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Circuit Opening Relay

WARNING: This page is about a different car, the 1993 Toyota MR2. However, it is still accessible from the selected car via links, so may be relevant.

Circuit opening relay controls fuel pump circuit. The Engine Control Module (ECM) 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. Circuit opening relay then provides voltage to fuel pump or fuel pump relay. Fuel pump relay is used on Turbo only.

Circuit opening relay is grounded by the ECM through the FC terminal. On all other models, fuel pump switch in airflow meter provides ground for circuit opening relay. Circuit opening relay and fuel pump relay are located in different locations. See Figure & 2.

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