1994 JAGUAR XJ6 ignition

Climate Control Systems
0 14.5 FAULT CODES
J&&: Displayed error codes are NOT compatible with Jaguar Diagnostic Equipment (JDE).
23 Refrigerant Pressure Switch Open /short circuits. Low gas charge*
24 Differential Potentiometer. Open /short circuits
31 LH Fresh
/ Recirc.
Potentiometer I I I I RH Fresh / Recirc. Potentiometer
Open / short circuit in pot. feed.
32
, In certain
circumstances, the motor can over- 0 33 Cool Air Bypass Potentiometer
34 Defrost Potentiometer travel and log further faults.
35
36 Foot Potentiometer Cycling
the ignition two or three times can cure
this.
Centre
Vent Potentiometer
41
42
I LH Fresh / Recirc. Motor
I RH Fresh / Recirc. Motor
43 Cool Air Bypass Motor
44 Defrost Motor lines. Motor flap sticking
/ jammed.
Check
for short
/ open circuits in motor drive
1 45 I Centre Vent Motor I
1 46 IFoot Motor I
W: In ambient temperatures below OOC, the system may log fault code 23 because low ambient can cause a tem-
porary low gas pressure. In ambient temperatures above 35"C, the system may log fault code 23 as temporary
high pressure can exist within the system. *
Associated Faults
Other symptoms that may exist without storing fault codes:
Airlock in system.
Water pump inoperative.
Water valve stuck closed.
Faulty engine coolant thermostat.
Broken linkage.
Blower motors
- incorrect operation.
No heat
One vent failing to open /close
Poor airflow
X300 EDM 11 Issue 1 August 1994

Climate Control Systems
14.6 ACTUATOR CHECK
The system self test procedure drives all the actuator motors, to checktheir operation. If an actuator is operating incor- rectly or operating outside of its limits then a fault code will be present.
Before commencing with the actuator check procedure, ensure the car is operating under normal conditions.
Actuator Check Procedure
. Switch off the ignition.
. Press and hold the 'Auto' and 'Fresh / Recirc.' buttons simultaneously, and run the engine.
All the control panel LED's and all LCD segments will flash on and off. Any function LED indicator which does not
. Any LCD element which fails to flash on / off indicates a fault within the display element or panel.
. Press 'Auto'.
. Press 'Fresh / Recirc.' button to instigate actuator check mode.
. Use 'Face' to cycle through actuator mode conditions 20 to 27, as detailed in the table below.
flash
on
/ off suggests a fault condition within that area of the panel or, with the LED.
Press the 'Push Off button to restore normal operation with default panel settings, ie AUTO at 24OC.
1ynfe: * The water valve operates on a 6 second pulse, ie 3 seconds ON, 3 seconds OFF.
Issue 1 August 1994 12 X300 VSM

Climate Control Systems
DIAGNOSTIC TESTS 0 14.7 14.7.1 Fault Code 11
Motorized In-car Aspirator
The Motorized In-car Aspirator (MIA) comprises of a small motor and a thermistor.
o Thermistor, harness or A/ CCM open circuit.
0 Thermistor, harness or A/ CCM short circuit to ground.
The MIA operates in the range of
0 to 5 volts and forms the main reference point for the whole system.
If the signal on pin 33 (12-way connector, A/ CCM) remains at less than 1 volt, suspect either a short circuit to ground
on the signal wire or an open circuit on the 5 volt supply to the thermistor. If the signal on pin 33 rises to approximately 5 volts, suspect an open circuit on the earth supply to the thermistor.
Check the voltage, against the graph below (Fig.
I), measured between pin 33 (12-way connector) and pin 19 (22-way
connector) A/ C CM.
If the voltage is within the set limits, the system is operating correctly.
A resistance check can be carried out at the thermistor and should conform with the figures below, measured between
pin 1 and pin 2 (&way connector).
10°C 3.1
-3.7 w1 25°C 1.6- 1.8 lcrz
50°C 0.5 - 0.7 lcrz
0 If the resistance is outside the set limits, renew the thermistor.
14lnfe: The resistance should continue to decrease as the temperature increases and vice versa.
Inspect thermistor harness for open circuit or short circuit to ground. Rectify as necessary.
If the voltage is outside the set limits, renew the A / CCM.
The operation of the motor can be checked by applying fused ignition feed to pin 3 and a ground to
pin 4, motor white,
4-way connector.
V
J66-1770
Fig. 1
X300 EDM 13 Issue 1 August 1994

Climate Control Systems
14.7.22 BLOWER MOTORS
Disconnect the blower motors (LH & RH) multi-plugs and check motor operation by applying battery voltage (+12V) across pin 5 (+vel and pin 9 (-ve).
Non-functioning of both L H and RH motors *
Cause:
1. Loss of ignition voltage.
Remedy:
1.
2.
*
Examine fuse F12 in RH heelboard fuse-box. If fuse is blown determine reason for failure and renew.
Examine harness wiring from
RH heelboard fuse-box connection CA044/010 to splice CAS53. Repair or renew
wiring as necessary.
This fault will also affect the operation of seat control modules, power steering control module and door mirror
heaters.
Non-functioning of RH blower motor only
Cause:
1. Faulty relay operation.
2. Faulty harness wiring.
Remedy:
1. Ensure 12Vsupply between relay pin 1 and ground.
Ensure continuity between pins 3 and
5 when relay operated.
Ensure relay coil impedance of
7552 to 135Q across pins 1 and 2.
Ensure correct seating of relay on base. Examine pins for damage or deformity.
Check continuity of wiring from fuse F12
(RH heelboard fuse-box) to relay pin 1 and from relay pin 2 to A / CCM
pin 53 (26-way connector).
Check continuity of wiring from fuse
F11 (RH heelboard fuse-box) to relay pin 3, from relay pin 5 to motor pin 5, from motor pin 13 to A / CCM pin 41 (16-way connector), from motor pin 8 to ground and from motor pin 10 to A / CCM pin 42 (16-way connector).
2.
Non-functioning of L H blower motor only
Cause:
1. Faulty relay operation.
2. Faulty harness wiring.
Remedy:
1. Ensure 12V supply between relay pin 1 and ground.
Ensure continuity between pins 3 and
5 when relay operated.
Ensure relay coil impedance
of 7552 to 135Q across pins 1 and 2.
Ensure correct seating of relay on base. Examine pins for damage or deformity.
2. Check continuity of wiring from fuse F12 (RH heelboard fuse-box) to relay pin 1 and from relay pin 2 to A / CCM
pin 66 (26-way connector).
Check continuity of wiring from fuse
F11 (LH heelboard fuse box) to relay pin 3, from relay pin 5 to motor pin 5, from motor pin 13 to A / CCM pin 49 (16-way connector), from motor pin 8 to ground and from motor pin 10 to
A / CCM pin 50 (16-way connector).
X300 EDM 23 Issue 1 August 1994

E I ect r ica I
15.1 SUPPLEMENTAL RESTRAINT SYSTEM
15.1.1 System Description
The Supplemental Restraint System (SRS) installation comprises:
0 electronic Diagnostic Module (DM)
0 driver and passenger-side air bag modules (including firing mechanisms)
0 two front impact sensors (left and right)
0 one safing sensor
0 dedicated wiring harness
0 two cable reel cassettes (integral part of the steering column harness)
0 Malfunction Indicator Lamp (MIL) and driver information message
The system is designed to provide protection for both driver and front seat passenger by automatically deploying air
bags in the event of a collision during forward travel. The driver
-side air bag is located in the centre of the steering
wheel assembly and the passenger-side air bag in the fascia panel.
In the event of a collision the impact
/ safing sensors operate, completing the electrical firing circuit and causing the
air bags to inflate within 32 milliseconds. At least two of the three sensors (at least one impact, and the safing sensor)
.must be activated to initiate firing. System operation is dependent upon battery voltage supplied directly, and via the
ignition switch, to the DM and the correct installation and operation of all system components, including the wiring
harness. Faults in system components, installation or wiring will be indicated by the MIL Lamp, located on the instru
- ment panel, which will illuminate 'SRS AIR BAG'. Indication is also given by the driver information message'AIR BAG'
displayed on the LCD panel below the speedometer.
15.1.2.1 Diagnostic Module (Fig. I)
The Diagnostic Module (DM), mounted below the passenger-side air bag module, behind the console fascia panel, is
the electronic microprocessor unit which monitors the whole SRS system. The state of the three system sensors, two
air bag modules and the wiring harness is monitored constantly to detect activation criteria and component faults.
15.1.2 COMPONENT DESCRIPTIONS
The unit also confirms correct supply conditions by compar- ing a direct battery voltage input with an input, via the igni- tion switch, of the same voltage value. Detection of system
faults will be relayed by the DM to the instrument panel and
the air bag MIL Lamp illuminated.
The DM contains a reserve power supply unit, enabling the
air bagsto fire even if supply voltage is lost during an impact
situation. The reserve power charge will be retained for ap
- proximately one minute after the positive supply voltage is
disconnected. An auxiliary internal circuit, known as the
'dwell enhancer', provides a temporary ground to compen
- sate for damaged primary crash sensors. If either primary
crash sensor operates for 5 milliseconds the 'dwell en- hancer' circuit will turn on, completing the firing circuit to
ground for 90 milliseconds. The purpose of this is to allow
air bag deployment even if the operated primary crash sen- sor circuit is defective or opens.
15.1.2.2 Wiring Harness
Fig. 1
A dedicated wiring harness, covered with yellow sheathing, independent of any other vehicle system, is used to electri- cally connect all the component items. To allow movement of the steering mechanism, two cable reel cassettes are
incorporated into the driver-side air bag module circuitry, as a means of compensating for steering wheel rotation is
required to prevent harness damage or disconnection. The two cable reel cassettes form an interface between the
steering column and air bag module and, due to their coiled construction, are able to contract or expand as required.
15.1.2.3 Air Bag Modules
The two air bag modules, driver and passenger side, are
each activated when either front impact sensor (Fig. 2) and
the safing sensor operate simultaneously. Both modules
contain a charge of sodium
azide/copper oxide which, when
ignited by an electrical impulse, generate a volume of ni
- trogen gassufficientto inflatetheair bag. Theamountof gas
generated is greater in the passenger-side air bag due to its
larger size. Both modules, including surrounding trim pan- els, are non-serviceable and once activated must be re-
newed as a complete assembly.
Fig. 2
X300 EDM 15.1 - 1 Issue 1 August 1994

Electrical rl
15.1.3 AIR BAG DISARMING/ ARMING PROCEDURE
warnings and cautions
WARNING: DISARM SRS BEFORE SERVICING ANY SRS OR STEERING COLUMN COMPONENT.
ALLOW A MINIMUM OF ONE MINUTE TIME DELAY FOR THE BACK
-UP POWER SUPPLY TO DISCHARGE,
AFTER THE BATTERY GROUND LEAD HAS BEEN DISCONNECTED.
THE SYSTEM COMPONENTS ARE NON
-SERVICEABLE, IF FAULTS ARE SUSPECTED, CHANGE COMPO- NENTS FOR NEW ITEMS ONLY.
NEVER PROBE THE CONNECTORS OF AN AIR BAG MODULE.
FAILURE TO OBSERVE THE ABOVE PROCEDURES MAY RESULT
IN ACCIDENTAL DEPLOYMENT OF AIR
BAG.
ALWAYS WEAR SAFETY GLASSES WHEN WORKING ON AIR BAG EQUIPPED VEHICLES.
PERSONNEL CARRYING AN AIR BAG MODULE MUST ENSURE THAT THE MODULE AND TRIM COVER
ARE POINTED AWAY FROM THE BODY. WHEN POSITIONED ON A BENCH
OR WORK SURFACE ENSURE
THAT THE AIR BAG MODULE AND TRIM COVER FACE UPWARDS, LIMITING MOTION ON ACCIDENTAL
DEPLOYMENT.
ALWAYS WEAR GLOVES WHEN HANDLING DEPLOYED AIR BAG MODULE, DEPOSITS OF SODIUM HY
- DROXIDE MAY BE PRESENT ON THE MODULE SURFACE. IF SODIUM HYDROXIDE CONTACTS ANY
AREA OF SKIN, WASH THE AFFECTED AREA IMMEDIATELY WITH MILD SOAP AND WATER. DISPOSE OF
THE DEPLOYED AIR BAG USING THE CORRECT PROCEDURES, REFER TO SECTION
15 OF THE VSM.
CAUTION:
When scrapping vehicles ensure air bags have been deployed.
If
a component has been renewed and the fault does not clear, refit original item and repeat diagnostic
procedure.
After servicing repeat diagnostic procedures to ensure correct system operation.
Renew air bag module if surrounding trim panels are damaged.
Do not attempt to repaint trim covers as paint may damage cover material.
Disarming
. Allow a minimum 1 minute time delay before attempting to diagnose or renew any component in the SRS system.
Remove driver-side air bag module and connect air bag simulator to cable reel cassette multi-plug.
. Remove passenger-side air bag module and connect air bag simulator to harness.
. Re-connect battery ground lead.
Disconnect
the battery ground lead.
This delay allows the DM back
-up power supply to discharge, preventing accidental firing of the air bag.
0
Arming
Disconnect the battery ground lead.
. Remove air bag simulators and install driver and passenger-side air bag modules. Ensure fasteners are tightened
. Re-connect battery ground lead.
Switch ignition 'on' and ensure air bag MIL Lamp extinguishes.
to specified torque.
X300 EDM 15.1 -3 Issue 1 August 1994

Electrical IT
To aid the following fault diagnosis, Fig. 1 displays the diagnostic module connector pins.
0
13 24
1
Pin No. Circuit Identification
1. Ignition Supply
2. LH Impact Sensor Monitor
3. Ground Input 4.
5. Ground
6. RH Impact Sensor Monitor 7. 8.
9. 10.
11.
12. Safing Sensor Output
Instrument
Pack Interface
- MIL Lamp
Not Used (Driver's only input)
Passenger Air Bag Module Feed
Passenger Air Bag Module Return
Driver Air Bag Module Feed
Driver Air Bag Module Return
Fig.
1
Pin No.
13.
14.
15.
16. 17.
18.
19.
20.
21.
22.
23.
24.
12
Circuit Identification
Battery Input
Not Used
Safing Sensor Input
Safing Sensor Ground Monitor
LH Impact Sensor Feed
RH Impact Sensor Feed
Not Used
LH Impact Sensor Ground Monitor
RH Impact Sensor Ground Monitor
Not Used
Safing Sensor Feed
Test Input
X300 EDM 15.1 - 5 Issue 1 August 1994

Electrical
0
NO AIR BAG MIl LAMP
Inoperative lamp Circuit or No Ignition to the Diagnostic Module
Normal Operation
The air bag MIL Lamp is designed to illuminate for approximately six seconds when the ignition is switched ‘on’; this
time has been allocated to prove the MIL Lamp operation.
The DM requires an ignition supply to Pin
1, to energize the air bag MIL Lamp circuit. If the MIL Lamp is open circuit
or the DM does not receive ignition voltage at Pin 1, the MII Lamp will not illuminate.
Open circuit in the
MII Lamp supply will cause the DM to emit five tones, or ‘beeps’ every 30 minutes while ignition
is on. Repair faulty circuitry before further diagnostics.
Possible Causes
0 Bulb blown or faulty wiring in the air bag MIL Lamp circuit.
0 Loss of ignition voltage at DM pin 1.
Fault Diagnosis
1. Ignition voltage -check
8 Disarm the SRS system.
8 Switch on the ignition.
8 Measure the voltage between pin 1 (+vel and pin 3 (-vel of the connector.
8 Battery voltage present, proceed with step 2.
8 Battery voltage not present; open circuit on R / W wire from RH fuse-box or faulty ground at pin 3.
8 Check fuse 17, RH fuse-box.
8 Check the fuse connectors and wiring.
8 Check the ground at pin 3 of the DM connector.
8 Arm and verify the SRS system.
2. MIL Lamp open circuit
8 Renew the DM.
8 Arm and verify the SRS system.
If the MIL Lamp is not illuminated, check the bulb, instrument pack and associated wiring.
Issue 1 August 1994 15.1 - 6 X300 EDM