relay JAGUAR XJ6 1994 2.G Electrical Diagnostic Manual

Climate Control Systems
High speed operation at all times - RH blower
a Cause:
1. Faulty high speed relay.
2. Faulty harness wiring.
Remedy:
1. Check the relay contact is not stuck 'ON'.
2. Check continuity of wiring harness between blower motor pin 8 and ground, pin 10 and A / CCM pin 42 (16-way connector) and pin 13 and A/ CCM pin 41 (16-way connector).
High speed operation at all times - LH blower
Cause:
1. Faulty high speed relay.
2. Faulty harness wiring.
Remedy:
1. Check the relay contact is not stuck 'ON'.
2. Check continuity of wiring harness between blower motor pin 8 and ground, pin 10 and A / CCM pin 50
(16-way connector) and pin 13 and A / CCM pin 49 (16-way connector).
14.7.23 Water Valve
For mechanical diagnosis of the water valve, refer to section 14 of the Vehicle Service Manual.
The solenoid coil fitted to the water valve housing has
a resistance of 17.4Q f 1P at 5 - 35 "C.
Check the continuity between pin 2 water valve white 2-way multi-plug and the A/ CCM (pin 52,26-way connector).
Check for ground
at pin 1 water valve white 2-way multi-plug.
14.7.24 Wafer Pump
Disconnect the black 2-way connector.
The motor operation can be checked by applying battery voltage to pin 1, motor 2
-way connector, and ground to pin 2.
Inspect the harness for open circuit or short circuit to ground. Rectify as necessary. If no harness faults are apparent,
renew the
A / CCM.
CAUTION: If removed the water pump should not be operated dry, and for a maximum of five minutes when wet. Failing to observe this may result in pump rotor and shaft damage.
The application of reverse polarity voltage at pins 1 and 2 will result in damage to the pumps internal cir-
cuitry.
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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
JOS 1776
1. Instrument Pack 7. Powerwash Relay
2. Body Processor Unit
(BPU) 8. Washer Fluid Level Sensor
3. Oil Pressure Sensor 9. Brake Fluid Level Sensor
4. Coolant Level Sensor 10. Ignition Switch 5. Coolant Temperature Sensor 11. Column Switch
6. Coolant Recirculation Pump Relay 12. Fuel Tank Level Sensor
Fig. 1 Component Location Diagram

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.

n E I ectr ical
2A. Seat movement motors (memory seats)
a.
b.
Check motor operation is not obstructed, and that mechanical linkage is not damaged
or disconnected.
Examine wiring harness, checking continuity between SCM Connector
A1 and motor
unit connector pins as follows:
SCM Motor Function Unit Pin
Pin 8 Seat forward 1
Pin
7 Seat rearward 3
Pin 5 Seat rear raise 1
Pin
6 Seat rear lower 3
Pin 3 Seat front raise 1
Pin
4 Seat front lower 3
Check resistance between motor pins 1 and 3, a value of approximately 2S2 should be
indicated.
Check motor position potentiometer as described in test
4.
C.
d.
28. Seat movement motor (manual seats)
a.
b.
C.
d.
Check motor operation is not obstructed, and that mechanical linkage is not damaged
or disconnected.
Check continuity from motor connector pins (1
& 3) to each relay contact connector
(pin
3, raise relay, pin 8, lower relay) respectively.
Check power supply
(+12V) from LH 'A' post base fuse box, fuse F6, to seat switch
connector pin
9.
Check power supply (+12V) from RH 'A' post base fuse box, fuse F3, to pin 5, raise relay
connector and pin 10, lower relay connector.
Check continuity from switch pack connector pin
4 to raise relay connector pin 5 and
from switch pack connector pin 5 to lower relay connector pin
6
Check continuity to ground from raise relay connector pins 2 and 4 and lower relay
connector pins
7 and 9
e.
f.
3. Seat squab 1 headrest motors
a.
b.
Check motor operation is not obstructed, and that mechanical linkage is not damaged
or disconnected.
Examine wiring harness, checking continuity between SCM Connector
A1 and motor
unit connector pins as follows:
SCM Motor Pin
Pin 1 Squab recline 1 incline +ve 3
Pin 2 Squab recline 1 incline -ve 1
Pin 11 Headrest raise
1 lower +ve 1
Pin 12 Headrest raise
1 lower -ve 3
Check resistance between motor pins 1 and 3; a value of approximately 28 should be
indicated.
Check motor position potentiometers as described in step
4.
C.
d.
Issue 1 August 1994 15.4 - 20 X300 EDM

68. Heating (manual seats)
0 a. Examine harness wiring, checking fuse F9 in RH 'A' post base fuse box.
Ensure continuity between heater relay connector pin 85 and BPU yellow 48
-way
connector pin 23. Measure resistance from heater relay pin 87 and console switch
connector pin 10.
Check continuity from BPU black 48
-way connector B pin 38 to center console seat
heater switch module connector pin
4. Operate switch and check continuity from
BPU black 48
-way connector pin 38 to ground.
Check for
+12V supply at seat heater relay connector pins 30 and 86.
Check continuity between cushion heater module and squab module pins; resistance
values
of 1.0-2.052 and 0.5-1.252 respectively should be achieved. Ensure secure
ground connection from squab connector pin 3.
Check continuity from console switch connector pin
10 through console switch LED to
ground;
a resistance value of 0-0.5Q should be recorded.
b.
C.
d.
e.
I' T
I 19 15 16
17 OK
J86 - 1873
Fig. 1 Manual Seat Heaters
Issue 1 August 1994 X300 EDM 15.4 - 25

E I ect r ica I rl
15.4.9.16 Key to schematic diagrams
I 2
I 3
i 7
, I 13
14
a1 15
j
20
p
23
30
Description
Seat control modules (driver and passenger side)
RH ,'A' post base fuse-box
LH
,'A' post base fuse-box
Head restraint motor and potentiometer
Squab recline motor and potentiometer
Seat movement motor
- fore 1 aft - and potentiometer
Seat movement motor
- rear raise 1 lower - and potentiometer
Seat movement motor
- front raise 1 lower - and potentiometer
Seat raise lower motor (manual seats)
Seat switch pack
Seat raise relay (manual seats)
Seat lower relay (manual seats)
Seat raise
/ lower selector switch (manual seats)
Lumbar pump unit
14.1 Pump
14.2 Solenoid valve
14.3 Pressure switch
Seat cushion heater
15.1 Thermostat
15.2 Inner cushion element
15.3 Outer cushion element
Squab cushion heater
Center console switch unit
17.1 Switch LED
17.2 Heatina select switch
Body processor unit
Heater relay (manual seat)
Column
tilt motor and potentiometer
Column reach motor and potentiometer
Column
I mirror control module
Column switches
23.1 Joystick
23.2 Passenger's rear view mirror up
I down motor and potentiometer
Passenger's rear view mirror left
I right motor and potentiometer
Mode switch (exit
I entry)
Driver's rear view mirror up
I down motor and potentiometer
Driver's rear view mirror left
1 right motor and potentiometer
Driver's door switch pack
Mirror polarity select switch
Mirror joystick
X300 EDM 15.4 - 35 Issue 1 August 1994