Circuit Description
WARNING: This page is about a different car, the 2003 Toyota 4Runner. However, it is still accessible from the selected car via links, so may be relevant.
Heated Oxygen Sensor (HO2S) monitors exhaust gas oxygen content and delivers input signals to ECM. HO2S is located on exhaust pipe in front of catalytic converter. ECM uses input signals to determine fuel injection system operation. DTC is set when oxygen sensor output voltage does not change after engine is started with engine at normal operating temperature. Possible causes are:
- HO2S (bank 1 or 2, sensor 1) circuit is open or shorted.
- Defective HO2S (bank 1 or 2, sensor 1).
- Defective HO2S heater (bank 1 or 2, sensor 1).
- Air induction system malfunction.
- Improper fuel pressure.
- Defective fuel injector.
- Vehicle has run out of fuel.
- Defective ECM.