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Fig. 3 Check Valve:

CHECK VALVE
A washer system check valve is standard equipment on this model. The check valve is integral to the washer nozzle plumbing wye fitting located in the cowl plenum area beneath the cowl plenum cover/grille panel near the base of the windshield. The check valve consists of a molded plastic body with a round center section. An arrow formation molded into the center section of the valve body indicates the direction of flow through the valve. Three barbed hose nipples are formed in a wye configuration on the outside circumference of the center section of the valve body. The check valve cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.

The check valve provides more than one function in this application. It serves as a wye connector fitting between the cowl grille panel and washer nozzle sections of the washer supply hose. It also 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 from when the washer switch is actuated until washer fluid was dispensed through the washer nozzles, because the washer pump would have to refill the washer plumbing from the reservoir to the nozzles. Finally, the check valve prevents washer fluid from siphoning through the washer nozzles after the washer system is turned Off.

Within the check valve body, a small check valve is held in place against a seat by a small coiled spring to restrict flow through the unit until the valve is unseated by a predetermined inlet fluid pressure. When the washer pump pressurizes and pumps washer fluid from the reservoir through the washer plumbing, the fluid pressure overrides the spring pressure applied to the check valve and unseats the valve, allowing washer fluid to flow toward the washer nozzles. When the washer pump stops operating, spring pressure seats the check valve and fluid flow in either direction within the washer plumbing is prevented.

Fig. 5 Washer Fluid Level Switch:

WASHER FLUID LEVEL SWITCH
The washer fluid level switch is a single pole, single throw reed-type switch mounted on the outboard side of the rearward facing surface near the bottom of the washer reservoir. Only the molded plastic switch mounting flange and the integral connector receptacle are visible when the switch is installed in the reservoir. A short nipple formation extends from the inner surface of the switch mounting flange, and a barb on the nipple near the switch mounting flange is pressed through a rubber grommet seal installed in the mounting hole of the reservoir.

A small, molded plastic float has two pivot pins near its center that are snapped into two receptacles near the ends of two stanchions that extend toward the float from the switch nipple formation. A small magnet is secured within the end of the float nearest the switch nipple formation, and a reed switch is concealed within the nipple. A diagnostic resistor is connected between the two switch terminals within the switch mounting flange. The washer fluid level switch cannot be adjusted or repaired. If faulty or damaged, the switch must be replaced.

The washer fluid level switch uses a pivoting, oblong float to monitor the level of the washer fluid in the washer reservoir. The float contains a small magnet. When the float pivots, the proximity of this magnet to a stationary reed switch within the nipple formation of the switch changes. When the fluid level in the washer reservoir is at or above the float level, the float moves to a vertical position, the influence of the float magnetic field is removed from the reed switch, and the normally open reed switch contacts open. When the fluid level in the washer reservoir falls below the level of the pivoting float, the float moves to a horizontal position, the influence of the float magnetic field is applied to the reed switch, and the contacts of the normally open reed switch close.

The washer fluid level switch is connected to the vehicle electrical system through a dedicated take out and connector of the right headlamp and dash wire harness. The switch is connected in series between a clean ground output of the Front Control Module (FCM) on a sensor return circuit and the washer fluid switch sense input to the FCM. When the switch closes, the FMC senses the ground on the washer fluid switch sense circuit. The FMC is programmed to respond to this input by sending an electronic washer fluid indicator lamp-on message to the instrument cluster over the Programmable Communications Interface (PCI) data bus. The instrument cluster responds to this message by illuminating the washer fluid indicator and by sounding an audible chime tone warning.

The washer fluid level switch may be diagnosed and tested using conventional diagnostic tools and procedures. However, conventional diagnostic methods may not prove conclusive in the diagnosis of the instrument cluster, the Front Control Module (FCM), or the electronic message inputs to or outputs from the instrument cluster and the FCM that control the operation of the washer fluid visual and/or audible indicators. The most reliable, efficient, and accurate means to diagnose the washer fluid level indicator, the instrument cluster, the FCM, or the electronic message inputs and outputs related to the washer fluid indicators requires the use of a DRB III scan tool. Refer to the appropriate diagnostic information.

Fig. 7 Engine Compartment Washer Hose:

WASHER HOSES/TUBES
The washer plumbing consists of a small diameter rubber reservoir washer hose that is routed from the barbed outlet nipple of the electric washer pump/motor unit on the washer reservoir through a trough molded into the back of the reservoir above the washer pump and to the engine compartment washer hose. The engine compartment washer hose is contained within the right headlamp and dash wire harness, which is routed through the engine compartment along the top of the right front fender wheel house to the dash panel.

The engine compartment washer hose is connected to the washer reservoir washer hose and to the cowl plenum washer hose with molded plastic in-line fittings that have a barbed nipple on each end. The cowl plenum washer hose is routed from the engine compartment into the cowl plenum area through a trough formation located near the right end of the cowl plenum cover/grille panel. The cowl plenum washer hose is connected to the washer system check valve/wye fitting on the underside of the cowl plenum cover/grille panel. The cowl plenum washer hose and the two washer nozzle hoses are routed through integral routing clips on the underside of the cowl plenum cover/grille panel. The cowl plenum washer hose is connected to one nipple on the wye fitting and the two washer nozzle hoses are connected to the other two wye fitting nipples. The washer nozzle hoses are then routed along the underside of the cowl plenum cover/grille panel to the two washer nozzles.

Washer hose is available for service only as roll stock, which must then be cut to length. The molded plastic washer hose fittings cannot be repaired. If these fittings are faulty or damaged, they must be replaced.

Washer fluid in the washer reservoir is pressurized and fed by the washer pump/motor 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.