Engine/Transmission (1998.5 - 2002) Truck Problems... Help!

[SmokinS]

I'm working on 2002 model automatic truck. The codes it shows are po 606, 118, 238, 343, 563, 606, 1286, 1475, 563, and 118. Truck is showing high voltage on scan tool and the gauges in the truck, like 15. 2 on the scan tool. The throttle is irratic, and normally if you touch it, the truck will go full throttle. It's showing high voltage to the transmission also. The temp gauge after startup will peg at 240. I've replaced the pcm, ecm twice, i took fuse out for alternator and still had an overcharge on scan tool. checked battery's and did't show an overcharge, 14. 2 volts. Cleaned serveral grounds. When heat gauge goes to hot, is when truck acts up, after about 30 secs of running. Replaced APPS too. Please Help! Thanks!

 

[AKAMAC]

Seeing as no one has stepped up, I'll try.

All of the codes are analog voltage signals that register high and go through the ECM.

Since you have replaced the ECM already I would try to isolate the ground pin from it. It seems like the inputs from the sensors are back feeding and causing the codes.

Try to find a source for the pin-out of the ECM or the grounding lug it references. If you have a schematic you can unplug the sensors one at a time and follow the scorce of the groung fault.

Hope this helps. Mike