2002 Chrysler Other

Engine Mechanical problem
2002 Other Chrysler Models Four Wheel Drive Automatic 80000. Miles

So my dodge 2500 SLT was running rough and I thought I might take it to the dealer for a check up. It seemed like it was running on 9 cylinders rather rough as it were. The first call I recived was that the compression check of the cylinders was 9 were 150 and one was 120#. Suspected a cracked head he said and that the bill was to be $5000.00 I told them to do a real tune up and then let me know. The next day I received a cal saying the tune up did well, however now the alternator was not charging properly. I, of course indicated that it was working well when gave it to them so I told them that the mechanic must have left a wire off or made a loose connection or something. Try again as it were.
The next day they call and indicate that the PCM is bad and it was causing the problem. So, I am thinging the mechanic did something in the tune up process to short the PCM. After all this was just a tune up. Ok The tune up is about $850.00 but the new PCM is $750.00 + labor. I told the service rep that the mechanic screwed up and shorted the PCM while doing a tune up.
My question is what are the chances this happens. The failure/replacement rate of a PCM are very low so I indeed suspect mechanic error.
Please let me know what may have happened while this tune up was being done.
Much appreciated,

Mike in Alaska
August 1, 2008.

Hi Mike: The chances are slim that he caused a problem with the PCM; however, I can tell you that the alt is regulated through the PCM. A charging problem may seem llike an alt until it's bench tested and determined to be good. The next place to point a finger is the PCM. Regardless, is it possible that the PCM was causing your rough running problem would be my question. That is possible. Also, a 30PSI variation in compression doesn't mean the head is cracked. It could cause a very mild problem, butit would be one that would be hard to recognize. Again, I wish I could give you a better answer, but after thinking about your question for some time, I can't imagine the tune-up process caused PCM failure.

If you have any other specific questions, let me know.