Originally Posted by ard

Perfect.


Did you search for those specific codes?

I had 4B52...search each of these codes, here and on bimmerfest. You'll get some background.

I agree with your assessment that it is unlikely for three things to fail simultaneously.... furthermore, the diesel emissions control seems to be plagued by software errors in which temperature errors in sensors- which are NOT identified as an actual fault- trip plausibility errors and other downstream errors.

As the dealer if they have created a PUMA case for this...you want engineers who understand the SYSTEM, as opposed to 'parts replacers' who see "EGR" in the code and figure 'bad EGR'. Could be, but you want experts making the calls.

For a while, any diesel emissions fault was a mandatory PUMA.... dealers were just guessing, resulting in multiple visits and lemon claims. BMW required dealers to work with their engineers to get it right.

If the dealer won't PUMA it, call BMWNA and ask them.

I am betting replace the temp sensor and reprogram....

A