OBD-II · Engine and powertrain (P)
P0152
Oxygen sensor high voltage bank 2 sensor 1
What it means
The upstream lambda sensor circuit on bank 2 reports voltage above the permitted threshold. Distinguish an electrical fault from a genuine mixture problem using the OEM test for the fitted sensor type. Confirm bank 2's location in the engine's service information.
Symptoms
- engine warning light
- higher fuel consumption
- possible hesitation or uneven running
- may fail the emissions part of the roadworthiness test
Likely causes, most likely first
| No. | Cause |
|---|---|
| 01 | rich mixture (leaking injector, purge valve stuck open) |
| 02 | faulty lambda sensor |
| 03 | signal wire short to voltage |
| 04 | fuel pressure too high |
| 05 | sensor contaminated by coolant or oil |
What to check, step by step
- 01Read fuel trims: if the ECU is removing fuel, find the rich cause first (purge valve, injectors, fuel pressure)
- 02Check for fuel-diluted oil and for unexplained coolant loss that could contaminate the sensor
- 03Check the signal wire for a short to voltage, including a heater-to-signal short inside the sensor
- 04Replace the sensor if the mixture and wiring are fine