Parking Brake System: Description and Operation

PARKING BRAKE VACUUM RELEASE SYSTEM

The automatic release system consists of a vacuum diaphragm, mounted on the pedal assembly, which is connected to the HVAC programmer.
When the transmission selector lever is moved from PARK or NEUTRAL into any drive range or reverse, the BCM signals the HVAC programmer to provide vacuum to the diaphragm on the pedal assembly. The programmer then energizes the vacuum solenoid which is connected to the pink vacuum hose for a period of approximately ten seconds. Vacuum is applied to the parking brake release diaphragm on the pedal assembly.

When vacuum is applied, the parking brake release mechanism is engaged and the parking brake pedal, if applied, returns to the released position.

The HVAC programmer supplies vacuum to the release mechanism for no longer than ten seconds after the transaxle selector lever is moved into a drive or reverse range from PARK or NEUTRAL. Because of this time limitation, the parking brake will remain applied if it is applied in any drive range or reverse. To release the parking brake after it has been applied with the transaxle in drive or reverse, the transaxle selector must be moved to PARK or NEUTRAL and then back to DRIVE or REVERSE.