Volvo: Pisition failure light on S80, s80, lamps

Question
I have a 2001 S80. I keep getting a message that reads "position light failure."  I have checked all the lamps that I can find and all appear to be working fine.  What am I missing?

Answer
Hello,
At the rear side there are four lamps for position lights. (two of them at left, two of them at right)
You checked and saw that everything was okay, but one of them should be defective, check again, you can remove the carpet and you can remmove the lamp panel and you can see easily which of them is defective.
Regards...