Door Module - Operation

OPERATION

The microprocessor-based electronic front door control modules (also known as a Driver Door Module/DDM, a Passenger Door Module/PDM or Front Door Multiplex/MUX Modules) contain logic circuits that monitor various hard wired low current, multiplexed and Local Interface Network (LIN) data bus message external inputs from the power window, power lock, power mirror, power sliding door and memory switches on their respective doors. The front door control modules also monitor hard wired power window motor Hall effect sensors and memory mirror position sensor inputs. The logic circuits of the microprocessor-based electronic rear door control modules monitor hard wired low current and multiplexed inputs from the power window and sliding rear door ajar switches as well as from the sliding rear door cinch latches on their respective doors.

In addition, each door control module receives electronic message inputs from and shares its resources through electronic message outputs to other electronic control modules in the vehicle over the Controller Area Network (CAN) Interior High Speed (IHS) data bus network. The program logic within the door control module allows the microprocessor to prioritize all of these inputs and determine the tasks it needs to perform. These tasks are then completed either by controlling hard wired outputs to the various motor, actuators, lamps or displays contained on its own door or by sending electronic message requests over the CAN-IHS bus to the appropriate electronic module in the vehicle.

The door control modules are powered by a fused B(+) circuit and are grounded at all times so that they can operate regardless of the ignition switch position. The door control modules use On-Board Diagnostics (OBD) and communicate with a diagnostic scan tool using the CAN data bus.

The hard wired inputs and outputs of the door control module 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 door control module electronic controls or the communication between modules and other devices that provide some features of the power window, power lock, power mirror, power sliding door and memory systems. The most reliable, efficient and accurate means to diagnose the door control modules or the electronic controls and communication related to system operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.