What it means
The BMS detects a circuit intermittent/erratic fault on voltage sense channel X 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 uses voltage sense channel X to track a cell group in the high-voltage battery. This code means the channel X reading changes erratically or drops in and out, so the module cannot rely on its voltage 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
- Save scan-tool freeze-frame data and review channel X voltage history, if available, to identify when the reading became erratic.
- Compare channel X with adjacent battery voltage readings and check whether the warning or reduced power appears during charging or vibration.
- Have a qualified hybrid technician inspect channel X's connector for incomplete seating, corrosion, damaged terminals, or signs of movement.
- With the high-voltage system made safe using the manufacturer's procedure, test channel X wiring and its ground reference for unstable continuity or excessive resistance.
- If the wiring is sound, have the battery management system's channel X input and the relevant cell-group measurement checked to the manufacturer's specifications.
Common fixes
- Securely reseat the channel X sense connector.
- Clean or repair channel X terminals with intermittent contact.
- Repair damaged channel X wiring or its unstable ground connection.
- Replace the confirmed faulty sensing component if channel X remains erratic after wiring repairs.
Can I keep driving?
If the warning or reduced power comes and goes, avoid long trips and heavy acceleration because the vehicle may unexpectedly limit power or charging. Arrange prompt diagnosis; stop safely if power drops substantially or a red 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.