Power Roof Operation

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2004 Oldsmobile Bravada, 2004 GMC Envoy XUV, 2004 GMC Envoy XL, 2004 GMC Envoy, and 2004 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.

The power roof can be opened or closed using the power roof switch in the overhead console or the end gate key cylinder switch. The endgate window must be in the full down position before the power roof can be opened, and remain down until the roof has been closed. When attempting to open the power roof from the overhead console switch and the endgate window is not in the full down position, the power roof module will command the end gate module to express down the endgate window before the roof can be opened. When opening the endgate window and power roof from the endgate key cylinder switch, the cylinder must by turned and held in the open position until the window is in the full down position. Once the window has stopped in the down position the cylinder must be released to the neutral position then again turned and held to the open position for the endgate module to command the power roof module to open the roof. If the open or close request cannot be completed, the appropriate status will be provided to the operator via a message displayed on the driver information center.

The midgate window, power roof, and endgate window switches in the overhead console are inputs to the power roof module and the endgate key cylinder switch is an input to the endgate module. The switch signal circuits to the power roof module are referenced from battery voltage within the module and are driven low when a switch is active. The endgate module and power roof module communicate switch inputs and power roof and endgate window status information through the Class 2 Serial Data circuit to ensure the proper sequence of roof and window operation is followed. The power roof motor is controlled by the power roof module through 2 motor control circuits. In an idle state the control circuits are floating and open or close motor operation occurs when the module switches the open and close control circuits to it's high current battery supply and ground. The power roof module continuously monitors roof panel operation and calculates it's location and direction of travel using 2 hall effect sensors located on the power roof motor. The hall effect sensors are 3 wire sensors and are supplied with high reference, low reference, and signal circuits from the power roof module. The hall effect sensor signal circuits are referenced from battery voltage within the power roof module and pulsed low by the hall effect sensors.