1994 JAGUAR XJ6 oil pressure

E I ect r ical
15.2.3 COMPONENT DESCRIPTION
15.2.3.1 Speedometer
The speed indication input signal, sent as a pulse rate, is generated by an open collectortransistor within the ABS con- trol module. The instrument pack converts the frequency of this signal to drive the speedometer and to provide two
road speed outputs:
Speed output
1 (pin 2,48 way connector)
This output is connected to the radio head unit, security control module and the power steering module.
Speed output 2 (pin
3,48 way connector)
This output is connected to the body processor unit, cruise control control module, air conditioning control module
and the engine management system.
15.2.3.2 Tachometer
The tachometer input, all engine variants, is provided by the engine management control module. When the engine
is running the control module generates three high state pulses per engine revolution.
15.2.3.3
This signal comes direct from the variable resistance type oil pressure sensor, mounted on the engine. The sensor
resistance values range from 75Q (8 Bar) to 330Q (0 Bar).
When the gauge reaches
a pre-determined reading the instrument pack illuminates the warning light.
Engine Oil Pressure and Warning lamp
15.2.3.4 Engine Coolant Temperature
This signal comes direct from the coolant temperature sensor (variable resistance type), mounted on the engine. The
sensor resistance values range from 34Q (hot) to 241Q (cold), when disconnected from the vehicle.
Note: The coolant temperature gauge is calibrated to indicate at approximately 'Normal' for a wide range of normal
engine operating temperatures.
15.2.3.5 Fuel Tank level Gauge and Warning lamp
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.
15.2.3.6
Battery voltage is displayed on the gauge by measuring the ignition voltage.
The red charge warning lamp will illuminate if either the voltage is too low (below
10.5V) or too high (above 15.5V). In addition, the generator provides a low signal to the instrument pack (pin 9,48-way connector) when battery charging
is unsatisfactory.
Battery Voltage Gauge and Warning lamp
15.2.3.7 Liquid Crystal Display
A single line, six digit, 7 segment display with six trip function flags used for odometer, trip computer and driver mess- ages.
!Y,Q&: If the instrument pack has not been PECUS programmed, the back illumination of the LCD will not switch on.
Check that a PECUS label is attached to the back of the pack.
Issue 1 August 1994 15.2 - 4 X300 EDM

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

rl E I ect r ica I
15.2.8 INSTRUMENT PACK PIN-POINT TESTS
15.2.8.1 Oil Pressure, Battery Condition, Coolant Temperature and Fuel Gauges
Gauge reads zero, full scale, too high or low
1.
2.
3. Oil
pressure and coolant gauges only; check relevant fluid level is within limits, top up if required and re-check
indication. If fluid levels are within limits on checking proceed to step 2.
Check connections to sensor are correct and secure. For battery gauge only check battery voltage is present at the
battery terminal posts.
Check resistance of sensor (if applicable) to ground, correct readings are as detailed in the following table:
Sensor title Resistance value
Oil pressure 3108 - 3308
Temperature
Fuel level 3461
(warm engine)
- 2418 (cold engine)
8061 (full tank) - 9008 (empty tank)
If resistance is out of range renew sensor.
If sensor resistance is proved correct, check the harness wiring continuity between the sensor and instrument pack
pin as detailed in the table below:
4.
I Sensor title I Instrument pack pin !
I Oil pressure I 21 (24-way connector) I Temperature I 19 (24-way connector) I
Fuel level 120 (24-way connector)
For battery condition gauge, checkvoltage between instrument pack 24
-way connector pins 2 and 4 is 13 f 2.5V. Refer to Section 15.5 for battery diagnostics.
If all previous checks prove correct remove and open the instrument pack. Examine flexi-circuit connections to
relevant gauge, ensuring correct and secure fitment.
Check continuity of flexi
-circuit tracks to gauge connections.
Check continuity of gauge driver windings by disconnecting gauge from flexi
-circuit and testing between the
upper central connection pin and each of the other two pins. If open circuit is recorded renew gauge.
5.
6.
7.
Gauge fluctuates
or gives erratic readings
1. Carry out steps 1 -4 above.
2.
Fit new sensor (where applicable) and re-check gauge.
3. Carry out steps 5
- 7 above
15.2.8.2 Speedometer
Gauge reads zero, full scale, too high or low
1.
2.
3.
4.
5. Refer
to Section 12,
ABS / Traction Control for fault diagnosis of wheel speed sensor.
Check harness wirin and connection from Instrument pack pin 15 (24
-way connector) and ABS /Traction Control
Control Module (AB!! /TC CM).
If all previous checks prove correct remove and open the instrument pack. Examine flexi
-circuit connections to
speedometer, ensuring correct and secure fitment.
Check continuity of flexi
-circuit tracks to speedometer connections.
Check continuity of speedometer driver windings by disconnecting from flexi
-circuit and testing between the
upper central connection pin and each of the other two pins. If open circuit is recorded renew speedometer.