Diagnostic Procedure
NOTE:
For connector terminal locations and wiring diagrams, see appropriate GENERAL MOTORS SHIFT INTERLOCK SYSTEMS article.
- Connect scan tool to DLC. Turn ignition switch to ON position. Using scan tool, command shift lock solenoid on and off. If shift lock solenoid turns on and off when commanded, go to DIAGNOSTIC AIDS . If shift lock solenoid does not turn on and off when commanded, go to next step.
- Turn ignition off. Disconnect shift lock solenoid harness connector. Solenoid is located at shifter mechanism. Turn ignition switch to ON position. Using test light connected to ground, probe coil side feed circuit of shift lock solenoid. If test light illuminates, go to next step. If test light does not illuminate, go to step 9 .
- Connect test light between control circuit of shift lock solenoid and coil side feed circuit of shift lock solenoid. Using scan tool, command shift lock solenoid on and off. If test light turns on and off with each command, go to step 7 . If test light does not turn on and off with each command, go to next step.
- If test light remains illuminated with each command, go to step 6 . If test light remains off with each command, go to next step.
- Check for short to voltage in shift lock solenoid control circuit. Repair as necessary. After repairs, go to step 12 . If shift lock control solenoid circuit is okay, go to step 8 .
- Check for short to ground in shift lock solenoid control circuit. Repair as necessary. After repairs, go to step 12 . If shift lock solenoid control circuit is okay, go to step 8 .
- Check for poor connections at shift lock solenoid. Repair as necessary. After repairs, go to step 12 . If connections at shift control solenoid are okay, go to step 10 .
- Check for poor connections at BCM harness connector. Repair as necessary. After repairs, go to step 12 . If harness connectors are okay, go to step 11 .
- Repair coil side feed circuit of shift lock solenoid. After repairs, go to step 12 .
- Replace shift lock solenoid. After repairs, go to step 12 .
- Replace BCM. After repairs, go to next step.
- Using scan tool, clear DTCs. Operate vehicle within conditions for running DTC. If DTC does not reset, repair is complete. If DTC resets, go to step 1 .