P0C43 code meaning
Hybrid/EV Battery Pack Coolant Temperature Sensor A Circuit Range/Performance
Powertrain system Generic code P0Cxx codes Check engine light
What P0C43 means
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.
P0C43 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyHard
- Typical labor0.5 to 2.5 hours
- Clears after repairAfter a drive cycle
Symptoms of P0C43
- MIL after a cold start, often with no other complaint
- Battery thermal management working on substitute values
Common causes of P0C43
- Most likelyToo tight plausibility limits in the control software (Audi Q5 TFSI e, update 80C9)
- PossibleCoolant sensor A drifting away from its characteristic
- Less likelyAdded resistance in the sensor circuit shifting the reading
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hv battery pack coolant temp sensor aWiring harnessBms
What each part of P0C43 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| C | Area: hybrid propulsion. |
| 43 | The exact fault in that area. |
What to do next
- Note P0C43 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0C43
What does P0C43 mean?
P0C43 means "Hybrid/EV Battery Pack Coolant Temperature Sensor A Circuit Range/Performance". P0C43 flags battery coolant temperature sensor A as electrically valid but not believable. It is a generic code, so it means the same on every make.
Is it safe to drive with P0C43?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P0C43 fail an emissions test?
Yes, it can. P0C43 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0C43 to fix?
Difficulty: hard. A typical repair takes 0.5 to 2.5 hours of work. This is a job for a workshop.
Will P0C43 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.