Almost 73,000 Second-Gen Chevrolet Volt PHEVs Probed For Power Loss

The National Highway Traffic Safety Administration (NHTSA) has opened an investigation on November 29 into 72,926 second-generation Chevrolet Volt plug-in hybrid vehicles over several issues including loss of power, reduced power state, and failure to restart.

The U.S. auto safety regulator said the preliminary evaluation into 2016-2019 model year Chevrolet Volts comes after receiving 61 complaints and multiple TREAD (Transportation Recall Enhancement, Accountability and Documentation) field reports alleging a loss of motive power related to the vehicle’s Battery Energy Control Module (BECM), Reuters reported.

According to the NHTSA’s Office of Defects Investigation (ODI), the alleged BECM failure “can cause a loss of motive power, including a stall, reduced power state, or a no-start condition.” The loss of motive power can occur at various speeds and the “vehicle may not have the ability to restart afterwards.”

Some of the complaints allege that the instances where loss of power or reduced power mode occurred came with little to no warning.

According to Reuters, an owner from Los Angeles said their Volt “suddenly, and unexpectedly lost propulsion while driving. The vehicle is no longer able to turn on or drive.” Another owner complained the Volt would not exceed 35 miles per hour on the highway “and it stops driving on electricity randomly.”

The ODI Resume document posted online counts a total of 61 complaints, but thankfully no crashes, fires, injuries, or fatalities have been reported so far as a result of the alleged defect.

It’s worth noting that General Motors previously issued a technical service bulletin (TSB 18-NA-261) stating that a “no-start condition or illumination of a malfunction indicator light (MIL) along with various diagnostic trouble codes (DTCs) is possible.” GM said this condition is caused by an internal issue in the BECM, in which case the module might need to be replaced and reprogrammed.

While ODI and GM have discussed internal and external data related to this issue on several occasions, the automaker has not recalled the vehicles.

“ODI is opening this Preliminary Evaluation (PE) to determine the scope and severity of the potential problem and to fully assess the potential safety-related problems,” the agency stated in the document.

If the Chevy Volt’s problem turns out to be real, it’s not hard to realize why it could be dangerous for users. A stalled vehicle represents a hazard because of its inability to move with the flow of surrounding traffic.

“The stalled vehicle along with its operator and occupants becomes a stationary target with traffic moving past the vehicle,” the ODI Resume document stated.

If the vehicle can be restarted immediately or within a reasonable amount of time and it can rejoin the flow of traffic, the hazard is reduced—especially if the surrounding traffic is not traveling at a significantly higher speed than the stalled vehicle, ODI notes.

GM told Reuters it was cooperating with the NHTSA investigation and said it believes it has “taken appropriate action to remedy customer concerns related to the battery energy control module.” The automaker added that it “will continue to support the agency’s review of the matter.”

Production of the second-generation Chevrolet Volt ended in early 2019.