P2C64O2 Sensor Pumping Current Trim Circuit High Bank 1 Sensor 3
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P2C64 is the high-side partner of P2C63: the oxygen reading attributed to sensor 3 of bank 1 climbs above what the probe can physically deliver. On GM's 3.0L Duramax diesel the value comes from NOx sensor 3 behind the second catalyst, and table 25OBDG04B sets the code once that O2 reading exceeds 29 percent, clearly more than the roughly 21 percent of fresh air, in 100 of 200 samples under the same enable conditions as the low check; Type B, MIL after two trips. Such a figure hints at a signal fault in the sensor or its wiring rather than real exhaust oxygen. The harness bulletins PIT5751C and 21-NA-149 for 2020-21 GM models with the 3.0L LM2 list P2C64 as well. P2C62 is the open circuit, P23AF the NOx circuit high code of the same sensor.
- What you may notice
- MIL on after two trips
- Further NOx sensor or aftertreatment codes stored
- Likely causes
- LikelyThird exhaust sensor (on GM diesels NOx sensor 3) delivering an implausibly high O2 value
- PossibleEngine harness chafed or shorted (GM 3.0L LM2, PIT5751C)
- RareMoisture or 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 · Usually a job for a workshop.Typical cost: €50 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.