P0A29
Battery Power Off Circuit High
- Severity
- High
- Driving
- Drive only to a garage
The battery power off circuit on a hybrid or electric vehicle is reading high - typically shorted to voltage or a lost earth. The vehicle cannot confirm control of its high-voltage shutdown, so it will refuse to bring the high-voltage system up.
Possible causes
- CommonWiring shorted to voltage or a lost earth in the shutdown circuit
- CommonCorroded or damaged connector
- CommonLow 12 volt battery voltage
- PossibleFailed contactor control circuit
- PossibleFailed battery management module
What you might notice
- Vehicle will not power up or move
- Will not charge
- High-voltage system warning
- Hybrid running on the engine alone
What to check, in order
- Check the 12 volt battery and its terminals before anything else.
- Check for disturbed high-voltage service plugs or covers.
- Read all codes for battery management faults alongside.
- Stop at the 12 volt system and the fuse box. Everything beyond that requires the manufacturer's high-voltage procedure.
Read this code from your own car
Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.
Where this code sits
P00xxP01xxP02xxP03xxP04xxP05xxP06xxP07xxP08xxP09xxP0AxxP0BxxP0CxxP0DxxP0ExxP0FxxP10xxP11xxP12xxP13xxP14xxP15xxP16xxP17xxP18xxP19xxP1AxxP1BxxP1CxxP1DxxP1ExxP1FxxP20xxP21xxP22xxP23xxP24xxP25xxP26xxP27xxP28xxP29xxP2AxxP2BxxP2CxxP2DxxP2ExxP2FxxP30xxP31xxP32xxP33xxP34xxP35xxP36xxP37xxP38xxP39xxP3AxxP3BxxP3CxxP3DxxP3ExxP3Fxx