thechad76437

This is my first post here so any help would be greatly appreciated.

The truck is a 2001 Cummins 2500 6 speed 4x4. Initial problem started when when my dad's truck just died on the way home. He was able to restart the truck, but it would only run for short while. After making it about a mile further it would no longer run for more than 1 or 2 secs before dying. He changed the fuel filter and bled the system up to the injection pump with no change in problem. After reading many posts about the troublesome lift pumps on these trucks, I ordered and installed an AirDog Raptor 100gph lift pump down by the tank. Before installing I pulled the codes by the on-off-on-off-on key switch method and got P-1594 (charging system voltage too high) and P-1693 (DTC detectedin ECM or PCM). After installing new pump no codes were present, but the truck acted the same. Every third or 4th bump of the starter, the truck will start and run smooth but for only 1 or 2 seconds. I never ran the starter for more than 5 or 6 secs. I re-bled the fuel system up to the pump and have what i would call good pressure at the IP. (No fuel pressure guage currently, but is on order) The next time I turned the key on the ASD relay started buzzing. Tried swapping with good relay from wiper motor but it buzzed too. Now after the key is on for about 20 sec or so I'm getting "no buS" code in the odometer window with the ASD relay buzzing as long as the key is in the "on" position. Don't know where to go from here. Please help.

Sorry for the lengthy explanation, but I wanted to give you guys as much info as possible.

Thanks,
Chad

Busboy

I would first remove your battery cables clean and inspect them for corrosion as that is most likely the cause. (ECM grounds at one of the battery terminals)

thechad76437

Checked more stuff out yesterday on the truck. Battery cable conections are are in good working order. Cleaned them anyway, but did not change situation on the truck. (ASD Relay still buzzing, "no buS" still in odometer window after 30 sec)
I checked voltages at the ASD relay (that buzzes non stop when the key is on) and got the following:

Terminal 4 - (not used)
Voltage between Terminals 3 and 5 = 12v with key off, 12v key on
voltage between Terminals 3 and 2 = 9v with key off, 6v key on
Voltage between Terminals 1 and 2 = 0v key off, 6v key on
voltage between Terminals 1 and 5 = 0v key off, 12v key on

I'm wondering why the voltages involving Terminal 2 are 9v and 6v. I'm thinking this is why the relay is buzzing. (The contact inside is not seeing a full 12v across it and thus is not staying closed?)
Does anybody know if Terminal 2 goes to the ECM? Because the only time the ASD relay will stop buzzing is when one of the black pugs is un hooked from the ECM behind the the air cleaner.

This truck does have a Dyno Sources Power Button installed, but is almost never used. I checked the connections where it taps into the IP wires and found a bare spot where it ties into the black wire going from the pump cover to one of the solenoids. (reference pic 4b and 4c here https://myeporia.eporia.com/resource...wer_button.pdf )
If this wire were grounded at some point could it have smoked anything in the pump or ECM?
Also Does anybody know how to contact Dyno Souces? The number on their web site said it has been disconnected. LOL! I had a question b/c it looks like the Power button installation on this truck varied slightly from the instructions linked above.
Anybody have any experience with one of these old boxes?
And does anybody have a good procedure for checking the liveliehood of circuits in the VP or the ECM?
Also any chance the Crank Pos sensor or TPS could causing this condition?

dodgeguy71

No bus I would think means that the comm line between computers has a problem or a computer is not responding, sending the appropriate "I'm alive" signal back to the other when it is requested. Something between the pcm and ecm.


I have a service manual for Dodge trucks in the shop, it's for a 2002 if you enter your try ID, year specifically I can look up that code or even see/ copy off the schematic with the asd relay and email it to ya.

thechad76437

Dodgeguy71
Not sure what you mean by "try ID". As for the truck it is a 2001 2500 HO 4x4 6 speed.
My email is thechad76437@yahoo.com
That would be great if you could look up the definition behind the code, and the shematic would also be great. Schematic for IP wires could also be very beneficial if you have access.
I'm afraid either the PCM or ECM went south. A friend said he can probably get a programmer to try flashing the comp and see if that works.
Thanks for the help!
Chad

mysterync

Check your PCM and ECM Grounds, Your code 1594 indicates that there is a variance of more than 1.0V between the desired charge voltage and actual charge voltage. I'd be looking at a PCM or PCM ground issue!