What it means
The BMS detects a circuit intermittent/erratic 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 monitors a battery cell group's voltage through sense channel K. This code sets when channel K's signal becomes erratic or intermittent, so the BMS cannot use it as a stable measurement.
Common causes
Most likely first.
- Sense connector not seated
- Noisy ground reference
- Connector with intermittent contact under vibration
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
- Record freeze-frame data and inspect live channel K voltage for dropouts or sudden changes compared with adjacent channels.
- With the vehicle powered down under the manufacturer's high-voltage safety procedure, inspect the channel K connector for incomplete seating, corrosion, or damaged pins.
- Inspect the accessible channel K harness for chafing or loose routing that could interrupt contact with vibration.
- Have a qualified hybrid/EV technician check channel K connector retention and ground-reference stability using the manufacturer's procedure.
- If connector and wiring checks pass, have the BMS input assessed for an intermittent fault before replacing a module.
Common fixes
- Reseat and secure the channel K connector.
- Clean corroded channel K pins or repair damaged terminals.
- Repair or replace a channel K harness section with an intermittent connection.
- Repair the ground reference or replace a BMS only if testing confirms that is the source.
Can I keep driving?
An intermittent channel K reading may cause sudden power limits or charging interruptions. Avoid long trips and hard acceleration until repaired, and stop safely if power drops unexpectedly or a stop warning appears.
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.