2003 Toyota Avalon Shifting out of PARK position

Hello

Excellent question... This is a safety lock. It is your Shift interlock control module. This prevents you from accidently putting it in gear and either the car moving forward through the front of the garage or reverse through the garage door. Much worse, hitting another car or a person.

SYSTEM OUTLINE

When the ignition SW is at ACC position, the current flows from ECU-ACC fuse to shift lock ECU TERMINAL ACC, and at ON position, the current flows from GAUGE NO.1 fuse to shift lock ECU TERMINAL IG.
1. SHIFT LOCK MECHANISM
When the signals that the brake pedal is depressed (Stop light SW ON) and the shift lever is placed in P position is input into the shift lock ECU while the ignition SW is ON, the shift lock ECU is activated and the current flows from shift lock ECU TERMINAL 10 to shift lock ECU TERMINAL SLS+ to shift lock solenoid to shift lock ECU TERMINAL SLS- to shift lock ECU TERMINAL E to GROUND.
As a result, the shift lock solenoid is turned on and (Plate stopper is released) the shift lever can be placed in a position other than P position.
2. KEY INTERLOCK MECHANISM
When the shift lever is placed to P position with the ignition SW ON or at ACC position, the current from shift lock ECU TERMINAL KLS+ to key interlock solenoid is cut off. As a result, the key interlock solenoid is turned off (The lock lever is released from lock position) and the ignition key can be placed to LOCK position from ACC.