Lumina V6-191 3.1L VIN T MFI (1993)
Shift Interlock: Symptom Related Diagnostic Procedures
Trans Won't Disengage Park W/Ignition @ Run & Brake Pedal Up
1. Place gear selector in Park and turn ignition switch to Run.
2. Using a test lamp, backprobe BTSI solenoid between terminal "A" and ground. It test lamp does not light, proceed to step 3. If test lamp lights, check
BTSI ground circuit. If ground circuit is satisfactory, replace BTSI solenoid.
3. Using a test lamp, backprobe stop lamp switch connector terminal between stop lamp switch and BTSI solenoid. If test lamp does not light, check for
an open in circuit between fuse panel and stop lamp switch. If circuit is satisfactory, adjust or replace stop lamp switch. If test lamp lights, find and repair
open in circuit between stop lamp switch and BTSI solenoid.
Trans Won't Shift Out of Park W/Brake Down & Ignition @ Run
1. Place gear selector in Park and turn ignition switch to the Run position.
2. Disconnect stoplamp switch connector.
3. Using a test lamp, backprobe BTSI solenoid between terminal "A" and ground. If test lamp does not light, proceed to step 4. If test lamp lights, repair
short to battery voltage in circuit from stop lamp switch to BTSI solenoid.
4. Reconnect stop lamp switch.
5. Depress brake pedal and backprobe circuit between stop lamp switch and BTSI solenoid with a test lamp. If test lamp lights, adjust or replace stop
lamp switch. If test lamp does not light, check shift linkage for binding. If linkage is satisfactory, replace BTSI solenoid.
