traction control JAGUAR XJ6 1994 2.G Electrical Diagnostic Manual

Automatic Transmission (AJ16) w
8.1.1 ZF 4HP 24 E TRANSMISSION, SYSTEM DESCRIPTION
The electronic transmission system fitted to normally aspirated 4.0 liter vehicles comprises the following components:
0 ZF 4HP 24 E Automatic Transmission
0 Rotary selector switch
0 Electronic Transmission Control Module
0 Decoder Module
0 Performance Mode Switch
0 Kickdown Switch
0 Gear Selection Illumination Module
System control is effected by the transmission control module (TCM), located behind the passenger side fascia, which
continuously monitors requests made by the drivervia the gearselector, throttle pedal etc. This data is used
inconiunc- 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 decoder module receives inputs from the rotary switch and decodes these to drive one of six possible outputs,
illuminating the correct gear indicator on the gear selector illumination module.
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 gear selector mechanism surround, can be
either NORMAL, 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.
8.1.2 COMPONENT DESCRlPTIONS
Transmission Unit
The ZF 4HP 24 E automatic transmission unit houses the three solenoid valves which control gear shifts. A pressure
control valve is also located on the solenoid valve block. These four valves initiate and control shift patterns within
the transmission unit by regulating fluid flow.
Rotary Selector Switch
The seven position rotary gear selector switch is mounted on the LH side of the transmission unit and indicates gear
selection to the TCM and decoder module.
Transmission Control Module
The electronic transmission control module regulates gear changes by controlling the operation of the transmission
unit solenoid valves, and monitoring the state of other vehicle systems which have an effect on torque demand, vehicle
speed etc. The module also interfaces with the engine management system, climate control system, body processor
unit and ABS
I traction control system.
Connections from the TCM are listed on the following page.
X300 EDM 1 Issue 1 August 1994

Automatic Transmission (AJ16)
8.1.3 DIAGNOSTIC FAULT CODES
The following codes are stored within the TCM whenever a fault is detected on the system. The codes can be accessed
using Jaguar Diagnostic Equipment or a hand held, proprietary scan tool.
Code Description
MIL Indication Page No.
P 0603 Internal control module memory error MIL on 26
P 0605 Internal control module ROM test error
MIL on 26 I P 0702 Transmission control system electrical MIL on 5
P 0705 Transmission range sensor circuit malfunction MIL on 6
P 0706 Transmission range sensor circuit range / performance MIL on 6
8
8
P 0712 Transmission fluid temperature sensor low input -
P 0713 Transmission fluid temperature sensor high input -
P 0721 Output speed sensor circuit range / performance MIL on 10
P 0722 Output speed sensor circuit no signal MIL on 10
P 0726 MIL on 12
P 0727 1 Engine speed input circuit no signal MIL on 12
P 0743 Torque converter clutch system electrical MIL on 14
P 0748 Pressure control solenoid electrical MIL on 14
' Engine speed input circuit range / performance
P 0753 Shift solenoid A electrical MIL on 14
P 0758 Shift solenoid B electrical MIL on 14
P 1608 TCM watch-dog fault MIL on 26
P 1780 Torque reduction signal malfunction - 16
P 1781 Torque signal malfunction - 16
P 1782 Traction control input electrical - 18
P 1785 Transmission fault lamp malfunction - 20
P 1790 TP signal system range / performance MIL on 21
P 1791 TP electrical signal system MIL
on 21
P 1792 Sport mode indicator - 23
P 1794 System voltage malfunction MIL on 24
P 1796 Kickdown switch system - 24
t: Codes which do not cause the MIL to illuminate cannot be read by the hand-held scan tool as they are not SA€ P- generated.
I. Transmission Control Module (TCM)
2. Transmission Unit
3. TCM Multi-pin Connector
4. Transmission Rotary Switch
5. Transmission Connector Plug
6. Engine Control Module
7. Instrument Pack
8. ABS /Traction Control Control Module
9. Kickdown Switch
Issue 1 August 1994 4 X300 EDM

lw Automatic Transmission (AJ16)
TRACTION CONTROL INPUT ELECTRICAL - P 1782
The traction control input allows the ABS/TC CM, which performs the traction control function to inform theTCM when
traction control is in operation. This allows the TCM to select a specific shift pattern which increases the effectiveness
of the traction control.
The signal has two states; active and inactive. In the inactive state the line is pulled high by
a 1 k21 resistor in the TCM
and should rest at battery voltage. In the active state, the ABS /TC CM drives a square wave signal at 2.5 Hz ie on for 200ms, off for 200ms. During the off phase the voltage should be greater than battery voltage minus 1.5V and during
the on phase the voltage should be less than 1V.
Because traction control is not fitted to all vehicles the traction control input will be open circuit on some cars. Diagnos- tics are limited to detection of permanent short circuit to ground. Fault detection is triggered if the signal line voltage is less than 1.8V for longer than 200ms. If a fault is detected code P 1782 is stored and the traction control shift pattern
is inhibited. The diagnostic test is performed continuously during initialization and operation.
TCM ABS
/ TC CM
CC007/029 LS027/003 LHD
RS027/003 RHD
Possible causes:
Faulty harness wiring / connector.
. Faulty signal from ABS CM.
Effects:
. Traction control shift pattern disabled
Remedy:
Repair or renew harness / connector.
. Examine ABS /TC CM fault diagnosis (refer to EDM, section 12.1).
0
0
0
0
X300 EDM Issue 1 August 1994 18

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TCM
Pressure switch manifold X 03 Pressure switch manifold Z 04
Performance mode select 05 Calibration select 06
Engine toque reduction 07 Throttle position 11 Engine troque 12 Sensor ground 14 Pressure switch Y 22
Traction control inpuit 23 Kickdown switch 24 Brake switch 25
Transmission temperature 26 Engine speed 30 Vehicle speed output 34 Transmission output speed 36
Transmission input speed 37 Shift solenoid A 39 Transmission malfunction lamp 40 Sport mode lamp 41
Torque converter clutch 42 Shift solenoid B 43 Force motor low 49 Transmission input speed GND 50 .ransmission output spped GND 51 Force motor high 52
55
Vban
53 Vignition
16JDSLIscantool
45 JDS K I scan tool
54 Power ground
I TRANSMISSION Ignition
-OK -OB
-Rw -P - su - GN -Pw - BU -ON - RP - BS - PU - OY - BIN - SB -U -G -OR -s
- GU -ow - OP -0s -N -R
-OB
14/01 Transmission input speed GND
14/02 Transmission input speed
13/01 Transmission output speed GND
13/02 Transmission output speed
1 - 12/10 TCCsolenoid high
- 12/09 TCC solenoid signal
-
-
- -
12/03 Shift solenoid A high
12/01 Shift solenoid A signal
12/03 Shift solenoid B high 12/02 Shift solenoid B signal
-
- 12/13 Force Motor Signal
1211 1 Force motor HI
-
-
-
12/04 Pressure switch manifold X
12/04 Pressure switch manifold Y
12/04 Pressure switch manifold Z
- 12/07 Transmission temperature
- 12/08 Sensor GND
44 Transmission malfunction
14 Sport mode indication
ABS 1 TC CM
03 Traction control signal
iI I
VI2 EMS
II
I -
I - 03 Engine torque
I - 06 torque reduction request
I - 10 Engine speed
I - 07 Vehicle speed
04 throttle position
I
I
I
I - I 04 throttle position
I - 03 Engine torque
I - 06 torque reduction request
I - 10 Engine speed
I - 07 Vehicle speed
I
I
I
I I
I 6 Cyl. GEMS I
I
I
I
1- I
I- 22 Engine speed I
I
,I I
I
I
I - 33 Engine toque
26 Torque reduction request
I - 32 Throttle position
' Performance Mode I
I
000 I
Switch I
I
02 Performance mode select
I
Vban + oq 04 I
r---- 1
I
Brake Switch
I
r---- 1
I
Kickdown Switch
I

Automatic Transmission (V12) Powertrain
8.2.3 OPERATING PRlNClPL ES
The electronic control system is split into four main functional areas:
0 Shift Point Control
0 Lock-up Control
0 Pressure Modulation
0 Engine Torque Control
0
Shift Point Control
The optimum gear ratio is selected as a function of transmission output speed, engine load, position of selector switch
and program switch.
Lock-up Control
The torque converter clutch is engaged as a function of load, output speed, gear selected and drive program. Lock-up
is possible in second, third and fourth gear. Apply and release quality is controlled by the pulse width modulated pres-
sure regulator solenoid.
Pressure Modulation
Hydraulic pressure in the transmission shift friction elements is accurately matched to transmission output torque
using an electrically operated solenoid valve to control pressure level. Transmission input torque is calculated from
an output torque value, supplied by EMS, and converter slip.
Engine Torque Control
Engine torque control reduces the energy dissipated within the system during gear shifts. The effect of this control
increase the transmission service life by reducing slippage time, increases comfort by reducing clutch torque trans- mission and allows a greater transfer of power by the transmission unit.
8.2.4 INPUTS / OUTPUTS
8.2.4.1 INPUTS
Transmission Range
The transmission range is detectec ,ythe pressureswitch manifold located within the transmission unit. The manifold
transmits a coded message to the TCM indicating gear selector position.
Performance Mode Select
Performance mode select uses a two wire input to the TCM allowing selection of different transmission operating
modes.
Line A; Used for selection of traction control shift pattern and controlled
by the ABS /TC CM.
Line
B; Used for selection of 'Normal' or 'Sports' mode, manually selected at a two position rocker switch mounted
on the gear selector unit. Switch resistance is equal to or greaterthan look$, open circuit and equal to or less than 0.5$ closed circuit, measured across contacts at a current of 10mA.
Kickdown Switch
This signal is controlled by the operation ofthe kickdown switch on depression of the accelerator pedal to its full extent.
The switch remains in 'normally open' position until contact with the pedal closes the contacts. Switch resistance is
equal to or greater than look$, open circuit, and equal to or less than 0.5$ closed circuit, measured across contacts at
a current of
10Ma.
Calibration Select
The calibration select input allows identification of different vehicle specifications, ie 4.0 liter supercharged, or 6.0 liter (V12). The link, to ground, from the TCM is either short or open circuit, dependant upon internal software calibration
for each vehicle variant.
X300 EDM 5 Issue 1 August 1994

8.2.6 DIAGNOSTIC FAULT CODES
The following codes are stored within the TCM whenever a fault is detected on the system. The codes relating to OBDll legislation can be accessed using Jaguar Diagnostic Equipment or a hand-held, proprietary scan tool.
Code 1 Description [ OBDII i Page No.
PO605 I TCM internal error Y 8 I
PO703 Brake switch input malfunction N I 9
PO706 Transmission range sensor fault Y I 10 1
1 PO7 12 Transmission fluid temperature sensor low input Y , 11
PO713 Transmission fluid temperature sensor high input Y 11
PO7 15 Turbine / input speed sensor malfunction Y 12 I
I PO716 I Turbine / input speed sensor range / performance IYll21
I PO720 I Output speed sensor circuit malfunction Iy 13 I
1 PO721 [Output speed sensor circuit range / performance Iy 13 I
I PO726 1 Engine speed input circuit performance Iy 14 I PO727 Engine speed input circuit no signal Y I 14
PO730 Incorrect gear ratio Y 15
PO7 4 1 TCC system stuck off Y 16
PO742 TCC system stuck on Y 16
16
PO743 TCC system electrical
17 Pressure control solenoid electrical PO748
ZhTfi solenoid A performance Y 18 PO751
__ p0753-- - -- Shift solenoid A electrical Y 18
Shift solenoid B performance Y I 18 PO756
PO758 Shift solenoid B electrical Y 18
PO780 Shift malfunction (Max-adapt) N 19
PI739 Transmission component slipping Y 19
- __ -
___ __ Y
N - ~_ ~
~
- _____ - __.__ ~ ~~~
~~
I
___. ________ I
__
PI780 Torque
reduction signal malfunction Y 20
PI781 Engine torque signal malfunction Y 20
PI782 Traction active input fault N 22
PI783 Transmission over temperature condition N - I I PI791 I Throttle position electrical signal failure Y 23
Issue 1 August 1994 8 X300 EDM

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

0
0
0
Brakes (
12.1 COMPONENT LOCATlONS
Fig. 1 AJ16 (normally aspirated)
Fig.
2 AJ16 (supercharged)
Fig.
3 VI2
Key to Figs. 1,2 and 3:
1. Throttle position sensor 4. ABS motor
2. Traction control actuator 5. Valve block 3. Pump 6. Control module (ABS / TC CM)
X300 EDM 1 Issue 1 August 1994

Brakes
12.2 SYSTEM DESCRIPTION
The anti-lock braking system (ABS) and traction control system CTC) comprise the following components:
0 Hydraulic module: incorporating a pump, motor, low pressure accumulator, valve block, and either an ABS Con-
trol Module (ABS CM) or an ABS / TC Control Module (ABS / TC CM).
U!&: Within the hydraulic module are contained the electro-hydraulic inlet and outlet valves which regulate brake
system pressure.
o Four wheel speed sensors; hub end mounted.
0 Three warning indicators plus a Brake Warning Lamp and a Traction OFF / ON switch; fascia mounted.
0 Throttle valve flap positioning mechanism; mounted adjacent to the hydraulic module.
0 Various auxiliary inputs; providing information to ABS / TC CM.
0 Diagnostic IS0 communication BUS input / output link.
The solenoid operated hydraulic valves
are activated by signals, from the ABS /TC CM, which are generated using in-
formation received from the wheel speed sensors.
For vehicles without traction control thevalves operate on threecircuits, two front and one rear, as necessaryto prevent
wheel locking during braking. Brake pressure is modulated individually
at the front wheels and collectively at the rear.
Rear wheel control operates
a 'select low' principle such that locking in either wheel is sensed, and controlled brake
pressure is applied to both wheels.
Vehicles with traction control fitted have
all four wheels individually controlled allowing selective regulation of tractive
and braking force to each wheel as necessary when traction control is in operation.
The ABS
/ TC system as a whole is monitored constantly by the ABS / TC CM and is disabled (switched off until fault
is rectified) automatically when certain failures are identified. In the event of
a failure being detected the ABS and TC
MIL lamps, located on the instrument panel will illuminate. Full boosted brake operation and normal acceleration con- trol is available when ABS /TC is disabled. The system will be disabled when the following conditions occur:
0 Valve failure.
0 Sensor failure.
0 Main driver failure (internal ABS / TC CM fault).
0 Redundancy error (internal ABS / TC CM fault).
0 Over-voltage.
0 Pump motor failure.
0 Throttle valve actuator motor failure.
In the event
of under-voltage both ABS and TC will be disabled and the ABS andTC MIL lamps on the instrument panel
will illuminate.
U!&: The TC MIL lamp will only illuminate providing a voltage is still present at pin 15 'IGN FEED'
Throttle potentiometer failure will disable the TC function only and illuminate the TC MIL lamp.
The
moduleABS/TC CM is activated when ignition is ON, after an initiation period of approximately 1.7 seconds. After
this time delay the control module is ready to process signals provided from the various input sources and, using the
software defined algorithm, control the electrical and hydraulic circuits.
The inductive sensors attached to each of the four wheels provide speed signals to the ABS
/ TC CM. These signals are processed by ABS/TC CM giving comparison between individual wheel speeds, controlling braking or traction as
necessary and generating a pulse to drive the speedometer. Each sensor is monitored for open and short circuit failure,
causing disabling of ABS / TC on detection of a fault condition.
Issue 1 August 1994 2 X300 EDM

Brakes (a)
The input frequency of each sensor signal is translated, by the ABS /TC CM, into a comparable wheel speed. Should
any sensed speed be in excess of 330 km / h the relevant sensor is designated 'faulty' and ABS /TC control disabled.
Similarly ABS/TCcontrol is inhibited (switched off until fault condition is cleared) at speeds up to 40 km/ h whenfre- quency fluctuations are detected that are inconsistent with wheel rotation. At speeds above 40 km / h both systems
are disabled when inconsistencies are detected.
Traction control (where fitted) is achieved by using
a small motor and pulley arrangement to adjust the position of the
throttle flap. Under normal operating conditions the system is enabled by default. Operation of the Traction OFF / ON switch, located on the RH side of the fascia switch pack, disables the system and illuminates the TRACTION OFF lamp
located in the instrument pack.
Control is effected to prevent wheel spin by regulating (reducing) the throttle flap position, irrespective of the acceler
-
ator pedal position, using sensor signal comparisons and applying braking force to the wheel affected. Precise posi- tioning of the flap is achieved by monitoring the position of a throttle position sensor. When traction control is
requested
a gearshift inhibit signal is transmitted to the traction control module and cruise control (if selected) is dis- abled.
1
2
3
4
Battery positive feed (via fuse F7,located in the left-hand 'A' post lower fuse-box).
Battery positive feed (via fuse
F7,located in the right-hand 'A' post lower fusebox).
Gearshift inhibit
- during traction control.
Cruise control inhibit
- during traction control.
5/6 Wheel sensor
- LHF
7/8 Wheel sensor
- RHF
9/10 Wheel sensor
- LHR
Control Module Connections
Control module connections numbering 1 - 28, inclusive, provide the necessary input / output signals to enable the
module to control and monitor ABS / TC operation.
Connections are as follows:
13 Ground
14 Ground
15
16
17
18
19 Not used
20 Brake pedal switch.
21
22
23
24
25
26 Throttle position sensor wiper.
27 Throttle position sensor ground.
28 Diagnostic
IS0 communication bus.
Ignition
feed
- monitoring battery voltage to ignition switch.
Throttle valve actuator motor
- battery voltage reference.
Throttle valve actuator motor switching
-during traction control.
Traction inhibit
- via traction OFF / ON switch.
ABS MIL
- malfunction indicator lamp.
ABS ground
- illuminates ABS MIL lamp if ABS /TC CM connector loose or not fitted.
TC MIL
- malfunction indicator lamp.
RL out
- LHR wheel sensor signal drive pulse to speedometer.
Throttle position sensor
5V supply.
I 1 11/12 1 Wheel sensor - RHR 1
X300 EDM 3 Issue 1 August 1994