Ford Fusion: Multifunction Electronic Modules / Module Controlled Functions - System Operation and Component Description. Description and Operation

System Operation

Battery Saver

The battery saver feature is use to save battery voltage. The BCM provides automatic shut-off of the interior and exterior lamps after a time-out period when the ignition is off.

For more information regarding the exterior lighting battery saver feature,
Refer to: Exterior Lighting (417-01 Exterior Lighting) .

For more information regarding the interior lighting battery saver feature,
Refer to: Interior Lighting (417-02 Interior Lighting) .

Automatic Engine Idle Shutdown

The automatic engine idle shutdown feature monitors the state of the vehicle to determine when the engine is running with no user interaction for an extended period of time. When this condition is detected, the vehicle informs the operator that a shutdown is imminent and if the driver does not intervene, the engine shuts down.

For more information regarding the automatic engine idle shutdown feature,
Refer to: Passive Anti-Theft System (PATS) (419-01 Passive Anti-Theft System (PATS) - Vehicles With: Push Button Start) .

Battery Load Shed

The BCM uses the battery current sensor to keep track of the battery state of charge in order to save the remaining battery charge when necessary.

For more information regarding the battery load shed feature,
Refer to: Charging System - System Operation and Component Description (414-00 Charging System - General Information, Description and Operation).

Post Crash Alert Function

The BCM controls the post crash alert function. If the RCM determines an impact of enough severity has occurred (the airbags may or may not be deployed), the post crash alert function activates. The post crash alert function activates the hazard lamp function and cycles the horn on 3 times, then off for 4.5 seconds, and repeats this cycle until the battery is discharged or the function is turned off.

The post crash alert function can be turned off by:

• pressing the hazard flasher lamp switch (which may need to be pressed twice).
• pressing the transmitter unlock button.
• pressing the RKE transmitter PANIC button.

Field Effect Transistor (FET) Protection

A Field Effect Transistor (FET) is a type of transistor that, when used with module software, monitors and controls current flow on module outputs. The Field Effect Transistor (FET) protection strategy prevents module damage in the event of excessive current flow.

The BCM utilizes a Field Effect Transistor (FET) protective circuit strategy for many of its outputs (for example, a headlamp output circuit). Output loads (current level) are monitored for excessive current (typically short circuits) and are shut down (turns off the voltage or ground provided by the module) when a fault event is detected. A short circuit DTC is stored at the fault event and a cumulative counter is started.

When the demand for the output is no longer present, the module resets the Field Effect Transistor (FET) circuit protection to allow the circuit to function once again. The next time the driver requests a circuit to activate (again, for example, the headlamps) that has been shut down by a previous short (Field Effect Transistor (FET) protection) and the circuit is still shorted, the Field Effect Transistor (FET) protection strategy again shuts off the circuit and increments the counter.

When the excessive circuit load / short occurs often enough, the BCM shuts down the specific circuit output. This occurs when certain programmed thresholds are reached, 1/3, 2/3, and 3/3 of the total tolerance level. In conjunction with the Field Effect Transistor (FET) shutdown, a DTC U1000:00 is set along with the short circuit DTC, for example B1D00:11. These Diagnostic Trouble Codes (DTCs) cannot be cleared until the shorted circuit is repaired.

After the repair of the shorted circuit it is mandatory to clear the Diagnostic Trouble Codes (DTCs) from the BCM so that it can reset the shut down Field Effect Transistor (FET) and function correctly again, Use the clear the Diagnostic Trouble Codes (DTCs) operation on the scan tool, then cycle the ignition, and re-run the BCM on-demand self-test. If the DTC U1000 and short circuit Diagnostic Trouble Codes (DTCs) are no longer shown than this indicates that the BCM has reset and the short has been repaired.

However, when the number of short circuit fault events reaches the final third level (3/3), DTCU3000:49 is set along with DTC U1000:00 and the associated short circuit DTC. DTC U3000:49 cannot be cleared and the BCM must be replaced after the initial fault is repaired.

Transport Mode

During vehicle build, some modules (such as the IPC and the BCM) are set to factory mode. When the vehicle build is complete, the vehicle is set to transport mode.

Transport mode reduces the drain on the battery during longer periods when the vehicle is not used. Various system functions can be altered or disabled when in the transport mode. While in transport mode, the IPC displays TRANSPORT MODE CONTACT DEALER in the message center. Transport mode can be disabled and placed into normal operation mode.
Refer to: Transport Mode Deactivation (419-10 Multifunction Electronic Modules, General Procedures).

Component Description

BCM

The BCM is a multifunction module that requires a PMI when replaced.
Refer to: Module Configuration (418-01 Module Configuration) .

DSM

The driver seat control switch and power memory seat motors are hard-wired to the DSM. The DSM controls the operation of the power memory seat. The DSM communicates on the MS-CAN. The DSM hard stop/soft stops must be set/reset any time a new DSM, driver seat track or driver seat backrest is installed. The DSM requires PMI when replaced.

DDM

The DDM receives power window commands from the driver door window control switch through a LIN. The DDM supplies voltage and ground to operate the driver door window regulator motor.

The DDM also communicates driver door window control switch requests to the Driver Rear Door Module (DRDM) through a LIN and to the PDM through the MS-CAN.

For the power mirror function, the DDM controls the LH exterior mirror glass position by supplying voltage and ground to the LH exterior mirror motors based on inputs from the exterior mirror control switch. When the RH exterior mirror is selected, the DDM forwards the movement requests to the PDM through the MS-CAN. To control the heated mirror function, the DDM supplies voltage and ground to the LH exterior mirror glass heating element based on messages received from the FCIM. For the memory mirror function, the DDM supplies voltage and ground to the LH mirror motor potentiometers. The DDM monitors the feedback from these potentiometers to determine the mirror glass position. Memory mirror positions are stored in the DDM memory.

PDM

For the power window function, the PDM receives power window commands from the passenger door window control switch or from the DDM through the MS-CAN. The PDM supplies voltage and ground to operate the passenger door window regulator motor.

The PDM also communicates driver door window control switch requests to the Passenger Rear Door Module (PRDM) through a LIN.

For the power mirror function, the PDM controls the RH exterior mirror glass position by supplying voltage and ground to the RH exterior mirror motors based on messages received from the DDM. To control the heated mirror function, the PDM supplies voltage and ground to the RH exterior mirror glass heating element based on messages received from the FCIM. For the memory mirror function, the PDM supplies voltage and ground to the RH mirror motor potentiometers. The PDM monitors the feedback from these potentiometers to determine the mirror glass position. Memory mirror positions are stored in the PDM memory.

Driver Rear Door Module (DRDM)

The Driver Rear Door Module (DRDM) receives power window commands from the LH rear window control switch or from the DDM through a private LIN. The Driver Rear Door Module (DRDM) supplies voltage and ground to operate the LH rear power window motor.

Passenger Rear Door Module (PRDM)

The Passenger Rear Door Module (PRDM) receives power window commands from the RH rear window control switch or from the PDM through a private LIN. The Passenger Rear Door Module (PRDM) supplies voltage and ground to operate the RH rear power window motor.

RTM

The RTM communicates all RKE and passive key information to the BCM over a LIN circuit and (when the network is awake) the CAN. The RTM is an antenna that receives the high frequency signals from Integrated Keyhead Transmitters (IKTs) and passive keys. The RTM requires PMI when replaced.