Engine/Transmission (1998.5 - 2002) 2001 HO 6-speed — identifying OEM ECM part number

[JLandry]

Dumb question, maybe... . how do you connect to those pins?

Insulated alligator clips work great. Just be sure to slip the insulating sleeve over the entire alligator clip so there's no chance of a short.



#ad




Going from memory, the pins on the VP44 are 2. 5mm in diameter, so you could also use insulated butt splices, or insulated female "bullet" or "snap" connectors if they were the proper ID...



#ad




#ad

Also, I have a reman VP44 on it now, so it should be OK.

Remanufactured BEFORE it was starved of fuel???



John L.

 

[Gordon Maney]

Insulated alligator clips work great. Just be sure to slip the insulating sleeve over the entire alligator clip so there's no chance of a short.

#ad


Going from memory, the pins on the VP44 are 2. 5mm in diameter, so you could also use insulated butt splices, or insulated female "bullet" or "snap" connectors if they were the proper ID...

#ad


#ad


Remanufactured BEFORE it was starved of fuel???

John L.

No. I put the VP44 on the truck during this whole chain of events, along with the Raptor pump. The injection pump is from Vulcan. Buying from them was an entirely different experience than the ECM managed to be.

 

[JLandry]

No. I put the VP44 on the truck during this whole chain of events, along with the Raptor pump.

Good.



Then that pretty much eliminates any worry about the VP44 being at fault.



John L.

 

[Gordon Maney]

I have bled lines 1, 3, 44, and 5 all three times. It still tries, but does not carry itself.

I used a scanner to clear the codes and it is not setting any codes at all.

If the VP44 was not getting a voltage, would it even try?

Try meaning firing cylinders.

 

[JLandry]

I have bled lines 1, 3, 44, and 5 all three times. It still tries, but does not carry itself.

Gordon,



Just so I'm clear about what's happening... are you saying the engine sounds like it's just about to start running while being cranked, but as soon as the starter is released it doesn't continue running?

I used a scanner to clear the codes and it is not setting any codes at all.

Perfect.

If the VP44 was not getting a voltage, would it even try?

It shouldn't. The VP44 must have power to provide any injection pressure. No fuel (i. e. : no injection) means the engine won't run.



Questions (please don't read anything into these... I'm only trying to make sure I understand the big picture and verify what I think I remember about your situation):

1. This remanufactured VP44... where did you get it?

2. Has the engine ever run using this remanufactured VP44, or did you install it after the engine wouldn't start due to the ECM problem?

3. Did you install the remanufactured VP44 or did someone else do the work?

4. Are you sure the correct VP44 pump shaft key-way was used, and was it installed in the correct orientation?

5. You haven't done anything to the fuel injectors or connecting tubes... correct?

6. Were any other maintenance, repair, or modifications done to *anything* before or since this whole problem started besides the aftermarket lift pump, a remanufactured VP44, and a "refurbished" ECM. Am I missing anything?​

As you know, your diesel engine only needs fuel and air to run. Presumably it's getting an adequate amount of air (I don't think you messed around with the air intake or exhaust system), so that only leaves fuel delivery as the culprit. So at this point it may be worth verifying the VP44 is actually getting power when the ignition key is on. It's worth pointing out you should be getting a trouble code from the ECM saying it can't communicate with the VP44 if the VP44 isn't getting power, but it can't hurt to check anyway. To do this, simply disconnect the VP44 wiring harness connector, turn the ignition key ON, and use your test light to check that voltage is present between sockets 6 and 7 of the connector. Since the ECM should report lost communications with the VP44 when you turn the ignition key on with the VP44 disconnected, you'll likely need to clear some trouble codes after doing this test.



#ad




Next, I'd recommend carefully hot wiring the VP44 and then try starting the engine again. With as much fuel injection line purging as you've done, it probably isn't necessary to do that again unless the engine just won't start. If the engine still won't start even with the VP44 hot wired and another injection line purging, then I'd suggest there's something wrong with the remanufactured VP44 or the way it's been installed and you'll have to work from there. If the engine does start with the VP44 hot wired, then you can probably assume the ECM is at fault.



Hang in there and please keep us posted!



John L.

 

[JLandry]

Gordon,



One more suggestion which I picked up from ANOTHER THREAD and thought it might be useful to you...

Got truck running this morning, had a leak from the filter housing to the relocate line to the VP44. Took your advice and held the pedal to the floor and cranked for 15 seconds or so. Could have done it last night I guess, but I was dog tired and the storm didnt help, I was cold, the truck was in the driveway NOT under cover! Have the lift pump wired through a relay to a oil pressure switch; now I just have to figgure a way to start the lift pump before the oil pressure switch makes up. Will change the lift pump when I recover from the cost of the injection pump!

So possibly it might be useful to hold the accelerator pedal to the floor when trying to get the truck to start for the first time? Note that the accelerator pedal will have no effect when hot wiring the VP44. This only applies with the VP44 connected in the normal manner.



Good luck,



John L.

 

[Gordon Maney]

Regarding post 45... .

Yes, it sounds as if cylinders are firing, perhaps random cylinders, but cylinders firing, yetit is not successful enough to be able to let go of the key.

I got the reman VP44 from Vulcan.

The engine has never been run with this VP44, as it was purchased, along with the Raptor and pressure gauge, to resolve this no start situation.

The correct key was used, as per markings, and it was installed correctly. [As an aside, that must be some magic key. ]

I installed the VP44.

I have done nothing to the injector tubes, other than remove and replace them. I did it in groups of three, as connected by the factory parts. A video I watched recommended that, so I followed that advice.

There have been no other modifications. The truck is stock, and I have not, had not, made any other changes to the truck.


I will do the voltage test at the multi pin connector. That is easy.

I need to verify the pins on the pump correctly, as I don't want to apply a voltage to the wrong terminal and damage the pump's computer. Is that drawing as viewing the connector, or the pump? ... . and recall, I had concerns about a means of connection.

 

[Gordon Maney]

Gordon,

One more suggestion which I picked up from ANOTHER THREAD and thought it might be useful to you...



So possibly it might be useful to hold the accelerator pedal to the floor when trying to get the truck to start for the first time? Note that the accelerator pedal will have no effect when hot wiring the VP44. This only applies with the VP44 connected in the normal manner.

Good luck,

John L.

What does that do? I would not think it would have any effect?

 

[JLandry]

What does that do? I would not think it would have any effect?

Holding the accelerator pedal to the floor while cranking should cause the ECM to command the VP44 to send the maximum allowable amount of fuel to the injectors (compared to simply cranking with the accelerator pedal at the idle position). More fuel being sent to the injectors should help push any trapped air out of the high-pressure lines faster and more effectively, hopefully leading to an engine start... finally!



John L.

 

[JLandry]

I need to verify the pins on the pump correctly, as I don't want to apply a voltage to the wrong terminal and damage the pump's computer. Is that drawing as viewing the connector, or the pump? ... . and recall, I had concerns about a means of connection.

The diagram I provided is of the VP44 connector attached to the wiring harness. The pins on the VP44 would be a mirror image.



In preparation for hot wiring the VP44, a quick and simple way to verify which pin on the VP44 is pos. (+) and neg. (-) can be accomplished when you're testing to see that power is present on the VP44's wiring harness connector:

• Disconnect the VP44 connector.
  
• Turn the ignition switch to the RUN position.
  
• Attach the ground lead of your test light to a good chassis or engine ground.
  
• Probe socket 6 and then socket 7 of the VP44's wiring harness connector.
  
• Note which socket illumnates the test light.
  
• Turn the ignition OFF.
  

​

The socket that illuminates your test light is the VP44's pos. lead and the one that doesn't is the VP44's ground. The corresponding pins on the VP44 are the pos. and neg. Piece of cake!



John L.

 

[Gordon Maney]

It started and seems to run well. I have not driven it yet.

I did the pedal to the floor thing. Whether that was it, I can't guess.

I am wondering what concern I should have about the recon ECM, given the circumstances under which it first arrived.

John, do you have a thought on that?

 

[JLandry]

It started and seems to run well. I have not driven it yet.

CONGRATULATIONS!!!

I am wondering what concern I should have about the recon ECM, given the circumstances under which it first arrived.



John, do you have a thought on that?

There are several things I'd recommend going forward:



1. Use the ECM you have as is. You know it works, and really, what other choice do you have?



2. Wire in a relay and fuse for the lift pump circuit so the ECM isn't carrying the load any longer which powers the lift pump... only switches the relay on and off.



3. Assuming you plan to keep your truck for a long time, I'd start setting aside money for the eventual purchase of a spare used or reconditioned ECM and PCM from either Bob Wagner or from eBay (so you have some semblance of purchase protection). Keep it on hand should something like this ever happen again. I don't think these discontinued Cummins ECM's will suddenly become more plentiful anytime soon... likely just the opposite. If you wind up never using them, you'd always be able to sell them for nearly what you paid... or maybe even more. And I know you said you don't use eBay, but you should have plenty of time to establish an account and get comfortable using it. Then when you see a good deal on an ECM you'll be ready to make your move. Please feel free to PM or email me with any questions you have about using eBay and I'll do my best to help.



Again, congratulations on your success. I'm glad you hung in there for so long... a lot of guys would have thrown in the towel long ago. We've all learned a lot from your experiences.



Best regards,



John L.

 

[Gordon Maney]

Do you see lift pump load as a risk?

 

[JLandry]

Do you see lift pump load as a risk?

The lift pump is definitely a weak point in the system... that's why smart owners have a fuel pressure gauge in the cab an monitor it for a low pressure condition that could damage the VP44 fuel injection pump. But I recall you've already added a Raptor lift pump... right? That should significantly reduce the failure risk. But you should still permanently install a fuel pressure gauge in the cab because anything can and eventually will fail.



I personally deal with the "lift pump risk" by using an aftermarket Airtex gearotor type lift pump (mounted in the stock location), I carry a spare one in the truck's parts box at all times, and I have a fuel pressure gauge mounted in the cab that I watch like a hawk!



John L.

 

[Gordon Maney]

My risk question was regarding your suggestion to wire in a relay to power the pump, rather than having the ECM power the pump.

Do you see that load as a risk?

The Raptor has a relay, so the ECM signal is triggering the relay, rather than powering the pump.

I would think the control coil for the relay would have a lower current draw than the OEM lift pump, and thus be a great improvement.

Do you agree? Or are you suggesting other risk in using that signal in any way?

 

[JLandry]

My risk question was regarding your suggestion to wire in a relay to power the pump, rather than having the ECM power the pump.

Sorry... I misunderstood the question.

The Raptor has a relay, so the ECM signal is triggering the relay, rather than powering the pump.



I would think the control coil for the relay would have a lower current draw than the OEM lift pump, and thus be a great improvement.



Do you agree?

I agree completely and you're all set already... nothing more to do in that area. The relay the Raptor has is a very tiny load which the ECM should handle just fine... no risk of overloading/wearing out the internal ECM components.



John L.