P0AC7 code meaning
Hybrid/EV Battery Temperature Sensor B Circuit Low
Powertrain system Generic code P0Axx codes Check engine light
What P0AC7 means
P0AC7 means the voltage of battery temperature sensor B is below its valid range. GM's sensors are NTC thermistors, so a low voltage equals an extremely hot reading, usually from a short to ground. The thresholds differ by program: the 2016 and 2019 tables fail it above 160 °C in 8 of 10 samples; the two-mode tables of 2011 and 2013 above 95 °C in 30 of 40 samples; GM's 2013 table 13OBDG05C below 0.3 V, about 90 °C, in 7 of 10. All are Type B, two trips. GM's Volt bulletin 18-NA-342 names P0AC7 among sensor codes that can set falsely and calls for a software update. A genuine hot pack would trip far lower thresholds first, so treat P0AC7 as an electrical fault.
P0AC7 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor0.5 to 5 hours
- Clears after repairAfter a drive cycle
Symptoms of P0AC7
- Check engine or hybrid warning light
- Sensor B shows an implausibly high temperature
- Charging and drive power reduced
Common causes of P0AC7
- Most likelySensor B signal shorted to ground inside the pack harness
- PossibleThermistor shorted internally
- Less likelyController software setting the code falsely (Volt bulletin 18-NA-342)
- Less likelyMoisture or coolant at the sensing board connector
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 bWiring harnessBms
What each part of P0AC7 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. |
| C7 | The exact fault in that area. |
What to do next
- Note P0AC7 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 P0AC7
What does P0AC7 mean?
P0AC7 means "Hybrid/EV Battery Temperature Sensor B Circuit Low". P0AC7 means the voltage of battery temperature sensor B is below its valid range. It is a generic code, so it means the same on every make.
Is it safe to drive with P0AC7?
Drive gently and only to a workshop. With P0AC7 the car can go into limp mode (reduced power) to protect itself.
Will P0AC7 fail an emissions test?
Yes, it can. P0AC7 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 P0AC7 to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 5 hours of work. This is a job for a workshop.
Will P0AC7 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.