Download the manuals and check the schematics for the 5V reference. Could be a short or break somewhere that affecting it.
And unplugging a sensor might not help if it's something like the pedal sensor or the throttle body, both of which are on the same 5V reference.
Thanks for the suggestion.
Here is the exact history as best I can recall:
Truck has been running perfectly for a couple of years since we got it.
Now about 3-4 times when we first got it if you gave it a lot of gas taking off fast it would go into reduced power mode and was fine on restart.
I never even ran the codes. It never did it to me as I take off easily. My wife got used to not hammering it and it was fine for 2 years.
I knew it was probably the tps on throttle body.
Out of the blue one day it started fine and then after about 20 to 35 seconds died. The reduced engine power light ( REP) came on as it died and stayed on.
It would not restart.
When turning key off and back on all the dash light would come on for the normal test etc and the y would go out but the REP light would stay on. It never did this before.
Tried a bunch of times to restart and no luck.
Was pushing it back to driveway and hit the key and it started and was fine all day.
The next day, same thing. Ran 30 seconds and died.
I put it in N and rolled it about 5 feet and it started up. I did this at least 3 days and it was fine for rest of day.
Then that stopped.
I went to pick and pay lot and got a fairly clean throttle body and replaced it. Same thing the next day.
Then I got another pedal...same thing.
I was getting all the signal a and b mismatch pedal codes etc and the loss of 5v reference and a cam sensor code.
I bought a new cheap amazon throttle body and put it on and did reset calibration procedure and it started right up and ran fine.
Did pop a cam code multiple times and I swapped it out for a used one and no change it was fine for a few days.
Then it would not crank one day. Went out and dash lights were dim but goo battery.
Has son sit in it and AS SOON as it touche the fuses inside the bod under hood the dash lights brightened. AHHH Happy now I'm getting somewhere.
One of the ing or pcm fuses was loose from having someone use one of those stereo taps and bent it out too wide.
I fixed that and it has been fine for about 3-4 MONTHS!
Yesterday I started it and in 30 seconds it died and REP light popped on and no start with light staying on just like originally. I pulled the fused and no change until I got to the yellow 20 amp pcm B I think by the fuel pump micro relay. I pulled the fuse and relay and when I put them back in the REP light was off with key on and it started and ran fine the rest of day.
I cleaned off fuse terms one last time with my shirt tail and hoped for the best.
Today, 20 seconds and died.
Pulled relay and fuse and on the 2nd time pulling them and putting back in it started!!!
I'm at a loss now.
I don't think it's a lose connection at lest not at the fuse and the FP relay wouldn't make the REP light come on.
It only messes up 20 secs after cold multi hour sitting start.
I did smack the top of ecm under hood with palm of my hand but don't think that did it. I pushed on the 3 connectors and wiggled and looked at wires and all look ok.
I think I might pull the 3 big connectors and reseat them but I am at a loss.
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So both days I pulled the same fuse and fuel pump relay (not because the FP relay could have anything to so with it but because it make the fuse easier to pull.
2nd day still died. After pulling again and restart I swapped the two solid state electronic relays and it has been fine for 2 days. ???????