BMW Repair: common obdII codes, dash board, reason 3

Question
"hi, & how are you?
what are the most common obdII codes for any  BMW "CHECK ENGINE"
usally pops up at dash board.

1-what are the most common trouble codes?
2-what/why is the reason?
3-how to diagnost them?

my questions are long & involve a lot info
any information is highly apprciated or web
thank you!"


Answer
ASIF,

 As stated in my description I only work on cars that were made between 1984-1991 (E30).  These are all OBDI cars.  In 1996 BMW (and ever other car in the US) had to go to OBDII.

 Since I dont work with 1996 and newer BMW's, I am not familiar with what are common codes.

 Check out www.bimmerforums.com and ask there.

 Good luck,
 Josh