— Chevy Volt battery energy control module failures caused the National Highway Traffic Safety Administration to open an investigation in November 2023 after the agency received at least 61 complaints.
Those complaints said 2016-2019 Chevrolet Volt cars were stalling, losing power and sometimes not starting because of battery energy control module failures.
The BECM is located inside the high voltage electric vehicle battery pack and is supposed to monitor the voltage, current and temperature of the battery cells.
NHTSA knew General Motors had issued technical service bulletin (TSB 18-NA-261) about 2016-2019 Volt BECM failures. And the government knew module failures caused these diagnostic trouble codes to set: U2603, U2604, U2605, U2606, U2617, U2618, U2619, U2620, U2621, U2622, U2623 and/or U2624.
GM dealers were told there were internal battery energy control module problems which could be repaired by replacing the modules.
NHTSA has closed its investigation because GM issued special coverage program N232432680 in March 2024 for 2016-2018 Chevrolet Volts. Customers were notified about the program and how it provided a warranty extension for the BECM from 8 years/100,000 miles, to 15 years/150,000 miles.
GM notes the battery energy control module replacements do not fail and are sourced from a different supplier.
According to NHTSA, safety regulators may reopen the investigation if circumstances change.