Communications Network
COMMUNICATIONS NETWORKPowertrain Control Module (PCM)
The PCM is located in the instrument panel on the right side behind the glove compartment. The PCM is on the standard corporate protocol (SCP) communication network. The PCM controls the engine for better fuel economy, emissions control, failure mode detection and storage. Refer to the Computers and Control Systems for diagnosis and testing of the PCM.
Anti-Lock Brake/Traction Control (ABS/TC) Module or Stability Assist Module
The anti-lock brake system/traction control (ABS/TC) module or stability assist module are on the SCP communication network. The ABS/TC module or stability assist module controls the brake pressure to the four wheels to keep the vehicle under control while braking.
Restraint Control Module (RCM)
The RCM is located under the center console towards the instrument panel. The RCM is on the international stardards organization (ISO) 9141 network. The RCM controls the deployment of the airbags based on sensor input.
Dual Electronic Automatic Temperature Control (DEATC) Module
The DEATC module is located in the instrument panel below the radio. The DEATC module is on the SCP communication network. The DEATC module controls automatic climate functions that maintain the vehicle interior temperature at a constant setting.
Instrument Cluster
The instrument cluster is located in the instrument panel above the steering column. The instrument cluster is on the SCP communication network. The instrument cluster serves as a universal asynchronous receiver-transmitter (UART)-based protocol (UBP) gateway to communicate to other modules on the UBP communication network. The instrument cluster displays a variety of information.
Tire Pressure Monitoring System Module
The tire pressure monitoring system module is located behind the right side C-pillar trim. The tire pressure monitoring system module is on the SCP communication network. The tire pressure monitoring system module uses one sensor mounted in each tire to sense low tire pressure. When low tire pressure is sensed, the module will send a warning to the driver.
Variable Assist Power Steering (VAPS) Module
The VAPS module is located behind the instrument panel behind the glove compartment. The VAPS module is on the SCP communication network. The VAPS module controls and varies the power steering effort needed at different vehicle speeds.
Driver Seat Module (DSM)
The DSM is located under the driver seat. The DSM is on the UBP communication network. The DSM controls the positioning and programming of the driver seat, pedals and both outside mirrors.
Vehicle Security Module
The vehicle security module is located behind the right rear quarter trim panel. The vehicle security module is on the UBP communication network. The vehicle security module controls the keyless entry functions for the vehicle.
Driver Climate Controlled Seat Module
The driver climate controlled seat module is located under the driver seat. The driver climate controlled seat module is on the UBP communications network. The driver climate controlled seat module controls the heating elements in the seat for passenger comfort.
Passenger Climate Controlled Seat Module
The passenger climate controlled seat module is located under the passenger seat. The passenger climate controlled seat module is on the UBP communications network. The passenger climate controlled seat module controls the heating elements in the seat for passenger comfort.
Parking Aid Module
The parking aid module is located in the right rear quarter trim panel towards the rear. The parking aid module is connected to the ISO 9141 communication module. The module controls sensors in the rear bumper that detect close objects when the vehicle is in reverse.
Four-Wheel Drive (4WD) Control Module
The one speed, all wheel drive (AWD) system utilizes a fully automatic, torque on demand (TOD) transfer case without a shifter motor. The AWD system is controlled by the 4WD control module, which is located in the center console towards the instrument panel. The 4WD control module is on the UBP communications network. The 4WD control module engages and disengages the transfer case between 2WD and 4WD when more traction is required.
Navigation System Module
The navigation system module is located behind the rear seat under the carpet. The navigation system module is on the SCP communications network. The navigation system module controls the global positioning system on the vehicle.
PRINCIPLES OF OPERATION
The vehicle has 3 module communication networks: the SCP, which is an unshielded twisted pair cable, data bus plus, circuit 914 (TN/OG) and data bus minus, circuit 915 (PK/LB), the single wire circuit 693 (OG) UBP communications network and the ISO 9141 communications network, which is also a single wire network, circuit 70 (LB/WH). All 3 networks are connected to the data link connector (DLC). This makes diagnosis and testing of these systems easier by allowing one diagnostic tester to be able to diagnose and control any module on the 3 networks from one connector. The DLC can be found under the instrument panel between the steering column and the driver door (near the parking brake lever).
The SCP communications network will remain operational even with the severing of one of the bus wires. Communications will also continue if one of the bus wires is shorted to ground or voltage, or if some but not all termination resistors are lost.
The ISO 9141 communications network does not permit intermodule communication. When the diagnostic tool communicates to modules on the ISO 9141 communication network, the diagnostic tool must ask for all information; the modules cannot initiate communications.
The ISO 9141 communications network will not function if the wire is shorted to ground or battery voltage. Also, if one of the modules on the ISO 9141 communications network loses power or shorts internally, communications to that module will fail.
The UBP communications network will not function if the wire is shorted to ground or voltage. The UBP communication network allows intermodule communication.