What it means
The BMS detects a circuit low fault on voltage sense channel F of the high-voltage battery. Cell-group voltage measurement is unreliable on this channel.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The battery management system (BMS) reads the voltage of a cell group through battery voltage sense channel F. This code sets when the channel's signal is lower than the BMS expects, so the module cannot rely on that cell-group reading.
Common causes
Most likely first.
- Short to ground in voltage-sense wiring
- Open or high resistance in voltage-sense wiring
- Loose, damaged, or corroded connector
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
- Save the freeze-frame and BMS data, then compare channel F's reported reading with nearby cell-group readings to see whether it is implausibly low.
- Check the service information for the safe inspection procedure; high-voltage battery covers and sense wiring can be hazardous even when the vehicle is off.
- With the battery isolated as specified by the manufacturer, inspect channel F's connectors and accessible wiring for looseness, corrosion, pin damage, or contact with ground.
- Test channel F wiring for a short to ground, an open, or excessive resistance using the manufacturer's procedure and specification.
- If the wiring and connections pass, follow the manufacturer's checks to determine whether the channel F sensing input or BMS circuitry is faulty.
Common fixes
- Reseat a loose channel F connector using the specified isolation procedure.
- Clean or repair corroded or damaged channel F connector terminals.
- Repair or replace channel F wiring that is shorted to ground, open, or high resistance.
- Repair or replace the battery sensing or BMS circuitry if testing identifies it as the cause.
Can I keep driving?
Avoid relying on electric drive or attempting charging if the vehicle has reduced power, enters limp mode, or rejects charging; the BMS cannot trust channel F's cell-group reading. Arrange prompt diagnosis, and stop driving if the vehicle's warnings or power loss make it unsafe.
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.