GM Service Manual Online
For 1990-2009 cars only

The park lock solenoid is energized within the automatic transaxle control when the ignition is turned to one of the following positions:

    • OFF
    • RUN
    • BULB TEST
    • START

The energized park lock solenoid pulls the mechanical lock that is connected to the park lock solenoid away from the shifter. The Brake Transmission Shift Interlock (BTSI) solenoid is de-energized when the brake pedal is depressed. The de-energized BTSI solenoid pulls away the mechanical lock that is connected to the BTSI solenoid away from the shifter. You can move the shifter out of the PARK position at this point. The park position switch opens and de-energizes the steering column electric park lock when the vehicle is taken out of the PARK position. The mechanical lock within the ignition lock cylinder disables the ignition key from moving so the key cannot be taken out of the cylinder. The park position switch within the automatic transaxle control closes when the shifter is placed in the PARK position. The closed park position switch within the automatic transaxle supplies voltage to the steering electric park lock. The energized electric park lock pulls the mechanical lock in the ignition key cylinder away from the cylinder. The ignition key can then be turned to the LOCK position. The key can then be taken out of the cylinder.

The steering column components perform functions other than steering. The following components on the steering column perform the described functions:

    • The column
        The column absorbs energy. The column will compress in a front end collision in order to lessen the chance of injury to the driver.
    • The ignition switch and the lock mount on the column
        The ignition and the steering operations will lock in order to inhibit the theft of the vehicle with the column mounted lock.
    • The multifunction lever
        The multifunction lever provides control of the following components:
       - The headlamp high-beams
       - The cruise control
       - The windshield wiper and the washer

The column is easily disassembled and reassembled. Use the specified screws, bolts and nuts in order to ensure that the energy absorbing action occurs. Take special care in handling the column when the column is removed from the vehicle.

The plastic fasteners that maintain the column rigidity may shear or loosen if the following conditions exist:

  1. Use of a steering wheel puller other than the recommended puller
  2. A sharp striking on the end of the steering shaft or the shift lever
  3. Something is leaning on the column
  4. A dropped column