Operation

OPERATION

For information covering details of operation for the individual switches, sensors and circuits contained within or connected to the Roof Control Module (RCM) (also known as the Overhead Control Panel/OCP control unit or DBE) or to the OCP, refer to the specific service information covering the system or circuit to which that switch or sensor belongs.

The microprocessor-based RCM utilizes integrated circuitry to monitor hard wired analog and multiplexed inputs from its integral push button switches, the optional power sliding sunroof switch, the optional rain/light sensor, the optional mobile telephone and the optional Vehicle Theft Security System (VTSS) front interior motion sensor. In response to those inputs, the internal circuitry and programming of the RCM allow it to transmit electronic message outputs to other electronic modules in the vehicle over the Controller Area Network (CAN) data bus.

The RCM is connected to a fused B(+) circuit and receives a path to ground at all times. These connections allow it to remain functional regardless of the ignition switch position. Any input to the RCM that controls a vehicle system function that does not require that the ignition switch be in the ON position, prompts the RCM to wake up and transmit on the CAN data bus.

The hard wired circuits between components related to the RCM may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.

However, conventional diagnostic methods will not prove conclusive in the diagnosis of the RCM. For proper diagnosis of the RCM, the CAN data bus or the electronic communication related to RCM operation, a diagnostic scan tool is required. Refer to the appropriate diagnostic information.