P0C44Hybrid/EV Battery Pack Coolant Temperature Sensor A 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
- P0C44 reports that the voltage of battery coolant temperature sensor A is too low. The sensor is an NTC thermistor, so a low voltage translates into a very hot reading, and a short to ground or a shorted element is the classic cause. GM documents the code in the battery energy control module: the 2011 Chevrolet Volt sets it when the inlet coolant value reaches 87.9 °C (ADC count 130 or less), the 2019 hybrid tables use the same temperature at an ADC count of 133 or less. The fault must be present for 1.75 s within a 2.5 s window; as a Type B code it turns on the MIL after the second trip. Because the controller can no longer trust the coolant value, it may limit battery power. P0C45 is the high counterpart, P0C42 the generic circuit code.
- What you may notice
- MIL and hybrid or EV system message
- Coolant temperature shown implausibly high in live data
- Limited charging or drive power
- Likely causes
- LikelySensor signal wire chafed through and shorted to ground
- PossibleInternally shorted coolant temperature sensor
- RareCoolant or water in the connector bridging the pins
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €60 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.