Power Sunroof - Operation

OPERATION

SINGLE PANE SUNROOF

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 - accessory) circuit and is configured to only allow the power sunroof to be operated with the switches in the overhead console when the ignition switch is in the ON or ACCESSORY positions, or using the accessory delay feature for a timed interval after the ignition is turned to the OFF position as long as neither front door has been opened.

The electric motor and electronic module unit of the sunroof moves the sliding glass panel through the use of mechanical drive cables as well as mechanical linkages and guides. 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 sunroof switches integral to the overhead console. 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 switches 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.

DUAL PANE SUNROOF AND SUNSHADE

The dual pane power sunroof sliding glass panel and power sunshade motors both receive battery feed through a fused B(+) circuit from the Power Distribution Center (PDC). However, the on-board electronic module of each sunroof or sunshade motor monitors an input on a fused ignition (run - accessory) circuit and is configured to only allow the power sunroof and the power sunshade to be operated with the switches in the overhead console when the ignition switch is in the ON or ACCESSORY positions, or using the accessory delay feature for a timed interval after the ignition is turned to the OFF position as long as neither front door has been opened.

The electric motor and electronic module unit of the sunroof or sunshade moves the sliding glass panel or the sunshade through the use of mechanical drive cables as well as mechanical linkages and guides. Sunroof - Description.

The on-board electronic modules integral to the power sunroof and sunshade motors provide both express (also known as one-touch) and manual opening and closing for their respective motors based upon module programming and the inputs received from the sunroof and sunshade switches integral to the overhead console. The electronic modules store and recall a sliding glass panel or a power sunshade hard stop position, then counts the direction and number of motor rotations from that hard stop to enable the express open and close features. These hard stops must be learned by a service replacement motor and electronic module unit during an initialization procedure.

In addition, the electronic modules are programmed to move only one motor at a time. The two motors communicate switch input information as well as sunroof and sunshade position information with each other through a serial bus circuit, but do not communicate with any other electronic modules in the vehicle. The electronic modules are programmed to move the sunshade out of the way into a safe mid-open position automatically before allowing the sliding glass panel to move. Likewise, if the sunshade switch is depressed to close the sunshade while the sliding glass panel is in an open position, the electronic modules are programmed to automatically close the glass panel before closing the sunshade.

The electronic modules also provide an obstacle detection (also known as Excess Force Limitation/EFL) feature for both the sliding glass panel and the sunshade. The modules each monitor motor closing load through motor speed. When an obstacle is detected due to a significant decrease in motor speed, the module will stop the motor closing motion while limiting the forces applied to the obstacle, then reverse the motor direction to allow the obstacle to be removed.

The electronic modules provide a thermal protection feature to protect the motors from abuse or overheating. If the motor is cycled enough to cause overheating, the software will allow one final closing cycle before it stops responding to further switch inputs. Once a motor has cooled sufficiently, normal operation will be automatically restored. However, the ignition switch must remain in the ON or ACCESSORY positions so that the module remains awake long enough to monitor the cool down of the motor.

The power sunroof and sunshade 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 modules or the power sunroof and power sunshade motors. If there are no issues with the power sunroof and sunshade mechanisms and the power sunroof or power sunshade switches and circuitry test okay, but the motor and express or EFL features are still ineffective following the initialization procedure, the motor and electronic module unit must be replaced.