This vehicle with five modules capable of performing door system control functions. Vehicle door system components (windows, locks, mirrors, etc.) are controlled directly by these modules. There is a door module located inside of each vehicle door:

Simple Bus Interface (SBI)

Each Door Module communicates with the other Door Modules on the SBI. The LH Front Door Module (LFDM) is the only Door Module that is capable of communicating over the Class 2 Data Line as well as the SBI.

LH Front Door Module (LFDM)

LFDM directly controls the LH Front door lock actuator, power window motor and the power outside mirror. The LFDM sends and receives messages received from the LH Front Power Window Switch to the RFDM, LRDM and RRDM modules over the Simple Bus Interface (SBI) line. Also, the LFDM sends and receives message from other vehicle system modules via the Class 2 Data Line.

RH Front Door Module (RFDM)

RFDM controls the RH Front door lock actuator, power window motor, and outside rearview mirror. The RFDM recieves direct inputs from RH Front Door Lock Switch, RH Front Power Window Switch, and the RH Front Door Jamb Switch. The RFDM sends and receives messages from the LFDM, LRDM, and the RRDM via the SBI.

Left Rear Door Module (LRDM)

The LRDM controls the Left Rear door lock actuator and power window motor. The LRDM recieves direct inputs from the Left Rear Door Lock Switch, Left Rear Power Window Switch, and the Left Rear Door Jamb Switch. The LRDM sends and receives messages from the LFDM, RFDM, and the RRDM via the SBI.

Right Rear Door Module (RRDM)

The RRDM controls the Right Rear door lock actuator and power window motor. The RRDM recieves direct inputs from the Right Rear Door Lock Switch, Right Rear Power Window Switch, and the Right Rear Door Jamb Switch. The RRDM sends and receives messages from the LFDM, RFDM, and the LRDM via the SBI.

LH Front Power Window Switch (LFPWS) Assembly

The LFPWS Assembly provides messages for controlling the power door locks, power windows, and outside mirrors to the LFDM via the SBI. The LFPWS Assembly receives direct inputs from the LH Front Power Door Lock Switch and Memory Function Switch.

Door Module Functions

Each Door Module is capable of performing multiple door control functions. The Door Module outputs control the door system components that are directly connected to that Door Module. Each Door Module controls the outputs using this input information received from the sensors and the switches directly connected to the Door Module. The Door Module also borrows information from other systems on the serial data line in order to control the outputs. The Door Module evaluates this information and commands an output ON or OFF in order to control certain body systems. The Door Module also commands other systems to control systems that are not directly wired to the Door Module. The Door Module accomplishes this by sending specific messages on the serial data line. The system capable of performing this function will respond to the message.

Each Door Module is capable of performing the following functions:

LH Front Door Module Wake-up/Sleep States

The LFDM, which is the power mode master, is responsible for sending a power mode message on the SBI and Class 2 data line to other systems. When the power mode message is sent, other systems respond to this message by entering a power-up state and sending a State of Health Code (SOH) code message. This SOH message indicates they are able to communicate information between other systems.

The LFDM is able to control or perform all of the LFDM functions in the wake-up state. The LFDM enters the sleep state when active control or monitoring of system functions has stopped, and the LFDM has become idle again. The LFDM must detect certain wake-up inputs before entering the wake-up state and monitors these inputs during the sleep state. The LFDM is able to detect switch transitions that cause the two wake-up states, activated or deactivated. Multiple switch wake-ups are need in order to sense both the insertion and the removal of the ignition key.

The LFDM will enter a wake-up state if any of the following wake-up inputs are detected:

The LFDM will enter a sleep state when all of the following conditions exist:

If all these conditions are met the LFDM will enter a low power or sleep condition. This condition would indicate the LFDM, which is the power mode master of the vehicle, must have sent a message to the other systems on the serial data line to stop broadcasting their state of health message.

Power Requirements

The LFDM has two main power feeds (high and low current), and two main grounds. The low power feed (battery 1) is used to provide power for the LFDM's logic and internal driver operation. The high power feed (battery 2) is used to provide power for systems that draw higher amounts of current (motors, lights, etc.). Operating current at the LFDM's battery should not exceed 3.0 amperes at battery 1, and 7.5 amperes (for 2  seconds) at battery 2 while the LFDM is awake, and 2.5 milliamps when the LFDM is asleep. For most LFDM functions, the LFDM will operate properly with a system voltage of 9.0-16.0 volts. If system voltages exceed 16.0 volts the LFDM will provide protection by disabling certain functions that may damage due to higher than normal system voltages.

LFDM Input/Output Information

The following components provide direct input to the LFDM. Other systems can use this input information in order to carry out certain functions:

LFDM Inputs

The LFDM directly controls the following outputs. Other systems may request the LFDM to control these outputs for certain functions:

LFDM Outputs

LFDM Fail-Soft Condition

If a particular LFDM malfunction would result in unacceptable system operation, the LFDM takes a fail-soft action in order to minimize the condition. A typical fail-soft action would be the substitution of a fixed input or output value when the LFDM is unable to interpret data correctly.