P0151 Jeep Grand Cherokee - O2 Sensor 2/1 Circuit Low | Step-by-Step Diagnosis

P0151 (O2 Sensor 2/1 Circuit Low) on a Jeep Grand Cherokee? This video walks through the complete 8-step factory diagnostic procedure with the wiring diagram and connector views - no guesswork, no parts cannon.

When monitored: Engine running for less than 30 seconds and the O2 Sensor Heater Temperature is less than 251°C (484°F) with battery voltage greater 10.99 volts.
Set condition: The oxygen sensor signal voltage is below 2.5196 volts for 3 seconds after starting engine. Two Trip Fault. Three good trips to turn off the MIL.

In this video:
1. O2 Sensor Below 2.52 Volts
2. (K43) O2 2/1 Signal Circuit
3. O2 Sensor
4. (K902) O2 Return Upstream Circuit Shorted To Ground
5. (K43) O2 2/1 Signal Circuit Shorted To Ground
6. (K43) O2 2/1 Signal Circuit Shorted To The (K902) O2 Return Upstream Circuit
7. (K43) O2 2/1 Signal Circuit Shorted To The (Z42) Heater Ground Circuit
8. PCM

Possible causes covered: (K902) O2 Return Upstream Circuit Shorted To Ground; (K43) O2 2/1 Signal Circuit Shorted To Ground; (K43) O2 2/1 Signal Circuit Shorted To The (K902) O2 Return Upstream Circuit; (K43) O2 2/1 Signal Circuit Shorted To The (Z42) Heater Ground Circuit; O2 Sensor; PCM.

Applies to the Jeep Grand Cherokee third generation (WK, 2005-2010) with the 3.7L V6, 4.7L V8 and 5.7L HEMI V8 (and SRT-8 6.1L). Much of the diagnostic logic is shared with the related Jeep Commander (XK) of the same era.

This is general information for educational purposes - always confirm against the service information for your exact vehicle.

Видео P0151 Jeep Grand Cherokee - O2 Sensor 2/1 Circuit Low | Step-by-Step Diagnosis канала Diagnostic Trouble Codes