1994 JAGUAR XJ6 Electrical Diagnostic Manual

Automatic Transmission (V12) Powertrain
Force Motor (Variable Pressure Control Solenoid) Fault - PO748
Function:
Pressure control manifold operation monitoring.
Connections: TCM Multi-plug TCC
Connector
CCO48/052 GBO 10/005 GBOl2/0
CC048/049 GBO 10/006 GBOl2/0
Possible causes:
8 Faulty harness wiring I connectors.
8 Faulty force motor.
Effects:
8 Harsh gearshifts
Remedy:
. Repair or renew harness 1 connectors.
. Renew force motor.
8 Refer to VSM, Section 8.2.
1
3
P52
P49
Force motor -fault code PO748
2
1
Fia. J86 . 1748
X300 EDM Issue 1 August 1994 18

Powertrain Automatic Transmission (V12)
Solenoid Valves A and B - Performance /Electrical - PO75 1 / PO753 and PO756 / PO758
Function:
Valve operation monitoring.
Connections: TCM
CCO48/039
CCO48/043
Multi-plug
Connector
GBO
10/002
GBOl0/004
GBO 10/003
(+12V)
Transmission
GB012/001 SOL A
GBOl2/002 SOL B
GB012/003 SUPPLY
Possible causes:
. Faulty valve.
. Faulty harness wiring 1 connectors.
. Blown fuse.
Effects:
9 MIL illuminated.
Second gear selected permanently ie 'Limp Home' mode.
Remedy:
. Renew faulty valve.
Repair or renew harness 1 connectors.
. Renew fuse F14 in LH heelboard fuse-box on determining reason for rupture.
1 1
Solenoid valves -fault codes PO751 / PO753 / PO756 / PO758
1
Fia. 1 JUl3 ~ 1749
&@: * +12V present
only when ignition switched ON
X300 EDM 19 Issue 1 August 1994

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

Automatic Transmission (V12) W Powertrain
1
Torque reduction / engine torque signal malfunction - PI780 / PI781
-
8
J86.175~3
Fig. 1
Note: * Torque reduction request * Torque reduction signal
0
0
0

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