P0C45Hybrid/EV Battery Pack Coolant Temperature Sensor A Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0C45 indicates that the signal of battery coolant temperature sensor A sits near the reference voltage. On an NTC circuit with pull-up this looks like extreme cold and usually comes from an open circuit, an unplugged connector or a short to voltage. GM uses the code in the battery energy control module: the 2011 Chevrolet Volt fails the test below -40 °C at an ADC count above 3823, the 2019 hybrid tables at a count above 3890. In both cases 1.75 s within 2.5 s are needed, and the Type B rating lights the MIL after two trips. With the inlet reading lost, the controller runs the battery cooling and heating on substitute values and may cut power in hot or cold weather. The low counterpart is P0C44; sensor B reports the same fault as P0CD8.
- What you may notice
- MIL after two trips
- Coolant temperature shown at about -40 °C in live data
- Reduced charging power in extreme temperatures
- Likely causes
- LikelyOpen signal or ground wire, or connector not latched
- PossibleCoolant temperature sensor open internally
- RareSignal wire shorted to a voltage source
- 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.