1994 JAGUAR XJ6 Electrical Diagnostic Manual

4
ON PW
P473 P21* P32
1 K21
1 Kz1 B 31K6
-I-
31 K6 d rz:
(D 51 Kl
i
Fig. 1 Fault Codes PI790 / PI791
iw
6
U
1
P
a-1736
Issue 1 August 1994 22 X300 EDM

Automatic Transmission (AJ16)
SPORT MODE INDICATOR - P 1792
The sport mode lamp is located in the instrument pack. The input is 'pulled up' to nominal battery voltage (+12V) and
is supplied by an ignition switch feed. The TCM drives the signal to ground to turn the lamp on. The diagnostic runs
on the sport mode indicator output continuously during initialization and operation. The
checkcan detect an open cir- cuit, a short circuit to battery and short circuit to ground, although the diagnostic cannot distinguish between an open
circuit and a short to ground.
TCM
(CC007) BULKHEAD HARNESS (FC007) INSTRUMENT PACK (FCOO9)
PIN 49 - SPORT PIN 14
PIN 14
Possible causes:
. Faulty wiring harness I connectors.
. Faulty indicator lamp.
Faulty instrument pack.
Effects:
. No illumination of indicator lamp on instrument pack.
. Permanent illumination of indicator lamp on instrument pack.
Remedy:
. Repair or renew harness 1 wiring.
. Renew indicator lamp.
0 . Examine instrument pack fault diagnosis (refer to EDM, Section 15).
1
Y.IM
Fig. 1 Fault Code PI792 ~~
X300 EDM 23 Issue 1 August 1994

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 (AJ16) w
I
1 ---
I 9
I
I
0
1
JBd. 1737
Fig. 1 Fault Code PI796
X300 EDM 25 Issue 1 August 1994

Automatic Transmission (AJ16)
TCM FAULTS - PO603 / PO605 / P1608
0 Internal Control Module Keep Alive Memory Error - PO603
0 Internal Control Module ROM Test Error - PO605
0 Watch-dog Fault - PI608
Possible causes:
. Internal TCM circuit faults
Effects:
MIL illuminated.
. Transmission warning lamp illuminated (PO605 and PO1608 only).
. Maximum fluid pressure available (PO605 and PI608 only).
. Limp home mode applied (PO605 and PI608 only).
Remedy:
. RenewTCM.
Issue 1 August 1994 26 X300 EDM

Automatic Transmission (AJ16) w
8.1.5
nector.
TRANSMISSION CONNECTOR
(GB003)
TRANSMISSION ELECTRICAL PIN POINT TESTS
THE FOLLOWING TESTS describe methods of testing the transmission control solenoid valves from the multi-pin con-
0 A = Road Speed Sensor
0 B = Pressure Regulator
0 D = Oil Temperature Signal
0 F = Road Speed Sensor
0 H = MVI Solenoid
0 J = Oil Temperature Ground
0 K = MV2 Solenoid
0 L = MWVK Solenoid
0 M = Solenoid Supply
The solenoid valves are located on the valve block in the transmission assembly and can be identified by their position.
Connection is made via a connector located on the LHS of the transmission assembly.
Impedance Checks
M
-L)
M
-K) 28-60ohm
0 M-H)
M-B 5-70hm
M)(A
K)(D
L 1-( F O/C
H)(J
B)(
L-K)
L
- H ) 56- 120 ohm
K
-H)
L
-B)
K
-B) 33-67ohm
H
-B)
All Pins
- Ground OK
5
m- 1738
Fig. 1 Transmission Multi-plug Connector
X300 EDM 27 Issue 1 August 1994

Automatic Transmission (V12) Powertrain
SECTION CONTENTS
Subsection Title SRO Page
8.2.1 ............. Powertrain 4L-804 Transmission. Systeni Description ..................................... 1
8.2.2 ............. Component Descriptions .............................................................. 1
8.2.3 ............. Operating Principles .................................................................. 5
8.2.4.1 ........... Inputs ........................................................................\
...... 5
8.2.4.2 ........... Outputs ........................................................................\
.... 6
8.2.5 ............. Diagnostic Links ..................................................................... 7
8.2.6 ............. Diagnostic Fault Codes ............................................................... 8
8.2.7
............. Fault Diagnosis ...................................................................... 9
8.2.8 ............. Transmission Electrical Pin Point Tests .................................................. 27
8.2.4
............. Inputs / Outputs ...................................................................... 5
X300 EDM i Issue 1 August 1994

Automatic Transmission (V12) Powertrain
8.2.1 POWERTRAIN
41-80-E TRANSMISSION, SYSTEM DESCRIPTION
The electronic transmission system fitted to 6.0 liter and 4.0 liter super-charged vehicles comprises the following com- ponents:
0 Hydra-matic 4L-80-E Automatic Transmission
0 Electronic Transmission Control Module
0 Performance Mode Switch
0 Kickdown Switch
0 Gear Selection Module (illuminated)
System control is effected by the transmission control module
(TCM), located behind the passenger side fascia, which continuously monitors requests made bythe driver via the gearselector, throttle pedal etc. This data is used inconjunc- tion with the speed input from the transmission and inputs from the engine management system, to calculate optimum
shift points and control parametersfor shift pressure and ignition retardation to enhance shift quality and reduce trans- mission unit wear.
TheTCM is also able to detect faults within the system and store the relevant fault codes for interrogation with diagnos- tic equipment.
Gear shifts are controlled
by three solenoid valves, and a pressure control regulator, located on the valve block within
the transmission unit assembly. If a serious fault occurs, the TCM removes all electrical power from these valves and
the transmission system reverts to a mechanical default condition. This condition allows only mechanical selection
of reverse and one forward gear, either
third or fourth, depending on prevailing conditions at the time of the default.
The performance mode switch and kick
-down switch are used to adjust transmission operation as required by the
driver. Performance mode selection, made via a switch mounted on the selector switch surround, can be either NOR- MAL, for everyday use, or SPORT, for enhanced performance. Kick-down is activated by a switch mounted below the
accelerator pedal and is used to initiate a downward gear change, increasing torque and acceleration.
8.2.2 COMPONENT DESCRIPTIONS
Transmission Unit
The powertrain 4L-80-E transmission unit houses the two solenoid valves which control gear shifts. A pressure control
valve is also located on the solenoid valve block. These three valves initiate and control shift patterns within the trans- mission unit by regulating fluid flow.
Performance Mode Switch
The two position performance mode switch allows selection of 'sport' or 'normal' mode as required by the driver. The
switch input to TCM causes a gear shift pattern change so that gear shifts take place at higher engine revs, enhancing
performance, when in 'sport' mode. For everyday use, 'normal' mode utilises a shift pattern for optimum driver com- fort.
Kickdown Switch
The 'kick-down' facility is activated when full downward travel of the accelerator pedal occurs.
Activation of the switch provides a signal to TCM indicating that greater acceleration, and hence downward gear shifts
are required. Switch height is adjustable
so that kick-down can be achieved at a pre-determined throttle opening.
Gear Selection Illumination Module
This module is located above the gear selector mechanism and its sole purpose is to display the selected gear (in red)
on receipt of a signal from the decoder module.
X300 EDM 1 Issue 1 August 1994