P2BDDMotor Electronics Coolant Temperature Sensor C Circuit Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2BDD is the plausibility check of coolant temperature sensor C: electrically the signal looks fine, but the reported value cannot be right when set against other temperatures. No manufacturer documents P2BDD publicly. Two published approaches show how such a check can run while driving instead of after a cold soak. GM's 2011 Volt compares its electronics coolant sensor with the high-voltage charger temperature and flags a gap above 38 °C while the inverter module requests pump operation, or 40 °C otherwise, in 32 of 40 samples at 250 ms, Type B. A Nissan patent compares the inverter power element temperature with the coolant reading and applies a tighter limit when the element appears colder than the water, which physics rules out. Hard faults of sensor C are P2BDE and P2BDF.
- What you may notice
- Check engine light without an obvious drivability problem
- Cooling fan behaviour that does not match the conditions
- Power or charging limitation under heavy load
- Likely causes
- LikelySensor C reading drifted away from the true coolant temperature
- PossibleAir or weak flow at the sensor C location, so it sees a local hot or cold spot
- PossibleCorroded terminals adding resistance in the sensor C circuit
- RareFaulty comparison temperature from another sensor in the system
- 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: €60 – €500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.