Shift Interlock: Description and Operation

BRAKE TRANSAXLE SHIFT INTERLOCK (BTSI)
The brake transaxle shift interlock (BTSI) system prevents the transaxle from being shifted out of the PARK position without the brake pedal being depressed while ignition is in RUN mode. When the brake pedal is depressed, the BCM receives the brake switch information over the serial data link from the engine control module (ECH), and energizes the shift interlock solenoid which allows the transaxle control assembly to be shifted out of PARK.
The transaxle can be shifted out of Park without the brake pedal being depressed if ignition key is in Acc.
In cold temperatures -40°C to -25°C (-40°F to -13°F), if the temperature gauge light is On, You will not be able to move the shift lever out of Park until the variable transaxle has warmed up. At engine idle the transaxle warm-up cycle may take up to two minutes. When the temperature gauge light goes out you may shift out of Park and have normal transaxle operation.
If the temperature is below -25°C (-13°F) the TCM will tell the BCM to inhibit shifting. To determine if the TCM is telling the BCM to inhibit shifting monitor the Scan tool parameter.
Under TCM, Transaxle Data List, Shifter Inhibit on the Scan tool either LOW TFT or NORMAL will be displayed. If LOW TFT is displayed then the TCM is telling the BCM to inhibit shifting.