What it means
The BMS detects a circuit intermittent/erratic 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 BMS monitors cell-group voltage through battery voltage sense channel F. This code sets when that signal changes erratically or drops in and out, so the BMS cannot maintain a dependable reading from the channel.
Common causes
Most likely first.
- Loose or damaged voltage-sense connector
- Intermittent open or short in voltage-sense wiring
- Intermittent fault in the battery voltage-sensing circuitry
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 freeze-frame and BMS data, and check whether channel F's reading or the warning changed with vibration, temperature, charging, or a particular drive condition.
- Follow the manufacturer's high-voltage isolation instructions before inspecting the battery sense circuit.
- Inspect channel F's connector for a loose lock, damaged pins, corrosion, or signs of movement, and check accessible wiring for chafing or strain.
- Using the manufacturer's test procedure, check channel F wiring for intermittent continuity or short circuits while carefully moving the accessible harness.
- If the connector and wiring remain stable during testing, have the channel F sensing input and BMS circuitry checked by the manufacturer's diagnostic procedure.
Common fixes
- Secure a loose channel F connector and ensure its lock engages.
- Repair corroded or damaged channel F connector terminals.
- Repair or replace channel F wiring with an intermittent open or short.
- Repair or replace the sensing circuitry or BMS if testing isolates the intermittent fault there.
Can I keep driving?
If the vehicle loses power, enters limp mode, or charging is interrupted, avoid continued use and arrange prompt diagnosis; intermittent channel F readings can cause the BMS to limit battery operation without warning. Stop if the power loss makes the vehicle 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.