09 prostar with ISX randomly shutting down

[Rawze]

Truck would die randomly ...

Forum member 'earnies2' went to Mr. hags shop with a truck on a flat bed that was doing the same thing. He had it to several different shops, spent countless hours with several people on it, spent a lot of time and money trying to find it. He tried even resorting to using a second wiring harness, tried hard-wiring the ecm, bypassing the ignition system, etc.etc.etc. - They even replaced the ECM, some of the solenoids, and even had ground jumpers everywhere trying to see if it was a bad ground. -- nothing would fix the problem.

Sometimes it would run for a day or more and sometimes it would not make it out of a parking lot. The problem did not seem to follow vibration or rough roads, it was just annoying to the point that the truck could not be driven very far at a time.


Mr. Hag called me up when it arrived for some ideas and they both explained the whole story to me. - I told them I would stop by and help em towards fixing it since no one seemed to be able to find it so far. I told them it should not likely take more than a few minutes to find,.. and the guy laughed at me in disbelief, considering all that he has tried.


- I went there, looked over the truck a bit, then pointed out their problem. It took about 30 seconds after my arrival for me to show them that the truck died instantly whenever the top of the ECM was smacked with a hammer lightly at a certain place (top center of it where the ribbon folds over inside it).

They disagreed with me, saying it was coincidence because they had replaced the ECM before and it did not change the problem. -- I told them to buy a brand new one, put it on, and smack it on top and see if the truck still dies ...


They replaced the ECM with a new one (that didn't die when you smacked it) and they have been driving that truck ever since.

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That may not be what is wrong with your truck at all, but I have seen it about 10 times. Point being,... sometimes it is the simple things getting overlooked that make a problem so hard to find, and yeah.. it is not unusual to get a reman ecm and it already have this problem in it when you buy it.