Powertrain, generic · Hybrid propulsion

P0BF5 Drive Motor B Phase V Current Sensor Circuit

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modePossible

P0BF5 stands for a general circuit fault of the phase V current sensor in the motor B inverter, an electrical problem the controller does not narrow down to offset, low or high. No manufacturer documents this exact code publicly. GM's hybrid tables for the 2011 Volt, the 2012 and 2013 two-mode trucks and the 2016 to 2019 models use only the specific siblings P0BF6, P0BF7 and P0BF8; GM's single-motor BAS Plus (eAssist) system has no motor B codes at all. CARB requires circuit monitoring of hybrid sensors. Since the three phase currents of motor B are used together and their sum is cross-checked (P0BFE), losing the V signal normally forces motor B into restricted operation.

Likely causes

Failed phase V current sensor in the motor B inverter

Supply or signal fault on the inverter's sensor board

Software fault in the motor B control processor

Symptoms

Hybrid system warning and malfunction indicator lamp
Reduced power from drive motor B

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: law.cornell.edu, gsi.ext.gm.com, gsi.ext.gm.com.