Circuit Opening Relay
WARNING: This page is about a different car, the 1989 Toyota Pickup, 1989 Toyota Camry, 1989 Toyota Cab & Chassis, and 1989 Toyota 4Runner. However, it is still accessible from the selected car via links, so may be relevant.
- Circuit opening relay controls fuel pump circuit. ECU receives an input signal at "STA" terminal when engine is cranking. This same starter signal is also applied to terminal "STA" of circuit opening relay.
- Starter signal energizes circuit opening relay during cranking, which in turn activates the fuel pump. On all models, when airflow meter senses airflow to engine, fuel pump switch in airflow meter provides the relay ground.
NOTE:
For more information on testing relays and fuel system components, see I - EFI SYS/COMP TESTS article.