What it means
The BMS detects a circuit range/performance fault on voltage sense channel B 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
Voltage sense channel B measures a cell group's voltage in the high-voltage battery for battery monitoring and control. P0B41 sets when channel B's reading falls outside its expected range or does not perform plausibly, often because resistance or damage in its sense circuit distorts the measurement.
Common causes
Most likely first.
- Poor connection or high resistance in the sense circuit
- Damaged sense wiring
- 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 B's reading with other cell-group voltages and any related battery codes.
- Watch channel B data for a value that drifts, lags, or disagrees with neighboring cell-group readings as operating conditions change.
- Inspect accessible channel B wiring and connectors for damage, looseness, corrosion, or poor terminal contact.
- Have the channel B circuit tested for high resistance and wiring faults against the manufacturer's specification using its high-voltage safety procedure.
- If the wiring passes, have the sensing module and relevant cell-group voltage checked using the manufacturer's diagnostic procedure.
Common fixes
- Secure the channel B connector and restore proper terminal contact.
- Clean or repair corroded terminals or damaged channel B wiring.
- Repair a high-resistance connection in the channel B sense circuit.
- Replace or repair the voltage-sensing module if testing identifies it as faulty.
- Service a verified cell-group issue according to the manufacturer's procedure.
Can I keep driving?
Channel B's implausible reading can prompt reduced power, slow charging, or limited electric range. Keep driving modest and arrange diagnosis soon, particularly if the vehicle enters reduced-power mode.
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.