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

Fig. 5 Main Relay Pin Locations.:

Fig. 6 Main Relay Pin Location.:

1. Measure resistance between terminals 1 and 2, Figs. 5 and 6. Resistance should be 40-100 ohms.
2. Ensure continuity does not exists between terminals 3 and 4, 1 and 3, 1 and 4, 2 and 3 or between terminals 2 and 4.
3. Supply battery power to terminals 1 and 2.
4. Ensure continuity exists between terminals 3 and 4.
5. If any test fails, replace main relay.
6. Perform main relay circuit test.

Fig. 42 ECU System Diagnosis, EFI Main Relay Check (Part 1 Of 2):

Fig. 42 ECU System Diagnosis, EFI Main Relay Check (Part 2 Of 2):