P0A1C code meaning
Drive Motor B Control Module Performance
Powertrain system Generic code P0Axx codes Check engine light
What P0A1C means
P0A1C is the counterpart of P0A1B for the second electric machine, drive motor B, and reports that its control processor is no longer trustworthy. GM hybrid tables use it for the motor control processor B: in 2016 calibrations the code sets when an inhibit path test at power-down fails three or more times, in 2011 calibrations internal processor integrity faults such as SPI, RAM or cache errors are counted. Both are Type A with MIL on the first trip. The code concerns the control electronics, not a phase current sensor; those faults use their own codes. Expect a hybrid warning and loss of the affected motor function.
P0A1C at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor0.5 to 8 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0A1C
- Hybrid warning and MIL
- Reduced drive power or no electric drive
Common causes of P0A1C
- Most likelyInternal processor or memory fault on the motor B control board
- PossibleCalibration or software fault in the inverter
- Less likelyUnstable 12 V supply or ground to the inverter electronics
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Drive motor b control moduleInverter
What each part of P0A1C 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. |
| 1C | The exact fault in that area. |
What to do next
- Note P0A1C 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 P0A1C
What does P0A1C mean?
P0A1C means "Drive Motor B Control Module Performance". P0A1C is the counterpart of P0A1B for the second electric machine, drive motor B, and reports that its control processor is no longer trustworthy. It is a generic code, so it means the same on every make.
Is it safe to drive with P0A1C?
Drive gently and only to a workshop. With P0A1C the car can go into limp mode (reduced power) to protect itself.
Will P0A1C fail an emissions test?
Yes, it can. P0A1C 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 P0A1C to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 8 hours of work. This is a job for a workshop.
Will P0A1C clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.