Powertrain, generic · Hybrid propulsion

P0BE5 Drive Motor A Phase U Current Sensor Circuit

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modePossible

The inverter of drive motor A measures the current in each motor phase with a current sensor; the controller needs these values for torque control and overcurrent protection. P0BE5 is the general circuit code for the phase U sensor, used for an electrical fault that is not classed as offset, low or high. No manufacturer documents this exact code publicly; GM's hybrid tables (2011 Volt through 2019) only use the siblings P0BE6, P0BE7 and P0BE8, and CARB requires hybrid sensor circuits to be monitored. Without a reliable phase U reading the inverter typically switches to a reduced or alternate control mode, so motor A loses power. The sensor sits inside the inverter, which usually means inverter replacement.

Likely causes

Failed phase U current sensor inside the inverter

Supply or signal fault on the inverter's sensor board

Software fault in the motor control processor

Symptoms

Hybrid system warning and malfunction indicator lamp
Reduced power from drive motor A
Possible loss 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 a phase u current sensorwiring harnesshybrid control module

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