For 1990-2009 cars

When the ignition switch is in the RUN position, the Brake Transaxle Shift Interlock (BTSI) system prevents the driver from shifting out of PARK without simultaneously pressing the brake pedal.

When the BTSI solenoid is energized, the BTSI solenoid locks the automatic transaxle control lever. The BTSI solenoid is de-energized when pressure is applied to the brake pedal. This releases the automatic transaxle control lever.