What it means
The BMS detects a circuit high fault on voltage sense channel K 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 measures a battery cell group through high-voltage battery sense channel K. This code sets when the channel K signal is above its expected range, making that cell-group voltage reading unreliable.
Common causes
Most likely first.
- Sense wire shorted to higher voltage
- Reference regulator overvoltage
- Connector pins corroded - high contact resistance
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 data and compare live channel K voltage with neighbouring channels to confirm whether the high reading is isolated to K.
- With the vehicle powered down using the manufacturer's high-voltage safety procedure, inspect channel K wiring and connectors for damage, corrosion, moisture, or contact with another voltage source.
- Check that channel K connector pins are clean and seated securely, since poor contact can distort the signal.
- Have a qualified hybrid/EV technician test the channel K wire for a short to a higher-voltage or reference circuit using the manufacturer's procedure.
- If the harness checks out, have the BMS reference supply and channel K measurement input checked against manufacturer specifications.
Common fixes
- Clean and secure corroded or loose channel K connector pins.
- Repair channel K wiring that is contacting a higher-voltage or reference circuit.
- Replace damaged channel K sense wiring.
- Replace a faulty BMS only after channel K wiring and reference checks pass.
Can I keep driving?
The BMS cannot trust the channel K cell-group reading and may reduce power or limit charging. Keep driving to short, necessary trips and avoid heavy acceleration until diagnosed; stop safely if the vehicle displays a stop warning.
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.