Shift Interlock System GMC Yukon Denali GMT800

DESCRIPTION & OPERATION

INTRODUCTION

The automatic transmission shift lock control is a safety device that prevents an inadvertent shift out of Park when the ignition switch is ON. The driver must press the brake pedal before moving the shift lever out of the Park position. The system consists of the following components

1. Shift lock solenoid (also known as "shift lock actuator").
2. Shift lock control switch (stoplamp switch).
3. Park/Neutral Position (PNP) switch.

With the ignition switch in the ON position, battery positive voltage is supplied to the PNP switch. When the transmission is in Park, the contacts in the PNP switch are closed. This allows current to flow through the switch to the stoplamp switch. The circuit continues through the normally closed switch to the shift lock solenoid. The shift lock solenoid is permanently grounded. This energizes the shift lock solenoid, locking the shift linkage in the Park position. When the driver presses the brake pedal, the contacts in the stoplamp switch open, causing the shift lock solenoid to release. This allows the shift lever to move from the Park position.

ELECTRONIC COLUMN LOCK ASSEMBLY

Gearshift lever is locked in Park position when ignition switch is in LOCK position. With ignition on, gearshift lever is allowed movement to desired position. Ignition key cannot be removed until gearshift lever is returned to Park position. Electronic column lock is located on steering column. (Scheme 196)

Scheme 196

DIAGNOSTIC STARTING POINT

Begin the system diagnosis by reviewing DESCRIPTION & OPERATION . Reviewing the description and operation information will help you determine the correct symptom diagnostic procedure when a malfunction exists. Reviewing the description and operation information will also help you determine if the condition described by the customer is normal operation. See SYMPTOM DIAGNOSIS in order to identify the correct procedure for diagnosing the system and where the procedure is located.

Visual/Physical Inspection

Inspect for aftermarket devices which could affect the operation of the automatic transmission shift lock control system. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittents

Intermittent faulty electrical connections or wiring may be the cause of intermittent conditions. Check for loose, bent or corroded terminals and terminal tension. Check for cut, bare or pinched wiring. Simulate the condition that is potentially causing the intermittent connection, either by wiggling the connections or the wiring, test driving or performing other operations while observing scan tool, DVOM or other testing equipment. See WIRING DIAGRAMS .

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

1. Shift Lever Does Not Move With Brake Pedal Depressed.
2. Shift Lever Can Be Moved Without Brake Pedal Depressed.

See appropriate test under SYMPTOM TESTS .

SYMPTOM TESTS

SYMPTOM TEST INDEX

TEST A: SHIFT LEVER DOES NOT MOVE WITH BRAKE PEDAL DEPRESSED

Note. For circuit reference, see CONNECTOR IDENTIFICATION and WIRING DIAGRAMS .

1. Did you review SYMPTOM DIAGNOSIS and all the necessary inspections? If so, go to next step. If not, see SYMPTOM DIAGNOSIS under TROUBLE SHOOTING.
2. Turn ignition switch to the ON position. Depress the brake pedal. Attempt to move the gearshift lever out of the Park position. Does the gearshift lever move out of the Park position? If so, check for intermittent condition. See SYMPTOM DIAGNOSIS under TROUBLE SHOOTING. If not, go to next step.
3. Turn ignition switch to the OFF position. Disconnect the stoplamp switch. Turn the ignition switch to the ON position. Press and hold the brake pedal. Attempt to move the gearshift lever out of the Park position. Does the gearshift lever move out of the Park position? If so, go to step 6 . If not go to next step.
4. Turn ignition switch to the OFF position. Disconnect the shift lock solenoid. Turn the ignition switch to the ON position. Press and hold the brake pedal. Attempt to move the gearshift lever out of the Park position. Does the gearshift lever move out of the Park position? If so, go to step 7 . If not, go to next step.
5. Inspect shift lock solenoid for poor connections. Did you find and correct the condition? If so, go to step 10 . If not, go to step 9 .
6. Inspect the stoplamp switch for poor connections. Did you find and correct the condition? If so, go to step 10 . If not, go to step 8 .
7. Repair the short to battery voltage in the shift lock solenoid voltage supply circuit (Dark Green/White wire). After repairs, go to step 10 .
8. Replace the stoplamp switch. See STOPLAMP SWITCH under REMOVAL & INSTALLATION. After repairs, go to step 10 .
9. Replace the shift lock solenoid. See SHIFT LOCK SOLENOID under REMOVAL & INSTALLATION. After repairs, go to next step.
10. Operate the system in order to verify the repair. Did you find and correct the condition? If so, system is okay. If not, go to step 2 .

TEST B: SHIFT LEVER CAN BE MOVED WITHOUT BRAKE PEDAL DEPRESSED

Note. For circuit reference, see CONNECTOR IDENTIFICATION and WIRING DIAGRAMS .

1. Did you review SYMPTOM DIAGNOSIS and all the necessary inspections? If so, go to next step. If not, see SYMPTOM DIAGNOSIS under TROUBLE SHOOTING.
2. Turn ignition switch to the ON position. Apply the parking brake and block the wheels. Attempt to move the shift lever out of the Park position without pressing the brake pedal. Does the shift lever move out of the Park position? If so, go to next step. If not, see SYMPTOM DIAGNOSIS under TROUBLE SHOOTING.
3. Turn ignition switch to the OFF position. Ensure gearshift lever is in the Park position. Connect a test light between ground and the voltage supply circuit at the BTSI fuse (10-amp). Turn the ignition switch to the ON position. Does the test light illuminate? If so, go to next step. If not, go to step 8 .
4. Connect a test light between ground and the stoplamp switch voltage supply circuit (Light Green/Black wire) at stoplamp switch. Does the test light illuminate? If so, go to next step. If not, go to step 14 .
5. Connect a test light between ground and the stoplamp switch control circuit (Dark Green/White wire) at stoplamp switch. Press and release the brake pedal several times. Does the test light turn ON and OFF with the brake pedal? If so, go to next step. If not, go to step 11 .
6. Connect a test light between ground and the shift lock solenoid voltage supply circuit (Dark Green/White wire) at the shift lock solenoid. Does the test light illuminate? If so, go to next step. If not, go to step 15 .
7. Test the shift lock solenoid ground circuit (Black wire) for an open or high resistance. Did you find and correct the condition? If so, go to step 20 . If not go to step 12 .
8. Turn ignition switch to the OFF position. Disconnect the PNP switch connector. Connect a test light between ground and the PNP switch ignition feed circuit (Pink wire) at the PNP switch. Turn the ignition switch to the ON position. Does the test light illuminate? If so, go to next step. If not, go to step 13 .
9. Turn ignition switch to the OFF position. Connect a 10-amp fused jumper between the ignition feed circuit (Pink wire) and the park signal circuit (Light Green wire) at the PNP switch. Connect a test light between ground and the stoplamp switch voltage supply circuit at the BTSI fuse (10-amp). Turn the ignition switch to the ON position. Does the test light illuminate? If so, go to next step. If not, go to step 16 .
10. Inspect for proper PNP switch adjustment. See appropriate AUTOMATIC article in AUTOMATIC TRANSMISSIONS. Inspect the PNP switch for poor connections. Did you find and correct the condition? If so, go to step 20 . If not, go to step 17 .
11. Inspect the stoplamp switch for poor connections. Did you find and correct the condition? If so, go to step 20 . If not, go to step 18 .
12. Inspect the shift lock solenoid for poor connections. Did you find and correct the condition? If so, go to step 20 . If not, go to step 19 .
13. Repair the open or short in the PNP switch ignition feed circuit (Pink wire). After repairs, go to step 20 .
14. Repair the stoplamp switch voltage supply circuit (Light Green/Black wire) for an open or short. After repairs, go to step 20 .
15. Repair the open in the shift lock solenoid voltage supply circuit (Dark Green/White wire). After repairs, go to step 20 .
16. Repair the open or short in the PNP switch park signal circuit (Light Green wire). After repairs, go to step 20 .
17. Replace the PNP switch. See appropriate AUTOMATIC article in AUTOMATIC TRANSMISSIONS. After repairs, go to step 20 .
18. Replace the stoplamp switch. See STOPLAMP SWITCH under REMOVAL & INSTALLATION. After repairs, go to step 20 .
19. Replace the shift lock solenoid. See SHIFT LOCK SOLENOID under REMOVAL & INSTALLATION. After repairs, go to next step.
20. Operate the system in order to verify the repair. Did you find and correct the condition? If so, system is okay. If not, go to step 2 .

ADJUSTMENTS

Note. For additional adjustment procedure information, see appropriate AUTOMATIC article in TRANSMISSION SERVICING.

Note. For adjustment procedure, see ELECTRONIC COLUMN LOCK ASSEMBLY under REMOVAL & INSTALLATION.

SHIFT LOCK SOLENOID

Note. For adjustment procedure, see STOPLAMP SWITCH under REMOVAL & INSTALLATION.

REMOVAL & INSTALLATION

Note. Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

Note. Tools required: Steering Column Lock Plate Compressor (J-23653-SIR), Cam Orientation Plate Adapter (J-42137), and Ignition Switch Connector Release Tool (J-42759).

Removal

1. Disable the SIR system. See AIR BAG DEACTIVATION PROCEDURES article in GENERAL INFORMATION. Remove inflator module on steering wheel. Remove steering wheel and SIR coil. See appropriate STEERING COLUMNS article in STEERING.
2. Install the steering column lock plate compressor and cam orientation plate adapter to the steering shaft and compress the shaft lock shield (2). (Scheme 197) Remove the lock shield retainer from the steering column shaft. Remove the steering column lock plate compressor and cam orientation plate adapter from the steering shaft.
3. Remove the following components from the steering shaft: shaft lock shield (4) and turn signal cancel cam (3). (Scheme 198)
4. Rotate the steering column lock cylinder to the OFF-LOCK position. Insert a small screwdriver into the slot on the electronic lock module and push down on the park lock cable locking tab and remove park lock cable (1) from the electronic lock module. (Scheme 199) Rotate the key alarm switch connector from the electronic lock module.
5. Disconnect the passlock electrical connector from the electronic lock module. (Scheme 200) Remove the ignition lock cylinder. Disconnect the ignition switch (2) from the electronic lock module using the ignition switch connector release tool. (Scheme 201)
6. Remove the ignition switch (2) from the electronic lock module (2). (Scheme 202) Allow the ignition switch (2) to hang freely. Remove the electronic lock module (1) mounting screws (2). Remove the electronic lock module (1) from the steering column housing.

Installation

1. Install the electronic lock module (1) to the steering column housing. (Scheme 202) Install the electronic lock module (1) mounting screws (2). (Scheme 201) Install the ignition switch (2) to the electronic lock module (2). (Scheme 200) Install the ignition lock cylinder.
2. Connect the passlock electrical connector from the lock module. Rotate the key alarm switch connector to the electronic lock module. Install park lock cable (1) to the electronic lock module. (Scheme 199)
3. Install the following components to the steering shaft: turn signal cancel cam (3) and shaft lock shield (4). (Scheme 198)
4. Install the steering column lock plate compressor and cam orientation plate adapter to the steering shaft and compress the shaft lock shield (2). (Scheme 197) Install the lock shield retainer to the steering column shaft. Remove the steering column lock plate compressor and cam orientation plate adapter from the steering shaft.
5. Install the SIR coil, the steering wheel and inflator module. Enable the SIR system. See AIR BAG DEACTIVATION PROCEDURES article in GENERAL INFORMATION.

Scheme 197

Scheme 198

Scheme 199

Scheme 200

Scheme 201

Scheme 202

Remove the knee bolster screws. Unsnap the knee bolster. Twist the brake release cable in order to disengage the knee bolster. Remove the lap cooler hose. Remove knee bolster. (Scheme 203)

Install the lap cooler hose. Connect the brake release cable. Snap the knee bolster into the instrument panel assembly. Install the knee bolster screws. (Scheme 203) Tighten the knee bolster screws to 18 INCH lbs. (2 N.m).

Scheme 203

Note. Shift lock solenoid is also known as "shift lock actuator".

1. Disable the SIR system. See AIR BAG DEACTIVATION PROCEDURES article in GENERAL INFORMATION. Remove the knee bolster. See KNEE BOLSTER. Remove the body control module bracket. See appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
2. Place the shift lever clevis into the Neutral position. Disconnect the electrical connector.
3. Use a small screwdriver to pry the shift lock actuator away from the steering column jacket assembly and the cable shift cam assembly. (Scheme 204) Remove the shift lock actuator.

1. Firmly install the shift lock actuator onto the steering column jacket assembly and the cable shift cam assembly. Connect the electrical connector. Adjust the shift lock actuator (with the shift lever clevis in the Neutral position) as follows: Pull out the tab on the adjuster block side of the shift lock actuator. (Scheme 205) Press on the adjuster block to compress the internal adjuster spring which disengages the adjuster teeth. Slide the adjuster block as far away from the actuator as possible. Lock the adjuster block in place by pushing in on the tab. (Scheme 205) The shift lock actuator must lock the shift lever clevis when the shift lever clevis is put into the Park position. Depress the brake pedal to move the shift lever out of the Park position. The actuator will energize. Readjust the shift lock actuator if needed.
2. Install the body control module bracket. See appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT. Install the knee bolster. See KNEE BOLSTER. Enable the SIR system. See AIR BAG DEACTIVATION PROCEDURES article in GENERAL INFORMATION.

Scheme 204

Scheme 205

Disconnect the electrical connection from the stoplamp switch (2). Remove the pushrod retaining clip (4). (Scheme 206) Remove the stoplamp switch (2).

Install the stoplamp switch (2). Install the pushrod retaining clip (4). (Scheme 206) Connect electrical connection to the stoplamp switch (2). The stoplamp switch is self adjusting.

Scheme 206

Scheme 207

Scheme 208

Scheme 209

See also:
• DESCRIPTION & OPERATION
• SYMPTOM DIAGNOSIS
• SYMPTOM TESTS
• A
• B