Diagnostic Aids
- Use a scan tool to verify there are no brake pedal position sensor and/or transmission internal mode switch (IMS) DTCs set that could cause the BCM not to provide battery voltage to the A/T shift lock solenoid.
- If the automatic transmission shift lock control circuit is shorted to battery positive voltage, the A/T shift lock solenoid will be inoperative. The vehicle will shift out of PARK without depressing the brake pedal, with Floor Shift. On vehicles with Column Shift the shifter will be locked in PARK.