Engine Temperature Display

Fault symptom
Engine temperature display not working.

Temperature gauge in min. position, see point 1.

Temperature gauge/tank gauge i max. position, see point 2.

Temperature meter/fuel meter in min. position. Rheostat in min. position (light on) causes the right-hand direction indicator lamp to "glow". Rheostat in max. position causes the right-hand direction indicator lamp to light brightly. The temperature gauge moves about 5 mm when the rheostat is changed from min. to max., see point 3.

Action
1 Connect the Intelligent Saab Tester (ISAT) and activate "ENGINE TEMP GAUGE and check that the values programmed in ° C in the ISAT correspond with the temperature gauge display.
Unplug the connector from the back of the temperature gauge. Measure the voltage on pin 7 of the temperature gauge. This should be between 1 and 9 V depending on the engine temperature.
If there is voltage, change the instrument.
If there is no voltage, check the cable assembly between pin 7 on the instrument and pin 30 on the Electronic Display Unit (EDU) control module for open/short circuit.
If the fault remains, proceed to "Action Before Changing A Control Module".






2 Unplug the connector from the back of the temperature gauge. Measure the voltage between pin 2 and ground. Should be about 1 V under battery positive voltage.
If there is voltage, change the temperature gauge.
If there is no voltage, check the cable assembly between control module pin 22 and temperature gauge pin 2 for open/short circuit.
If the fault remains, proceed to "Action Before Changing A Control Module".
3 Check the lead between temperature gauge pin 5 and grounding point G8 for open circuit. Localize and remedy the fault.
If the fault remains, change the fuel gauge.