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Repeated failure of Dodge Caravan transmission control module

In 13 months my 1991 Dodge Grand Caravan has managed to kill 4 transmission control modules – the original plus three factory replacements. The first replacement (by a Dodge garage) failed within weeks, after which they threw up their hands in despair (never recognizing the defective part) and sent me to an electrical specialist. The specialist’s first replacement survived until April; their 2nd has just died. I find it hard to accept that all of these TCMs were simply defective. So please, someone, what is killing them?!

transman318, you here today?

What symptoms are you having? Has the electrical been carefully checked for bad wires? Really you need to give us some detail to work with.

The pins in the harness connectors are famous for having bad connections. It is entirely possible that none of those TCM’s were bad and that you just have connection issues. Chrysler even sells connector repair kits for the 60 pin connectors. I’m willing to bet you’re problem lies somewhere in the harness, whether it be a wire or a pin in one of the connectors. Its just all too common of a problem.

transman

Thanks for your suggestions. The dealer garage folks checked connectors extensively in one or more of the 4 times I took it back to them over a 6-week period. The electrical specialists said not a problem, and both times they found the TCM defective (by doing pin-by-pin tests). Before their last replacement, I also replaced both speed sensors myself. The 2nd and 3rd TCMs “died slowly,” in that I could manage to get the system back into normal mode some of the time – by turning off and on initially, later by disconnecting the battery. In April, it seemed to return to normal better when the engine was warm. But eventually, I could not get it back into normal mode at all. The last failure occurred Saturday, and I have not yet been able to get it back into normal mode, nor have I confirmed that the TCM is again defective. I will add that the indicators in the instrument panel have been sticky for a number of years, and that includes the speedo sometimes sticking on zero, which is certainly sensed by the automatic door locks. I have identified speed sensor error codes on such circumstances; but clearing them doesn’t return the trans to normal.