Yesterday night while driving my car started to show up message "Checking License Plate Lamp L, R"

I checked at back they were working correctly. I have two lamps over license plate both were working.

Why did message came ?

Another one what is the use of HeadLamp washers ? When do we need ?

 

You might have a bulb that ready to burn up or maybe the connection was loose. What year is your C? If its a newer version 203 chassis, than they have a updated wiring pigtale for rear tail lights and license plate lights. These lights tend to burn out rather quickly, so they use the pigtales to cause a resistance. Helps the bulb last longer.

 

it is 2002 C 240