Rain Sensor Control Module: Operation

WARNING: This page is about a different car, the 2006 Dodge Sprinter. However, it is still accessible from the selected car via links, so may be relevant.

The microprocessor-based Rain Sensor Control Module (RSCM) is only used in vehicles equipped with an optional automatic wiper system. The RSCM monitors inputs from the ignition switch, the wiper and washer switch circuitry of the multi-function switch on the steering column, the park switch within the wiper motor, and the rain sensor on the inside of the windshield glass. Based upon these inputs the RSCM sends the proper control outputs to the wiper motor and the washer pump motor to provide all of the requested wiper and washer system functions.

The RSCM operates on battery current received from a fuse in the fuse block on a fused ignition switch output (run-start) circuit so that the RSCM will operate whenever the ignition switch is in the On or Start positions. The RSCM receives ground at all times through its connection to the instrument panel wire harness. It is important to note that the default condition for the wiper system is automatic wipers Off; therefore, if no input is received from the rain sensor by the RSCM, the automatic wipers will be disabled and the RSCM will default the wiper and washer system to normal manual operation for continuous low or high speed wiper or washer mode.

The hard wired RSCM circuits may be diagnosed using conventional diagnostic tools and methods. However, conventional diagnostic methods may not prove conclusive in the diagnosis of the internal circuitry of the RSCM. Refer to the appropriate wiring information.