1998 JAGUAR X308 engine

System Self-test
Control Panel Fault Code Listing • NOTE: Reference fault code #23*: In ambient temperatures below 0° C, this code may be logged because the low
ambient causes a tempor ary low gas pressure.
• NOTE: Where the ambient temperature rises above 40° C, with the engine close to overheating, electrical feed to the
compressor clutch may be cut and code #23 registered.
SymptomPossible SourcesAction
0 Normal operation no
fault codes presentNone
*Wait 30 seconds for system
self-check.
*
11 Motorized in-car
aspirator malfunctionHarness / connector fault
Sensor open / short circuit
*
*Panel fault codes are not
stored for motorized in-car
aspirator motor failure.
*
12 Ambient
temperature sensor
malfunctionHarness / connector fault
Sensor open / short circuit
*
*After rectification, disconnect
the vehicle battery for 10
seconds to reset the system.
*
13 Evaporator
temperature sensor
malfunctionHarness / connector fault
Sensor open / short circuit
*
*Refer to PDU
*
14 Water temperature
input malfunctionInstrument cl uster output
*Refer to PDU
*
15 Heater matrix
temperature sensor
malfunctionHarness / connector fault
Sensor open / short circuit
*
*Refer to PDU
*
21 Solar sensorSensor open /short circuit
*Refer to PDU
*
22 Compressor lock
signal faultLow refrigerant charge, low compressor oil level, loose drive
belt Harness / connector fault
*
*Adjust items as required
*
23 Refrigerant pressure
switch malfunctionHarness / connector fault
Switch open / short circuit
*
*Refer to PDU
*
23 Refrigerant pressure
low refrigerant charge * Leak from damaged pipe or joint
*Rectify as required and
recharge system
*
24 Face vent demand
potentiometer faultPotentiometer open / short circuit
Harness / connector fault
*
*Refer to PDU
*
31 LH fresh / recirc.
potentiometer faultHarness / connector fault
In certain circumstances the servo motor may over-travel
and cause further logged faults. This may be cured, following
fault rectification, by cycling the ignition ON-OFF-ON 3 times
*
*Refer to PDU
*
32 RH fresh / recirc.
potentiometer faultHarness / connector fault
In certain circumstances the servo motor may over-travel
and cause further logged faults. This may be cured, following
fault rectification, by cycling the ignition ON-OFF-ON 3 times
*
*Refer to PDU
*
33 Cool air by-pass
potentiometer faultHarness / connector fault
In certain circumstances the servo motor may over-travel
and cause further logged faults. This may be cured, following
fault rectification, by cycling the ignition ON-OFF-ON 3 times
*
*Refer to PDU
*
34 Defrost vent
potentiometer faultHarness / connector fault
In certain circumstances the servo motor may over-travel
and cause further logged faults. This may be cured, following
fault rectification, by cycling the ignition ON-OFF-ON 3 times
*
*Refer to PDU
*
35 Centre vent
potentiometer faultHarness / connector fault
In certain circumstances the servo motor may over-travel
and cause further logged faults. This may be cured, following
fault rectification, by cycling the ignition ON-OFF-ON 3 times
*
*Refer to PDU
*
36 Foot vent
potentiometer faultHarness / connector fault
In certain circumstances the servo motor may over-travel
and cause further logged faults. This may be cured, following
fault rectification, by cycling the ignition ON-OFF-ON 3 times
*
*Refer to PDU
*
41 LH fresh / recirc.
motor faultHarness / connector fault
Servo motor seized or sticking
Flap seized or sticking
*
*
*Refer to PDU
*
42 RH fresh / recirc.
motor faultHarness / connector fault
Servo motor seized or sticking
Flap seized or sticking
*
*
*Refer to PDU
*

System Self-test
Other conditions which may exist but will NOT log fault codes:
Associated Faults
System Self-test
Panel Communication Check
The panel communication check veri fies the inputs and outputs from the control panel to the A/CCM.
Actuator Check Procedure
The system self test procedure drives all the actuator moto rs, to check their operation. If an actuator is operating
incorrectly or operating outside of its limi ts then a fault code will be present.
Before commencing with the actuator check procedure, ensure the ca r is operating under normal conditions.
1. 1. Switch ignition OFF.
2. 2. Press and hold the RECIRC and AUTO buttons simult aneously, switch ignition ON and run the engine.
3. 3. All the control panel LEDs and all LCD segments will flas h on and off. Any function LED indicator which does not
flash on / off suggests a fault condition within that area of the panel or, with the LED.
Any LCD element which fails to flash on / off indicates a fault within the display element or panel.
4. 4. Press AUTO
43 Cool air by-pass
motor faultHarness / connector fault
Servo motor seized or sticking
Flap seized or sticking
*
*
*Refer to PDU
*
43 Cool Air by-pass
motor faultHarness / connector fault
Servo motor seized or sticking
Flap seized or sticking
*
*
*Refer to PDU
*
44 Defrost vent motor
faultHarness / connector fault
Servo motor seized or sticking
Flap seized or sticking
*
*
*Refer to PDU
*
45 Centre vent motor
faultHarness / connector fault
Servo motor seized or sticking
Flap seized or sticking
*
*
*Refer to PDU
*
46 Foot vent motor
faultHarness / connector fault
Servo motor seized or sticking
Flap seized or sticking
*
*
*Refer to PDU
*
SymptomPossible SourcesAction
No heatAirlock in system.
*Refer section 303-03 for fill / bleed procedure
*
Heater water pump inoperative
Coolant flow valve stuck closed
*
*Check operation and circuit
*
Faulty engine coolant thermostat
*Renew as required
*
One vent failing to open / closeBroken linkage.
*Renew as required
*
Poor airflowBlower motors - incorrect operation
*Check operation and circuit
*
ItemCheck LEDCondition
IgnitionDefrostIGN input at 12V, check LED is illuminated
AuxiliaryFaceAUX input at 12V, check LED is illuminated
ClockFeet / faceClock input normal, check LED is illuminated
Start inputFootStart input normal, check LED is illuminated
Data outScreen / footData out input normal, check LED is illuminated
Dimmer overrideRecirc.Dimmer override input ON, check LED is illuminated

Horn - Horn
Description and Operation
The horns, located behind the radiator gril le, each side of the radiator, are controlled by the Body Processor Module (BPM),
as described below.
The switch, located on the steering wheel pad, is operated, it signals the BPM to sound the horn. The BPM responds by
providing an earth from the horn-output to the horn relay coil. The relay contacts are subsequently closed and the horns
sound.
The horn operating relay, R6 is located in the engine compartm ent fusebox at the left hand side of the engine compartment.

Generator and Regulator - Generator
Description and Operation
Generator - General View
Features
Manufacturer - Denso Type - L3B-HE Drive Ratio - 3.04:1 Output - 120 Amps at 5000 rpm (generator speed) at 25° C
The generator is fitted at the front right hand side of the engine, to a sepa rate mounting bracket, which in turn is bolted to
the cylinder block. Two bolts secure th e generator to the mounting bracket; one is reached from above and one from below
the vehicle.
The voltage regulator is integral with th e generator body. Battery charging capabi lity has been optimised for charging a
battery which is located remotely, in the luggage compartment. The design of the generator and regulator has been finely
matched, to generate charging current with very low ripple. This provides the best electrical refinement to the system.
The generator is driven by a single, multi-ribbed belt which also drives all other front-e nd accessories; except for the
supercharger (where fitted).
No special service tools are required to remove the generator from the vehicle.
ItemPart NumberDescription
1—Generator
2—Bolt - Mounting Upper
3—Bolt - Mounting Lower
4—Voltage Regulator (Internal component)
5—Drive Belt - Multi-Ribbed

The interference suppression module (where fitted) connects to the generator main terminal 'B +' and a ground stud on the
rear face of the generator.
A multi-plug (3 pin) is connecte d to the rear of the generator:
Pin 1 not connected. Pin 2 ignition supply to the regulator. Pin 3 output to the charge warning lamp.
Generator - Internal Circuit Diagram

As with most vehicle ac generators, there is only minimal residual magnet ism in the field (rotor) windings. To compensate
for this and to achieve high current outp ut at low engine speed, the field is excited by battery voltage supplied to the
generator at the 'IG' terminal.
To control the level of field excitation and ultimately, generator output, the voltag e supplied to the field (rotor) is controlled
by the voltage regulator.
The voltage regulator senses (at the 'B' terminal) battery terminal voltage, which within limits is proportional to the state o f
charge of the battery. The regulator then adjusts the supplied voltage between the 'IG' terminal and the regulator 'F'
terminal (a continuously variable process) to maintain the 'B+' output at a constant level.

ItemDescription
1Generator Assembly
2Voltage Regulator
3Main Terminal 'B+'
4Ignition Supply Terminal 'IG' to Rotor
5Output Terminal L to Charge Lamp
6Rotor
7Stator
8Rectifier Pack

If the field were not controlled, the 'B+' output would rise to a level which could damage bulbs and ECMs. The regulator
compares the output voltage to an intern al voltage reference circuit to achieve the controlled output of the generator.
Suppression Module

Although the output from the generator is fi nely controlled and relatively smooth, it is still a pulsed DC output at a varying
frequency proportional to engine speed.
The suppression module damps ou t any ripple which may be sensed on the main output of the generator. This prevents
possible interference via the power supply, affecting the radio reception or, where fitted, the telephone.
The module is located on the right hand side of the engine compartment, on the inner panel just above the chassis leg,
adjacent to the generator. It is secured to two anti-vibration rubber moun tings. The illustration shows the suppression
module viewed from below the vehicle.
A fuse is fitted internally to the suppression module to protect the generator output in the event of a short circuit within th e
suppression module.
Drive Belt Automatic Tensioner

Generator and Regulator - Generator
Diagnosis and Testing
Refer to PDU User Guide
Refer to the PDU User Manual for detailed instructions on testing the charging circuit.
When diagnosing the charging ci rcuit, the PDU indicates only whether the generator is charging or not charging. The reason
for this is that the PDU cannot handle the potential full charging current and that the voltage control circuits are located
within the generator assembly, making th em inaccessible by the PDU directly.
It is possible that the battery has failed. In this case, the voltage output at the generator could be correct, but the voltage
at the battery terminals, and therefore the rest of the vehicl e system, will be adversely affected by the faulty battery.
The same result is given by the PDU if the battery is faulty (generator not faulty), wiring fault (damaged or severe corrosion
at the terminals) or if th e generator is at fault.
Inspection and Verification
The following manual tests help to pinpoint which component is at fault.
Testing the Battery Circuit
Using the Vehicle Battery

Remove the battery cover.
Ensure that all electrical loads are swit ched OFF and that the engine is cool.
Start the engine and allow to IDLE.
Whilst the engine is idling, disconnect the battery negative terminal and, using a digital multimeter (DMM), measure the
voltage between the terminal on the batter y negative cable and the battery positive terminal. If the generator is working,
the measured voltage should be within the range 13V to 15V.
This indicates the system voltage without the battery in circuit. If the generator is inoperative, the engine will stall when t he
ground lead is disconnected.
Repeat the test, using the ground bolt, as indicated (shown dotted on the illustration). There should be hardly any
MechanicalElectrical
Visually check the condition of the drive beltConnections on the rear face of the generator
are fully located?
Check that the belt we ar indicator, located on the automatic belt
tensioner, is within the limit marks

detectable difference in the voltage reading (due to minimal current flow); if there is a detectable difference, clean the cable terminal and the adjacent area of the body.
When the voltage has been measured, STOP THE ENGINE.
Reconnect the battery or fit a new battery if it was established that the battery was at fault (Refer to 414-01).
If the cooling fans operate during the above test, the large demand of current will overload the generator and cause the
engine to stall.
If the battery is in a low state of charge the voltage will rise momentarily when the battery is disconnected. However, the
maximum that the voltage can increase to with this new gene rator is 25V and then only for a maximum time of 200 mS.
Using a Substitute Battery
A substitute battery may be fitted for the tests. This batter y must be a known good example and must have been off-charge for at least twelve hours, with a term inal voltage of approximately 12.8V.
Ensure that all electrical loads are swit ched OFF and that the engine is cool.
Start the engine and allow to IDLE.
Measure the voltage across the battery term inals. It should have dropped a little due to the large start current and then
risen to a value of between 13V and 15V.
If the above test (whichever one used) indicates that the generator is not working then the connections on the rear face of
the generator should be checked. If there is a faulty connection, then the ge nerator will not perform correctly no matter
how fast it is driven.
Checking Generator Connections

ItemDescription
1Multi-Plug Connector
2B+ Main Output Terminal