Testing Air/Fuel (A/F) HTR Relay, Circuit Opening Relay, EFI Main Relay Or Starter Relay
WARNING: This page is about a different car, the 2003 Lexus RX 300 and 2003 Lexus ES 300. However, it is still accessible from the selected car via links, so may be relevant.
- Remove relay to be tested. On RX300, circuit opening relay (CIR OPN) may be located in fuse/relay box on left side of engine compartment or relay box under left side of instrument panel. On ES300, circuit opening relay is located in fuse/relay box on left side of engine compartment. On all models, A/F HTR relay, EFI main relay and starter relay are located in the main fuse/relay box on left side of engine compartment.
- Check for continuity between relay terminals No. 1 and 2. See Fig 1 or Fig 2 . Continuity should exist. Check for continuity between relay terminals No. 3 and 5. Continuity should not exist.
- Using jumper wires, apply battery voltage across relay terminals No. 1 and 2. Check for continuity between relay terminals No. 3 and 5 with relay energized. Continuity should exist. If continuity is not as specified, replace relay.