LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 1990 >> Land Cruiser >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Basic Testing - EFI >> Fuel Pump Control Circuit Test >> 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 Celica, Corolla (4A-FE), Supra (7M-GTE) and Tercel, when airflow meter senses airflow to engine, fuel pump switch in airflow meter provides the relay ground. On Celica, Corolla (4A-FE), Supra (7M-GTE) and Tercel, circuit opening relay is grounded by ECU through FC terminal.
scientia non olet · About LEMON Manuals