P0A1B: Drive Motor A Control Module Performance
What to do
The car may drive on the engine alone or at reduced power — safe to get home, not to ignore. Ask the workshop, in order: has the module's supply and earth been tested, and is there a software update for this code? Both questions come before any inverter quote.
What this code means
The module controlling the main drive motor has failed its self-check.
This is the module that fires the inverter's switches thousands of times a second to turn battery DC into the three-phase currents that move the car — on most vehicles it is a board inside the inverter assembly rather than a box of its own. When its self-check fails, the vehicle's response ranges from reduced power to refusing electric drive entirely, because a motor controller that cannot vouch for itself is not allowed to command torque.
Two checks come before any talk of replacement. Supply and earth first — the P0882 argument applies to this module like any other, and a corroded ground can fail a self-check on a healthy board. Then software: several manufacturers have issued updates for exactly this code, and a reflash is a fraction of an inverter's price. A genuine module failure is real but sits at the end of that list, and a replacement usually needs programming to the vehicle — so a wrong guess costs more than the part.
Likely causes
Start here
- Failed power or earth supply to the module · moderate
- Module software fault needing an update · specialist
Less common
- Faulty power inverter · specialist
- Poor module ground connection · easy
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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- The car — make, model, year and engine. The same fault behaves differently on each.
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