P2212NOx Sensor Heater Sense Circuit Intermittent (Bank 1 Sensor 1)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- Besides driving the heater, the upstream NOx sensor on bank 1 has a sense path that reports back how the heater actually responds; GM measures heater resistance on a separate HTemp pin. P2212 means this feedback keeps dropping out or jumping instead of failing for good. No manufacturer publishes thresholds for P2212; GM's 3.0L LZ0 tables cover only the steady cases (P2208 open, P2210 short to ground, P2211 short to power). CARB requires heater circuit faults that contradict the commanded state to be caught. Typical causes are a loose contact or cracked lead that opens with heat or vibration. P2209 is a plausible but poor heater response; P2205-P2207 concern the control side. The MIL may come and go.
- What you may notice
- Malfunction indicator lamp on, possibly intermittent
- Upstream NOx value briefly invalid
- Likely causes
- LikelyLoose or corroded contact in the NOx sensor connector
- PossibleCracked conductor in the probe lead that opens with heat or vibration
- PossibleIntermittent fault in the sensor module's heater measurement
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €50 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.