GM recalls over 3,000 Volts due to software glitch affecting battery


Warren, Mich. – June 25, 2018 – General Motors LLC has recalled several thousand of its Chevrolet Volt models due to a software update flaw that may adversely affect the plug-in vehicle’s battery functionality, according to documentation submitted to the National Highway Traffic Safety Administration. The automaker believes the recall is warranted because affected cars may result in a crash, especially in situations where drivers need to accelerate to keep pace with the flow of traffic.

The Defect

Earlier this month, GM recalled approximately 3,233 Chevrolet Volts – with 2013 model years – after dealers performed a software update of the plug-in hybrid’s on-board battery, specifically its Hybrid Powertrain Control Module 2 or HPCM2. The update was meant to improve the life and sustainability of the HPCM2, but some of the software updates were corrupted, the company believes, potentially resulting in a voltage imbalance situation between the individual cells that give the plug-in hybrid the energy it needs to operate. Should the voltage dip below a certain threshold, the vehicle may enter a reduced power mode, thus preventing motorists from accelerating.

Although General Motors suspects just 2 percent of the 3,200+ Volts are affected, the automaker contends the recall is warranted because motorists operating the Volts with the flaw are at an increased risk for a crash due to a loss of propulsion that impacted vehicles may experience. No known crashes, injuries or deaths have been linked to the improper cell balancing defect.

Timeline of Events

The issue first came to light in May, when a GM engineer discovered the problematic software and informed GM of the issue after filing a Speak Up for Safety report, based on a chronology of events submitted to and published by the NHTSA. GM subsequently launched an investigation, although the automaker was already looking into a similar but unrelated issue relating to low-voltage output. The investigation revealed that the likelihood of Volts losing propulsion seemed to depend upon whether the vehicles had received a software update.

By June 7, GM’s Safety and Field Action Decision Authority determined that a safety recall was appropriate out of an abundance of caution.

The Solution

GM says it will inform owners of 2013 Volts about the software glitch, who can then go to their nearest dealership to have their HPCM2 reprogrammed for free, according to an NHTSA internal briefing document. The reprogramming will entail an update to the Volt’s vehicle interface control modules. However, GM didn’t say when the notifications would be sent out or how motorists will be informed. All of the affected Volts were sold within the continental U.S.

Owners who believe they may be impacted may get in touch with their Chevrolet dealer by dialing the toll free number at 1-800-222-1020. The reference number for this specific recall is 18215.

Alternatively, drivers may also go to NHTSA’s website at or call the Department of Transportation Vehicle Safety Hotline at 1-888-327-4236.

Sean ReyesGM recalls over 3,000 Volts due to software glitch affecting battery