Ignition Relay Diagnosis

Ignition Relay Diagnosis:

CIRCUIT DESCRIPTION
The ignition relay is the positive voltage supply source for the following components:
^ The gas mass sensor/mixture control valve (GMS/MCV)
^ The fuel gauge select switch

The ignition relay coil is energized when the ignition switch is turned to the run or start positions. The ignition relay switch contact is supplied voltage at all times.

TEST DESCRIPTION

Steps 1-9:

Steps 10-19:

Steps 20-22:

The numbers below refer to the step numbers on the diagnostic table.
1. The System Check MUST be performed before proceeding with this diagnostic table. Failure to perform the System Check will result in mis-diagnosis.
3. This step tests the AF ECU fuses for opens and also tests the voltage supply to the fuses.
5. This step tests the battery positive and switched ignition voltage circuits to the AF ECU.
6. This step tests the AF ECU ground circuits.
7. This step inspects for proper operation of the FIL. If the FIL illuminates then the ignition relay is ON.
9. This step inspects the ignition relays ability to turn OFF.
12. This step tests the Ignition Relay coils ground circuit. If the test lamp illuminates then the Ignition relay must be faulty.
13. This step indicates the components or circuits that may have caused a fuse to blow. Some components may require they be turned ON in order to blow the fuse. An example would be depressing the fuel gauge select switch in order to test the select switch circuit for a short.