P0053HO2S Heater Resistance Bank 1 Sensor 1
- 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
- On bank 1, this monitor checks the heating element of the upstream sensor (sensor 1, before the catalytic converter) not for an open or short circuit, but for its resistance. Many systems measure it once after a genuine cold start, when coolant and intake air temperatures show that the sensor is at ambient temperature, and correct the value for temperature; some manufacturers evaluate the heater current instead. The code is set when the value lies outside the limits for this sensor type, typically because the element has aged. Since the test often runs only after a long standstill, the code may take a night to confirm or clear.
- What you may notice
- Check engine light on, sometimes only after a cold start
- Readiness for the sensor heater stays incomplete
- Usually no drivability symptoms
- Likely causes
- LikelyHeating element aged or partly damaged
- PossibleContact resistance or corrosion at connector or pins
- PossibleReplacement sensor with a different heater type fitted
- RareEngine control module faulty
- 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.