Circuit Operation

The park relay is supplied battery voltage by the PARK/REV fuse through CKT 1940 (ORN) to terminal A1 and ignition voltage by the CRUISE fuse through CKT 339 (PNK) to terminal A3.The Body Control Module (PZM) receives park/neutral position switch status from the Powertrain Control Module (PCM)via the Class 2 serial data line CKT 1807 (PPL). When the PZM determines that the vehicle is in PARK, it energizes the park relay by grounding CKT 434 (ORN/BLK). Once the park relay is energized, voltage is supplied from terminal B3 of the park relay to terminal A of the stoplamp/btsi switch through CKT 275 (LT BRN). When the brake pedal is in the rest position (not pressed), battery voltage is supplied from terminal B of the stoplamp/BTSI switch through CKT 1135 (DK GRN/WHT) to terminal A of the shift interlock solenoid. The solenoid, grounded by CKT 850 (BLK) or CKT 50 (BLK), energizes, locking the gear shifter in PARK. When the brake pedal is in the applied position (pressed), the stoplamp/BTSI switch opens, removing the voltage from the shift interlock solenoid. The solenoid dc-energizes, unlocking the gear shifter. When the PZM determines that the vehicle is no longer in PARK it de-energizes the park relay, unlocking the gear shifter.