Powertrain, generic · Hybrid propulsion

P0BF7 Drive Motor B Phase V Current Sensor Circuit Low

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modePossible

P0BF7 reports that the phase V current sensor of the motor B inverter outputs a signal below its valid range. In GM's hybrid tables the converted current must fall below -800 A on the 2011 Volt (Type A, one trip), below -700 A on the 2012 and 2013 two-mode trucks (Type B, two trips, 10 of 15 samples) or below -700 A for 0.05 of 0.1 s (2016) and 0.1 of 0.15 s (2019), both Type A. Values like these are physically impossible for the motor phase, so the controller treats them as a sensor or circuit failure, for example a shorted output or a lost sensor supply. Unlike P0BF6 the sensor is not merely offset but outside its measuring range. Drive motor B then runs restricted.

Likely causes

Failed phase V current sensor in the motor B inverter

Sensor signal or supply pulled to ground on the sensor board

Poor contact at an internal or external inverter connector

Symptoms

Malfunction indicator lamp and hybrid warning
Reduced power or no contribution from drive motor B
Possible shutdown of electric drive

Repair estimate

DifficultyShop_onlyWorkshop job

Parts and labour€150–4,000

Time1–6 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

drive motor b phase v current sensorwiring harnesshybrid control module

References: gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com.