P2236O2 Sensor Signal Circuit Shorted to Heater Circuit (Bank 2 Sensor 3)
- 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
- P2236 would be set if the heater of the third oxygen sensor on bank 2 leaked into its signal wire. Such a sensor sits furthest downstream and exists only on engines with two catalyst stages per bank. No manufacturer documents this code publicly, and Jaguar Land Rover's 2015 list for its V6 with sensors 3 on both banks does not use it either. The mechanism matches P2232/P2235: the heater is pulsed with battery voltage while the sensor signal stays below about 1 V, so any coupling shows up as a voltage step when the heater switches; GM uses more than 2 V within 0.04 s. CARB requires every monitored oxygen sensor circuit to be checked. P2233 is bank 1. Driving is unaffected; the lamp and a failed inspection are the consequences.
- What you may notice
- Check engine light with normal driving behaviour
- Readiness for catalyst or oxygen sensor monitor not set
- Likely causes
- LikelyInternal leakage between heater and sensing element of sensor 3 on bank 2
- PossibleLong underbody wiring to the rear sensor chafed or heat-damaged
- RareRoad salt corrosion in the 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.