2013 Chevrolet Volt Owner Manual - Page 219

Driving and Operating 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 5‑8 and Driver Information Center (DIC) on page 5‑41. In the event of a controller problem, the brake pedal may be harder to push and the stopping distance may be longer. 9-33 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 slipping 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 automatically comes on whenever the vehicle is turned on. To limit wheel spin, especially in slippery road conditions, the system should always be left on. But, TCS can be turned off if needed. When the vehicle is started and begins to move, the system performs several diagnostic checks to ensure there are no problems. The system may be heard or felt while it is working. This is normal and does not mean there is a problem with the vehicle. The system should initialize before the vehicle reaches 32 km/h (20 mph). In some cases, it may take approximately 3.2 km (2 mi) of driving before the system initializes. The TCS may activate on dry or rough roads or under conditions such as heavy acceleration while turning or abrupt changes in output from the electric drive unit. When this happens, a reduction in acceleration may be noticed, or a noise or vibration may be heard. This is normal. d flashes to indicate that TCS is active. See Traction Control System (TCS)/StabiliTrak® Light on page 5‑24.