P0A00 code meaning
Motor Electronics Coolant Temperature Sensor A Circuit
Powertrain system Generic code P0Axx codes Check engine light
What P0A00 means
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.
P0A00 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0A00
- Hybrid system or check engine warning light
- Reduced electric drive power
- Inverter coolant pump or radiator fan running constantly as a precaution
Common causes of P0A00
- Most 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
- Less likelyFault in the input stage of the hybrid or inverter control module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Motor electronics coolant temperature sensorHybrid inverterWiring harness
What each part of P0A00 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| A | Area: hybrid propulsion. |
| 00 | The exact fault in that area. |
What to do next
- Note P0A00 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 P0A00
What does P0A00 mean?
P0A00 means "Motor Electronics Coolant Temperature Sensor A Circuit". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P0A00?
Drive gently and only to a workshop. With P0A00 the car can go into limp mode (reduced power) to protect itself.
Will P0A00 fail an emissions test?
Yes, it can. P0A00 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 P0A00 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P0A00 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.