Hybrid Battery Precharge Contactor Circuit Stuck Closed
What it means
The hybrid control system found the battery precharge contactor stuck closed. This relay briefly feeds the high-voltage system through a resistor at start-up to limit inrush current, and then opens. If it stays closed, the resistor can overheat and the system cannot confirm a safe start-up.
Can I keep driving? Use caution: the hybrid system may cut power or shut down to protect the battery, so get it checked soon rather than driving on.
What this part does
A battery contactor is a heavy-duty electrically operated switch that connects the high-voltage battery pack to the rest of the vehicle when the system starts and disconnects it when the car shuts down or a fault is detected. The battery control system closes it and checks that it behaves correctly. It involves high voltage, so work on it is for trained people. A fault may stop the car from starting or limit power.
Common symptoms
What you'll notice
- Hybrid system or check-engine warning light on
- Car will not go to ready mode, or shuts down
- Reduced power
- Unusual or missing click from the contactors at start-up
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Common causes
Most likely first
- Real contactor stuck closed from wear or welded contacts
- Wiring or connector fault in the contactor control or feedback circuit
- Battery control module or relay driver fault
- Low 12-volt supply giving false feedback
Repair
Likely repair
- Parts often involved: high-voltage contactor, wiring or connector, high-voltage battery control unit or sensor
- Labor: 1–5 h
- Difficulty: Hard
- DIY: Garage only
How to diagnose & fix
Work through it in order
- Read all hybrid codes and any contactor codes together.
- Check the 12-volt battery voltage and terminals.
- Inspect the contactor connectors and wiring for damage, with the system off.
- Leave contactor and pack testing to a trained high-voltage technician.
- Do not open the battery pack or touch orange high-voltage cables; leave any high-voltage testing to a trained technician.
Related codes
About this page
Scan figures come only from diagnostic scans recorded through our own apps and tools. Cars are usually scanned because a symptom or warning light prompted it, so these figures describe our scan records, not how often a fault occurs in any make or model.
Notes about specific manufacturers summarise public records (NHTSA owner complaints, recalls and manufacturer service bulletins), cited under each note. They report what those records say, not our measurements, and they do not suggest that any manufacturer or vehicle is better or worse than another.
Repair time and cost estimates come from a public repair dataset and are typical ranges, not quotes.
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