LED

Fault Diagnosis, LED

Fault symptom
The LED does not light up







Diagnostic procedure
1 Check the operation of the LED
- Connect an Intelligent Saab Tester (ISAT) scan tool.
- Select "ACTIVATE".
- Select "LED"
- Select "ON".
The LED should light up.
Does it light up?
[YES] The fault is of intermittent nature, proceed to point 6.
[No] Continue with point 2.

2 Check the operation of the LED
- Unplug the LED.
- Connect the test lamp to the LED's 2-pin connector.
- Repeat the ISAT scan tool command as in point 1.
The test lamp should light up.
Does it light up?
[YES] Change the LED.
[NO] Continue with point 3.






3 Check the LED'S power supply
- Unplug connector H33-i.
- Connect the test lamp to pin 29 of connector H33-1 and a good grounding point.
- Repeat the ISAT scan tool command as in point 1.
The test lamp should light up.
Does it light up?
[YES] Continue with point-4.
[NO] Proceed to point 5.

4 Check the LED wiring
Check the wiring harness for continuity between
- pin 29 of connector H33-1 and pin 2 of the LED's 2-pin connector.
- pin 1 of the LED's 2-pin connector and grounding point G34S.
The resistance should be < 1 ohm.
Is the resistance OK?
[YES] Proceed to point 6.
[NO] Repair or replace the wiring harness.







5 Check the wiring connected to the electronic control module
Check the wiring harness for continuity between pin 29 of connector H33-1 and pin 2 of the electronic control module.
The resistance should be < 1 ohm.
Is the resistance OK?
[YES] Continue with point 6.
[NO] Repair or replace the wiring harness.

6 Final test
Check to see if the fault symptom persists.
Does the trouble persist?
[YES] Continue as described in "Before Changing The Electronic Control Module".
[NO] The remedial measures taken were correct or the fault is of intermittent nature.