What it means
The BMS detects a circuit 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 uses voltage-sense channel F to monitor a battery cell group through its wiring and sensing circuitry. This code sets when it detects a fault in channel F's circuit, making that cell-group measurement unreliable.
Common causes
Most likely first.
- Open or short in voltage-sense wiring
- Loose, damaged, or corroded connector
- Fault in the battery voltage-sensing or control 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
- Capture freeze-frame data and compare channel F live voltage with neighboring group readings to determine whether it is absent, unstable, or implausible.
- With the vehicle shut down according to the manufacturer's instructions, inspect accessible channel F wiring for opens, shorts, abrasion, or pinching.
- Inspect channel F connectors for damage, looseness, corrosion, and poor pin contact.
- Have a qualified technician isolate the high-voltage battery and test channel F wiring and connections according to the manufacturer's procedure.
- If the circuit checks correctly, compare channel F's module input with scan data to investigate a sensing or control-circuit fault.
Common fixes
- Repair open or shorted channel F sense wiring.
- Clean, secure, or repair a loose or corroded channel F connector.
- Replace damaged channel F terminals or harness sections.
- Repair or replace the battery voltage-sensing or control circuitry if channel F remains faulty with verified wiring.
Can I keep driving?
Avoid extended driving if the vehicle shows reduced power or charging problems, since the BMS cannot rely on channel F's cell-group reading. The vehicle may enter limp mode or further limit electric operation.
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.