I have a scan gauge II that would not read the code when my ML's cel came on...the local shop had a reader that worked and he fixed the problem.

Now, a couple months later, the CEL came on again and then went back off, but no codes shown on the scan gauge.

I checked out the Actron readers and see the they do not list MB in the supported vehicle list. Does the ML-350 take a special reader?

__________________
2008 ML350
2007 Honda Element
2007 Honda Accord
2009 Honda Civic

Looks like the answer is yes. My scan gauge II showed nothing so I took it to Auto Zone...same result. Took it to my favorite mechanic and he read three codes: P0015, P0629, and P0633. His reader is made by Snapon (several thousand dollars) with yearly updates (also thousands).

__________________
2008 ML350
2007 Honda Element
2007 Honda Accord
2009 Honda Civic