That code is for no 5 volt reference signal to MAP sensor.... but, you are actually getting 5 volts there?

 

Correct. Although it's higher than 5v. Almost 7. But I think voltmeter is out. Shows my battery at 15+, with engine off. Unless this is related. Battery almost new.

I think the no voltage map code is probably from when I tried driving with the map sensor unplugged. (It drove worse, boggy and still with sputtering) I'll erase the code and see if it comes back.

I do think we may be onto something with the 5v circuit though. With all these factors and the neutral safety switch seeming to fix things temporarily... Is there power to that connector when it's unplugged? There must be, right? Maybe wires shorting inside the connector? I tried snipping the pcm wire which didn't help, but I guess that's a signal wire. I might try snipping them all if I can't find a wiring diagram, although it seems silly in a way. Code 107 for the map sensor also has been a constant, although not all the time, it's come up from early on consistently. I replaced map sensor and PCM which didn't help, so I went back to both originals, after I fried the new PCM. The ASD circuit failed at one point. Changed the relay, didn't help. When it failed I replaced the fuse. It looked fine, but wasn't. Started back up, but still ran like ****.

 

Is there a known splice short on these trucks perhaps?

I'll check grounds this morning. Hopefully I can find them all.

 

As I recall, all the wires to the map come from/go back to the PCM. The power feed also goes to the TPS..... I have no idea how the PCM determines if the map is getting it's 5 volts, or not.... The PCM actually SUPPLIES the 5 volt signal...... Weird.

 

Well, thanks. It is weird. But it does appear to be getting the 5 volts, with key on, and also running. I wonder about checking the TPS, if it's shorting perhaps it could throw off the map voltage. But I would think that would be indicated by checking the voltage at the map, which is fine...

I always go back to, why does it seem to run fine in reverse? A tranny shop suggested torque converter, but it sounds like a rich fuel mix, not a torque converter, but I have no experience with that, so what do I know. Since it did throw a torque converter solenoid code a couple times, maybe that's it...

 

Funny, the one time I thought I had it, a few days ago by pushing the pins in at the neutral safety switch, I had idled for well over an hour, then drove. I wonder now if that was part of the coincidence that everything ran fine, that it was just idling for so long beforehand.

 

I wonder if pulling/tugging/manipulating the harness isn't what is fixing it, not necessarily reseating the NSS..... Might be worth a shot... While it is running bad, (at idle) crawl under there, and play with the harness. See if anything interesting happens.

 

Yes! I did that actually. I did hear a difference in the idle. But it still drove ****ty. I just finished snipping all the wires while idling, to take the harness or short within it completely out of the equation. Drove it like that, no change. However, it does seem to be the one single point that success has been found, first with the switch, then pushing the harness pins. However when I snipped them while running right now, I didn't think first, and using scissors I made some arcing between the wires with the scissor blades cutting everything at once. It started fine and the dash indicator worked once I reattached the wiring, so I guess it's fine.

I do wonder now though, if the harness was shorting at the connector somehow (I just can't see how they would do this, but maybe? It was wet, maybe water shorted it) this could have shorted the neutral safety switch internally somehow, and I'm missing that point because it's almost brand new. I could buy another one. And a harness. It drove perfect for two weeks after the shop replaced that switch. How easily could the short be within the tranny? A trans shop said unlikely...

 

Do you have the five wire 'transmission range sensor'? If so, internal to the trans is purely mechanical. One thing that IS somewhere in the harness further up though, is the crank and cam sensors..... but, if one of those were screwing up, I would expect that to set a code.... (though on the older trucks, they have many failure modes that WON'T set a code....)

What year is your truck? I am guessing an 02, or 03, with the 5.9, and 46RE trans?

 

Exactly. 2002, 5.9 with 46re

I was just going to start looking upstream of the harness to what you're mentioning. How can I test those sensors? Maybe it's not the sensor but the wiring perhaps? Could bad wiring upstream of the range sensor harness somehow tie into all this? I've noticed that the crankshaft position sensor has been mentioned on here commonly. Just change that perhaps? Thanks again