Operation CHARM: Car repair manuals for everyone.

Main Relay (Computer/Fuel System): Testing and Inspection




Circuit Description
When the ignition is turned ON or to the START position, the ignition 1 relay is energized. The ignition 1 relay then supplies voltage to the engine fuse box fuse EF16 and the engine fuse box fuse EF17. The Electronic Ignition (EI) system ignition coil, and the evaporative emission canister purge solenoid are supplied voltage through the engine fuse box fuse EF16. The fuel injectors are supplied voltage through the engine fuse box fuse EF17.

Diagnostic Aids
- An intermittent problem may be caused by a poor connection, rubbed through wire insulation, or a broken wire inside the insulation.
- A faulty ignition 1 relay will cause a no start condition. There will be no voltage supplied to the EI system ignition coil, or the fuel injectors. Without voltage supplied to these components, they will not operate.

Steps 1 - 14:




Test Description
The number(s) below refer to specific step(s) on the diagnostic table.
1. If the test light is ON at both of the fuse terminals, the ignition 1 relay is OK.
5. This step, along with steps 6, 7, and 8, checks for correct voltage and ground to the ignition 1 relay terminals.
14. After confirming correct voltage and ground to the ignition 1 relay terminals, it can be determined that the ignition 1 relay is faulty.