Chevrolet Equinox Service Manual: Automatic Transmission Shift Lock Control Description and Operation Transmission Control Shift Interlock

The automatic transmission park lock control system is asafety device that prevents an inadvertent shift out of PARK. Thedriver must press the brake pedal before moving the park lever outof the PARK position. The system consists of the followingcomponents:

The automatic transmission park lock solenoid (serviced asthe automatic transmission shift lock actuator), is located withinthe floor shift control assembly.The body control module, which controls the voltage supplycircuit of the park lock control solenoid.The engine control module.

The body control module controls the voltage to the park lockcontrol solenoid through the park lock control solenoid controlledvoltage circuit. The following conditions must be met before thebody control module will supply voltage to the park locksolenoid:

The ignition is in the ON position.The engine control module sends an input via GMLAN serialdata to the body control module indicating the transmission is inthe PARK position.The body control module determines the brake pedal is appliedaccording the brake pedal position.

Since the park lock control solenoid is permanently grounded,the body control module supplies voltage to the automatictransmission park lock control solenoid, unlocking the park leverallowing the driver to move the park lever out of the PARK positionas the solenoid energizes. When the brake pedal is not applied, thebody control module turns the control voltage output of the parklock control solenoid OFF, de-energizing the park lock controlsolenoid. The de-energized solenoid mechanically locks the parklever in the PARK position.