P0C43Hybrid/EV Battery Pack Coolant Temperature Sensor A Circuit Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P0C43 flags battery coolant temperature sensor A as electrically valid but not believable. GM's 2019 hybrid tables describe a cold-soak comparison: once all high-voltage contactors and the battery heater have been off for at least 14,400 s, the hybrid controller compares inlet coolant temperature with the average cell temperature and with outside air, failing when the gaps reach about 23 °C and 22 °C; 8 s out of 10 s set a Type B code, so the MIL follows on the second trip. Audi uses P0C4300 in the thermal management module of the 2020 Q5 TFSI e. Bulletin 2059530 and update 80C9 explain that the stored limits were set too tightly for everyday conditions, so the code and P0CE100 appeared without a defect; new software fixes it. CARB demands rationality checks for battery thermal inputs.
- What you may notice
- MIL after a cold start, often with no other complaint
- Battery thermal management working on substitute values
- Likely causes
- LikelyToo tight plausibility limits in the control software (Audi Q5 TFSI e, update 80C9)
- PossibleCoolant sensor A drifting away from its characteristic
- RareAdded resistance in the sensor circuit shifting the reading
- 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: €0 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.