P0ACE code meaning
Hybrid/EV Battery Temperature Sensor C Circuit Intermittent/Erratic
Powertrain system Generic code P0Axx codes Check engine light
What P0ACE means
P0ACE flags erratic behaviour of battery temperature sensor C, meaning the reading jumps faster than the heavy battery mass could ever warm or cool. In GM's 2016 and 2019 hybrid tables the controller sums the absolute changes of the sensor value across a 10-sample window taken every 100 ms; a sum above 10 fails the window, and 4 failed windows out of 5 store the code as Type B, two trips. This is the same logic GM uses for sensors A and B. The older two-mode and 2013 programs do not list an erratic code for sensor C. Typical culprits are a loose terminal, a partly broken wire or a connector not fully latched after pack service. Several jumping sensors at once point to the sensing board.
P0ACE at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor1 to 5 hours
- Clears after repairAfter a drive cycle
Symptoms of P0ACE
- Hybrid warning light that appears intermittently
- Sensor C value jumps in live data
- Occasional power limitation
Common causes of P0ACE
- Most likelyLoose terminal or unlatched connector at sensor C
- PossiblePartly broken sensor wire inside the pack
- Less likelyFault on the battery sensing board affecting several inputs
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hv battery temp sensor cWiring harnessBms
What each part of P0ACE 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. |
| CE | The exact fault in that area. |
What to do next
- Note P0ACE 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 P0ACE
What does P0ACE mean?
P0ACE means "Hybrid/EV Battery Temperature Sensor C Circuit Intermittent/Erratic". P0ACE flags erratic behaviour of battery temperature sensor C, meaning the reading jumps faster than the heavy battery mass could ever warm or cool. It is a generic code, so it means the same on every make.
Is it safe to drive with P0ACE?
Drive gently and only to a workshop. With P0ACE the car can go into limp mode (reduced power) to protect itself.
Will P0ACE fail an emissions test?
Yes, it can. P0ACE 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 P0ACE to fix?
Difficulty: workshop only. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will P0ACE 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.