Wiper System & Washer System - Service Information: Overview RAM Pickup 2500

Scheme 3

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

1. ElectroMechanical Instrument Cluster - The ElectroMechanical Instrument Cluster (EMIC) (also known as the Cab Compartment Node/CCN) is located on the instrument panel above the steering column opening, directly in front of the driver. Refer to «Description»(ref-457793-S37239600182012030200000) .
2. Multi-Function Switch (5) - The multi-function switch is secured to a bracket integral to the clockspring housing on the top of the steering column, just below the steering wheel. The Steering Control Module (SCM) is internal to the multi-function switch housing. Only the control stalk that extends from the left side of the steering column is visible, while the remainder of the switch housing containing the SCM is concealed beneath the steering column shrouds. The switch control stalk has a control knob on the end that is dedicated to providing all of the driver controls for the wiper and washer systems. Refer to «SWITCH, Multifunction , Description»(ref-457789-S35471144692012030200000) .
3. Steering Control Module - The Steering Control Module (SCM) is internal to the multi-function switch housing, which is secured to a bracket integral to the left side of the clockspring housing on the top of the steering column just below the steering wheel. Only the switch control stalk extending from the left side of the steering column is visible, while the remainder of the switch housing containing the SCM is concealed beneath the steering column shrouds. Refer to «MODULE, Steering Column , Description»(ref-457810-S01434116752012030200000) .
4. Totally Integrated Power Module - The Totally Integrated Power Module (TIPM) is located in the engine compartment, near the battery. Refer to «MODULE, Totally Integrated Power (TIPM) , Description»(ref-457819-S42047325282012030200000) .
5. 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.
6. Washer Nozzle (2) - 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.
7. 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.
8. 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.
9. Washer Reservoir (1) - 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.
10. Wiper Arms and Blades (4) - 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.
11. Wiper Linkage Module (3) - 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.

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.

Scheme 4

The wiper and washer system is designed to provide the vehicle operator with a convenient, safe, and reliable means of maintaining visibility through the windshield glass. The various components of this system are designed to convert electrical energy produced by the vehicle electrical system into the mechanical action of the wiper blades to wipe the outside surface of the glass, as well as into the hydraulic action of the washer system to apply washer fluid stored in an on-board reservoir to the area of the glass to be wiped. When combined, these components provide the means to effectively maintain clear visibility for the vehicle operator by removing excess accumulations of rain, snow, bugs, mud, or other minor debris from the outside windshield glass surface that might be encountered while driving the vehicle under numerous types of inclement operating conditions.

The vehicle operator initiates all wiper and washer system functions with the control knob (1) on the end of the control stalk (2) of the multi-function switch that extends from the left side of the steering column, just below the steering wheel. Rotating the control knob on the end of the control stalk, selects the OFF, DELAY, LOW, or HIGH wiper system operating modes. In the DELAY mode, the control knob also allows the vehicle operator to select from one of five intermittent wipe delay intervals.

Depressing the control knob towards the steering column to the first detent actuates a momentary switch and selects the MIST mode, which cycles the wiper blades for as long as the switch is held closed then completes the current cycle and parks the blades at the base of the windshield after the switch is released. Depressing the control knob to the second detent actuates the momentary washer system switch, which selects the WASH or WIPE-AFTER-WASH modes depending upon when and how long the switch is held closed.

The multi-function switch provides hard wired analog and resistor multiplexed inputs to the Steering Control Module (SCM) internal to the multi-function switch housing for all of the wiper and washer system functions. The SCM then sends electronic wiper and washer switch status messages to the ElectroMechanical Instrument Cluster (EMIC) (also known as the Cab Compartment Node/CCN) over a Local Interface Network (LIN) data bus. The EMIC responds to the SCM inputs by sending electronic wiper and washer system request messages to the Totally Integrated Power Module (TIPM) over the Controller Area Network (CAN) data bus requesting the appropriate wiper and washer system operating modes.

Wiper and washer system operation are completely controlled by the SCM, EMIC and TIPM logic circuits, and that logic will only allow these systems to operate when the ignition switch is in the ACCESSORY or ON positions. The TIPM uses intelligent, high current, self-protected high side switches to control wiper system operation by energizing or de-energizing the wiper motor low and high speed brushes. The TIPM uses a high side driver to control the operation of the washer pump/motor unit. The multi-function switch circuitry receives battery current and a clean ground output from the SCM, then provides analog and resistor multiplexed inputs to the SCM to indicate the selected wiper and washer system mode.

The hard wired circuits and components of the wiper and washer system may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the wiper and washer system or the electronic controls or communication between other modules and devices that provide some features of the wiper and washer system. The most reliable, efficient, and accurate means to diagnose the wiper and washer system or the electronic controls and communication related to wiper and washer system operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.

OPERATION

The wiper arms are designed to mechanically transmit the motion from the wiper pivots to the wiper blades. The wiper arm must be properly indexed to the wiper pivot in order to maintain the proper wiper blade travel on the glass. The tapered mounting hole in the wiper arm pivot end interlocks with the serrations on the tapered outer circumference of the wiper pivot shaft, allowing positive engagement and finite adjustment of this connection.

The mounting nuts lock the wiper arms to the threaded studs of the wiper pivot shafts. The spring-loaded wiper arm hinge controls the down-force applied through the tip of the wiper arm to the wiper blade on the glass. The hook formation on the tip of the wiper arm provides a cradle for securing and latching the wiper blade pivot block to the wiper arm.

Scheme 5

1. Lift the wiper arm (3) to its over-center position to hold the wiper blade off of the glass and relieve the spring tension on the wiper arm to pivot shaft connection.
2. Carefully pry the plastic nut cap (1) off of the nut (2) on the pivot end of the wiper arm.
3. Remove the nut that secures the wiper arm to the wiper pivot shaft. CAUTION: The use of a battery terminal puller when removing the wiper arm is NOT recommended as this may damage the wiper arm.
4. Use a slight rocking action to disengage the wiper arm pivot end from the pivot shaft and remove the wiper arm.

The wiper blades are moved back and forth across the glass by the wiper arms when the wipers are being operated. The wiper blade superstructure is the flexible frame that grips the wiper blade element and evenly distributes the force of the spring-loaded wiper arm along the length of the element. The combination of the wiper arm force and the flexibility of the superstructure makes the element conform to and maintain proper contact with the glass, even as the blade is moved over the varied curvature that may be encountered across the glass surface.

The wiper element flexor provides the claws of the blade superstructure with a rigid, yet flexible component on the element which can be gripped. The rubber element is designed to be stiff enough to maintain an even cleaning edge as it is drawn across the glass, yet resilient enough to conform to the glass surface and flip from one cleaning edge to the other each time the wiper blade changes directions.

Washer fluid in the washer reservoir is pressurized and fed by the washer pump/motor unit through the washer system plumbing and fittings to the two washer nozzles. Whenever routing the washer hose or a wire harness containing a washer hose, it must be routed away from hot, sharp, or moving parts; and, sharp bends that might pinch the hose must be avoided.

Scheme 6

The wiper linkage module is secured by a rubber insulated mounting tab and two screws through two rubber grommet-type insulators to the cowl plenum panel. The module is concealed beneath the molded plastic cowl plenum cover/grille panel between the base of the windshield and the rear edge of the hood panel. The ends of the pivot shafts that protrude through openings in the cowl plenum cover/grille panel to drive the wiper arms and blades are the only visible components of the wiper linkage module. The wiper linkage module consists of the following major components

1. Bracket - The wiper linkage module bracket consists of two long tubular steel main members (1) that are each crimped at their outboard ends to a die cast pivot bracket (3) to which the two wiper pivots are secured. A die cast center motor bracket (4) is secured by crimps at the inboard ends of the tubular main members to provide both a mounting point for the wiper motor and a center support for mounting the wiper linkage module to the cowl plenum panel.
2. Crank Arm - The wiper motor crank arm is a stamped steel unit with a hole on the driven end that is secured to the finely splined wiper motor output shaft with a nut, and has a long ball stud secured to the drive end to accept the wiper linkage.
3. Linkage - Two tubular steel drive links (2) connect the wiper motor crank arm to the wiper pivot lever arms. The right side drive link has a plastic socket-type bushing on each end. The left side drive link has a plastic socket-type bushing on one end, and a plastic sleeve-type bushing on the other end. The socket-type bushing on one end of each drive link is snap-fit over the ball stud on the lever arm of its respective pivot. The left side drive link sleeve-type bushing end is then fit over the motor crank arm ball stud, and the other socket-type bushing of the right side drive link is snap-fit over the exposed end of the wiper motor crank arm ball stud.
4. Motor - The wiper motor (5) features a transmission housing from which the wiper motor output shaft exits, and has three mounting bosses with internal threads to which the motor is mounted to the center wiper linkage module bracket with screws. A nut secures the wiper motor crank arm to the motor output shaft. The two-speed permanent magnet wiper motor features an integral transmission, an internal park switch, and an internal automatic resetting circuit breaker. A short pigtail wire and connector connect the wiper motor to the vehicle electrical system through a dedicated take out and connector of the left headlamp and dash wire harness.
5. Pivots - The two wiper pivots (6) are secured within the die cast pivot brackets on the outboard ends of the wiper linkage module main members. The lever arms that extend from the center of the pivot shafts each have a ball stud on their end. The upper end of each pivot shaft where the wiper arms will be fastened each has a finely splined and tapered driver with a threaded stud extending from the top. The lower ends of the pivot shafts are installed through permanently lubricated bushings in the pivot brackets.

The wiper linkage module cannot be adjusted or repaired. The wiper motor is available for separate service replacement. If any other component of the linkage module is ineffective or damaged, the entire wiper linkage module unit must be replaced.

The wiper linkage module operation is controlled by the battery current inputs received by the wiper motor from the Totally Integrated Power Module (TIPM). The wiper motor speed is controlled by current flow to either the low speed or the high speed set of brushes.

The park switch is a single pole, single throw, momentary switch within the wiper motor that is mechanically actuated by the wiper motor transmission components. The park switch alternately opens and closes the wiper park switch sense circuit to ground, depending upon the position of the wipers on the glass. This feature allows the motor to complete its current wipe cycle after the wiper system has been turned OFF, and to park the wiper blades in the lowest portion of the wipe pattern. The automatic resetting circuit breaker protects the motor from overloads.

The wiper motor crank arm, the two wiper linkage members, and the two driven wiper pivots mechanically convert the rotary output of the wiper motor to the back and forth wiping motion of the wiper arms and blades on the glass.

The hard wired inputs and outputs of the wiper motor may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the electronic controls or communication between other modules and devices that provide some features of the wiper motor. The most reliable, efficient, and accurate means to diagnose the wiper motor or the electronic controls and communication related to wiper motor operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.

Scheme 7

Note. The wiper linkage module includes the wiper motor. The wiper motor is also available for separate service replacement and can be removed from the wiper linkage module without removing the module from the vehicle. Refer to MOTOR, Wiper , Removal .

1. Unlatch and open the hood.
2. Remove both wiper arms from the wiper pivots. Refer to «ARM, Wiper , Removal»(ref-457801-S31199743122012030200000) .
3. Disconnect and isolate the battery negative cable.
4. Remove the cowl plenum cover/grille panel from over the cowl plenum (6). Refer to «COVER, Cowl Panel , Removal»(ref-457777-S06222653182012030200000) .
5. Disconnect the left headlamp and dash wire harness connector (4) from the wiper motor pigtail wire connector.
6. Remove the two screws (3) that secure the wiper linkage module (2) to the top of the cowl plenum panel.
7. Lift the left end of the wiper linkage module upward out of the cowl plenum far enough to disengage the rubber insulated tab (1) on the end of the right pivot bracket from the slot (7) in the cowl plenum.
8. Remove the wiper linkage module from the cowl plenum panel as a unit.

The two washer nozzles are designed to dispense washer fluid into the wiper pattern area on the outside of the windshield glass. Pressurized washer fluid is fed to each nozzle from the washer reservoir by the washer pump/motor unit through a single hose, which is attached to a barbed nipple on each washer nozzle below the inner hood panel. A fluidic matrix within the washer nozzle causes the pressurized washer fluid to be emitted from the two nozzle orifices as oscillating streams to more effectively cover a larger area of the glass to be cleaned.

The integral check valve in each nozzle prevents washer fluid from draining out of the washer supply hoses back to the washer reservoir. This drain-back would result in a lengthy delay after the washer switch is actuated until washer fluid was dispensed through the nozzles, because the washer pump would have to refill the washer plumbing from the reservoir to the nozzles. Such a drain-back condition could also result in water, dirt, or other outside contaminants being siphoned into the washer system through the washer nozzle orifice. This water could subsequently freeze and plug or damage the nozzle, while other contaminants could interfere with proper nozzle operation and cause improper nozzle spray patterns. In addition, the check valve prevents washer fluid from siphoning through the washer nozzles after the washer pump stops operating.

When the washer pump pressurizes and pumps washer fluid from the reservoir through the washer plumbing, the fluid pressure unseats a diaphragm from over a sump well within the nozzle by overriding the spring pressure applied to it by a piston. With the diaphragm unseated, washer fluid is allowed to flow toward the nozzle orifice. When the washer pump stops operating, the spring pressure on the piston seats the diaphragm over the sump well in the nozzle and fluid flow in either direction within the washer plumbing is prevented.

Scheme 8

1. From the underside of the hood, remove the push-in retainers that secure the rear edge of the hood silencer pad to the inner hood reinforcement as necessary to access the washer nozzle hose connections (4).
2. From the underside of the hood, disconnect the washer nozzle hose from the barbed nipple of the washer nozzle.
3. From the underside of the hood, release the integral latch features of the washer nozzle (1) and push the nozzle out through the mounting hole toward the top side of the hood.
4. Remove the washer nozzle from the top of the hood panel.

The washer pump/motor unit features a small Direct Current (DC) electric motor. The motor is connected to the vehicle electrical system through a single take out and two-cavity connector of the Front End Module (FEM) wire harness. The motor is grounded at all times through another take out of the FEM wire harness with a single eyelet terminal connector that is secured by a screw to the left front fender upper hydroform support in the engine compartment.

The Totally Integrated Power Module (TIPM) controls the washer pump/motor control circuit through a high side driver based upon electronic washer request messages received over the Controller Area Network (CAN) data bus from the ElectroMechanical Instrument Cluster (EMIC) (also known as the Cab Compartment Node/CCN). The EMIC receives electronic washer switch status messages over a Local Interface Network (LIN) bus connection from the Steering Control Module (SCM) within the multi-function switch housing. The SCM monitors hard wired analog and multiplex inputs from the washer switch circuitry contained within the multi-function switch to determine the proper electronic messages to send.

Washer fluid is drawn through the pump inlet nipple from the washer reservoir to the inlet port of the washer pump housing. A filter screen integral to the pump grommet seal prevents most debris from entering the pump housing. When the pump motor is energized, the motor spins the rotor within the washer pump. The spinning pump rotor pressurizes the washer fluid and forces it through the pump outlet nipple, the washer plumbing, and the washer nozzles onto the windshield glass.

The washer pump/motor unit and the hard wired circuits connected to the unit may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the electronic controls or communication between other modules and devices that provide many features of the wiper and washer system. The most reliable, efficient, and accurate means to diagnose the washer pump/motor unit or the electronic controls and communication related to washer pump/motor unit operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.

Scheme 9

Note. The washer pump/motor unit can be removed from the washer reservoir without removing the reservoir from the vehicle.

1. Disconnect and isolate the battery negative cable.
2. Siphon the washer fluid from the washer reservoir (3) into a clean container for reuse.
3. Remove the splash shield from the left front fender (1) wheel housing of the vehicle. Refer to «SHIELD, Splash, Front Wheelhouse , Removal»(ref-457777-S20081177382012030200000) .
4. Disconnect the Front End Module (FEM) wire harness connector (6) from the washer pump/motor unit (2) connector receptacle on the top of the motor housing.
5. Pull lightly outward on the top of the washer pump/motor housing, away from the washer reservoir to disengage the top of the motor from the receptacle in the reservoir.
6. Pull the washer pump/motor unit straight up and out of the washer reservoir far enough to disengage the inlet nipple on the base of the pump housing from the rubber grommet seal/filter screen in the reservoir.
7. Raise the washer pump/motor unit far enough to access and disconnect the washer hose from the barbed pump outlet nipple.
8. Remove the washer pump/motor unit from the front of the washer reservoir.
9. Remove the rubber grommet seal/filter screen from the washer pump mounting hole in the reservoir and discard.

Scheme 10

Note. The washer pump/motor unit can be removed from the washer reservoir without removing the reservoir from the vehicle.

1. Disconnect and isolate the battery negative cable.
2. Siphon the washer fluid from the washer reservoir (1) into a clean container for reuse.
3. Remove the grille from the front of the vehicle. Refer to «GRILLE , Removal»(ref-457777-S02947677742012030200000) .
4. Disconnect the Front End Module (FEM) wire harness connector (3) from the washer pump/motor unit connector receptacle on the top of the motor housing.
5. Pull lightly outward on the top of the washer pump/motor housing, away from the washer reservoir to disengage the top of the motor from the receptacle in the reservoir.
6. Pull the washer pump/motor unit straight up and out of the washer reservoir far enough to disengage the inlet nipple on the base of the pump housing from the rubber grommet seal/filter screen in the reservoir.
7. Raise the washer pump/motor unit far enough to access and disconnect the washer hose (4) from the barbed pump outlet nipple.
8. Remove the washer pump/motor unit from the front of the washer reservoir.
9. Remove the rubber grommet seal/filter screen from the washer pump mounting hole in the reservoir and discard.

The washer fluid reservoir provides a secure, on-vehicle storage location for a large reserve of washer fluid for operation of the washer system. The washer reservoir filler cap provides a clearly marked and readily accessible point at which to add washer fluid to the reservoir.

The washer/pump motor unit is located in a sump area near the bottom of the reservoir to be certain that washer fluid will be available to the pump as the fluid level in the reservoir becomes depleted. The washer fluid level switch is mounted far enough above the washer pump inlet nipple in the sump area of the reservoir so that there will be adequate warning to the vehicle operator that the washer fluid level is low, well before the washer system will no longer operate.

Scheme 11

1. Disconnect and isolate the battery negative cable.
2. Siphon the washer fluid from the washer reservoir (4) into a clean container for reuse.
3. Remove the two screws (1) that secure the mounting brackets of the washer reservoir filler neck to the left fender support hydroform vertical member (2), just to the left of the cooling module.
4. Pull the washer reservoir upward just far enough to disengage the mounting post (3) integral to the bottom of the reservoir from the locator hole in the support bracket at the base of the hydroform vertical member.
5. Remove the splash shield from the left front fender (1) wheel housing of the vehicle. Refer to «SHIELD, Splash, Front Wheelhouse , Removal»(ref-457777-S20081177382012030200000) .
6. Disconnect the Front End Module (FEM) wire harness connector (6) from the washer pump/motor unit (2) connector receptacle on the top of the motor housing.
7. Disconnect the FEM wire harness connector (5) from the washer fluid level switch connector receptacle (4) on the front of the reservoir.
8. Disconnect the reservoir washer hose from the barbed pump outlet nipple of the washer pump/motor unit.
9. Disengage the reservoir washer hose from the routing trough integral to the reservoir.
10. Move the washer reservoir away from the support bracket at the base of the hydroform vertical member far enough to enable lowering the reservoir down and out of the vehicle through the left front fender wheel housing.

Scheme 12

1. Disconnect and isolate the battery negative cable.
2. Siphon the washer fluid from the washer reservoir (1) into a clean container for reuse.
3. Remove the grille from the front of the vehicle. Refer to «GRILLE , Removal»(ref-457777-S02947677742012030200000) .
4. Remove the two screws (5) that secure the inboard washer reservoir mounting brackets at the top and bottom members of the Front End Module (FEM) carrier (also known as the radiator closure), just to the left of the cooling module.
5. Pull the washer reservoir upward far enough to disengage the two mounting tabs (2) on the outboard side of the reservoir from the two slotted loops integral to the FEM carrier.
6. Disconnect the FEM wire harness connector (3) from the washer pump/motor unit connector receptacle on the top of the motor housing.
7. Disconnect the reservoir washer hose (4) from the barbed pump outlet nipple of the washer pump/motor unit.
8. Disengage the reservoir washer hose and FEM wiring bundle from the routing trough integral to the front of the reservoir.
9. Rotate the outboard side of the washer reservoir (3) away from the FEM carrier far enough to access and disconnect the FEM wire harness connector (1) from the washer fluid level switch connector receptacle (2) on the back of the reservoir.
10. Remove the washer reservoir from the left side of the FEM carrier.

The washer fluid level switch uses fluid conductivity to monitor the level of the washer fluid in the washer reservoir. Electricity is conducted between the two switch pins or electrodes only when they are immersed in the washer fluid, which closes the switch circuit. When the fluid level in the washer reservoir falls below the pins, electrical current cannot be conducted and the switch becomes an open circuit, which signals a low fluid condition.

In order to prevent an electrical charge from accumulating in the electrical leads of the switch, the switch receives current that is pulsed from the Totally Integrated Power Module (TIPM) located in the engine compartment near the battery. The TIPM monitors the switch return signal and is programmed to respond to three consecutive open switch readings by sending an electronic washer fluid indicator lamp-ON request message to the ElectroMechanical Instrument Cluster (EMIC) (also known as the Cab Compartment Node/CCN) over the Controller Area Network (CAN) data bus. The EMIC responds to this message by illuminating the washer fluid indicator and by sounding an audible chime tone warning.

The washer fluid level switch is connected to the vehicle electrical system through a dedicated take out and connector of the Front End Module (FEM) wire harness. The switch is connected in series between a sensor return circuit and the washer fluid switch sense input to the TIPM.

The washer fluid level switch and the hard wired circuits between the switch and the TIPM may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the washer fluid level indicator or the electronic controls or communication between other modules and devices that provide some features of the washer system. The most reliable, efficient, and accurate means to diagnose the washer fluid level indicator or the electronic controls and communication related to washer fluid level switch operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.