Use a clean screwdriver to lower the float in the tank. The control lamp should light up when the float falls below the mark «Min», and go out when the float rises above the mark.
Pic. 10.21. Checking the operation of the brake fluid level sensor with an ohmmeter
The brake fluid level sensor can also be checked with an ohmmeter connected to the sensor connector. The sensor contacts should close when the float falls below the mark «Min», and open when the float rises above the mark (pic. 10.21).