SENSOR-WASHER FLUID LEVEL
DESCRIPTION
The washer fluid level switch (1) is a single pole, sin-
gle throw reed-type switch mounted on the outboard
facing side of the washer reservoir, just forward of the
washer pump. Only the molded plastic switch mount-
ing flange and the integral connector receptacle (4)
are visible when the switch is installed in the reservoir.
A short nipple formation extends from the inner sur-
face of the switch mounting flange, and a barb on the
nipple is pressed through a rubber grommet seal (2)
installed in the mounting hole of the reservoir.
A small, molded plastic float (3) pivots on hinge stan-
chions that extend toward the float from the nipple for-
mation. A small magnet is secured within the end of
the float nearest the nipple, and a reed switch is con-
cealed within the nipple. A diagnostic resistor is con-
nected 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.
OPERATION
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 con-
nector of the 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 FCM senses the ground on the washer fluid switch sense circuit. The FCM is pro-
grammed to respond to this input by sending an electronic washer fluid indicator lamp-on message to the instrument
cluster over the Controller Area Network (CAN) data bus. The instrument cluster responds to this message by illu-
minating 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
FCM, or the electronic message inputs to or outputs from the instrument cluster and the FCM that control the oper-
ation of the washer fluid visual and/or audible indicators. The most reliable, efficient, and accurate means to diag-
nose the washer fluid level indicator, the instrument cluster, the FCM, or the electronic message inputs and outputs
related to the washer fluid indicator requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic
information.
REMOVAL
NOTE: The washer fluid level switch can be removed from the washer reservoir without removing the res-
ervoir from the vehicle.
8R - 42
WIPERS/WASHERS - SERVICE INFORMATION
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