Fuel Level

Fault symptom
The fuel gauge shows zero, the range indicator is normal and the fuel level sensor signal is correct (read tank contents using Intelligent Saab Tester (ISAT)). see point 1.

Fuel gauge/temperature gauge in max position, range meter normal and fuel level sensor signal correct (read lank contents using ISAT), see point 2.

Fuel meter/temperature 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 ISAT, activate "FUEL GAUGE" and check that those values programmed in liters in ISAT correspond with the fuel gauge display.
Unplug the connector from the back of the fuel gauge and measure the voltage between pin 1 and ground.
With the ignition on, the voltage should be between 1 V (empty tank) and 8.25 V (full tank). If there is a voltage between about 1 - 8.25 V, the fault is in the fuel gauge and this should be changed.
If there is no voltage, test between pin 1 on the instrument and pin 24 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 fuel gauge. Measure the voltage between pin 2 and ground. This should be 1 V under battery positive voltage.
If there is voltage, change the fuel gauge.
If there is no voltage, check the cable assembly between pin 22 on the control module and pin 2 on the fuel gauge connector for open/short circuit.
If the fault remains, proceed to "Action Before Changing A Control Module".
3 Check the lead between pin 5 on the fuel gauge connector and grounding point G8.