2011 Chevrolet Volt Owner's Manual - Page 339

Driving and Operating 9-37 Regenerative Braking Regenerative braking takes some of the energy from the moving vehicle and turns it back into electrical energy. This energy is then stored back into the high voltage battery system, contributing to increased energy efficiency. The hydraulic disc brakes work with the regenerative braking to ensure effective braking, such as when a high braking demand is requested. The braking system is computer controlled and blends the regenerative braking with the conventional hydraulic disc brakes to meet any requirements for deceleration. The controller interprets the braking request and uses regenerative braking, conventional hydraulic braking, or a combination of both as necessary. Because the controller applies the hydraulic brakes through its high pressure accumulator, you may occasionally hear the motor‐driven pump when it recharges the system. This is normal. See Warning Lights, Gauges, and Indicators on page 5‑9 and Driver Information Center (DIC) on page 5‑43. In the event of a controller problem, the brake pedal may be harder to push and the stopping distance may be longer. Ride Control Systems Traction Control System (TCS) The vehicle has a Traction Control System (TCS) that limits wheel spin. The system operates if it senses that one or both of the drive wheels are spinning or beginning to lose traction. When this happens, the system brakes the spinning wheel(s) and/or reduces power to limit wheel spin. The system may be heard or felt while it is working, but this is normal. To assist with directional control of the vehicle, TCS comes on automatically whenever the vehicle is started and cannot be turned off.