In order to release the electric/auto park brake, move the shift lever from the park (P) position. The pull button switch closes, allowing the current to flow to the solenoid valve. The solenoid valve closes and holds system pressure. The park brake pump motor switch opens at approximately 10 756 kPa (1,560 psi) and closes at 7 619 kPa (1,105  psi ), turning on the pump motor to supply fluid pressure to the actuator. A large spring inside the actuator applies the parking brake. Fluid pressure overcomes spring tension and moves the piston in the actuator. This movement is transferred to the parking brake through the parking brake cable. When the fluid pressure reaches approximately 3 792 kPa (550 psi) the pressure maintenance switch opens and the pump shuts off. The pressure maintenance switch opens and closes depending on system pressure. If the pressure drops too low (2 413 kPa (350 psi), the low pressure maintenance switch turns the pump back on in order to build the system pressure back to its working range.

Putting the shift lever back into park (P) or turning the ignition OFF de-energizes the parking brake solenoid, returning the fluid back to the reservoir. As the pressure decreases, the spring in the actuator moves the piston and applies the parking brake through movement of the parking brake cable.