P0AC1 code meaning
Hybrid/EV Battery Pack Current Sensor A Circuit Low
Powertrain system Generic code P0Axx codes Check engine light
What P0AC1 means
P0AC1 is set when the output of the pack current sensor falls below the valid window, so that the converted current would be an impossible discharge or charge value. GM documents it in several hybrid tables. In the 2016 and 2019 versions the Hall-effect sensor fails when the result is below -365.1 A for 8 of 10 samples at 25 ms with system voltage above 10.2 V; the code is Type A with MIL on the first trip. An earlier GM pack in the 2013 table uses an output below 0.2 V, equal to about -230 A, with 7 of 10 samples and Type B. Typical causes are a lost supply or a signal shorted to ground. P0AC2 is the high side and P0AC0 the plausibility check.
P0AC1 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor1 to 5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0AC1
- Hybrid system or check engine warning on
- Electric drive limited or vehicle will not go ready
Common causes of P0AC1
- Most likelySensor 5 V supply open or shorted
- PossibleSignal wire shorted to ground
- PossibleHall current sensor failed internally
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hv battery pack current sensor aWiring harnessBms
What each part of P0AC1 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. |
| C1 | The exact fault in that area. |
What to do next
- Note P0AC1 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 P0AC1
What does P0AC1 mean?
P0AC1 means "Hybrid/EV Battery Pack Current Sensor A Circuit Low". P0AC1 is set when the output of the pack current sensor falls below the valid window, so that the converted current would be an impossible discharge or charge value. It is a generic code, so it means the same on every make.
Is it safe to drive with P0AC1?
Drive gently and only to a workshop. With P0AC1 the car can go into limp mode (reduced power) to protect itself.
Will P0AC1 fail an emissions test?
Yes, it can. P0AC1 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 P0AC1 to fix?
Difficulty: workshop only. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will P0AC1 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.