P0A1A: Generator Control Module
What to do
Do not accept an inverter or module quote until the module's own power supply and earth have been tested — a module short of voltage reports faults it does not have. This is high-voltage territory; use a hybrid-qualified workshop.
What this code means
The module controlling the generator has failed its own self-check.
In a full hybrid the generator is the second electric machine in the transaxle: it starts the engine, charges the traction battery, and in an eCVT it is half of how the gear ratio is made. Its control module is physically part of the inverter assembly on most vehicles rather than a separate box.
A module reporting itself faulty deserves the corpus's standard scepticism. Modules starved of supply voltage or a clean earth fail self-checks while perfectly healthy — the P0562 and P0882 argument — so the module's power and ground connections are checked before the module is condemned. That ordering matters more than usual here, because "the module" is the inverter assembly, and inverters are among the most expensive electrical parts on the car.
Likely causes
Start here
- Failed power or earth supply to the module · moderate
- Poor module ground connection · easy
Less common
- Faulty power inverter · specialist
- Module software fault needing an update · specialist
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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What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
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