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Discussion Starter #1 (Edited)
I've searched for everything I can find and get alot of convoluted information. Any help here would be great!

Truck- 1999 Dodge Ram 2500 24v 5.9L Cummins, SLT Laramie, 4x4, A/T w/AC 165xxx on the truck with 66k on a rebuilt long block (53 Block rebuild under warranty/recall by Rocky Mountain Cummins).

Yesterday, while in the acceleration lane my truck stuttered and the engine went to idle. When I would depress the accelerator, the engine would attempt to rev, but would stutter around 1000-1100 rpms. I shut it down and had it towed home. I did get a CEL.

A buddy brought his scanner by and this is what it showed:
Engine Codes:
P1693 MIL Fault in Companion Module
00594 Undocumented Code
P1688 Internal INJ Pump Failure
P0251 VP44 Fuel Valve Feedback Circuit

The transmission also had a code:
P1693 MIL Fault in Companion Module

From what I've gathered so far, the P1688 is indicative of the VP44 electronic control module failure. Meaning, it isn't communicating with ECM, so it doesn't know how to fuel the engine. What I can't find, is a replacement VP44 electronic controller.

The truck will start and idle. The lift pump runs, as per normal when the key is switched to the run position. The only thing "new" is a rattle of an unknown nature coming somewhere, from inside the engine compartment.

Am I way off here? Any guidance would be appreciated.

Thanks,
Randy
 

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Not good, probably not good at all. The P0251 is a death code for your VP-44. The 1693 is just the companion code.

What you are experiencing is known as "Dead Pedal" most of us who own / owned VP-$$ trucks have had this issue at one point or another.
 

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:welcome:

Good trouble shooting, one thing missing is what is your Fuel Pressure?

You may get lucky and only have a failed lift pump and your VP$$, will be fine after you replace the Lift Pump.

Fuel pressure should be about 15 psi at idle and no less than 10 psi at WOT.

Now the bad news the control module is an integrated part of a new (rebuilt) VP$$:doh:

Look here for more detailed trouble shooting.

Blue Chip Diesel Performance Specialists
 

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DieselAutoPower.com
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The link provided above is the best means of troubleshooting the pump. But given the codes, it's likely a goner. If we can help on a pump please let me know.
 

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Discussion Starter #5
:welcome:

Good trouble shooting, one thing missing is what is your Fuel Pressure?

You may get lucky and only have a failed lift pump and your VP$$, will be fine after you replace the Lift Pump.

Fuel pressure should be about 15 psi at idle and no less than 10 psi at WOT.

Now the bad news the control module is an integrated part of a new (rebuilt) VP$$:doh:

Look here for more detailed trouble shooting.

Blue Chip Diesel Performance Specialists
Yeah, see here's the thing..... My truck is bone stock, no upgrades at all. That being said, I don't have a fuel pressure guage. I'll see if my buddy can bring his scanner over again, it read the fuel pressure among a bunch of other things while the engine is running. I want to say when it was running last night, while hooked up that the fuel pressure was 14.7 psi. I remember thinking that was good.

Now, if his scanner doesn't read the fuel pressure, and I'm just making that up....where should I go from here?

- Randy
 

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Yeah, see here's the thing..... My truck is bone stock, no upgrades at all. That being said, I don't have a fuel pressure guage. I'll see if my buddy can bring his scanner over again, it read the fuel pressure among a bunch of other things while the engine is running. I want to say when it was running last night, while hooked up that the fuel pressure was 14.7 psi. I remember thinking that was good.

Now, if his scanner doesn't read the fuel pressure, and I'm just making that up....where should I go from here?

- Randy
1st upgrade to a Cummins 2nd gen should be at least a Fuel Pressure gauge. The fuel pumps on these tend to die, and the engine will continue to run, but in the process it eats up your VP$$ and you are out $1,000 to $1,500 for a VP$$ and Lift Pump.

If your VP$$ is dead JKidd at DiselAutoPower has some good prices.
 

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The little control module you looking for is readilly avalible. It comes attached and calibrated to a reman VP44. see if one of our vendors will shoot you a good price and add Lift pump to make a package deal.
 

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Discussion Starter #8
The little control module you looking for is readilly avalible. It comes attached and calibrated to a reman VP44. see if one of our vendors will shoot you a good price and add Lift pump to make a package deal.
LOL
Kinda what I figured, knowing what I know now.

Thanks!
 

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Discussion Starter #9
My plan is to test the VP44 per the instructions linked above. I'll do that tomorrow and post back the results.

Thanks everyone.
 

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Supporting Vendor
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Most likely your computer is bad. Replacing the computer is about $500-550 + install and bench time for calibration ($175-400). You can get a rebuilt pump for under $1000 exchange.... Exchange is usually a better option and less down time and cost is almost the same + you get a warranty.

jacob
 

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Mopar1973Man.Com
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P1688 and P0251 are both death code for sure...

P0594 I've got no clue... My books don't show it either... :confused013:

(Google search)
Possible causes of OBD code P0594
- Open or short speed control servo circuit - Poor speed control servo electrical connection - Faulty Brake Light Switch The Error code is generally activated on detection of the following conditions: Open or shorted condition in the cruise control servo circuit
 
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