E I ect r ical
15.2.3 COMPONENT DESCRIPTION
15.2.3.1 Speedometer
The speed indication input signal, sent as a pulse rate, is generated by an open collectortransistor within the ABS con- trol module. The instrument pack converts the frequency of this signal to drive the speedometer and to provide two
road speed outputs:
Speed output
1 (pin 2,48 way connector)
This output is connected to the radio head unit, security control module and the power steering module.
Speed output 2 (pin
3,48 way connector)
This output is connected to the body processor unit, cruise control control module, air conditioning control module
and the engine management system.
15.2.3.2 Tachometer
The tachometer input, all engine variants, is provided by the engine management control module. When the engine
is running the control module generates three high state pulses per engine revolution.
15.2.3.3
This signal comes direct from the variable resistance type oil pressure sensor, mounted on the engine. The sensor
resistance values range from 75Q (8 Bar) to 330Q (0 Bar).
When the gauge reaches
a pre-determined reading the instrument pack illuminates the warning light.
Engine Oil Pressure and Warning lamp
15.2.3.4 Engine Coolant Temperature
This signal comes direct from the coolant temperature sensor (variable resistance type), mounted on the engine. The
sensor resistance values range from 34Q (hot) to 241Q (cold), when disconnected from the vehicle.
Note: The coolant temperature gauge is calibrated to indicate at approximately 'Normal' for a wide range of normal
engine operating temperatures.
15.2.3.5 Fuel Tank level Gauge and Warning lamp
This signal (pin 20,24-way connector) comes direct from the variable resistor type fuel level sensor. The sensor resis- tance values range from 80 ohms (full tank) to 900 ohms (empty tank).
When the gauge reaches a pre
-determined reading, the instrument pack illuminates the warning lamp.
15.2.3.6
Battery voltage is displayed on the gauge by measuring the ignition voltage.
The red charge warning lamp will illuminate if either the voltage is too low (below
10.5V) or too high (above 15.5V). In addition, the generator provides a low signal to the instrument pack (pin 9,48-way connector) when battery charging
is unsatisfactory.
Battery Voltage Gauge and Warning lamp
15.2.3.7 Liquid Crystal Display
A single line, six digit, 7 segment display with six trip function flags used for odometer, trip computer and driver mess- ages.
!Y,Q&: If the instrument pack has not been PECUS programmed, the back illumination of the LCD will not switch on.
Check that a PECUS label is attached to the back of the pack.
Issue 1 August 1994 15.2 - 4 X300 EDM
0 15.3.3 SYSTEM FLOW CHARTS
Systematic fault diagnosis of the speed control system cannot be accurately achieved by attempting to simulate actual
driving conditions. The system can only be reliably and safely tested using Jaguar Diagnostic Equipment.
15.3.4 DIAGNOSTIC SUB-ROUTINES
The following information details possible fault conditions, causes and remedies.
components are covered in Pin-point Tests. Detail test procedures
for
Fault: System inoperative
Possible causes:
1. Fuse FIO (LH 'A' post base fuse-box) blown.
2. Pneumatic circuit fault (ie vacuum leak)
3. Brake switch fault.
4. Clutch switch or link fault. Gear position input fault (automatic transmission only).
5. Harness wiring or connector faulty.
6. Set switch faulty.
7 Paddle switch faulty
8. Traction control input high.
9. Road speed input missing.
10 Dump valve failure.
11 Vacuum pump 1 control valve unit failure.
Remedy: 1. Examine fuse F10, if blown determine reason for failure and renew.
2. Examine all pipework, connections and components for damage or
disconnections, repair
or renew as necessary.
3. Check brake switch operation, renew if necessary.
4. Check clutch switch operation (manual transmission) or link connection I position input
(automatic transmission), renew if necessary.
5. Examine harness wiring. Examine connectors for corroded, damaged or distorted pins.
6. Check set switch operation and wiring, renew if necessary.
7. Check paddle switch operation and wiring, renew if necessary.
8. Examine harness wiring between SC CM and ABS / TC CM, check ABS /TC CM fault
diagnosis.
9. Examine harness wiring between SC CM and instrument pack, check pack fault diagnosis.
10 Renew faulty valve.
11 Renew faulty unit
0
Fault:
Cause:
1. Clutch pedal switch or harness failure.
Clutch pedal operation does not disable system
1. Remedy: Check switch operation and wiring connections. Repair or renew switch / wiring
as necessary.
Fault:
Cause:
1, Faulty signal from gear selection module.
Remedy: 1. Examine transmission fault diagnosis.
Neutral gear selection does not disable system (automatic transmissions only)
2.
2.
Harness wiring or connector fault
Examine harness between gear selection module and SC
CM pin 18.
X300 EDM 15.3 - 5 Issue 1 August 1994
Electrical rl
15.4.8 DlAG NOSTIC SUB-ROU T1 NES
0
The following information details possible fault conditions, causes and remedies. Detail test procedures for compo-
nents are covered in 'PIN-POINT TESTS' (Sub-Section 15.4.9).
Fault:
Possible causes:
Remedy:
Fault: Possible causes:
Remedy:
0
Fault:
Possible causes:
Remedy:
Fault:
Possible causes:
Remedy: Driver's
seat adjustment inoperative
1.
2.
3. Mechanical mechanism fault.
1.
2.
3.
No power supply to SCM.
Wiring harness or connectors faulty.
Check fuses
in 'A' post base fuse boxes.
Check harness and connectors between
SCM -fuse box,
SCM
-switch pack and SCM - motors.
Identify and repair mechanical faults.
Seat positional adjustment restricted
1.
2. Motor faulty.
3. Switch faulty.
4. Mechanical mechanism fault.
5. SCM faulty.
1.
2. Renew motor.
3. Renew switch pack.
4.
5. SCM faulty.
Harness
wiring or connector fault.
Examine wiring and connectors between SCM
- switch
pack and SCM
- motors.
Identify and repair mechanical faults.
Seat lumbar pump only inoperative
1.
2.
3. Motor faulty.
4. Switch faulty.
5. Mechanical mechanism
fault.
1.
2.
3. Renew motor.
4. Renew switch.
5. No
power supply to SCM.
Harness wiring or connector fault.
Check fuses in
'A' post base fuse boxes.
Examine wiring and connectors between SCM
- switch
pack and SCM
- motors.
Identify and repair mechanical faults.
Seat heaters only inoperative
1.
2.
3. Heater element faulty.
4. Heater thermostat faulty.
5. Heater switch faulty.
6. Body processor signal fault.
1.
2.
3.
4. Renew faulty switch.
5.
No power supply to SCM.
Wiring harness or connectors faulty.
Check fuses in
'A' post base fuse boxes.
Examine harness and connectors between SCM
- heater
circuit and SCM
- BPU.
Locate and renew faulty heater and thermostat unit.
Refer to BPU fault diagnosis.
X300 EDM 15.4 - 17 Issue 1 August 1994
