P2235O2 Sensor Signal Circuit Shorted to Heater Circuit (Bank 2 Sensor 2)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2235 concerns the post-catalyst oxygen sensor on bank 2, found on V engines with a catalyst per bank. The ECM sets it when switching off the heater makes the sensor voltage spike. GM runs the check only once the sensor is past its dew-point phase and the modelled exhaust has been above 250 °C for 90 s (and below 800 °C); the failure threshold, as for P2232, is a jump above 2 V within 0.04 s in more than 4 of 6 switch-offs. It appears in the 2005 2.8/3.6 V6 tables, the 2008 3.6 LLT tables and the 2024 set 24OBDG07, each with the MIL after two trips. Because the fault is tied to one sensor position, swapping banks is a quick plausibility check before parts are ordered. P2232 is bank 1, P2234 the front sensor of bank 2.
- What you may notice
- Check engine light after two drives
- Bank 2 catalyst monitor not completed
- Likely causes
- LikelyInternal leakage between heater and sensing element of the bank 2 rear sensor
- PossibleSensor wires damaged by heat or chafing near the bank 2 catalyst
- RareWater ingress in the rear sensor connector
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €60 – €280
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.