LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 1989 >> Van Base, Van Window, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Basic Testing - 4-CYL EFI >> Fuel Pressure >> Fuel Pump Control Circuit >> Circuit Opening Relay
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Circuit Opening Relay

  1. 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.
  2. Starter signal energizes circuit opening relay during cranking, which in turn activates the fuel pump. On all except Corolla (4A-FE) when airflow meter senses airflow to engine, fuel pump switch in airflow meter provides the relay ground. On Corolla (4A-FE) and Supra (7M-GTE), circuit opening relay is grounded by ECU through "FC" terminal.
  3. On Van only, the fuel pump check connector is wired through the circuit opening relay. See Figure. When fuel pump check connector is jumpered with ignition on, the circuit opening relay is turned on. This in turn, activates the fuel pump.
scientia non olet · About LEMON Manuals