Description And Operation

DESCRIPTION 

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The Body Control Module (BCM) is secured by three screws to the front bulkhead on the passenger side as shown in illustration (red module under the dashboard).

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Two fuse protection slots are also present on the front of the BCM to protect the various electrical components and systems.

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The BCM is equipped with eight connectors positioned on the front of the module. There are no connectors on the back of the module.

The BCM controls the following:

• Interior lighting
• Power windows
• Window function
• Door lock/unlock
• Decklid locking/unlocking
• Hood opening/closing switch
• Windshield wiper
• Headlight washers
• Fuel level
• External temperature
• Brake fluid level
• Brake pedal switch status acquisition
• Hazard light activation
• DNA driving mode selector status acquisition
• SDA button status acquisition (shock absorber damping electronic control system)
• Start & Stop enable button status acquisition
• Horn relay control.
• Lane Departure Warning (LDW) on/off button
• Power mirrors + Mirror heater
• Universal Garage Door Opener (UGDO)
• Gateway function for the CAN and LIN data bus networks.
• Vehicle configuration.

VIN Management 

The BCM module stores the following data in its Electronically Erasable Programmable Read-Only Memory (EEPROM):

• Original VIN
• Current VIN
• Blocked VIN

The "VIN locked" value may be "False" or "True". "False" means that the VIN is not locked in the BCM memory. "True" instead means that the VIN is locked in the BCM memory.

If the VIN is locked, the original VIN of the control module cannot be updated.

Logistics Mode 

In order to prevent the vehicle battery from discharging during transportation and storage before delivery to dealerships, the BCM is initially configured with the logistic mode enabled. When enabled, the BCM transmits "Logistic Mode ON" on the Controller Area Network (CAN) data bus network. Once that message is broadcast, all of the modules that are listening to the CAN bus deactivate their power loads as required by logistic mode function.

Using the diagnostic scan tool, the authorized server dealership can deactivate the logistic mode function in the BCM EEPROM to restore standard functions of the electrical system.

BCM Replacement - New Part 

In case of replacement, the BCM will be supplied by the FIAT with the software installed. Once the BCM is installed to the vehicle, the module must be programmed by connecting the diagnostic scan tool, navigating to the BCM menu and then launching the "ECU Replacement" routine. After performing a flash programming procedure on a BCM, the vehicle must be driven above 20kph (13 mph) to make sure all vehicle functions will operate normally.

OPERATION 

The BCM manages the Logistic mode function. Some electrical loads are deactivated when the function is active.

The Logistic mode can be deactivated using the diagnosis equipment (the command is in the "miscellaneous functions" menu of the BCM).

The configuration of the vehicle on those with Next-Generation architecture is called proxy. The proxy consists of a computer file with a maximum of 255 bytes. All modules requiring configuration will store a specific version of the proxy file. All other modules store only the part of the file pertaining to that module.

The BCM uses the proxy file to perform a vehicle configuration check when the ignition key is turned to the ON position. The BCM sends a proxy configuration code to proxy configured modules on all the networks. proxy configured modules will reply with their own configuration code. The BCM then compares the codes. If a code mismatch is detected, the BCM will set a Diagnostic Trouble Code (DTC). If the DTC is present for three ignition cycles, the BCM sends a message to the IPC to flash the odometer.

The following diagnosis functions are in the "Miscellaneous Functions" menu of the BCM:

1. Restore proxy configuration
2. Proxy alignment

Restoring the proxy configuration allows you to rewrite the proxy in the BCM via an internet connection and using the diagnostic scan tool.

Proxy alignment allows the BCM to send the appropriate part of the proxy to each individual module. For example If the Occupant Restraint Classification (ORC) module is replaced during servicing, it needs to receive the ORC proxy information from the BCM in order to configure itself. The BCM extracts the part relating to the ORC module from the proxy and sends it to the latter in a file.

The proxy alignment must always be carried out after running "restore vehicle configuration".