I am a mechanic. I have five Tn1 Sprinters, and I have had two blowing the transmission computer . I replace them, and they run fine for a few hundred miles, then fail again. Is this a common problem? Has anyone found the cause? Can the computers be fixed?
Well to answer your question I would say emphatically NO!
Like most solid state controllers the thing that kills them are sudden voltage spikes, reversed polarity and short downs caused by poor connections/lack of insulation and of course the age old problem of grounding--or the lack of it!
I would say the most overlooked part of the vehicle repair business either at DIY or Pro level!~
All that stated, be mindful that MB wiring harnesses/connectors are not the best in the industry (Ford has that accolade with ISO 9000 certification and the Japanese are on par with it) They are especially bad on 2002 to 2003 Tin models as they age giving rise to all sorts of driveability problems.
If you have two units that are exhibiting the same issue (theoretically at this stage) it might be time to open the TCM and study the circuit board. If it shows a distinct failure similarity then focus in on the actual circuit affected. From there you can go to say Mitchel for the wiring diagram and trace where your short or circuit mal-function might possibly be.
Yes you can get SOME solid state controllers repaired and the first company that comes to mind is Carquest . However I urge you to find the fault first before throwing yet another module at it.
As a footnote have you consulted Identifix as a Pro in the business?
When faced with a strange problem or a platform I don't work on too often (like bloody awful BMW's) its the first thing I go to?
Best of luck
Dennis