HIGH SHIFT EFFORT OUT OF PARK/ LOCKED IN PARK

SUBJECT: BRAKE-TRANSAXLE SHIFT INTERLOCK HIGH EFFORT/ LOCKED IN PARK

MODELS AFFECTED: 1991 DE VILLES AND FLEETWOODS

Some 1991 DeVille and Fleetwood owners may complain that their vehicle is difficult to shift out of park. This may be caused by the customer not following the proper shifting procedure for the Brake-Transaxle Shift Interlock (BTSI) system or may indicate the need for system adjustment. Outlined below is a description of proper system operation and diagnosis guidelines.

Normal Operation:

The shift interlock prevents the driver from shifting the vehicle out of park unless the brake pedal is fully depressed with the ignition switch in the run position. Once the brake pedal is fully depressed, the solenoid is de-energized. The BTSI lever then moves clear of the shift tube lever pin on the steering column shift tube lever allowing the gear selector to operate normally. Proper use of the system is outlined below.

Proper USE:

1. Ensure that the shift lever is resting in the park position under no tension.

2. Start the engine.

3. Apply the regular brakes by fully depressing the brake pedal.

4. Grasp the shift lever and shift as normal.

NOTE: It is extremely important that the above steps be followed in the order listed. Do not put any strain upon the shift lever prior to brake application. Doing so may cause increased shift efforts or a no-shift condition.

Diagnosis:

----------- Begin by testing the system for proper operation by performing the "proper use" steps above several times. If operation is repeatedly normal, instruct the owner in proper use of the system. A conscious effort to perform the "proper use" steps in the order listed should rectify most complaints. If operation is not repeatedly normal, follow the steps listed below to repair the condition. Verify that the shift cable is installed with no tension on the steering column shift tube lever.

1. Place the ignition lock cylinder in the "off " position.

2. Place the shift lever in the "neutral" position.

3. Unlock the shift cable to eliminate any tension in the shift cable at the transaxle shift arm.

4. Push the lock for the shift cable back down to lock the cable.

5. Return the shift lever to "park" position.

6. Check shift indicator for proper adjustment. If adjustment is required, refer to Service Information Manual Section 3F4, Shift Indicator Adjustment.

7. Check the neutral start switch for proper operation. If adjustment is required, refer to Service Information Manual Section 7A, Shift Control Cable, to adjust the shift cable.

Check the BTSI system for proper operation. If condition still exists, proceed to next step. Refer to Figures 1 and 2.

8. Loosen the bolts to the interlock and solenoid assembly through the steering column lower support bracket.

9. Move the interlock and solenoid assembly toward the steering column, approximately 2mm (1/8").

NOTE: Proper adjustment will place the shift tube lever pin approximately in the center of the BTSI lever channel.

10. Tighten the bolts for the interlock and solenoid assembly evenly to 16.0 N.m (12 lbs. ft.).

Check the BTSI system for proper operation. If condition still exists, repeat steps 8 through 10.

For warranty purposes use Labor Operation N3475 at .6 hour.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.