Information Bus: Description and Operation
COMMUNICATIONS NETWORKFour-Wheel Drive (4WD) Control Module
The 4WD control module (if equipped) uses the international standards organization (ISO) 9141 communications network. The 4WD control module monitors and regulates the 4-wheel drive operation for the vehicle.
Anti-Lock Brake System (ABS) Module
The ABS module uses the controller area network (CAN). The ABS module monitors the wheel speed readings from each anti-lock brake sensor and processes this information to determine an impending wheel lock-up. If a wheel lock-up is detected, the ABS module modulates the brake pressure to the appropriate brake caliper.
Electronic Automatic Temperature Control (EATC) Module
The EATC module (if equipped) uses the universal asynchronous receiver-transmitter (UART) based protocol (UBP) communications network. The EATC module controls the automatic climate functions to maintain the vehicle at a constant temperature setting.
Instrument Cluster
The instrument cluster uses the UBP communications network and the CAN. Diagnostic data is supplied through the CAN to the diagnostic tool. The instrument cluster serves as a communications network gateway between the CAN and the UBP communications network for inter-network module communication. The instrument cluster contains a variety of warning lights and gauges that display vehicle specific information. This allows the driver to continually monitor vehicle conditions.
Parking Aid Module
The parking aid module (if equipped) uses the ISO 9141 communications network. The module monitors sensors mounted in the rear bumper that detect the proximity of objects to the vehicle when the vehicle is in reverse.
Powertrain Control Module (PCM)
The PCM uses the CAN. The PCM receives input from sensors and other electronic components (switches, relays). Based on the information received and programmed into its memory, the PCM generates output signals to control various relays, solenoids and actuators.
Restraint Control Module (RCM)
The RCM uses the ISO 9141 communications network. The RCM monitors and controls the supplemental restraint system (SRS). The SRS is designed to provide increased crash protection for front seat occupants. The RCM deploys the vehicle air bags based on sensor input during a crash event.
Trailer Brake Controller
The trailer brake controller (if equipped) uses the CAN. The trailer brake controller operates the trailer brakes.
Vehicle Security Module
The vehicle security module uses the UBP communications network. The vehicle security module controls:
- remote keyless entry (RKE)
- exterior lamps (RKE flash and panic)
- lock/unlock functions