NHTSA Complaint #11632232 — 2013 CHEVROLET VOLT

This is a reoccurring problem that is worsening. It is difficult to replicate (but becoming easier to replicate as the problem worsens). The problem conditions are as follows: -The car is fully charged The following drive conditions are required: - The beginning of a drive, with the car in the fully charged state, is driven in the “L” mode (aggressive regenerative braking), AND the beginning (first mile or two) of the trip includes some conditions that would NORMALLY engage regenerative breaking and redirect energy flow back to the high voltage battery. (E.g.: Beginning a drive by going up a small incline; then proceeding to drive down a decline.) OR - The beginning of a drive, with the car in the fully charged state, is driven in the “D” mode, AND the beginning (first mile or two) of the trip includes almost exclusively conditions that would NORMALLY trigger regenerative breaking and redirect flow back to the high voltage battery. IN BOTH cases: the instrument cluster, during conditions that would reflect regenerative breaking and energy flow back into the high voltage battery, instead reflects suddenly INCREASED electrical OUTPUT despite there being no increased demand for output from the driver. Expected behavior in these conditions would reflect a negative power output while the car is driven in regenerative conditions (e.g.: going down hill). In either of these cases, the final condition is that you fully stop the vehicle (via brake) during the regenerative conditions. DESPITE full depression of the brake, the car jerks forward violently and erratically, attempting to accelerate. Engaging the emergency brake does not cure the condition while the car is still in L or D driving mode, and it will continue to attempt to accelerate while held in place. Shifting in to neutral does stop the behavior. Shifting back to L or D from neutral will cause the vehicle to continue to attempt to accelerate. There are no error codes/lamps and sensors appear normal.