Initial Inspection and Diagnostic Overview

Principles of Operation-Automatic Parking Brake Release (Lincoln Navigator)
The automatic parking brake release consists of the following components:
^ Release actuator
^ Electromechanical solenoid
^ Gearshift lever position switch
^ Parking brake warning indicator switch
^ Wiring harnesses connecting the various components

When the parking brake is set and the gearshift lever is moved to "R" or "D", the gearshift lever position switch closes. The instrument cluster module energizes the parking brake return solenoid. Once the parking brake is released, the parking brake warning indicator switch opens, and the instrument cluster module's second signal releases the actuator. The solenoid is energized only when both the parking brake warning indicator switch and the gearshift lever position switch are closed with the brake pedal applied.

Inspection and Verification

1. WARNING: The electrical power to the air suspension system must be shut off prior to hoisting, jacking or towing an air suspension vehicle. This can be accomplished by turning off the air suspension switch located in the RH kick panel area. Failure to do so can result in unexpected inflation or deflation of the air springs, which can result in shifting of the vehicle during these operations.

Check the operation of the parking brake with the vehicle on a hoist and the parking brake control fully released. Check for any cable damage and install a new cable as necessary.
2. Check the parking brake by depressing the parking brake control pedal. The parking brake must fully set upon full apply.





3. Inspect to determine if one of the mechanical or electrical concerns apply.