P0036HO2S Heater Control Circuit (Bank 1 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
- The heated oxygen sensor on bank 1 is the downstream sensor 2 behind the (first) catalytic converter, used mainly to monitor the converter. Its heating element brings it quickly to operating temperature. Typically the heater receives battery voltage via a fuse, and the engine control module switches the ground side with a pulsed signal while checking that the circuit state matches the command. P0036 is the general circuit fault: the measured state of the heater circuit does not fit the command, most often because the circuit is interrupted. Which physical fault sets the general, low or high code is defined by each manufacturer. Without heating, the sensor becomes ready late and catalyst monitoring may not complete.
- What you may notice
- Check engine light on
- Usually no noticeable drivability problem
- Catalyst monitor does not complete
- Emissions test or readiness check failed
- Likely causes
- LikelyHeating element inside the sensor burnt out
- LikelyWire or connector damaged by heat or road spray
- PossibleHeater fuse blown; a shared fuse can set several heater codes
- RareOutput driver or software of the engine control module
- 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: €80 – €350
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.