Washer Fluid Level Indicator: Description and Operation

WASHER FLUID INDICATOR

DESCRIPTION
A washer fluid indicator is standard equipment on all instrument clusters. However, this indicator is only functional on vehicles equipped with an optional washer fluid level switch integral to the washer pump/motor unit on the washer reservoir. The washer fluid indicator is located near the lower edge of the instrument cluster, to the right of the multifunction indicator display. The washer fluid indicator consists of the International Control and Display Symbol icon for "Windshield Washer Fluid" imprinted within a rectangular cutout in the opaque layer of the instrument cluster overlay. The dark outer layer of the overlay prevents the indicator from being clearly visible when it is not illuminated. An amber Light Emitting Diode (LED) behind the cutout in the opaque layer of the overlay causes the icon to appear silhouetted against an amber field through the translucent outer layer of the overlay when the indicator is illuminated from behind by the LED, which is soldered onto the instrument cluster electronic circuit board. The washer fluid indicator is serviced as a unit with the instrument cluster.

OPERATION
The washer fluid indicator gives an indication to the vehicle operator that the fluid level in the washer reservoir is low. This indicator is controlled by the instrument cluster circuit board based upon cluster programming and a hard wired input from the optional washer fluid level switch that is integral to the washer pump/motor unit. The washer fluid indicator is completely controlled by the instrument cluster logic circuit, and that logic will only allow this indicator to operate when the instrument cluster detects that the ignition switch is in the On position. Therefore, the indicator will always be off when the ignition switch is in any position except On. The indicator only illuminates when it is switched to ground by the instrument cluster circuitry. The instrument cluster will turn on the washer fluid indicator for the following reasons:

- Bulb Test - Each time the ignition switch is turned to the On position the brake wear indicator is illuminated by the instrument cluster for about two seconds as a bulb test.
- Washer Fluid Level Switch Input - Each time the cluster detects ground on the washer fluid switch sense circuit (washer fluid level switch closed = washer fluid level low) while the ignition switch is in the On position, the washer fluid indicator is illuminated. The indicator remains illuminated until the washer fluid level switch input to the cluster is an open circuit (washer fluid level switch open = washer fluid level acceptable), or until the ignition switch is turned to the Off position, whichever occurs first.

The instrument cluster continually monitors the washer fluid level switch to determine the level of the washer fluid. The instrument cluster logic applies a delay strategy to this input to reduce the negative effect that fluid sloshing within the reservoir can have on reliable indicator operation. The washer fluid level switch and circuit can be diagnosed using conventional diagnostic tools and methods. For proper diagnosis of the instrument cluster circuitry that controls the washer fluid indicator, a diagnostic scan tool is required. Refer to the appropriate diagnostic information.