P0153
O2 Sensor Circuit High Voltage (Bank 2 Sensor 1)
The ECU detects an abnormally high voltage from the upstream O2 sensor on bank 2. Indicates persistently rich exhaust, shorted sensor or wiring shorted to voltage.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: easy
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Common causes
Ordered by how often each turns out to be the cause.
- Bank 2 running rich (leaking injector, high fuel pressure)Common
- Signal wire shorted to voltagePossible
- Upstream O2 sensor failedPossible
Parts involved
- Oxygen Sensor B2s1
- Oxygen Sensor Wiring
- Fuel Injector Bank2
P0153 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.