2009 Cadillac CTS-V: Tech Link Article: Electric Parking Brake



The Electric Parking Brake (EPB) is new on the 2009 Cadillac CTS-V as standard content (fig. 9). The Electric Parking Brake takes the place of the manual parking brake system, the foot pedal and release handle. Vehicles with EPB have a switch in the center console. The system has two warning lights identified as BRAKE and (P) and five Driver Information Center (DIC) messages. In case of insufficient electrical power, the EPB cannot be applied or released.

figure 9

The BRAKE light (fig. 10 -- U.S. and fig. 11 -- Canada) is used for all apply and release functions as well as "hard" failures which require the vehicle to be towed to the dealer.

The (P) light (fig. 12) is used only to indicate there is a problem with the Park Brake System. The vehicle can be driven to the dealer, but is functioning at a reduced level.

FUNCTIONS

EPB Apply - The EPB can be applied any time the vehicle is stopped. The EPB is applied by momentarily lifting up on the EPB switch. Once fully applied, the BRAKE light is on, and the DIC message Park Brake Set is displayed. If the BRAKE light does not come on, or is flashing, the vehicle requires service. Do not drive the vehicle if the BRAKE light is flashing.

- If the EPB is applied while the vehicle is in motion, a chime will sound, and the DIC message Release Park Brake Switch will be displayed. The vehicle will decelerate as long as the switch is held in the up position. Releasing the EPB switch during the deceleration will release the parking brake. If the switch is held in the up position until the vehicle comes to a stop, the EPB will remain applied.

- If the BRAKE light is on, either the EPB is applied, or there is a failure in the hydraulic brake system.

- If the BRAKE light is flashing, the EPB is only partially applied or partially released, or there is a problem with the EPB. The DIC message Service Park Brake will be displayed.

If the BRAKE light is flashing, release the EPB, and attempt to apply it again. If the BRAKE light continues to flash, do not drive the vehicle.

figure 10
figure 10
figure 11
figure 11
figure 12
figure 12

- If the BRAKE light is on, the EPB has detected an error in another system and is operating with reduced functionality. To apply the EPB when the BRAKE light is on, lift up on the EPB switch and hold it in the up position. Full application of the parking brake by the EPB system may take a longer period of time than normal when the BRAKE light is on. Continue to hold the switch until the BRAKE light remains on. If the BRAKE light is on, the vehicle requires service.

- If the EPB fails to apply, the rear wheels should be blocked to prevent vehicle movement.

EPB Release - To release the EPB, turn the ignition switch to the ON/RUN position, apply and hold the brake pedal, and push down momentarily on the EPB switch. If you attempt to release the EPB without the brake pedal applied, a chime will sound, and the DIC message Press Brake Pedal to Release Park Brake will be displayed. The EPB is released when the BRAKE light is off and the DIC message Park Brake Released is displayed.

TIP: Be sure that the parking brake is fully released and the BRAKE warning light is off before driving.

- If the BRAKE light is on, the EPB has detected an error in another system and is operating with reduced functionality. To release the EPB when the BRAKE light is on, push down on the EPB switch and hold it in the down position. EPB release may take a longer period of time than normal when the BRAKE light is on. Continue to hold the switch until the BRAKE light is off. If the BRAKE light is on, the vehicle requires service.

Automatic EPB Release - The EPB will automatically release if the vehicle is running, placed into gear and an attempt is made to drive away. Avoid rapid acceleration when the EPB is applied, to preserve park brake lining life. The EPB can also be used to prevent roll-back for vehicles with a manual transmission taking off on a hill. In a situation where no roll-back is desired, an applied EPB will allow both feet to be used for the clutch and accelerator pedals in preparation for starting the vehicle moving in the intended direction. In this situation, perform the normal clutch and accelerator actions required to begin moving the vehicle. There is no need to push the switch to release the EPB.

DIC WARNINGS AND MESSAGES

- Park Brake Released - This message displays when the parking brake has been released from the set position.

- Park Brake Set - This message displays when the parking brake has been applied to the set position.

- Press Brake Pedal to Release Park Brake - This message displays if you try to release the park brake system without first pressing the brake pedal.

- Release Park Brake Switch - This message displays if the Park Brake switch is pulled while the vehicle is moving.

- Service Park Brake - This message displays if a problem is detected with the electric parking brake system that requires dealer/retailer service.

- Thanks to Amy Talerico
July 2008 issue of TechLink.