What it means
The supply voltage circuit of the HV battery pack cooling fan reports a circuit/open condition. Cooling fan operation may be impaired.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The hybrid battery cooling fan moves air through the battery pack to help control its temperature, and the control system monitors the fan’s supply circuit. P0BBF sets when that supply circuit is open, so the fan may not receive power and pack cooling can be impaired.
Common causes
Most likely first.
- Open in supply wire
- Supply fuse blown
- Pin pushed back out of connector body
Symptoms
- EV/hybrid system warning light on
- Reduced power output or limp mode
- Charging may fail or be slowed
- Reduced electric range
How to diagnose it
- Review freeze-frame data and live data for the battery fan command and supply status to confirm when the fault occurs.
- With the vehicle powered down as specified by the manufacturer, inspect the fan supply fuse, connector, and harness for damage or a pushed-back pin.
- Check the fan supply wire for an open circuit using the manufacturer’s wiring diagram and test procedure.
- Test the fuse and supply feed under the conditions specified by the manufacturer to find where power is interrupted.
- If the supply circuit is intact, follow the manufacturer’s procedure to check the fan and its control circuit.
Common fixes
- Reseat a pushed-back supply connector pin and secure the connector.
- Replace a blown fan supply fuse after checking for the cause of the failure.
- Repair an open or damaged fan supply wire.
- Repair a faulty connector or supply feed if testing identifies a poor connection.
- Repair the fan or its control circuit if the supply circuit tests correctly.
Can I keep driving?
Keep trips short and avoid heavy acceleration, hot conditions, and charging if battery cooling may be impaired. Stop if a battery temperature warning or reduced-power alert appears, since continued use can increase pack heat.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.