Power Top - Operation

OPERATION

The single pane sunroof receives battery feed through a fused B(+) circuit from the Power Distribution Center (PDC). However, the on-board electronic module of the sunroof motor monitors an input on a fused ignition (run) circuit and is configured to only allow the power sunroof to be operated with the switch in the headliner when the ignition switch is in the ON position.

The electric motor and electronic module unit of the sunroof moves the sliding glass panel through the use of mechanical spiral drive cables as well as mechanical linkages and guides. See the Body system for additional information on these components. Sunroof - Description.

The on-board electronic module of the power sunroof motor provides both express (also known as one touch) and manual opening and closing based upon module programming and the inputs received from the power sunroof switch. The electronic module stores and recalls a sliding glass panel hard stop position, then counts the direction and number of motor rotations from that hard stop to enable the express open and close features. The hard stop must be learned by a service replacement motor and electronic module unit during an initialization procedure.

The electronic module also monitors the motor opening load through current draw, and the motor closing load through motor speed. Monitoring the motor load and speed is how the module logic is able to implement the obstacle detection (also known as Excess Force Limitation/EFL) feature. The EFL feature stops and reverses the sliding glass panel movement when an obstruction to sliding panel closing travel is encountered.

The power sunroof circuits and switches may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the on-board electronic module or the power sunroof motor. If there are no mechanical issues with the power sunroof assembly and the power sunroof switch and circuitry test okay, but the motor manual and express or EFL features are still ineffective following performance of the initialization procedure, the motor and electronic module unit must be replaced.