Hello,
Sometimes I am having a Reverse Right Light Failure. However both LED reverse lights bulbs works fine. It used to show me error message everytime I start the car. After that I thought I might try to switch both sides LED reverse lights and see if there was a problem with a bulb or some wiring in the right taillight of the car. Since then as I mentioned in the beginning the error pops up not always. Could it be something wrong with wiring or tailight adapter? I checked it out but there was not seem to be any problems.

IMPORTANT TO MENTION: When I get in a car, put key in ignition, put my feet on a brake, press START button and car starts, error never pops up.
When I get in a car, put key in ignition, press START button without starting the car, the error message pops up.

Thanks for your advices

 

The LED lights are causing the error. The car does a bulb check when you first turn it on and then every so often when you are driving. The LED bulbs do not behave electrically the same as incandescent bulbs and that's why you are getting the error. Put back the incandescent bulbs or code out the bulb check or add load resistors for the existing LED bulbs.