Power Latch

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2007 GMC Yukon XL, 2007 GMC Yukon, 2007 Chevrolet Tahoe, 2007 Chevrolet Suburban, and 2007 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

The latch motor is a bi-directional motor and latch or unlatch operation is the result of the direction of the motor rotation. The liftgate module controls the latch motor through the control circuits by suppling power and ground in the appropriate polarity. The motor control circuits are monitored by the liftgate module prior to activation for a high or low condition and during motor operation for an insufficient current flow condition. The ratchet, pawl, and sector switches are part of the latch motor assembly and are used by the liftgate control module to determine the state of the latch during the process of latching or unlatching. Each of the latch switch signal circuits are supplied battery voltage through a resistor and monitored within the liftgate module. The latch switches share a common low reference circuit from the liftgate module and when the switch contacts close the signal circuit goes low and the liftgate module determines the switch to be active.

The handle switch and close switch are parallel circuits and provide a single input to the liftgate control module. The handle/close switch signal circuit is supplied battery voltage through a resistor and monitored within the liftgate module. The switches share a common low reference circuit from the liftgate module and when the switch contacts close the signal circuit goes low and the liftgate module determines the switch to be active.