Parking Brake System: Description and Operation

Park Brake System Description and Operation

Electronic Parking Brake System Components

The parking brake system consists of the following:

Electronic Parking Brake Control Module (EPBCM)

Transfers the electronic parking brake system (EPB) apply input force to the parking brake cable system.

Electronic Parking Brake Switch

Applied and released by the driver and activates the EPBCM or the electronic stability control (ESC) braking system.

Parking Brake Cable

Note:
Plastic coated parking brake cables do not need periodic lubrication.

Coated parking brake cables are used to reduce apply effort and increase corrosion protection. The cables are coated with a plastic material which slides against nylon seals inside the conduit end fittings.

Transfers the input force received from the EPBCM, through the parking brake cable equalizer, to the rear brake caliper actuation lever.

Parking Brake Cable Equalizer

Is mounted on the parking brake cable and distributes the parking brake force between the cable of the right-hand and the left-hand rear wheel.

Rear Brake Caliper Actuation Lever

Multiplies and transfers the input force from the parking brake cable to the mechanically apply of the rear disc brake calipers.

Disc Brake Caliper

Transfers the input force from the rear brake caliper actuation levers to the rear disc brake pads.

Disc Brake Pads

Applies the mechanical output force from the disc brake calipers to the friction portion of the rear disc brake rotors.

Electronic Parking Brake System Operation

Instead of a parking brake lever there is an electric switch in the mid-console. By pulling the switch upwards the parking brake is activated and the parking brake warning lamp in the instrument panel cluster (IPC) is illuminated. By pushing it downwards the parking brake is released and the warning lamp goes off. The driver's input is transmitted to the EPBCM. Refer to Electronic Parking Brake Control Module Description Description and Operation

In the EPB system the brake cables are pulled by the motor in the EPBCM.

The motor in the EPBCM pulls the parking brake cables. An equalizer is mounted on the output cable and distributes the parking brake force to the rear wheel brakes.

The function of the EPBCM is divided into:

* Static apply / release

* Dynamic apply / release