Xterra 2010 4.0 Burnt PCM

Hello, I have a problem with a 2010 Nissan Xterra, it arrived with a burned-out computer, there was no communication and the 5-volt network sources were burned, according to the computer workshop that tried to repair it without success as it said the proccesor was likely done. We got another computer and got the car to run succesfully but checking all the connections to verify that everything is fine and this computer does not burn again, I find an anomaly, backprobing pins 66 and 67, which are typified as sensor grounds, I find the presence of 5 volts, According to the procedure manual it is indicated that there should be close to 0 volts as would be expected when dealing with grounds. I am surprised that the same thing happens in both circuits as they are separate circuits, I do not know if they join inside the computer and, if they are an anomaly, what could be causing it? I appreciate your attention and any help you could give me. Greetings. I attached the respective wiring diagrams.

What do you have on 82 & 83?

Near zero volts in pins 82 and 83, they are the  throttle pedal ground and near zero is what one would expect, as for pins 66 ( throttle body sensors ground) and 67 (rest of the 5 volt network sensors ground) i noticed there exists continiuity as soon as i put the key in ignition....

    The 5 volts are coming through pin 67, as i cutted off the pin 66 wire, so its coming from the various sensors that ground feeds.. according to the diagram they all connect through a multi connector.. if i could identify where that is maybe i can isolate the circuit thats causing this...

Ok, so i had the throttle body disconnected before i had cut the wire of pin 66, so i connected the throttle body and now have 5 volts too through the loose wire of pin 66... could this be just normal behavior of the circuit or something else ??

wrote:

 backprobing pins 66 and 67, which are typified as sensor grounds, I find the presence of 5 volts

That 5 volts is coming from the sensors looking for a ground from the computer. Your reading of 5v backprobed at the computer indicates, that both 66 and 67 wires are either not reaching the computer pins, or there's a break inside the computer board for the ground circuit. I'd try and wiggle the connector and see if the circuit reads 0 volts, check for pin fitment issue, and or re-route both of those grounds to another sensor ground and see if that fixes it.

Check your TPS signal wire at pin 50, if you read 5v there, well, then all those sensors are just missing a ground.

  So apparently all was caused by a problem with my backprobing (?) 

https://imgur.com/a/5ST5CdH

So i had 5 volts in the needle but not in the wire.... took the needle out and reinserted it and now the reading is close to zero volts, been wiggling the harness and everything looks fine... thank you very much for the input.. apparently all is well.. i hope. Needless to say the reading in pin 50 from TP1 is .470 volts or so...

Cheers.

i dont know how to attach images correctly...

I do now 

Pin 50 is the signal wire.
Do you have a scan tool?
Also can you post page 4 of your wiring diagram as a single pdf as you did with pages 1-3.
Thanks

wrote:

Also can you post page 4 of your wiring diagram as a single pdf as you did with pages 1-3.
Thanks

Do you mean #1? OP posted diagram 2, 3 and 4. Here's 1:
 

wrote:

Pin 50 is the signal wire.
Do you have a scan tool?
Also can you post page 4 of your wiring diagram as a single pdf as you did with pages 1-3.
Thanks

Yeah, do have scan tool, cant figure out how i would work these cars with out one.. either way i took the reading from the white wire directly from the throttle body, i get that what you were telling me is would see the 5 volts (ungrounded) from tps 1 if my grounds were missing...  so thats what was strange about it that i did not have any symptoms at all.. thats why my conclusion is that it was an error with my backprobing, as you can see in the picture i attached, the needle is backprobing the circuit and my clamp is attached to the wire of that same pin.. thats were i noticed that i had 5 volts in the needle but not in that same wire, took the needle out, reinsterted it and got the same reading i was getting at the wire... strange, but i wiggled  it around for a while, took it for a test ride and never got to see the 5 volts again. In fact i delivered the car yesterday to my customer. Hope all is well.. thanks for your attention and input. Will be seeing you around.

Cheers.