General Motors Co. said it will improve the Chevrolet Volt’s vehicle structure and battery-coolant system to better protect against fires after crashes.
GM is making the change in response to a National Highway Traffic Safety Administration investigation, the automaker said on its website. GM’s fixes may or may not conclude NHTSA’s investigation, North America President Mark Reuss said.
“We are optimistic this will have a positive outcome,” Reuss said on a conference call with journalists. “You’ve got to ask NHTSA.”
The company said it’s asking all 8,000 Volt owners to bring their cars to dealerships to have the changes made, including strengthening part of the “vehicle safety structure” to better protect the battery pack and adding a sensor in the reservoir of the battery-coolant system. Future Volts will also have those features, GM said.
NHTSA hasn’t concluded its investigation, the agency said on its website. Preliminary results of a crash test indicate GM’s changes “should address the issue.”
The agency started investigating the Volt after a side-impact crash test in May led to a fire three weeks later.
During that test, the battery pack was broken open and some of the vehicle’s coolant leaked into the battery, Rob Peterson, a GM spokesman, said in a phone interview. When the car was rotated as part of the test, more coolant leaked into the battery pack and came in contact with a circuit board, he said, and over time, a reaction occurred and caught fire.
NHTSA replicated the fire in three more tests in November and started an official investigation Nov. 25.
To remedy the problem, GM will reinforce the structure on the sides of the car to spread energy away from the battery during a side-impact crash. The fix should prevent intrusion into the battery pack, Peterson said.
The coolant sensor will notify the driver if coolant levels are dropping fast to warn of potential leaks. If coolant levels drop fast enough, the driver can’t recharge the battery, Peterson said.
GM is voluntarily asking Volt owners to bring their cars in for service before NHTSA has concluded the investigation. That avoids designating the action as an official recall because it isn’t being coordinated through NHTSA.
The investigation lowered demand for the car, according to Bandon, Oregon-based CNW Marketing Research Inc. U.S. dealers sold a total of 7,671 Volts last year, missing GM’s target of 10,000 for 2011.
GM plans to expand production of the Volt to 60,000 this year, with 45,000 of the car earmarked for the U.S. Not including sales to corporate fleet customers, GM sold 992 Volts in December and ended the month with 4,200 in inventory.
It remains to be seen if GM can raise Volt sales to the level that the company aims to produce, Reuss said. GM won’t make too many, he said.
“What true demand is is a great unknown,” Reuss said. “That’s a good question. We’re going to match supply with demand.”
GM gained 4.8 percent to $22.17 at the close in New York.