1994 JAGUAR XJ6 Electrical Diagnostic Manual

Electrical rl
Electrkal schematic - Fault Code 14
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J86-1667
1. Instrument Panel Fuse 6. Passenger-side Air Bag
2. Engine Compartment Fuse 7. RH Impact Sensor 3. Safing Sensor 8. LH Impact Sensor 4. Cable Reel Cassettes 9. Air Bag MIL Lamp
5. Driver-side Air Bag 10. Diagnostic Module
Fig. 1
X300 EDM 15.1 - 15 ~~ Issue 1 August 1994

FAULTCODE 21
Safing impact Sensor Incorrectly Mounted to Vehicle
Normal Operation
The DM monitors the resistance value between pins 16 and 3. If a resistance value of greater than 2.051 is detected the
MIL Lamp will illuminate and fault code 21 will be present, indicating incorrect mounting of the safing impact sensor.
Secure connections to ground at both the sensor case and the vehicle are necessary to avoid this fault.
Possible Causes
0 Poor or dirty connection between safing sensor case and vehicle ground.
0 Poor or dirty termination at safing sensor internal ground.
0 Open circuit on wiring between DM pin 16 and safing sensor ground terminal.
Fault Diagnosis
1. Resistance - check
Disarm SRS system.
Disconnect battery ground lead.
Measure resistance between pin 3 (ground) and pin 16 (ground - safing sensor).
Is resistance value greater than 251 ?
No - Proceed to step 2
Yes
- Renew DM
2. Sensor ground
-check
Disconnect safing sensor from harness.
Measure resistance between sensor pin 5 and sensor mounting (chassis ground).
Is resistance value greater than 251 ?
Yes - Proceed to step 3
No - Examine wiring between internal sensor ground and harness connection 10. Rectify faults as necessary.
3. Sensor mounting -check
Remove safing sensor from mounting.
* Clean all mounting surfaces thoroughly and refit sensor.
Re-test resistance between harness connection 10 and sensor internal ground.
* Is resistance value greater than 251 ?
Yes - Renew sensor
No - Refit sensor and connect harness and battery ground lead.
4. On completion
Arm and verify the SRS system.
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Issue 1 August 1994 15.1 - 16 X300 EDM

E I ect r ica I rl
Electrkal schematic - Fault Code 2 1
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2 P15 P23 PI 6
i I
10
1. Instrument Panel Fuse 6. Passenger-side Air Bag 2. Engine Compartment Fuse 7. RH Impact Sensor
3. Safing Sensor 8. LH Impact Sensor 4. Cable Reel Cassettes 9. Air Bag MIL Lamp
5. Driver-side Air Bag 10. Diagnostic Module
Fig. 1
J86-1668
X300 EDM 15.1 - 17 Issue 1 August 1994

rl E I ect r ica I
Vbatt 1 9.0 9.5
10.0 10.5
11.0 11.5 12.0 12.5 ~ 13.0
13.5
Vpin
I 2.3 2.4 2.5 2.7 2.8 3.0 3.1
3.2 1 3.4 3.5
FAULT CODE 22
Safing Impact Sensor
Output Circuit Shorted to Battery Voltage
Normal Operation
The DM measures voltage level at pins 11 and 12 which varies in accordance with charging voltage. If voltage
measured at these two pins exceeds
5V the MIL Lamp will illuminate and fault code 22 will be present, indicating a short
to battery voltage.
14.0 14.5 15.0 15.5 16.0
3.7 3.8 4.0
4.1 4.3
Possible Causes
0 Air bag supply
wiring faulty.
0 Safing impact sensor supply wiring faulty.
0 Safing impact sensor internal contacts short circuit.
0 Cable reel cassette faulty
0 Charging system voltage too high (above 17V).
2. Resistance - check
. Measure resistance across safing sensor contacts.
. Does resistance value indicate open circuit.
Yes
-Examine harness wiring for short circuits. Rectify faults as necessary.
No - Renew safing sensor.
3. On completion
Arm and verify the SRS system.
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issue 1 August 1994 15.1 - 18 X300 EDM

Electrical IT
Electrical schematic - Fault Code 22
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PO'
A A . P15 P23 P16
c-
PO9
PI E
P13 N
PO3 I
10
RP I
4
'I
15
1
4
J86-1669
1. Instrument Panel Fuse 6. Passenger-side Air Bag
2. Engine Compartment Fuse 7. RH Impact Sensor 3. Safing Sensor 8. LH Impact Sensor
4. Cable Reel Cassettes 9. Air Bag MIL Lamp
5. Driver-side Air Bag 10. Diagnostic Module
Fig. 1
X300 EDM 15.1 - 19 Issue 1 August 1994

Electrical rl
FAULT CODE 23
Safing Impact Sensor Input Feed / Return Open Circuit
Normal Operation
The DM monitors the voltage on pins 15 and 23. Thevoltage on both pins should be identical. If a discrepancy between
the two measurements is detected the MIL Lamp will illuminate and fault code 23 will be present, indicating open circuit
between DM and safing sensor.
Possible Causes
Open circuit in wiring between DM pins 15 / 23 and safing sensor or internal sensor connection fault.
Fault Diagnosis
1. Voltage - check
. Disarm the SRS system.
. Measure and compare voltage at both pin 15 and pin 23, using pin 3 as a common ground.
No - Proceed to step 2
Yes - Renew DM
Turn
ignition switch to 'run' and wait 30 seconds.
Is the voltage on both pins between 23V and 26V ?
2. Resistance -check
. Disconnect safing sensor from main harness and measure resistance between YP and RN connector wires.
Is resistance value less than 2S2 ?
Yes - Examine harness wiring for open circuit. Rectify faults as necessary
No - Renew safing sensor
3. On completion
. Arm and verify the SRS system.
15.1
- 20 X300 EDM Issue 1 August 1994
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Electrical rl
Electrical schematic - Fault Code 23
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-I
YG
f
P13
10
1. Instrument Panel Fuse
J86-1670
6. Passenger-side Air Bag 2. Engine Compartment Fuse 7. RH Impact Sensor 3. Safing Sensor 8. LH Impact Sensor 4. Cable Reel Cassettes 9. Air Bag MIL Lamp 5. Driver-side Air Bag 10. Diagnostic Module
Fig.
1
X300 EDM 15.1 - 21 Issue 1 August 1994

Electrical
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FAULT CODE 24
Safing Impact Sensor Output Feed / Return Open Circuit
Normal Operation
The DM measures voltage level at pins 11 and 12 which varies in accordance with battery voltage. DM calculates what
the value at pins 11 and 12 should be from the value measured at pin 13, battery voltage. If voltage measured at pins 11 and 12 is not as expected by DM the MIL Lamp will illuminate and fault code 24 will be present, indicating a safing
sensor circuit fault.
Vbatt
9.0 9.5 1 10.0 10.5
11.0 i 11.5 12.0 12.5 I 13.0 13.5 14.0
14.5 15.0
15.5
Vpin 2.3 2.4 ~ 2.5
2.7
2.8 ~ 3.0
3.1 3.2 1 3.4 3.5 3.7 3.8 4.0
4.1
Possible Causes
0 Air bag wiring fault.
0 Safing impact sensor wiring fault.
0 Grounding of air bag /sensor circuits.
0 Intermittent battery voltage at DM pin 13.
16.0 4.3
Fault Diagnosis
1. Voltage - check
8 Disarm the SRS system.
8 Turn ignition switch OFF, then ON.
8 Measure the voltage between DM pins 11, 12 and pin 3 (ground) and compare to following table.
Are voltages within
0.5V of normal ?
Yes -
8 Check battery +ve input voltage wiring to DM pin 13.. Rectify wiring faults, if any.
8 Check fuse F17 in RH fuse-box, renew if blown.
8 Check battery, renew if necessary.
8 Renew DM if no other faults are located.
8 Proceed to step 2 if both voltages are low.
8 Proceed to step 3 if only one voltage is low.
N
O -
2. Resistance -check
8 Switch off the ignition
and disconnect battery earth lead.
8 Disconnect DM and measure resistance between pin 11 and pin 3.
8 Does resistance value indicate open circuit ?
Yes - Renew DM.
No
-Examine wiring andcomponents insafing sensor, air bag and primarysensorcircuitsforshortstoground. Rectify
faults as necessary.
3. Sensor - check
8 Switch on the ignition.
8 Disconnect safing sensor from main harness and measure resistance across connector wires YP and RN.
8 Is resistance less than 29 ?
Yes - Examine harness wiring for open circuit. Rectify faults as necessary.
No - Renew safing sensor.
4. On completion
8 Arm and verify the SRS system.
X300 EDM Issue 1 August 1994 15.1 - 22