What it means
The BMS detects a circuit low fault on voltage sense channel D 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 (BMS) reads the voltage of cell groups through individual sense wires, including channel D. This code sets when the channel D signal falls below the range the BMS expects, so it cannot rely on that cell-group measurement.
Common causes
Most likely first.
- Sense wire shorted to ground
- Open or high-resistance connection in the sense circuit
- Fault in the battery voltage-sensing module
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 compare channel D's live reading with adjacent cell-group readings to confirm whether it is persistently low or the fault is intermittent.
- With the vehicle powered down as specified by the manufacturer, inspect channel D's accessible harness and connectors for pinched insulation, contamination, or a wire touching ground.
- Check channel D connector seating and pin condition, looking for corrosion or looseness that could create an open or high-resistance connection.
- Have a qualified technician isolate the high-voltage battery and test channel D wiring for a short to ground and continuity using the manufacturer's procedure.
- If the wiring and connections pass, compare the channel D input at the sensing module with its reported scan data to assess a possible module fault.
Common fixes
- Repair damaged channel D sense-wire insulation that is shorting to ground.
- Clean, secure, or repair a loose or corroded channel D connector.
- Repair an open or high-resistance section of channel D wiring.
- Replace or repair the battery voltage-sensing module if its channel D input is faulty after wiring checks.
Can I keep driving?
Avoid relying on electric drive or attempting long trips while the BMS cannot trust channel D; reduced power, limp mode, or charging problems may occur. Arrange prompt diagnosis, since continued use with an unreliable cell-group reading can lead the system to limit operation further.
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.