Description And Operation
DESCRIPTION
The front of the Display Screen Module (DSM) (1) allows for touchscreen input commands to the radio via a short Low Voltage Differential Signaling (LVDS) wire harness which is routed from the radio to the DSM and retained by wire harness clips. The back of the DSM houses the wire harness connections necessary for Controller Area Network (CAN) communication, power and ground circuits in one 8-terminal connector and LVDS touchscreen input and output circuits in the 4-terminal connector.
The wiring information includes wiring diagrams, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds. For proper wire repair, and connector repair procedures. Refer to CIRCUIT TESTING PROCEDURES or CONNECTOR TERMINAL REMOVAL or CONNECTOR TERMINAL INSTALLATION . Refer to the appropriate wiring information.
The DSM cannot be repaired. If the DSM is damaged or ineffective, it must be replaced. Refer to MODULE, DISPLAY SCREEN (DSM), REMOVAL AND INSTALLATION .
OPERATION
The DSM receives fused B(+) from the Power Distribution Center (PDC) and is supplied by a ground eyelet secured to the instrument panel carrier behind the instrument panel. In addition, the DSM status is broadcast over the Controller Area Network - Interior High Speed (CAN-IHS) data bus to be used by the radio when the radio sends a CAN message for the status of the DSM.
The radio receives touchscreen signals via the LVDS wire harness that connects directly between the radio and DSM. The DSM communicates via a hardwired backchannel protocol with the radio over the LVDS wire harness.
The DSM provides all of the functions of the radio with integral touchscreen. Unlike a radio with integral touchscreen, the DSM is disassociated from the radio.
The DSM receives vehicle configuration and network configuration information from the vehicle configuration management system via the CAN-IHS data bus. Any diagnostic or loss of communication states are also sent via the CAN-IHS data bus.
Hardwired Inputs
- Video data from radio.
Hardwired Outputs
- LVDS backchannel touchscreen messages to radio.
CAN-IHS Inputs
- Vehicle configuration from Body Control Module (BCM).
- Network configuration from BCM.
- Disable diagnostics on CAN.
- Disable loss of communication on CAN.
- Requested display intensity from radio.
- Display status.
- Battery voltage from BCM.
CAN-IHS Outputs
- Remote display status.
- Remote display controls data.