P0AC8: Hybrid/EV Battery Temperature Sensor B Circuit High
What to do
As P0A9E — sudden hard fan running with this code is usually a broken wire, not a hot pack.
What this code means
Sensor B's circuit reads at the top of its range — the fan-runs-flat-out false alarm of P0A9E, at this sensor's position. Wiring first.
Likely causes
Start here
- Open circuit in sensor wiring · moderate
- Corroded or loose connector · easy
Less common
- Wiring shorted to voltage · moderate
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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