nilsson

So, I was very confused about the whole thing, even replaced the whole wiring harness in the engine bay. So I'm really not sure if the new PCM was bad or were those problems caused by bad wires or something. I did also put in new ESS, it has been working ok. I could try if those symptoms occur again if I switch PCM's, since I have the old PCM in the truck and the new one in garage. If the new PCM turns out to be ok, I can send it to you so you can try if that fixes your truck.

Hope this doesn't confuse you too much, I know that I was veeeeery lost with my truck last winter.

Regards,
Juho Lod

Hi,

I had problems with overdrive and TC lockup not working, turned out that PCM was not the problem. But I also had same symptoms that you are having with charging, tacho etc. I can't remember if those symptoms were only present with the new PCM or was there those problems with the old one also. Now I have the old PCM in my truck and the one I bought is sitting in the garage. Charging, tacho, etc worked fine when the truck was started cold. But if I drove for some time, then let the truck sit for half an hour, then the no tacho, no charging, no WTS light etc. problems were present. And they wouldn't start working until the truck sat long enough to be cold again.