Loss of Motive Power due to the Battery Energy Control Module

What NHTSA is examining

On November 29, 2023, the Office of Defects Investigations (ODI) opened PE23022 to investigate allegations of a loss of motive power, including a stall, reduced power state, and/or a no start condition due to the Battery Energy Control Module (BECM) in model year (MY) 2016-2019 Chevrolet Volt passenger car vehicles manufactured by General Motors (GM). The BECM is located within the high voltage electric vehicle (EV) battery pack and monitors the temperature, current, and voltage of the high voltage battery cell groups. GM stated that the root cause was identified as an internal failure leading to a loss of communication within the BECM and does not pose a risk to motor vehicle safety. GM further stated that the failure cannot result in a complete stall, only a reduced power mode, no start condition, or a no charge condition. GM additionally stated that if these conditions occur, the driver will be warned via a Malfunction Indicator Lamp (MIL) and/or a reduced-propulsion message in the Driver Information Center (DIC). Data received and analyzed by ODI from all sources indicates that nearly all related BECM failures caused conditions aligning with GM’s predicted outcomes. Despite the large number of warranty claims, nearly all failures were not safety-related, i.e., not a stall or reduced power mode. ODI isaware of a single minor crash and no injuries or deaths. In March 2024, GM issued Special Coverage N232432680, which was mailed to consumers, addressing BECM failures in…

Vehicles under investigation