P2BDEMotor Electronics Coolant Temperature Sensor C Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2BDE reports that the voltage from coolant temperature sensor C has dropped below its lower limit. Low describes the voltage: for the usual NTC sensor it corresponds to a reading far hotter than the coolant can be, and the cause is mostly a grounded signal wire, a crushed pigtail or a sensor that has shorted internally. No manufacturer documents P2BDE publicly. GM's electronics coolant sensor in the Volt and ELR, monitored as P0CF0, shows typical limits: below 2 % of the 5 V reference (0.1 V) in the 2011 tables and below 4 % (0.2 V) in the 2016 Volt table, 16 of 20 samples at 250 ms, Type B. The open or high case is P2BDF, while the matching low fault of sensor B is P2BDA. Drive power may be limited as a precaution.
- What you may notice
- Hybrid warning or check engine light
- Very high electronics coolant temperature shown in live data on a cold vehicle
- Fan running at full speed shortly after start
- Likely causes
- LikelySensor C signal wire shorted to ground or to the sensor ground
- PossibleSensor C shorted internally
- PossibleCrushed or melted sensor pigtail near hot components
- RareFaulty analog input in the evaluating module
- 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.