P0A00Motor Electronics Coolant Temperature Sensor A Circuit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- General circuit fault on temperature sensor A in the separate coolant loop that cools the inverter and other drive electronics of a hybrid or electric vehicle. The module flags it when the sensor signal cannot be used at all, without a more specific low, high or plausibility verdict; those cases have their own codes P0A01 to P0A04. No manufacturer documents P0A00 publicly. GM's Two-Mode hybrid trucks monitor the same sensor only through P0A01 to P0A03, and CARB requires every input of the inverter thermal management to be checked for circuit faults. Without a valid reading the control unit usually limits electric drive power to protect the electronics.
- What you may notice
- Hybrid system or check engine warning light
- Reduced electric drive power
- Inverter coolant pump or radiator fan running constantly as a precaution
- Likely causes
- LikelyCorroded or loose connector at the sensor in the inverter coolant loop
- PossibleTemperature sensor element failed
- PossibleDamaged signal or reference wire between sensor and hybrid control module
- RareFault in the input stage of the hybrid or inverter control 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: €80 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.