Section 927 (Wiper System & Washer System (Service Information) - 2500 Hd & 3500 Hd): Description: Description

An electrically operated intermittent wiper and washer system is standard factory-installed safety equipment on this vehicle. The wiper and washer system includes the following major components, which are described in further detail elsewhere in this service information:

• Washer Fluid Level Switch  - On vehicles with a gasoline engine, the washer fluid level switch is located in a dedicated hole on the lower, rearward facing surface of the washer reservoir on the front of the Front End Module (FEM) carrier (also known as the radiator closure) just to the left of the cooling module. On vehicles with a diesel engine, the washer fluid level switch is located in a dedicated hole on the lower, forward facing surface of the washer reservoir on the back of the left vertical post of the left fender support hydroform just outboard of the FEM carrier.
• Washer Nozzle  - Two fluidic washer nozzles with integral check valves are secured by latch features to dedicated openings in the hood panel near the base of the windshield.
• Washer Plumbing  - The plumbing for the washer system consists of rubber hoses and molded plastic fittings. The reservoir hose is routed from the washer pump near the base of the reservoir through a trough integral to the reservoir to the outboard side of the reservoir, then through the FEM carrier (also known as the radiator closure) to the engine compartment where it is joined to the engine compartment hose. The engine compartment hose is routed along the left side of the engine compartment from the FEM to the cowl along with the left headlamp and dash wire harness through a molded plastic trough. The engine compartment hose is joined to the hood hose near the left hood hinge. The hood hose is routed between the underside of the inner hood panel reinforcement and the hood silencer pad to the washer nozzles.
• Washer Pump/Motor  - On vehicles with a gasoline engine, the electric washer pump/motor unit is located in a dedicated hole in a sump area on the lower, forward facing surface of the washer reservoir on the front of the FEM carrier (also known as the radiator closure), to the left of the cooling module. On vehicles with a diesel engine, the electric washer pump/motor unit is located in a dedicated hole in a sump area on the lower, forward facing surface of the washer reservoir on the back of the left vertical post of the left fender support hydroform just outboard of the FEM carrier.
• Washer Reservoir  - On vehicles with a gasoline engine, the washer reservoir is located on the front of the FEM carrier (also known as the radiator closure), to the left of the cooling module. On vehicles with a diesel engine, the washer reservoir is located on the back of the left vertical post of the left fender support hydroform just outboard of the FEM carrier. On all vehicles, regardless of engine type, the clearly identified washer reservoir filler cap is accessed from the left front corner of the engine compartment.
• Wiper Arms And Blades  - The two unique right and left wiper arms are secured with nuts to the threaded ends of the two wiper pivot shafts, which extend through the cowl plenum cover/grille panel located near the base of the windshield. The two equal length wiper blades are each secured to their wiper arm with an integral latch, and are parked on the glass near the bottom of the windshield when the wiper system is not in operation.
• Wiper Linkage Module  - The wiper pivot shafts are the only visible components of the wiper linkage module. The remainder of the module is concealed within the cowl plenum area beneath the cowl plenum cover/grille panel. The wiper linkage module includes the wiper linkage module bracket, three rubber-isolated wiper linkage module mounts, the wiper motor, the wiper motor crank arm, the two wiper drive links, and the two wiper pivots.
• Wiper Relays  - The wiper high and low relay and the wiper on and off relay are both soldered onto the Printed Circuit Board (PCB) located within the Power Distribution Center (PDC) and are not serviceable. The PDC is located in the left front corner of the engine compartment just forward of the battery.

Certain functions and features of the wiper and washer systems rely upon resources shared with other electronic modules in the vehicle over a Local Interface Network (LIN) data bus as well as over the Controller Area Network (CAN) data bus. Other electronic modules in the vehicle that may affect wiper and washer system operation are:

• Body Control Module  - The Body Control Module (BCM) (also known as the Common Body Controller/CBC) is located on the upper left corner of the dash panel within the passenger compartment, where it is concealed behind the instrument panel to the left of the steering column and pedal support bracket. Refer to MODULE, BODY CONTROL, DESCRIPTION .
• Clockspring  - The clockspring is completely concealed beneath the shrouds at the top of the steering column, just below the steering wheel. The clockspring also includes a Steering Angle Sensor (SAS) that is secured to the back of the clockspring housing and is serviced only as a unit with the clockspring. The clockspring housing is constructed of molded black plastic and is secured to the steering column by three screws. Refer to CLOCKSPRING, DESCRIPTION .
• Light Rain Sensor Module  - A Light Rain Sensor Module (LRSM) (also known as the Light Sensor Module/LSM, the Rain Sensor Module/RSM or the Rain Light Sensor/RLS) is used on vehicles equipped with the optional automatic wiper feature. The LRSM is located on a bracket bonded to the inside surface of the windshield glass, near the inside rear view mirror mount.
• Multifunction Switch  - The only visible component of the multifunction switch (1) is the control stalk, which includes a control knob that extends through the shrouds on the left side of the steering column. The switch housing and control stalk are constructed of molded black plastic. A single integral latch feature and slide tabs on the switch housing engage channels and a striker that are integral to the left side of the mounting bracket that is integral to the clockspring. The multifunction switch includes an integral Local Interface Network (LIN) data bus slave node. The multifunction switch is available for separate service replacement. Refer to SWITCH, MULTIFUNCTION, DESCRIPTION .
• Steering Angle Sensor  - The Steering Angle Sensor (SAS) is completely concealed on the back of the clockspring housing beneath the shrouds at the top of the steering column. The SAS housing is constructed of molded black plastic and is serviced only as a unit with the clockspring. The SAS includes an integral Local Interface Network (LIN) data bus master node and is also a gateway to the Controller Area Network (CAN) data bus network.

The BCM and the SAS each contain a microcontroller and programming that allow them to communicate with each other and other electronic modules in the vehicle using the Controller Area Network (CAN) data bus. In addition the multifunction switch and the SAS communicate with each other, and the BCM and the RLSM communicate with each other using the Local Interface Network data bus. Refer to COMMUNICATION, DESCRIPTION .

Hard wired circuitry connects the wiper and washer system components to the electrical system of the vehicle. These hard wired circuits are integral to several wire harnesses, which are routed throughout the vehicle and retained by many different methods. These circuits may be connected to each other, to the vehicle electrical system and to the wiper and washer system components through the use of a combination of soldered splices, splice block connectors, and many different types of wire harness terminal connectors and insulators. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, further details on wire harness routing and retention, as well as pin out and location views for the various wire harness connectors, splices and grounds.