Note: If there is less than one liter of liquid in the washer reservoir, then with the ignition on, the corresponding control lamp in the on-board control system display unit should light up. Otherwise, the block of light indication is faulty (see "The display unit of the onboard control system - removal and installation") or, the sensor of insufficient fluid level in the washer reservoir, or their circuit is faulty. It is possible that the terminals in the sensor wiring harness block are oxidized.
You will need a multimeter to do the job (in voltmeter and ohmmeter mode).
Removing
1. We prepare the car for work (see "Preparing the car for maintenance and repair").
2. Disconnect the wiring harness block from the sensor.
3. With a piece of wire or a metal clip, we close the terminals of the connecting block. If the control lamp of insufficient fluid level in the washer reservoir lights up, then the sensor is faulty. If the lamp does not light up, then with the ignition on, we measure the voltage at the terminals of the connecting block with a voltmeter. The voltage should be about 12 V. If the voltage is not supplied to the block, then there may be a bad contact or a wire break in the sensor circuit or the display unit is faulty.
4. Unscrew the sensor cover. Removing the sensor float from the tank, remove the sensor.
5. Connect the multimeter (in ohmmeter mode) to the sensor outputs.
6. By moving the float from one extreme position to another, we control the readings of the device. The electrical resistance of a serviceable sensor in the upper position of the float should be infinitely large, and in others it should be close to zero.
Recommendation: Oxidized terminals in the block should be cleaned with an awl or a thin needle file. Damaged sections of wires must be repaired. Faulty sensor and display unit are replaced (see "The display unit of the onboard control system - removal and installation").
Installation
Install the new sensor in reverse order.