Faulty phase V current sensor internal to the drive motor B inverter or motor assembly; Damaged or corroded wiring and connector terminals between the current sensor and the control module; Poor electrical ground or reference voltage supply to the current sensor circuit; Signal interference or a short to voltage or ground on the sensor signal circuit; Failed inverter assembly causing incorrect sensor supply or processing; Software calibration issue in the motor control module requiring a reflash or update

DTC codes / P0Bxx · Hybrid propulsion / P0BF6

P0BF6Drive Motor B Phase V Current Sensor Circuit Range/Performance

P0BF6 indicates that the inverter or motor control module has detected an out-of-range or erratic signal from the current sensor monitoring phase V of drive motor B, which is the second electric traction motor in a hybrid or electric vehicle. The computer compares this sensor's output against expected values during key-on and running conditions, and it sets the code when the voltage or calculated current falls outside a calibrated window or fails a rationality check.

SystemPowertrain

Code typeGeneric (all makes)

SeverityHigh

Fix difficultyProfessional

AreaHybrid propulsion

Symptoms you may notice

Illumination of the hybrid or electric vehicle warning light, often accompanied by a reduced power message
The vehicle may enter a fail-safe mode that limits motor output or prevents the use of one drive motor
Intermittent hesitation or shudder during acceleration when the affected motor is commanded to produce torque
Possible inability to start in electric-only mode or a forced switch to the combustion engine in a plug-in hybrid
Often no symptoms besides the warning light, especially if the fault is stored but not currently active

Common causes, most likely first

Faulty phase V current sensor internal to the drive motor B inverter or motor assembly
Damaged or corroded wiring and connector terminals between the current sensor and the control module
Poor electrical ground or reference voltage supply to the current sensor circuit
Signal interference or a short to voltage or ground on the sensor signal circuit
Failed inverter assembly causing incorrect sensor supply or processing
Software calibration issue in the motor control module requiring a reflash or update

How to diagnose and fix it

Perform a visual inspection of the drive motor B current sensor connector and harness for chafing, corrosion, or loose pins
Check for related diagnostic trouble codes in the inverter and motor control modules to confirm the fault is isolated to the phase V current sensor circuit
Measure reference voltage and ground at the current sensor connector with the key on and compare to manufacturer specifications
Back-probe the sensor signal wire and observe the voltage or current reading on a scan tool while wiggling the harness to detect intermittent faults
If the signal is out of range with good wiring and power supplies, replace the current sensor or the inverter assembly as required by the manufacturer's service procedure
After repair, clear codes and perform a road test or relearn procedure to verify the current sensor reading returns to normal

What the phase V current sensor code hides

A loose or corroded ground connection at the inverter chassis can skew all three phase current sensor readings, so technicians who replace only the sensor often see the code return.
The code can be set by a momentary glitch during a low-voltage event, such as a weak 12-volt auxiliary battery, even when the current sensor itself is healthy.
On some vehicles, the phase V current sensor is integrated into the inverter and cannot be serviced separately, making a full inverter replacement the only official fix.
A failing drive motor B resolver or stator insulation fault can produce current waveforms that the sensor correctly reports as abnormal, so the sensor is blamed when the motor is the real problem.
After any inverter or motor replacement, a calibration or learn procedure is mandatory; skipping it can immediately reset P0BF6 even with all-new hardware.

Can I keep driving with P0BF6?

Do not continue driving at high speeds or under heavy load because a faulty current sensor can cause the inverter to misjudge motor current and trigger an abrupt shutdown or reduced power mode. Limp the vehicle to a qualified repair facility and avoid sustained highway driving until the fault is repaired.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.