NHTSA upgraded its eBoost probe to an engineering analysis covering 1,164,820 GM, Honda and Acura vehicles.
Investigators logged 745 eBoost failure reports, 22 crashes or fires and six injuries, with no deaths reported.
Engineering analysis is the step before regulators can force a recall.
NHTSA has elevated its look at GM's eBoost brake system to an engineering analysis, the last step before regulators can force a recall. The scope now covers about 1.16 million GM, Honda and Acura vehicles with the electronic brake booster, an expansion detailed in the official ODI engineering analysis.
The upgrade means investigators see enough risk signals to dig into hardware, software and vehicle data behind hundreds of complaints, even though they have not yet labeled the system a safety defect.
