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

Fig. 31 Circuit opening relay terminal identification:

Circuit Opening Relay

1. On all except Van and Camry, remove right kick panel. On Camry, remove glove box.
2. Remove relay from mounting bracket (located on radiator support on Van), leaving connectors connected.
3. Insert positive probe of voltmeter into rear of connector at Fp terminal and ensure that meter indicates voltage during cranking and with engine running.
4. Disconnect electrical connector from relay and check resistance between relay terminals, Fig. 31.
5. Meter should read 17-25 ohms between terminals STA and E1, 88-112 ohms between B and Fc and should indicate no continuity between B and Fp.
6. If readings are not as indicated, relay is defective.

Fig. 32 Main relay terminal identification:

Main Relay

On Celica models, 2 main relays are used. Relay No. 1 is at left front of engine compartment and relay No. 2 is mounted on right inner fender.
1. On Pickup, remove left kick panel; on Camry, remove engine main relay from panel at left front of engine compartment.
2. Turn ignition on while listening to relay. An audible click should be heard as relay is energized.
3. Remove relay and check resistance between terminals, Fig. 32.
4. Meter should read 40-60 ohms between terminals 1 and 2 on all except Celica relay No. 2, 60-120 ohms between terminals 1 and 2 and on relay No. 2, and meter should indicate no continuity between terminals 3 and 4.
5. If readings are not as specified, or if relay fails to operate when energized, relay is defective.