lock JAGUAR XJ6 1994 2.G Electrical Diagnostic Manual

FAULT CODE 35
Passenger-side Air Bag Circuit L o w Resistance or Shorted
Normal Operation
The DM monitors the resistance between pins 8 and 9. The value of this resistance is normally between 0.9Q and 1.2Q. If the resistance measured is less than 0.7Q the MIL Lamp will illuminate and fault code 35 will be present, indicating
low resistance or short circuit on the air bag circuit.
Possible Causes
0 Shorting between DM pins 8 and 9, passenger-side air bag not fitted.
0 Poor connection of air bag harness.
0 Faulty air bag harness connector.
0 Short circuit in air bag harness.
0 Short circuit across passenger-side air bag terminals.
Fault Diagnosis
8 Disarm the SRS system and disconnect the passenger-side air bag.
8 Disconnect the DM and remove the plastic locking wedge from the black harness connector.
8 Measure resistance across harness connections to passenger-side air bag, wires RP and Kf?
8 Does resistance indicate open circuit ?
Yes - Proceed to step 2.
No - Inspect harness wiring, cable reel cassettes and terminals for short circuit. Rectify as necessary.
2. Code verification
8 Install air bag simulator in place of passenger-side air bag module.
8 Re-connect DM.
8 Switch on the ignition and wait 30 seconds.
8 Is code 35 still present ?
Yes - Renew DM
8 Examine shorting bar on driver-side air bag connector for correct operation, rectify if necessary.
8 Renew air bag module if shorting bar is operating correctly
NO -
3. on completion
8 Arm and verify the SRS system.
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Issue 1 August 1994 15.1 - 30 X300 EDM

rl Electrical
FAULT CODE 53
Front Impact Sensor Circuits Resistance to Ground or Internal Diagnostic Monitor Failure
Normal Operation
The DM measures the voltage on pins 2,6,17 and 18. If there is any resistance to ground on any of these pins or across
the front impact sensors contacts, it will cause the diagnostic voltage on these pins to drop below normal levels. If the
DM measures voltage drop to between 5 and 10 volts, the DM senses an internal voltage regulation failure and code
53 will be present.
A direct short to ground in the front impact sensor circuits
will drop the voltage to less than 5 volts and code 14 will
be present.
!!IQ&: The DM also performs several system self-tests every ignition cycle. If any of these tests fail, fault code 53 will
be present.
Fault Diagnosis
1. System verification
. Disarm the SRS system.
. Disconnect the battery ground lead, allow one minute for DM back-up power to drain.
. Disconnect the DM.
Remove the plastic locking wedge from the grey harness multi-plug connector.
= Measure the resistance between pin 3 (ground) and the following circuits:
. Pin2(ON)
. Pin 6 (VU)
. Pin 17 (KU)
* Pin 18 (KG)
. Are all circuit readings infinite (open circuit) ?
Yes - Renew DM.
No
- Proceed to step 2.
2.
. Using schematic, identify suspect sensor and circuitry.
. Disconnect the suspect sensor.
9 Measure the resistance across the normally open contacts.
. Is the resistance reading infinite (open circuit) ?
Yes - Locate and rectify short to ground on low resistance circuit.
No - Renew front impact sensor.
Impact
sensor open circuit
- check
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Issue 1 August 1994 15.1 - 44 X300 EDM

Electrical IT
15.2.2 INSTRUMENT PACK CONNECTORS
0
Socket A (24-way)
Pin Circuit Input
1. Fuel used 2. 12V ignition feed 3. Ground 4. Ground 5. Battery feed 6. 12V auxiliary feed 7. Anti-lock fail 8. -
Socket 6 (48-way)
Pin Circuit Input
1. - 2. Speed output 1
3. Speed output 2
4. Trip stalk cycle 5. - 6. - 7- 8. - 9. Generator indicator voltage 10. Brake fluid level 11. - 12. Trip reset 13. Screenwash fluid level 14. Transmission sport mode 15. Seat belt 16. Luggage compartment open
Pin
9.
10.
11.
12.
13.
14.
15.
16.
Pin
17.
18.
19. 20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
Circuit Input
Illumination feed
-
- -
Diagnostic serial output (K) Diagnostic serial input (L)
Distance
-
Circuit Input
Park brake (on)
D.I.
bulb fail - - -
Check engine
Exhaust temperature
Main beam
- - - - - - - -
Fig. 1 Pin Locations
Pin
17.
18.
19.
20.
21.
22.
23.
24.
Pin
33.
34. 35.
36.
37.
38.
39. 40.
41.
42.
43.
44.
45.
46.
47.
48.
Circuit Input
-
Coolant temperature
Fuel level
Oil pressure
Coolant temperature output
Tachometer
input - ECM
-
Circuit Input
Ground - trip keyboard
Traction control status
Trip clear
Coolant level
Side lights (on)
Left D.I. (on)
Right D.I. (on)
Trip
km / miles
General bulb fail
Transmission fail
Air bag fail
Door ajar
- Driver’s
Door ajar - Passenger’s
-
X300 EDM 15.2 - 3 Issue 1 August 1994

15.2.3.8 Trip Computer
The instrument pack provides the trip computer functions, selected via the momentary stalk input and two action in- puts: 'Reset' and 'Odo'.
The signal used for each function are:
Distance:
Computed from the speed signal from the ABS control module.
Average Speed
Computed from the speed signal from the ABS control module.
Fuel Used
Computed from a pulsed signal from the engine management system.
Average Fuel Consumption
Computed from the speed signal and the fuel used signal.
Range
Computed from the speed signal, the fuel used signal and fuel level.
instantaneous Fuel
Computed from the speed signal and the fuel used signal.
15.2.4 PRIMARY WARNING LAMPS - ILLUMINATED RED
15.2.4.1 Exhaust Temperature (Japan only)
The exhaust temperature input (pin 23,48 way connector) is provided by the catalyst switching module (pin 6), which
pulls the line low when a fault occurs.
15.2.4.2 Low Oil Pressure
This signal comes direct from the variable resistance type oil pressure sensor. The sensor resistancevalues range from
7552 to 310Q.
15.2.4.3 Seat Selt
The seat belt input (pin 15,48 way connector) is provided by the seat belt stalk switch, via the body processor unit
(pin 26).
The seat belt lamp will illuminate when
a low signal is seen on the instrument pack input.
15.2.4.4 Trunk Lid Open
A microswitch located in the trunk lid lock provides a signal (pin 16,4&wayconnector) causing the trunk lid open indi- cator to illuminate whenever the trunk lid is opened or not closed correctly.
The trunk lid open indicator will illuminate when
a low signal is seen on the instrument pack input.
15.2.4.5 Door Ajar
Switches located in each door closing mechanism supply signals to indicate when any door is either open, or has not
been closed correctly. The system operates from two signals; an input from the driver's door (pin 46, 48-way con- nector) or a combined signal input from the passenger doors (pin 47,4&way connector).
The door ajar lamp will illuminate when
a low signal is detected on either of the two inputs.
X300 EDM 15.2 - 5 Issue 1 August 1994

15.2.5 SECONDARY WARNING LAMPS - ILLUMINATED AMBER
15.2.5.1 Transmission Fault
The transmission fault indicator is controlled by a signal from the Transmission Control Module (TCM). The signal to
the instrument pack (pin 44,48-way connector) is switched high when a transmission fault occurs, and the indicator
lamp is illuminated.
15.2.5.2 Washer Fluid Level
The washer fluid level sensor, mounted in the fluid reservoir, provides a signal (pin 13, 48-way connector) when the
amount of fluid drops below a predetermined level. The switch is normally in the closed position, providing a low sig-
nal to the instrument pack, when the fluid level is acceptable. If the fluid level drops, the switch will open, removing
the low signal and illuminating the indicator lamp.
15.2.5.3 Bulb Fail
Bulb failure indication is controlled from two different sources:
If a direction indicator lamp fails, a signal is sent to the instrument pack (pin 18,48-way connector) from the Body. :o- cessor Unit (BPU). The signal is normally low but switched high if a bulb failure occurs; thuscausing the bulbfail indica-
If any of the other bulbs, monitored by the three lamp control modules, fail, a signal is sent direct to the instrument
pack (pin 43, 48-way connector). The signal is normally low but switched high if a bulb failure occurs; thus causing
the bulb failure indicator lamp to illuminate.
tor lamp to illuminate.
15.2.5.4 Traction Control Fail
Two traction control lamps are provided: control fail and control off. Both lamps are controlled from one input from
the ABS / TC Control Module.
Under normal operating conditions, the input signal should be high.
If the input line is continuously low, traction con- trol has failed and both lamps will illuminate. If the input signal is a 4 Hz square wave the traction control system is
switched off, therefore the ‘traction off lamp will illuminate.
15.2.5.5 Anti-lock Fail
The input to the instrument pack (pin 7,24-way connector) is provided by the ABS Control Module. The warning lamp
illuminates if the signal voltage is less than 5.0 volts or greater than 11.9 volts.
- 15.2.5.6 Low Fuel Level
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.
15.2.5.7 Check Engine
The ’checkeng’ indicator will illuminate when the Engine Control Module (ECM) detects a fault within the system, and
sends a signal to the instrument pack (pin 22,48-wayconnector). The signal line is pulled low by the ECM when a fault
is detected.
The indicator lamp will illuminate during each ignition cycle, until the engine fires.
X300 EDM 15.2-7 Issue 1 August 1994

15.4.1.4 Remote Recall
Remote activation of memory positions 1 and 2 can be achieved using the key fob transmitters (one per set of keys).
lfthe vehicle is unlocked using the remote transmitter the stored driving position will be adopted automatically. If the
vehicle is unlocked using the remote transmitter and an exit position is already set the corresponding entry position
will be adopted until the ignition key is inserted, the stored driving position will then be restored. 0 ~
15.4.1.5
Reverse Mirror Dip
On selection of reverse gear and operation of the mirror toggle switch downwards, the passenger side rear view mirror
will automatically tilt downwards to assist reverse parking. Upward adjustment disables reverse dip, a further down- ward adjustment when still in reverse gear reinstates reverse dip. The mirror will return to normal position when any
other gear position is selected.
15.4.2 SYSTEM COMPONENTS
15.4.2.1 Seats
- Driver and Passenger
The driver and passenger seat adjustment systems comprises the following components:
o Fore / aft motor
o Front raise / lower motor
o Rear raise / lower motor
0 Squab recline motor
0 Headrest motor
0 Lumbarpump
0 Squab heater
0 Inner cushion heater
0 Outer cushion heater
0 Heater thermostat
0 Switch pack
o Seat Control Module (SCM)
o Wiring harness
15.4.2.2 Motors
The five seat position adjustment motors are located below the seat cushions (horizontal and vertical adjustment) and
behind the squab (recline and headrest adjustment). Each motor unit incorporates a potentiometer which provides
directional movement position control via feedbackvoltage variations to the SCM. Positional variations are activated
by the SCM in response to signals from switches mounted on the seat switch pack.
15.4.2.3 Lumbar Pump
The lumbar pump, located behind the seat squab allows adjustment of seat rigidity by increasing/decreasing air pres- sure in the lumbar pad. The pump motor is controlled from a switch on theseat switch pack and governed by an in-line
pressure switch.
A solenoid valve is used to regulate air flow to the lumbar pad.
15.4.2.4 Heaters and Thermostats
The two cushion heaters and squab heater are regulated by a single in-line thermostat and operated by a switch
mounted on thecenter console switch pack. Operation of this switch causesthe Body Processor Unit (BPU) to energize a timed input to SCM (for 11 minute f 1) which in turn causes SCM to energize the heater supply. The supply will
remain on until timed out, although the heater circuit will be broken by the thermostat if the set temperature is ex- ceeded.
Note: Heatingcan only occur when the ignition switch is position I1 and the ambient temperature is belowthe thermo- stat pre-set value of 26°C.
X300 EDM 15.4 - 3 Issue 1 August 1994

E I ect r ical
15.4.2.5 Switch pack
The seat switch pack located on the side of the seat cushion houses the following switches:
Headrest; raise
/ lower
Seat cushion
-front; raise 1 lower
Seat cushion
- rear; raise 1 lower
Squab recline
/ incline
Seat assembly forward
/ backward
Lumbar pad firm
1 relax
Each switch has
a dual function and is capable of bi-directional action, so that any setting made can be reversed using
the same switch.
15.4.3 SEAT CONTROL MODULE
The Seat Control Module (SCM) is located inside the seat frame, below the cushions. The SCM controls the actions
of all position adjustment devices by monitoring switch and feedback potentiometer inputs. The SCM also provides
an interface to and from external devices with a bearing on seat operation. The module works in conjunction with the
ColumnIMirror Control Module (C/M CM) and the Securityand Locking Control Module (S/LCM) to provide positional adjustment memory functions as described previously.
There are four connectors to the SCM, designated
AI, A2, B1 and B2, which connect the various inputs 1 outputs and
peripheral devices to the module. Connections are as listed in subsection 15.4.3.1.
A1A2 B1B2
1 1 1
i 11
1 I
6
I
1' ~

1 7i 1 I 1 122
J86 1903 12 22 12 12 7 12
Fig. 1 SCM
Pin Location Diagram
X300 EDM 15.4 - 5 Issue 1 August 1994

IT Electrical
15.4.5 COLUMN / MIRROR CONTROL MODULE
The Column / Mirror Control Module C/ M CM controls the operation of position adjustment motors by acting upon
inputs from the relevant switches. The module also forms an interface with signals from associated systems which
affect column /mirror movement. The
C/ M CM works in conjunction with SCM and SL CM to provide positional adjust- ment memory functions as previously described.
There are three connectors to the
C I M CM single multi-pin socket, designated block A, B and C, which connect the
various inputs / outputs and peripheral devices to the module. Connections are as listed below.
I BLOCK A [26-WAY GREY) 1
I .. I I 41 Input Switched to 12V ..
20 Memory set selected
Input Switched to 12V
21
Tilt restrict ident Input Switched to ground 1 open
22 Key in ignition barrel active
Input Switched to ground
circuit
23
1 Auxiliary ground on Input 1 Switched to ground
24 1 Reference voltage +ve feedback output I4.5v
25 1 Passenger mirror R/L Output 1 +ve 1 -ve
26
1 Mirror motor common Output I +ve / -ve
BLOCK B (lgWAY, GREY)
Pin No. I Description I In / out lsignal
1 Driver mirror L/R feedback Input 140mV - 4.36V
2 Passenger U/D feedback
Input 140mV - 4.36V
3 Driver mirror U/D feedback Input 140mV - 4.36V
4 Column tilt feedback Input 140mV - 4.36V
5 Column reach feedback
input 140mV - 4.36V
6 Reverse gear selected
Input Switched to ground
-

0
I I- - I 13 l-
BLOCK B (W-WAY, GREY) continued
' 7 Tiltawayonsignal Input Switched to ground
8 Gear selector not in park Input Switched to ground
9 Park brake ON signal Input
Switched to ground
10 Driver's door open signal Input Switched to ground
11 Remote call active Input
Switched to ground
12 Brake pedal ON signal Input
Switched to ground
I I 16 1- - -
Pin No.
1
2
3
4
Description I In/ out Signal
Power battery i Input 12v
Power ground Input ov
- - -
JDS
L I/O Serial Data
5 IJDSK I/O
13
I I
Serial Data
A B C J86 1902
I j 6
i7
'8
9
10
11
12
Fig. 1 Control Module Pin Location Diagram
I Lowcurrent battery ~ Input 12v
- - -
- - -
- - -
- - -
- - -
- - -
X300 EDM 15.4-11 Issue 1 August 1994

rl E I ect r ical
15.4.6 NON-MEMORY AND MANUAL APPLICATIONS
15.4.6.1
Non-Memory
Seats, column and mirrors may be supplied without memoryfacilities on certain vehicles. In this case, adjustment of
each application is still controlled in the same way but the memory facility is disabled and the memory switch pack
not fitted.
15.4.6.2 Manual Seats
Manual seats are adjustable vertically and horizontally, vertical adjustment being motorized but horizontal adjustment
manually effected. The seats have heated cushions and squab, but are not operated by an electronic control module.
Control is effected using three relays, two for vertical adjustment and one for heating.
Vertical adjustment is requested
by operation of a switch located on the left-hand side of the seat front which completes
the electrical supply to either the raise or lower relay as required. When either relay is energized a change of contact
state connects one side of the motor to
+12V and the other side to ground. Reverse operation reverses supply and
ground connection.
Heating is still controlled by a timed output from the BPU. Operation of a switch located on the
center console indicates
to BPU that heating is required. Battery voltage is then applied to the heater relay for 11 minutes. The relay contact
completes the heater circuit, providing seat heating (and illuminating the switch surround) until the timer expires, or
optimum seat temperature is achieved. Operation of the heater switch before 'time-out' is achieved cancels the heat- ing request. Operation of the heater switch after 'time-out' has been achieved re-starts the heating cycle.
15.4.6.3 Manual Column
Manual column adjustment in the two planes is achieved by purely mechanical means, release catches allowing col-
umn movement within a fixed locking mechanism.