System Operation
BCM
The BCM controls various systems by monitoring inputs from switches, sensors and network messages from other modules and components on the HS-CAN1, LIN and the GWM. Based on the inputs, the BCM activates outputs. For example, the BCM monitors the HCM inputs and provides voltage to the exterior lamps.
BCMC
The BCMC controls various systems by monitoring inputs from switches, sensors and network messages from other modules and components on the HS-CAN1. Based on these inputs, the BCMC activates outputs. For example, the BCMC monitors the HVAC controls inputs and provides voltage to the blower motor and/or the A/C clutch.
Battery Load Shed
The BCM
monitors the battery state of charge and, when necessary, shuts off
accessories to save the remaining battery charge. For additional
information,
Refer to: Charging System - System Operation and Component Description (414-00 Charging System - General Information, Description and Operation).
Battery Management
The battery management feature is used to conserve battery voltage. The BCM
provides automatic shut-off of the interior lamps after a time-out
period when the ignition is off. For additional information,
Refer to: Charging System - System Operation and Component Description (414-00 Charging System - General Information, Description and Operation).
Car Configuration Parameters
The parameters are set in the BCM. The parameters are also set in the IPC as backup data for service, in case online As-Built data is not available. For additional information,
Refer to: Module Configuration - System Operation and Component Description (418-01 Module Configuration, Description and Operation).
Factory-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 in use. Various system functions can be altered or disabled when in the transport mode. While in transport mode, the IPC displays TRANSPORT MODE in the message center. Transport mode can be disabled and placed into normal operation mode.
Field Effect Transistor (FET) Protection
The BCM utilizes a Field Effect Transistor (FET) protective circuit strategy for many of its outputs, for example, lamp output circuits. 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 FET is a type of transistor that the control module software uses to control and monitor current flow on module outputs. The FET protection strategy prevents module damage in the event of excessive current flow.
Output loads (current level) are monitored for excessive current draw (typically short circuits). When a fault event is detected the FET turns off and a short circuit DTC sets. The module resets the FET protection and allows the circuit to function when the fault is corrected or the ignition state is cycled off and then back on.
When the excessive circuit load occurs often enough, the module shuts down the output until a repair procedure is carried out. Each FET protected circuit has 3 predefined levels of short circuit tolerance based on a module lifetime level of fault events based upon the durability of the FET. If the total tolerance level is determined to be 600 fault events, the 3 predefined levels would be 200, 400 and 600 fault events.
When each level is reached, the DTC associated with the short circuit sets along with DTC U1000:00. These Diagnostic Trouble Codes (DTCs) are cleared using the module on-demand self-test, then the Clear DTC operation on the scan tool (if the on-demand test shows the fault corrected). The module never resets the fault event counter to zero and continues to advance the fault event counter as short circuit fault events occur.
If the number of short circuit fault events reach the third level, then Diagnostic Trouble Codes (DTCs) U1000:00 and U3000:49 set along with the associated short circuit DTC. DTC U3000:49 cannot be cleared and the module must be replaced after the repair.
Post-Crash Alert Function
The post-crash alert is a function controlled by the BCM. 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:
The post-crash alert function can be turned off by:
Component Description
BCM
The BCM is a multifunction module that requires PMI when replaced.
Refer to: Module Programming (418-01 Module Configuration, General Procedures).
BCMC
The BCMC is a multifunction module that requires PMI when replaced. For additional information,
Refer to: Module Programming (418-01 Module Configuration, General Procedures).
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 PDM through the MS-CAN.
For the power mirror functions, the DDM operates as follows:
For additional information:
The DDM requires PMI when replaced.
For additional information,
Refer to: Module Programming (418-01 Module Configuration, General Procedures).
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.
For the power mirror functions, the PDM operates as follows:
For additional information:
The PDM requires PMI when replaced.
For additional information,
Refer to: Module Programming (418-01 Module Configuration, General Procedures).
RTM
The RTM communicates all RKE and passive key information to the BCM over a LIN circuit and when awake the CAN. The RTM is an antenna that receives the high frequency signals from passive keys. For additional information:
The RTM requires PMI when replaced.
Refer to: Module Programming (418-01 Module Configuration, General Procedures).
The intelligent access key must be within 3 ft (1 m) of the door or luggage compartment you intend to lock or unlock.
At a Door
Electronic door handles are on each door. Gently depress the switch inside the exterior door handle to unlock and open the door. An unlock symbol illuminates on the door window trim indicating your vehicle is unlocked.