P0BF6: Drive Motor B Phase V Current Sensor Circuit Range/Performance

What it means

The current sensor for drive motor B phase V reports a circuit range/performance fault. Phase current measurement is unreliable.

At a glance

• Usually lights the check-engine light
• The engine or gearbox may go into limp mode

How it works

Drive motor B uses separate current sensors to measure current in its U, V and W phases. The hybrid or EV control module checks whether the phase V sensor reading stays within its expected range and agrees with motor operation; a drifting or magnetically offset reading can set this performance code.

Common causes

Most likely first.

1. Current sensor offset drifted
2. Magnetic offset
3. Sensor element aged beyond calibration window

Symptoms

• EV/hybrid system warning light on
• Reduced motor power or torque
• Possible limp mode or vehicle shutdown

How to diagnose it

1. Save the freeze-frame data and check live phase U, V and W current readings for a phase V value that is implausible or offset from the others.
2. With the vehicle powered down according to the manufacturer’s high-voltage safety procedure, inspect the motor B phase V sensor connector and nearby harness for damage, contamination or magnetic interference.
3. Check the phase V sensor wiring, connector terminals and grounds for poor connections or ground offset, comparing results with the manufacturer’s specification.
4. If wiring and connections are sound, compare phase V sensor output with the other phase readings under the manufacturer’s specified test conditions to identify offset drift.
5. Test the phase V sensor and related control module inputs using the manufacturer’s procedure before replacing a sensor or module.

Common fixes

• Remove any identified magnetic source affecting the phase V sensor.
• Clean and secure the phase V sensor connector or repair damaged terminals.
• Repair a damaged phase V sensor harness or ground connection.
• Replace the phase V current sensor if its output remains out of range after wiring checks.
• Replace or reprogram the control module only if its inputs are confirmed faulty.

Can I keep driving?

Reduced torque or limp mode can make acceleration unpredictable, and the vehicle may shut down. Avoid driving if power is limited or the warning is severe; arrange a safe stop and service, since continued operation with unreliable phase current feedback can worsen the fault or cause loss of propulsion.