P0AE2: Hybrid/EV Battery Precharge Contactor Circuit Stuck Closed
What to do
The car may seem fine — the risk is a component cooking quietly inside the battery. Treat as prompt business, and mention any burning smell immediately. Qualified workshop only.
What this code means
The precharge contactor stayed closed when commanded open — caught the same way as its bigger siblings, by watching at shutdown.
The risk is specific to this contactor's design: it is sized for a second of duty per start, feeding through a resistor sized the same way. Stuck closed, that resistor path stays connected across the main contactor — and if load current ever finds its way through the small path instead of the big one, a resistor built for one second of work carries it continuously and burns. That is why this variant earns urgency despite the car often driving normally: the failure it sets up is thermal, and it happens out of sight inside the pack.
Likely causes
Start here
- Welded battery contactor · specialist
Less common
- Wiring shorted to voltage · moderate
- Fault stored in the battery energy control module · 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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