1994 JAGUAR XJ6 brake

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1. Throttle flap actuator 2. Throttle position sensor 3. Cruise control inhibit (when traction control in operation) 4. Traction OFF / ON switch 5. Not Used 6. Gearshift inhibit (when traction control in operation) 7. Wheel speed sensors 8. Battery voltage input
9 IS0 communication BUS IO. Ignition voltage input
1 1. Speedometer signal 12 ABS MIL lamp 13. TCS MIL lamp 14. Traction control OFF lamp 15. Brake warning lamp 16. Brake fluid level switch 17. Stop lamp switch
Fig.
1 Anti-lock braking system and traction
control
-schematic diagram
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Issue 1 August 1994 4 X300 EDM

Brakes (a)
12.3 COMPONENT DESCRlPTlONS
ABS / TC CM (3 Fig. 1)
The ABS / TC CM, located just below the hydraulic valve
block on the bulkhead, is the system controller and pro-
cesses all thevarious information supplied from the external
sensors and probes. The unit monitors ABS / TC operation
giving fault indication and disabling the systems when de- fects are detected. The unit is self testing and cannot be fault
diagnosed beyond 'black box' level i.e. faulty module. Sys-
tem fault codes are stored in a non-volatile memory for in- terrogation by external diagnostic equipment.
Solenoid Valves (2 Fig. 1)
The solenoid operated hydraulic valves, located within the
hydraulic module valve block, regulate the supply of pres- sure to the braking circuits allowing individual control of all wheels with a full ABS /TC system.
Nnfe: For ABS only, the driving (rear) wheels are con-
trolled by a common braking circuit.
The traction control system isolating valve has the
same characteristics as
a normally open valve. a
Hydraulic Pump /Motor Unit (1 Fig. 1)
This unit, located above the hydraulic valve block, ensures
that brake fluid is transmitted around the system at the cor- rect operating pressure. The 250W ds. motor draws 32A
current at peak operation and has an internal resistance of 0.m.
Wheel Speed Sensors (Fig. 2)
The four wheel speed sensors are identical in function and
construction. Wheel rotation creates the signal within the
sensor. This signal is supplied to the ABS /TC
CM where it provides wheel speed information. The sensor coil has a re- sistance value of 1.1 k Q and will have a voltage of 2.5V pres- ent on each connecting pin when the vehicle is stationary.
Throttle Flap Actuator Motor / Position Sensor (Fig. 3)
The throttle flap actuator motor, mounted adjacent tothe hy- draulic control unit, adjusts throttle position, irrespective of
accelerator pedal position, by regulating throttle opening
when traction control is demanded. The actuator motor
nominal 12V terminal voltage is supplied by ABS
/ TC CMduring normal operation. The motor has an internal re- sistance of approximately 1.6Q. The throttle position sensor
supplies information relative to the position of its centre tap
to the ABS
/ TC CM which regulates actuator movement.
The sensor has a resistance of 6.4 K!2. Aterminal voltage of 5V is supplied by ABS/TC CM to connection 3 during normal
operation,voltage between connections 1 and 2 will vary be- tween 0 and 5V dependant on wiper position.
Fig. 1
Fig. 2
Jrn 270
Fia. 3
X300 EDM 5 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

(a) Brakes
Pin Point Tests
Wheel Sensor
The wheel sensors are connected across ABS / TC CM pins 5 - 12 inclusive, one sensor per pair of pins (see 'Control
Module Connections', page 3).
. Testing between pins of the 28 way multi-plug connector, checkthat the resistance of each sensor coil is 1.1kQ (toler- ance of * 50%).
Hydraulic Pump Motor
rn Disconnect the pump motor bi-pin connector.
rn Check the resistance value of the motor winding is approximately 0.m.
Throttle position sensor
With the vehicle ignition ON, test the throttle position sensor harness between ABSITC CM pins 25 and 27. Avoltage
of 5V (k 0.5V) should be recorded.
Repeat the test between ABS
/ TC CM pins 26 and 27 with the accelerator pedal pressed down approximately half
of full travel. Avoltage of approximately half the first value should be recorded. Variation in accelerator pedal posi- tion should cause a varying voltage value to be recorded.
Throttle Flap Actuator Motor
. Test the throttle flap actuator motor between ABS /TC CM multi-plug connector pins 16 and 17. A resistance value
of 1.651 should be recorded.
Brake Switch
. Measure the voltage at the brake switch between ABS /TC CM pin 20 and ground. With pedal UP, ie not operated,
a reading equivalent to battery voltage should be achieved. Operate brake pedal fully ensuring coinciding ground,
ie
0 volts, through switch.
Traction Switch
Check continuity of traction OFF / ON switch between ABS /TC CM pin 18 and ground. Operate switch ensuring CO- inciding short circuit.
Issue 1 August 1994 8 X300 EDM

Brakes
Code Fault
5246h Outlet valve, rear right
5254h Inlet valve, rear right
5242h Outlet valve, rear left
5250h Inlet valve, rear left
5120h Outlet valve, front right
5214h Inlet valve, front right
5194h Outlet valve, front left
5198h Inlet valve, front left
5404h Isolating valve
5168h Sensor, rear right
5178h Sensor, rear left
Stored Fault codes
The following information detailsfault codes which may be stored, automatically within the ABS/TC CM and accessed
as an aid to fault diagnosis using Jaguar Diagnostic Equipment.
Comment
r5148h 1 Sensor front right I
5158h Sensor, front left
5165h Sensor, rear right
5175h
5145h
Sensor, rear left
Sensor, front right Sensor
failure recognised by 'monitoring of
wheel speed continuity'
Fi&h- I Sensor, front left I
5260h
5261h
5259h
5258h
Sensor, rear right
Sensor, rear left
Sensor, front right comparison'
Sensor, front left Sensor
failure recognised
by 'wheel speed
1--- r- I
5236h
5234h
5233h
5235h I Sensor, rear right
Sensor, rear left
Sensor, front right
Sensor, front left Sensor
failure recognised by 'long term
detection of missing sensor signal'
Issue 1 August 1994 X300 EDM 9

Climate Control Systems
14.2.3 Solar Sensor (Fig. 1)
The solar sensor is mounted on top of the facia, between the
facia defrost grilles.
The sensor isconstructed around
a photo-diode to measure
direct sunlight. The sensor provides an output response sig-
nal totheA1CCM;thisensuresthe in-cartemperaturestabil- ity whilst reducing outlet temperature to compensate for
solar load heating. The solar sensor is fitted to aircondition- ing vehicles only.
14.2.4 Engine Speed Signal
The A 1 CCM receives an engine speed signal from the En- gine Control Module (ECM).
This signal facilitates compressor lock sensing (12 cyl. ve- hicles only).
This signal also aids the A
1 CCM inhibition of the heated
screen relays. At engine speeds lower than 800 RPM the A I CCM assumes poor idle or engine not running and will not
permit the selection of the heated screens.
14.2.5 Ambient Temperature Sensor (Fig. 2)
The ambient temperature sensor is located within the LH
brake cooling duct.
The sensor detects exterior airtemperature and provides the
A
I CCM with a signal to allow compensation for ambient
conditions.
The A
1 CCM is then capable of informing the control panel of the ambient air temperature in both Centigrade and
Fahrenheit, and updates the information every four
seconds.
The sensor is damped and
so does not detect temperature
fluctuations as quickly as other temperature sensors. This
facility prevents temporary temperature fluctuations affec
- ting overall temperature control.
14.2.6 Vehicle Speed Signal
The A 1 CCM receives a road speed signal from the instru- ment pack, derived from the ABS 1 TC CM.
This signal is required to control the blower fan speed to mi
- nimise the effects of ram air, i.e. blower fan speed changes
in proportion to vehicle road speed.
The signal also determines the frequency
at which the ambi- ent air temperature is updated. The road speed compensa-
tion for blower control is inhibited when the selected
temperature is 'LO (maximum cooling) and 'HI' (maximum
heating) and defrost mode.
14.2.7 Evaporator Temperature Sensor
Located next to the evaporator fins, the sensor detects the air temperature leaving the evaporator, and sends this sig- nal to the A 1 CCM.
When the temperature approaches
OOC, the A 1 CCM disen-
gages the compressor to prevent freezing conditions. When
thetemperature rises above3OC.theAlCCM re-engagesthe
compressor.
J82-L06 Fig. 1
Fig. 2
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Issue 1 August 1994 4 X300 EDM

Electrical IT
SECTION CONTENTS
Sub
-Section 15.2 lnsfrumenfs
Subsection Title SRO Page
15.2 ............. Instruments .................................................................... 15.2-1
15.2.1
............ Introduction .................................................................... 15.2-1
15.2.2
............ Instrument Pack Connectors - Pin Locations ......................................... 15.2-3
15.2.3
............ Component Description .......................................................... 15.24
15.2.3.1 .......... Speedometer ................................................................... 15.24
15.2.3.2 .......... Tachometer .................................................................... 15.24
15.2.3.3
.......... Engine Oil Pressure and Warning Lamp ............................................. 15.24
15.2.3.4 .......... Engine Coolant Temperature ...................................................... 15.24
15.2.3.5 .......... Fuel Tank Level Gauge and Warning Lamp .......................................... 15.24
15.2.3.6
.......... Battery Voltage Gauge and Warning Lamp .......................................... 15.24
15.2.3.7
.......... Liquid Crystal Display ........................................................... 15.24
15.2.3.8 .......... Trip Computer .................................................................. 15.2-5
15.2.4
............ Primary Warning Lamps (Illuminated Red) .......................................... 15.2-5
15.2.4.1
.......... Exhaust Temperature ............................................................ 15.2-5
15.2.4.2
.......... Low Oil Pressure ................................................................ 15.2-5
15.2.4.3
.......... Seat Belt ....................................................................... \
15.2-5
15.2.4.4
.......... Trunk Lid Open ................................................................. 15.2-5
15.2.4.5
.......... DoorAjar ...................................................................... 15.2-5
15.2.4.6
.......... Engine Coolant LeveL ............................................................ 15.24
15.2.4.7
.......... SRS Airbag Fault ................................................................ 15.24
15.2.4.8 .......... Charging Fault .................................................................. 15.24
15.2.4.9 .......... Brake System Fault .............................................................. 15.24
15.2.4.10 ......... Bark Brake ..................................................................... 15.24
15.2.5. ........... Secondary Warning Lamps (Illuminated Amber) ...................................... 15.2-7
15.2.5.1
.......... Transmission Fault ............................................................... 15.2-7
15.2.5.2
.......... Washer Fluid Level .............................................................. 15.2-7
15.2.5.3
.......... Bulb Fail ....................................................................... \
15.2-7
15.2.5.4
.......... Traction Control Fail ............................................................. 15.2-7
15.2.5.5
.......... Anti-lock Fail .................................................................. 15.2-7
15.2.5.6
.......... Low Fuel Level ................................................................. 15.2-7
15.2.5.7
.......... Check Engine ................................................................... 15.2-7
15.2.6.1
.......... Transmission Sport Mode ......................................................... 15.2-8
15.2.6.2
.......... Traction Control OFF ............................................................ 15.2-8
15.2.6.3
.......... Direction Indicators ............................................................. 15.2-8
15.2.6.4
.......... Main Beam .................................................................... 15.2-8
15.2.6
............ Status
and Warning Lamps ........................................................ 15.2-8
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X300 EDM ii Issue 1 August 1994