P0A1B code meaning
Drive Motor A Control Module Performance
Powertrain system Generic code P0Axx codes Check engine light
What P0A1B means
P0A1B flags a self-test failure of the processor that controls drive motor A, usually inside the inverter. In GM hybrid tables (2016) it sets when the processor fails an inhibit path test at power-down, three or more times, proving it could not take the system to a safe state; in 2011 tables internal SPI, RAM or cache faults in 28 of 32 samples count. Both are Type A, MIL on the first trip. Land Rover sets P0A1B in the inverter of 2024-25 PHEVs at start-up, VW lists P0A1B00 for the ID.4 front drive. Toyota uses subtype P0A1B-1F on the 2023-24 Corolla Hybrid. Drive motor B is P0A1C. Expect a red loss-of-drive warning.
P0A1B 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 P0A1B
- Loss of drive warning and MIL
- Vehicle cannot be driven electrically or not at all
- Fault may vanish after a full sleep cycle while the code stays stored
Common causes of P0A1B
- Most likelyControl software fault, several makers resolve it by reprogramming
- PossibleInternal processor or memory fault in the inverter control board
- Less likelyWeak 12 V supply during start-up or shutdown
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Drive motor a control module
What each part of P0A1B 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. |
| 1B | The exact fault in that area. |
What to do next
- Note P0A1B 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 P0A1B
What does P0A1B mean?
P0A1B means "Drive Motor A Control Module Performance". P0A1B flags a self-test failure of the processor that controls drive motor A, usually inside the inverter. It is a generic code, so it means the same on every make.
Is it safe to drive with P0A1B?
Drive gently and only to a workshop. With P0A1B the car can go into limp mode (reduced power) to protect itself.
Will P0A1B fail an emissions test?
Yes, it can. P0A1B 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 P0A1B to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 8 hours of work. This is a job for a workshop.
Will P0A1B clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.