Shift Interlock System: Other GMC Yukon Denali

BRAKE TRANSMISSION INTERLOCK SOLENOID

Note. Brake Transmission Shift Interlock (BTSI) solenoid may also be known as shift interlock actuator.

Gearshift lever cannot be moved from "P" position without depressing brake pedal if ignition is on. When pressure is applied to brake pedal, BTSI solenoid is de-energized to release gearshift lever from "P" position. Brakelight switch interrupts circuit to mechanically unlock gearshift lever by de-energizing BTSI solenoid. See WIRING DIAGRAMS .

PARK LOCK CABLE

Gearshift lever is locked in "P" 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 "P" position. Park lock cable is located on steering column. (Scheme 84)

Scheme 84

BTSI CONTROL INOPERATIVE

Note. Ensure Park/Neutral Position (PNP) switch is adjusted properly. See appropriate AUTOMATIC TRANSMISSION SERVICING article in TRANSMISSION SERVICING. Verify system operation after performing any repairs. See SYSTEM OPERATION CHECK under TROUBLE SHOOTING.

1. Connect test light between ground and PNP switch power feed circuit at PNP switch. Turn ignition on, engine off. If test light illuminates, go to next step. If test light does not illuminate, go to step 7 .
2. Ensure gearshift lever is in "P" position. Connect test light between ground and PNP switch signal circuit at PNP switch. If test light illuminates, go to next step. If test light does not illuminate, go to step 11 .
3. Connect test light between ground and PNP switch signal circuit at brakelight switch. If test light illuminates, go to next step. If test light does not illuminate, go to step 8 .
4. Connect test light between ground and brakelight switch signal circuit at brakelight switch. Depress and release brake pedal several times. If test light turns on and off with brake pedal movement, go to next step. If test light does not turn on and off with brake pedal movement, go to step 12 .
5. Connect test light between ground and brakelight switch signal circuit at BTSI solenoid. Depress brake pedal. If test light illuminates, go to next step. If test light does not illuminate, go to step 9 .
6. Connect test light between battery positive terminal and BTSI solenoid ground circuit at BTSI solenoid. If test light illuminates, go to step 13 . If test light does not illuminate, go to step 10 .
7. Repair open in PNP switch power feed circuit.
8. Repair open in PNP switch signal circuit.
9. Repair open in brakelight switch signal circuit.
10. Repair open in BTSI solenoid ground circuit.
11. Inspect for proper PNP switch adjustment. Inspect for poor connections at PNP switch. Repair as necessary. If condition was not corrected, replace PNP switch.
12. Inspect for poor connections at brakelight switch. Repair as necessary. If condition was not corrected, replace brakelight switch.
13. Inspect for poor connections at BTSI solenoid. Repair as necessary. If condition was not corrected, replace BTSI solenoid.

BTSI CONTROL ALWAYS ON WITH IGNITION ON

Note. Ensure Park/Neutral Position (PNP) switch is adjusted properly. See appropriate AUTOMATIC TRANSMISSION SERVICING article in TRANSMISSION SERVICING. Verify system operation after performing any repairs. See SYSTEM OPERATION CHECK under TROUBLE SHOOTING.

1. Disconnect brakelight switch. Turn ignition on, engine off. Depress and hold brake pedal. Attempt to move gearshift lever from "P" position. If gearshift lever moves from "P" position, go to step 4 . If gearshift lever does not move from "P" position, go to next step.
2. Turn ignition off. Disconnect BTSI solenoid. Turn ignition on, engine off. Depress and hold brake pedal. Attempt to move gearshift lever from "P" position. If gearshift lever moves from "P" position, go to next step. If gearshift lever does not move from "P" position, go to step 5 .
3. Repair short to battery voltage in brakelight switch signal circuit.
4. Inspect for poor connections at brakelight switch. Repair as necessary. If condition was not corrected, replace brakelight switch.
5. Inspect for poor connections at BTSI solenoid. Repair as necessary. If condition was corrected, replace BTSI solenoid.

Note. Brake Transmission Shift Interlock (BTSI) solenoid may also be known as shift interlock actuator. The following adjustment procedures applies to vehicles equipped with column shifter. Adjustment procedure for vehicles equipped with floor shifter is not available from manufacturer.

BTSI solenoid (actuator) is located on steering column. (Scheme 85) Pull locking tab outward from adjusting block. (Scheme 86) Press on adjusting block to disengage adjusting teeth. Slide adjuster block as far away from actuator as possible. Lock adjuster block in place by pushing inward on tab. Ensure proper system operation.

Scheme 85

Scheme 86

1. Lift cable lock button. Move gearshift lever to "P" position. Snap cable connector into shifter base. Ensure ignition switch is in ON position.
2. Snap cable housing into ignition switch inhibitor. Turn ignition switch to LOCK position. Snap cable end onto park lock lever pin. Remove slack from cable connector. Snap cable connector lock button down.