2011 Chevrolet Volt Brakes Problems

Your car suddenly accelerated on its own while stopped at a red light, and pressing the brake pedal made it accelerate faster instead of slowing down. The engine continued revving even after the car hit a tow truck, and you had to shut off the engine to stop the vehicle completely. This suggests a potential failure in the braking system or electronic throttle control that caused the car to become uncontrollable. Investigation of the brake system components, throttle control module, and related electronic systems may be needed to determine the cause.

Your brakes have occasionally failed almost completely while driving, accompanied by an ABS warning light—though restarting the engine restores braking function. You're having the electronic brake control module and brake pressure modulator valve replaced to fix the issue. A design problem appears to be causing the ABS malfunction to disable regular braking, which is a serious safety concern that shouldn't occur.