Description And Operation
The primary communication network between Electronic Control Units (ECUs) is the Controller Area Network (CAN) data bus system. The Controller Area Network (CAN) data bus allows all ECUs connected to the bus to share information with each other. Regardless of whether a message originates from an ECU on the higher speed CAN-Chassis (CAN-C1 and CAN-C2) (500K) bus or on the lower speed bus, CAN-IHS (125K) bus, the message structure and layout is similar, which allows the Body Control Module (BCM) to process and transfer messages between the CAN buses. The BCM stores Diagnostic Trouble Codes (DTCs) for certain bus network faults and is the CAN-C Network Manager.
DIGITAL NETWORKS
The vehicle features an electrical/electronic architecture called Next-Generation. Data transmission between the various ECUs in the Next-Generation architecture occurs through the following digital networks that use Stub and Daisy Chain architecture:
- CAN-C1 (high-speed 500 kb/s)
- CAN-C2 (high-speed 500 kb/s)
- CAN-IHS (medium-speed 125 kb/s)
There are two types of ECUs that can be connected to a CAN on this vehicle. An ECU connected in parallel (stub) and a ECU connected in series-parallel (daisy chained) having an internal connection that completes the rest of the CAN circuit. The CAN is still a series-parallel circuit, however, each module must remain connected in order to complete the circuit. The CAN use a two-wire bus using a twisted pair, where the wires are wrapped around each other to provide shielding from unwanted electromagnetic induction, thus preventing interference with the relatively low voltage signals being carried through them. While the CAN bus is operating (active), one of the bus wires will carry a higher voltage and is referred to as the CAN High or CAN bus (+) wire, while the other bus wire will carry a lower voltage and is referred to as the CAN Low or CAN bus (-) wire.
These networks and their subnetworks are protected by a Security Gateway Module (SGM).
CAN-C1
CAN-C1 reaches the DLC multiple diagnosis connector and The 120-ohm terminal resistors of the CAN-C1 are located in the BCM and in the ECM
The ECUs interconnected by the CAN-C1 are:
- BCM (Body Control Module)
- DLC (Data Link Connector)
- IPC (Instrument Panel Cluster)
- ETM (Entertainment Telematic Module - Infotelematic Module VP2 with Nav or VP4)
- ORC (Occupant Restraint Control - Airbag module)
- RFH (Radio Frequency Hub Module)
- DTCM (Drive Train Control Module - Transmission Module)
- ESM (Electronic Shifter Module - Automatic transmission selector lever module)
- ABS (Anti-lock Braking System Module)
- ACC (Adaptive Cruise Control Module)
- TCM (Automatic Transmission Control Module)
- ECM (Engine/Powertrain Control Module)
CAN-C2
The CAN-C2 manages the data which is exchanged at high speed between the ECU modules of the vehicle chassis.
The CAN-C2 is in the DLC multiple diagnosis connector and the 120-ohm terminal resistors are in the ABS module and the ORC Airbag module.
The control units interconnected by the CAN-C2 are:
- ABS (Anti-lock Braking System Module)
- BCM (Body Control Module)
- ESL (Electric Steering Wheel - Steering Lock Module)
- PAM (Parking Aid Module)
- EPS (Electric Power Steering Module.)
- HALF (Haptic Lane Feedback - Lane maintenance assistance module)
- ORC (Occupant Restraint Control)
CAN-IHS
The CAN-IHS manages the data exchanged at medium speed between the electronic modules which manage the passenger compartment comfort on the vehicle.
The control units interconnected by the CAN-IHS are:
- IPC (Instrument Panel Cluster)
- RRM (Radio Receiver Module)
- CSWM (Comfort Seat Wheel Module - Seat and Steering Wheel Heating Module)
- LBSS (Left Blind Spot Sensor)
- RBSS (Right Blind Spot Sensor)
- AMP (Amplifier - Hi-Fi system amplifier)
- HVAC (Heating Ventilation and Air Conditioning - Climate control module)
- BCM (Body Control Module)
The CAN-IHS is in the DLC multiple diagnosis connector.
The 120-ohm terminal resistors are in the BCM and the IPC module.
Refer to the appropriate SYSTEM WIRING DIAGRAMS COMMUNICATION service information to view the bus topologies and ECU bus assignments.
LINs
Some Modules dialogue with certain vehicle components via LINs. The BCM uses 4 LINs to dialogue with the following components:
- IBS (Intelligent Battery Sensor - negative battery terminal IBS)
- RLS (Rain Light Sensor - Rain sensor)
- SWS (Steering Wheel Switch bank)
- WCPM (Wireless Charging Pad Module - Wireless battery charger)
- ASBM (Auxiliary Switch Bank Module - controls on dashboard)
- ASBM2 (Auxiliary Switch Bank Module2 - controls on dashboard)
- RVCM (Rear View Camera Module)
- WSMP (Window Smart Motor Passenger)
- WSMD (Window Smart Motor Driver)
- CSWC (Cruise control Steering Wheel Commands)
There is a LIN line connecting the RFH module and the Run/Start starting button.