Operation CHARM: Car repair manuals for everyone.

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




- If the circuit is open, the engine will not start.
- If the circuit is shorted, the EEC PWR fuse (30A) will burn out.

Inspection
1. Measure resistance between pins 85 and 86 of the relay.




Specification: 40-120 Ohms.

2. Measure resistance between pin 85 and both pins 30 and 87 of relay.

Specification: greater than 10,000 Ohms.

3. Apply battery voltage (B+) and check for continuity between terminals of the relay.




4. If not as specified, replace the PCM power relay.