Grand Cherokee 2WD V8-4.7L VIN N (2000)
Washer Fluid Level Switch: Description and Operation
The washer fluid level sensor is mounted near the bottom of the washer reservoir on the forward facing side. A barbed nipple on the sensor is press-fit
into a rubber grommet seal installed in the mounting hole on the washer reservoir. The washer fluid level sensor uses a pivoting float to monitor the fluid
level in the washer reservoir. The pivoting float opens and closes the switch contacts in the sensor.
The washer fluid level sensor cannot be adjusted or repaired and, if faulty or damaged, the sensor unit must be replaced.
The washer fluid level sensor is hard wired directly to the Body Control Module (BCM). The BCM sends five volts to the sensor on a single circuit.
When the washer fluid level is at or above the float level in the reservoir, the internal switch contacts of the sensor are open. When the washer fluid level
in the reservoir falls below the float of the sensor, the float changes position and closes the internal switch contacts of the sensor to ground.
When the BCM senses ground on the circuit, it is programmed to send low washer fluid messages to the Electronic Vehicle Information Center (EVIC)
over the Programmable Communications Interface (PCI) data bus. The EVIC is programmed to respond to this message by displaying the Washer Fluid
Low warning and sending a chime request message back to the BCM over the PCI data bus. Then the BCM generates an audible chime tone warning.
