Circuit Opening Relay
- Circuit opening relay controls fuel pump circuit. The Electronic Control Unit (ECU) receives an input signal at STA terminal when engine is cranking. Starter signal is also applied to terminal STA of circuit opening relay.
- Starter signal energizes circuit opening relay during cranking. The circuit opening relay then provides voltage to the fuel pump or fuel pump relay. Fuel pump relay is used on Cressida and Supra.
- On all models except Supra Turbo, fuel pump switch in airflow meter provides the ground for circuit opening relay. On all other models, circuit opening relay is grounded by the ECU through the FC terminal.