P0AE3: Hybrid/EV Battery Precharge Contactor Circuit Stuck Open
What to do
As the family's other no-wake codes: twelve-volt battery first, service plug second, pack internals last. Do not keep retrying the start button — the diagnosis does not improve with repetition.
What this code means
The precharge contactor did not close when commanded — the capacitors never charge, the mains are never permitted to close, and the car does not wake.
This is the commonest way the precharge family presents, and the suspect list runs cheapest-first with the block's usual clarity: the twelve-volt battery (every coil in this ceremony runs on it), the service plug if anyone has been near the pack, then the precharge contactor and its resistor — a resistor failed open reads exactly like a contactor that never closed, because the module judges by whether voltage arrives, not by which part moved.
Likely causes
Start here
- Failing 12 volt battery · easy
- Failed precharge resistor · specialist
Less common
- Faulty battery contactor · specialist
- High voltage service plug not fully seated · 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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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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