P0BEF: Drive Motor A Phase W Current Sensor Circuit Low

P0BEF indicates that the phase W current sensor of the motor A inverter delivers a signal below its valid range. GM's limits: below -700 A for 0.05 of 0.1 s (2016 tables) or 0.1 of 0.15 s (2019), Type A; below -800 A, Type A, on the 2011 Volt; below -700 A, Type B, on the 2012 two-mode trucks; below -440 A, Type B, two trips, in the BAS Plus (eAssist) table. These readings lie far outside real phase currents, so a sensor output stuck near ground, a failed sensor or a supply fault is the likely cause. In the eAssist system this fault puts current control into a mode that ignores the sensors, and it disables the U-V-W correlation check P0BFD, so motor A runs with reduced output.

Symptoms

• Malfunction indicator lamp and hybrid warning
• Reduced power or no assist from drive motor A

Most likely causes

• Failed phase W current sensor inside the inverter
• Sensor signal or supply pulled to ground on the sensor board
• Poor contact at an internal or external inverter connector

What to check, in order

Start with the simplest. You can tick off each step.

1. Read the codes with a hybrid-compatible scanner and write down the freeze frame data
2. With the connector unplugged, check whether the signal wire is making contact with ground.
3. Make sure the battery cooling air intake is clean
4. Check the 12 V auxiliary battery, which can also trigger warnings
5. Leave any high-voltage measurements to a specialized repair shop

Good to know

• It can trigger limp mode.
• It affects emissions.

What each character of P0BEF means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• B: Subsystem depends on the code range
• EF: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0BEF?

If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.

What causes code P0BEF?

The most common causes are: failed phase W current sensor inside the inverter; sensor signal or supply pulled to ground on the sensor board; poor contact at an internal or external inverter connector.

Related codes

• P0BF0Drive Motor A Phase W Current Sensor Circuit High
• P0BEDDrive Motor A Phase W Current Sensor Circuit
• P0BEEDrive Motor A Phase W Current Sensor Circuit Range/Performance
• P0BE7Drive Motor A Phase U Current Sensor Circuit Low
• P0BEBDrive Motor A Phase V Current Sensor Circuit Low
• P0BFDDrive Motor A Phase U-V-W Current Sensor Correlation
• P0BFBDrive Motor B Phase W Current Sensor Circuit Low

Sources

• gsi.ext.gm.com: 19OBDG01 Hybrid Diagnostics
• gsi.ext.gm.com: 16OBDG02 Hybrid Diagnostics
• gsi.ext.gm.com: 11OBDG01 HYBRID Diagnostics
• gsi.ext.gm.com: 13OBDG05C Hybrid Diagnostics

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.