Powertrain, generic · Hybrid propulsion

P0BF3 Drive Motor B Phase U Current Sensor Circuit Low

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modePossible

P0BF3 is stored when the phase U current sensor of the motor B inverter reports a value below its valid range. GM converts the sensor voltage into amps and sets the code below -800 A on the 2011 Volt (Type A, 4 of 6 samples), below -700 A on the 2012 and 2013 two-mode trucks (Type B, two trips), and below -700 A for 0.05 of 0.1 s in the 2016 tables or 0.1 of 0.15 s in a 2019 table (Type A, one trip). No real phase current of motor B reaches such values, so the reading reflects an electrical defect, typically a sensor output pulled toward ground or a dead sensor. The offset check P0BF2 covers a shifted zero instead. Motor B is then restricted or shut off.

Likely causes

Failed phase U 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 u current sensorwiring harnesshybrid control module

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