engine ground, don't forget engine ground. You say it was out mudding, and the problems erupted from that, first thing I would look at is the ground.

 

Good point army.

Two ground wires up by the power steering pump, and one off the back of each head.

Do you have continuity on the ground wire for ASD (control circuit) to the PCM connector?

 

Today I checked for 5v at TPS/Cam/Crank sensor connectors and found nothing ... so I proceeded to the PCM where I had 12v at fused 12v source (red/white C1) & 12v fused ign(lt.green /black C1) &Good ground at 31-32 (black/tan C1) & 12v at ASD+ (C3 blue/yellow) & NO 5v source out of PCM at 5v+source (Orange C2)

So I pulled the PCM out and am gonna try and find a local guy with a 98 5.9 and see if their truck will start with my computer or possibly mine with theirs and work on finding the right replacement PCM because it looks like mine is fried. The only relay that clicks on with key is the blower motor relay.

 

I had good grounds to PCM I'm pretty sure because at the PCM connectors using the PCM ground wires with fused 12v wires I got 12v thru connectors using a multimeter .(C1 connector unplugged I jumped the black/tan Grounds to the white/red and green/black)

I didn't check the ground from asd to pcm but found 12v at ASD wire of Connector C3 - I hope that wasn't supposed to be a ground instead ill check the diagram for the blue/yellow C3 wire

 

I had 12v @ pin3 K51 20DB/YL AUTO SHUTDOWN RELAY CONTROL of C3 connector according to the diagram I read - wth PCM plugged in and key on
I do not know if that was coming in or going out though

I had nothing at pin 31 K7 18OR 5 VOLT SUPPLY of C2 connector
With connector plugged in and key on

I assume that is the 5v supply "from" PCM to sensors/relays

Therefore PCM has internal fault?

 

Does anyone know what pcm's I can use ? Part numberwise?

Mine is a P56046-347AF (the 0 might be a capital d instead)

My vin is 1B7HF16Z6WS761562

I found some -347Ad pcm's out there, but when I google my number NOTHING comes up, and I don't have a good dealership parts guy I can bother anymore.

 

I found the following in an old forum post. my last two digits are AF. is the following true for mine? Seems so (updated to AG)

The part number 50646347 to 50646347AG

All of these pcm's part num updated to this one number

05014152AA 56040564AA 56046347AA 56046347AB 56046347AC 56046347AD 56046347AE 56046347AF

*SO DOES THAT MEAN I CAN USE ANY ONE OF THE ABOVE PART NUMBERS FOR MY PCM REPLACEMENT?

 

According to my pcm list yes any of those should work.

 

Sweet thanks merc

 

As you have a 98 it will run with a replacement pcm, but you will need to get it vin matched/programmed at the dealership.

Your Welcome