig. 1

Steering @
10.3 DIAGNOSTICS
a Fault: Steering light at all times
Cause: 1. No speed signal
2. Wiring fault
Remedy: 1.
2a.
2b. Check
wiring harness continuity between PSCM pin
V and instrument pack
pin
2.
Check voltage between transducer pin 1 (+ve) and ground, with ignition
ON. If 12V is recorded repair or renew harness.
Check wiring between transducer pin
2 (-ve) and OV. If OV is recorded
repair or renew harness.
Fault: Steering heavy at all times
Cause: 1. Fuse blown
2. Wiring fault
Remedy: 1.
2a.
2b.
2c.
2d Examine
fuse F12 in
RH heelboard fuse-box, if blown determine reason for
failure and renew.
Check wiring harness continuity between fuse F12 in
RH heelboard
fuse
-box and PSCM pin V.
Check wiring harness continuity between PSCM pin W1 and transducer
pin 1.
Check wiring harness continuity between PSCM pin W2 and transducer
pin
2.
Check voltage between transducer pin 2 and ground, with ignition ON. If
12V is recorded repair or renew harness and renew PSCM.
Fault:
Cause:
1. Short circuit
Remedy:
Steering becomes heavy during driving until ignition cycled
la.
1 b.
Check resistance between transducer pins 1 and 2. If a value below 7.5f is
recorded renew transducer.
Check resistance of wiring harness between transducer connections. If
short circuit is recorded renew harness.
Note: Operation ofthe PSCM can bechecked using Jaguar Diagnostic Equipment. Generation of input speed signals
and measurement of the resulting current outputs indicate
if PSCM is faulty.
X300 EDM 3 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

Climate Control Systems
14.7.22 BLOWER MOTORS
Disconnect the blower motors (LH & RH) multi-plugs and check motor operation by applying battery voltage (+12V) across pin 5 (+vel and pin 9 (-ve).
Non-functioning of both L H and RH motors *
Cause:
1. Loss of ignition voltage.
Remedy:
1.
2.
*
Examine fuse F12 in RH heelboard fuse-box. If fuse is blown determine reason for failure and renew.
Examine harness wiring from
RH heelboard fuse-box connection CA044/010 to splice CAS53. Repair or renew
wiring as necessary.
This fault will also affect the operation of seat control modules, power steering control module and door mirror
heaters.
Non-functioning of RH blower motor only
Cause:
1. Faulty relay operation.
2. Faulty harness wiring.
Remedy:
1. Ensure 12Vsupply between relay pin 1 and ground.
Ensure continuity between pins 3 and
5 when relay operated.
Ensure relay coil impedance of
7552 to 135Q across pins 1 and 2.
Ensure correct seating of relay on base. Examine pins for damage or deformity.
Check continuity of wiring from fuse F12
(RH heelboard fuse-box) to relay pin 1 and from relay pin 2 to A / CCM
pin 53 (26-way connector).
Check continuity of wiring from fuse
F11 (RH heelboard fuse-box) to relay pin 3, from relay pin 5 to motor pin 5, from motor pin 13 to A / CCM pin 41 (16-way connector), from motor pin 8 to ground and from motor pin 10 to A / CCM pin 42 (16-way connector).
2.
Non-functioning of L H blower motor only
Cause:
1. Faulty relay operation.
2. Faulty harness wiring.
Remedy:
1. Ensure 12V supply between relay pin 1 and ground.
Ensure continuity between pins 3 and
5 when relay operated.
Ensure relay coil impedance
of 7552 to 135Q across pins 1 and 2.
Ensure correct seating of relay on base. Examine pins for damage or deformity.
2. Check continuity of wiring from fuse F12 (RH heelboard fuse-box) to relay pin 1 and from relay pin 2 to A / CCM
pin 66 (26-way connector).
Check continuity of wiring from fuse
F11 (LH heelboard fuse box) to relay pin 3, from relay pin 5 to motor pin 5, from motor pin 13 to A / CCM pin 49 (16-way connector), from motor pin 8 to ground and from motor pin 10 to
A / CCM pin 50 (16-way connector).
X300 EDM 23 Issue 1 August 1994