Washer Fluid Level Indicator: Description and Operation

A washer fluid indicator is standard equipment on all instrument clusters. The washer fluid indicator is located in the Information Center area of the instrument cluster, to the right of center. The washer fluid indicator consists of a stencil-like cutout of the International Control and Display Symbol icon for "Windshield Washer Fluid" 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 in amber 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.

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 a transistor on the instrument cluster circuit board based upon cluster programming and a hard wired washer fluid level switch input to the cluster. The washer fluid indicator Light Emitting Diode (LED) is completely controlled by the instrument cluster logic circuit, and that logic will only allow this indicator to operate when the instrument cluster receives a battery current input on the fused ignition switch output (run-start) circuit. Therefore, the LED will always be off when the ignition switch is in any position except On or Start. The indicator only illuminates when it is switched to ground by the instrument cluster transistor. 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 washer fluid indicator is illuminated for about two seconds as a bulb test.

- Washer Fluid Level Switch Input - If the cluster senses ground on the washer fluid switch sense circuit continuously during and following the bulb test for more than about thirty consecutive seconds, the washer fluid indicator will be illuminated. Otherwise, the cluster must sense ground on the washer fluid switch sense circuit for more than about sixty consecutive seconds before it turns on the indicator. Once illuminated, the indicator will remain illuminated until the ignition switch is cycled and the cluster senses an open circuit on the low washer fluid sense input. This strategy is intended to reduce the effect that fluid sloshing within the washer reservoir can have on reliable indicator operation.

- Actuator Test - Each time the cluster is put through the actuator test, the washer fluid indicator will be turned on, then off again during the bulb check portion of the test to confirm the functionality of the LED and the cluster control circuitry.

The washer fluid level switch is connected in series between ground and the washer fluid switch sense input to the instrument cluster. For more information on the washer fluid level switch, (Refer to ELECTRICAL/WIPERS/WASHERS/WASHER FLUID LEVEL SWITCH - OPERATION). For further diagnosis of the washer fluid indicator or the instrument cluster circuitry that controls the indicator, (Refer to ELECTRICAL/INSTRUMENT CLUSTER - DIAGNOSIS AND TESTING). The washer fluid level switch input to the cluster may be diagnosed using conventional diagnostic tools and methods.