[carjimost]

As I explained earlier the MAP sensor works fine with the B wire umplugged and as soon as I connected the B wire to the MAP the sensor stops working, so I went ahead and check for any short from the sensor connector to the ECM connector and founs that it was OK, so I opened the ECU and found a Diode that was bad(short) so I replaced the diode and the problem went away for a couple of minutes, then it came back and it was intermitent, I accidentally moved the harness and found that the the MAP started works everytime I move the harness, so I check the entire harness and found that two of them where shorting out, the harness was close to a sharp edge close the battery so I insulate the cables to avoid the short, start the truck again and everything works fine now, so that explain why the truck started failing when I entered the hard terrain, the short may blow the diode in the ECM, and that's why the truck was failing, the code 34 says that is low voltage, so due to the short the ECM was reading 0V.

I hope this post helps someone else.