Theory Of Operation

The Electronic Shift Module (ESM) monitors the Brake Transmission Shift Interlock (BTSI) Solenoid (Gear Shift Lock Solenoid) circuits for electrical failures. If the BTSI Solenoid circuit is shorted to ground or battery, a DTC will set. The shift lever could be locked in the Park or Neutral position and not releasable, or the shift lever may not be able to lock at all.