Principles of Operation
With the transmission in PARK, the powertrain control module (PCM) determines the PARK position from the digital transmission range (TR) sensor input. The PCM sends a message over the standard corporate protocol (SCP) communication link to the front electronic module (FEM). The FEM then allows operation of the convertible top.
The convertible top switch supplies a ground signal to the FEM. The FEM sends the signal to the rear electronics module (REM). The REM grounds the appropriate relay to raise or lower the convertible top.
When the raise or lower relay is operating, the other relay remains in its normal state supplying the motor/pump ground.