P1172

DTC P1172: A/F Sensor (Sensor 1) Out of Range High

1. Record this freeze data:

- Engine speed
- Vehicle speed
- Throttle position
- CLV
- Gear position

2. Reset the ECM with the HDS.
3. Start the engine. Hold the engine speed at 3,000 rpm with no load (in Park or neutral) until the radiator fan comes on, then let it idle.
4. Test-drive the vehicle in the range of the recorded freeze data.
5. Check for Temporary DTCs or DTCs with the HDS

Is DTC P1172 or P1171 indicated?

YES - Replace A/F sensor (Sensor 1).

NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the ECM.