Electronic Park Brake System

WARNING: This page is about a different car, the 2019 Buick Cascada, 2018 Buick Cascada, and 2017 Buick Cascada. However, it is still accessible from the selected car via links, so may be relevant.

In the electronic park brake (EPB) system the brake cables are pulled by the motor in the electric park brake control module (EPBCM). Refer to Electronic Parking Brake Description .

Instead of a park brake lever there is an electric switch in the mid-console. By pulling the switch upwards the park brake is activated and the park brake warning lamp in the IPC is illuminated. By pushing it downwards the park brake is released and the warning lamp goes out.

The motor in the EPCM pulls the cable to the right-hand rear wheel caliper. An equalizer is mounted on the cable and pulls the cable to the left-hand rear wheel.

The function is divided into:

Static apply/release
Dynamic apply/release
Automatic release

Static Apply/Release

Initial Vehicle Condition	Action Taken	Result
EPB released. Ignition OFF. Remove key and wait at least 30 seconds for the Bus to go to sleep	Lift switch	EPB applies Red tell-tale illuminates
EPB applied - Ignition OFF	Press switch	No operation
EPB applied - Ignition OFF, brake pedal applied	Press switch	No operation
EPB applied - Ignition in ACC	Press switch	EPB does not release DIC display = Press Brake Pedal to Release Park Brake Chime sounds
EPB applied - Ignition in ACC, brake pedal applied	Press switch	EPB releases Red tell-tale turns off
EPB applied - Ignition ON	Press switch	EPB does not release DIC display = Press Brake Pedal to Release Park Brake Chime sounds
EPB applied - Ignition ON, brake pedal applied	Press switch	EPB releases Red tell-tale turns off
EPB released - Ignition ON	Lift switch	EPB applies Red tell-tale illuminates
EPB released - Ignition in ACC	Lift switch	EPB applies Red tell-tale illuminates
EPB applied - Ignition in ACC	Ignition is OFF	Park Brake Set DIC message disappears after delay
Engine on, speed above 15 km/h	Lift and hold switch	If cruise control is on, cruise is disabled ESC controlled deceleration down to 6 km/h (4 mph) Red tell-tale illuminated Brake light applied Continuous chime above 15 km/h (9 mph) DIC display = Release Park Brake Switch (above 15 km/h (9 mph)) EPB static apply below 6 km/h (4 mph) DIC display = Park Brake Set Red tell-tale remains illuminated
Engine ON, speed between 6 - 15 km/h (4 - 9 mph)	Lift and hold switch	ESC controlled deceleration down to 6 km/h (4 mph) Red tell-tale illuminated Brake light applied No chime during vehicle motion No DIC message during vehicle motion EPB static apply below 6 km/h (4 mph) DIC display = Park Brake Set Red tell-tale remains illuminated
Engine ON, speed above 15 km/h (9 mph)	Lift and hold switch for several seconds	ESC controlled stop releases when switch is released. Tell-tale, brake light, chime and DIC go off after brief delay
ESC dynamic deceleration failed, but wheel speed available and pump working, vehicle speed above 15 km/h (9 mph)	Lift and hold switch	If cruise control is on, cruise is disabled ESC controlled deceleration down to 6 km/h (4 mph) Red tell-tale illuminated Brake light applied Continuous chime above 15 km/h (9 mph) DIC display = Release Park Brake Switch (above 15 km/h (9 mph)) EPB static apply below 6 km/h (4 mph) DIC display = Park Brake Set Red tell-tale remains illuminated
No wheel speed signals/ESC bus messages not valid, vehicle speed above 15 km/h (9 mph)	Lift switch and HOLD for at least 5 seconds, then release	EPB Slow Ramp Up to specified force Red tell-tale illuminated Brake light applied No chime due to missing speed signal No DIC display EPB statically applied after 5 seconds of continuous Apply button activation DIC display = Park Brake Set Red tell-tale remains illuminated
No brake pedal initial travel achieved signal/signal not valid, vehicle stopped, ignition ON, brake pedal NOT applied. EPB applied.	Press EPB switch for at least 2 seconds	EPB releases after pressing and holding switch for 2 seconds
Manual transmission, engine ON, clutch pedal applied. EPB applied.	Release clutch pedal Press accelerator pedal to drive forward/reverse	EPB releases for a smooth launch. Regulates according to grade.
Automatic transmission in gear, engine ON, brake pedal applied. EPB applied.	Release brake pedal Press accelerator pedal to drive forward/reverse	EPB releases for a smooth launch. Regulates according to grade.