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Engine/Transmission (1998.5 - 2002) Update on the truck Dying.

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Engine/Transmission (1998.5 - 2002) power in lockup

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One way to check for shorts is to disconnect the negative cables from your batteries and then rig a test light between the cable and battery post. You'll only need to do this on one battery. Then you pull one fuse at a time until the light goes out. This'll give you the circuit that is giving you the problem. Hood lights and open doors will fool you because the lights will complete the circuit so pull the bulbs ahead of time. Once you have the problem circuit you can get a wiring diagram and start chasing the problem. Usually it will be in the one circuit that powers most of the truck. Have fun, I've spent some serious hours doing this over the years.
 
Tool Man

A couple of thoughts on this issue:

1. ) If I recall correctly, the rule of thumb for current draw is: ~ 60 mA. draw is acceptable (all components, key off) Many of the ECM's that we work with only draw about 6-15 mA to keep their brain "alive" during the "key-off" mode. I can measure mine if you need a real number.

2. ) The communication link for the ECM/PCM is through the CAN bus. This is a pair of wires that carry the communication between the ECM, PCM, injection pump, transmission, and the dash instrumentation. If the CAN communication gets "interrupted" all sorts of weird issues can occur. Since the CAN communication passes through the dash instrumentation, it relies somewhat on chassis to body grounds. These grounds are separate from the engine grounding system that I think you are currently addressing. While you are sorting out ground issues, make sure body to chassis grounds are also intact, clean and fully functional. Frequently body grounds are not under the hood. I will have to research their location on the Ram. You will notice the addition of a number of grounds on '04 & '05 production vehicles. Many of these are in the form of a woven strap. The ground issue is huge!
 
Codes?

TMTT,

Have you ever checked if there are any codes set?

Not the ones in the dash! I mean the real ones read with a good scanner or DBRIII.



There is a brutal way to erease ALL codes. With the engine running, disconnect the ECM harness. Done that many times... :D



Marco
 
The heavy spark when reconnecting the battery cable is caused by the high inrush current to the air bag computer. The air bag computer has a large value capacitor built in to allow the system to work in the event of a crash when the batteries become disconnected.



If you touch the battery cable to the battery post and get a spark, then momentarily remove the cable then reconnect it there will not be a spark because the capacitor will hold the charge for a few seconds. Another test is to connect an amp-meter between the battery cable and battery post. The meter will read 5 or more amps at first and then drift down to about 100 mA.
 
Tool man,

I feel for ya man! I spent 18 years as a computer hardware debug tech and 6 years as a software engineer and can tell you the worst word in my tech vocabulary is "intermittant" :mad:



99% of the time it's something you have done while adding/modifing electical circuits on the truck. Often, the mod seems to have nothing to do with the circuit having the problem, but hindsight is 20/20 :rolleyes:



1) Go over each and every thing you have added/modified and check for problems, not just grounds. If you have tapped into any wire that is not purely +12 or ground this is a major suspect. ANY signal wire that connects to the computer could cause the problem. Best, but most work is to disconnect one thing you've added at a time until the problem goes away.



2) Electrical noise - It would be worth your while to add a noise killer/filter to the +12vdc that feeds the computer(s)



3) Batteries - If you can swap another set of batteries into the truck. Believe it or not batteries can cause this kind of problem.



Hope this helps... and remember you have to have bulldog persistance to find these kind of problems;)
 
Re: Codes?

Originally posted by Marco

TMTT,

I mean the real ones read with a good scanner or DBRIII.





Marco



Uhh marco oh ecm guru it's a DRBIII here in the states ;) :D :D



Just kiddin' I thought a discon withe engine on would just flat out kill the ecm. Ug. No I havent had codes pulled (Other than the ones I laid out thru previous posts. ) I am thinking of adding a ground for safe measure anyhow.





Classic example is actually PROOF on a dyno with 10 Subaru WRX's which were notorious for bad grounding issues. BRAND NEW mine had surging problems. I-Clubbers out in california ran a back to back comparo with 10 wrx's and had found gains of an averaged 4 H. P ... . 4HP! what they found was startling. The grounding for all the sensors and ecm , injectors , etc relied on the one main engine / chassis ground. This was causin an electrical resonance if you will. Adding 2 grounds smothed out idle and gains were found. Wicked!



So now to the cummins. All our sensors , inj pump , heater grids , etc rely on that single ground strap that goes from just under the oil filter to the batt. Take into consideration heat , vibration , and electrical noise over the wire , factor in resistance and you have an issue. So to elieviate that I am going to add another for peace of mind.





Tonite I will tell all on what I find in that main harness as that seems to be the culprit when played with. It just so happens that is the same harness that contains the APPS connetions.
 
dane and dave, Good points! I forgot that there was more to it. Airbag mod , ecm , clock , and such.



Batteries ... . yeah I am considering that option as well.



Doc Dyno, I had a NoBus displayed in my dash a few months back before any of this ever started happening if that means anything.
 
i took the wires for the APPS out of the harness this morning and relocated them



I also took out the wires for the engine speed sensor and relocated them



they were wrapped around the APPS wires so I thought maybe they were cross firing and causing the rythmic stumble and surging



STILL STUMBLING

THIS SUCKS!!!!!!!!!!!!



DOES ANYONE HAVE AN ECM I CAN TRY????
 
Well wednesday I diconnected the batteries for 26 hours. Truck has been running Flawless again ever scince Hmmm Odd indeed.



We had no chance to tackle the harness so I will keep tabs on this ordeal.



Agades Your apps is good right? How did it pass on the voltage test?
 
all I had to test the APPS was a fluke meter



no spikes showed at all, I ve heard this isnt the best method to test it so I swapped one off another truck



still stumbled



if I made a list of all the things Ive changed and replaced you would get sick of reading and become crosseyed



if I unhook my batteries, my truck will run great untill I accelerate a few times, then .....



or if I put my box on 9 and rod on it sometimes it straightens out , but only for a while , like 2 minutes



by the way mine wont stumble at WOT at any level with the box, only when holding speed with a load or real slight acceleration
 
Originally posted by Agades

I swapped one off another truck



still stumbled



if I unhook my batteries, my truck will run great untill I accelerate a few times, then .....



stumble only when holding speed with a load or real slight acceleration



EXACTLY TO THE TEE what I have going on. My last batt disconnect last wednessday for 20somethin hours has worked for me for now. I am going to have the batts load tested next week.
 
Oh definatly Bob! I want to hash this out then make a thread in one post that lists all I have done what worked , did not , and was the final fix.



This seems to be a more common thing that guys out there are replacing VP44's for no other reason. I saw one member that has this problem and he is on pump #7 ... in 30K miles! To me it's obvious there is nothing wrong with the VP's he has on his truck and maybe has what we have.
 
TMTT are you running with ''nowhere near stock'' enhancements? Would you consider runnin stock to see what -if any- effect it would have after batteries are disconnected for a time? When addressing a similar problem, the TDR magazine spring 03 mentions that reflash may be needed in some cases , and that replacing sensors is more expensive because they are part of more expensive [more reliable?] assemblies. . Yes I know that reflash means trip to the dealer, but what ya gonna do? Same article also says troubleshooting trees in service manual are good places to start.

Just wondering if boxes could be corrupting the truck computers-- mabe it is possible bad connection putting out bad signal.

Good luck --we will pray and shake some chicken bones :eek:
 
Dave, I dont think TTMT could ever run around stock,LOL. i think he rather push him bombed Dodge than driver a stocker:D . I am the same way,whenever i drive a stock one,its like Yuck this things is a pig,and the trans(auto is a total slushbox).
 
Originally posted by Snow man

Dave, I dont think TTMT could ever run around stock,LOL. i think he rather push him bombed Dodge than driver a stocker:D . I am the same way,whenever i drive a stock one,its like Yuck this things is a pig,and the trans(auto is a total slushbox).
Stock for a week is better than Ankle drive for a week. Ron Bissett In Metro Louisville KY:-{} :D
 
stumble only when holding speed with a load or real slight acceleration



Sorry I'm late on this one didn't get it sooner:{



That's the software in the ECM. The fuelling table... .

The fuel table is organized for different Rpm/load values.

What happens is that under certain circumstances (load) the ECM reads two different load tables at the same time and is not able to determine which one is the right one. The fuel goes then rich-lean-rich-lean = stumble, hesitation, call it however you want but that's the problem you're having. Get a different calibration for the ECM, could solve your problem.



Marco.

P. S. Usually that problem becomes more noticable with bigger injectors. Then bigger them injectors then worse the problem...
 
I believe you Marco, because my problem started after the dealer reflashed my ecm

problem is

in the US you cant get another calibration other than the one out at the time



cummins isnt allowed to put in an old calibration and dodge doesnt keep any other calibrations on disc, only new ones



im kind of screwed unless I can find an old ECM that will work or find a hacker that can fix the calibration or find a cummins dealer that keeps the old calibration even though they are not supposed to



Im not having any luck finding a used ECM for my truck



today my truck really ran terrible so I shut off the PM 3 and ran on stock fueling (no fun)



it still stumbled the same



I drove my dads early 01 HO stocker and noticed it had the same stumble only it was barely noticeable

I noticed it because Ive drove with it for about 9 months, so its permanently etched in my brain



Ive had a frown on my face for 9 months every time I get in this thing



Im really tired of it,
 
Oh yeah I hear ya daveshoe, That is just basic troubleshooting. The blue chip I discon'd , The V/A off the truck , Pump cover removed and that took out all the fueling things I have done ELECTRICLY. Still did it. Again , It hasn't acted up scince I reconnected the batteries last thursday. Today I changed the oil , pulled all battery connections and gave them all a perfect finnish ... . WITH NEW TOOLS I didn't even use my old batt brush ... . I got a new one. Yep did those (Noticed the passenger battery + trminal was shoddy allready ... . Hmmmmmm) used those cute cuddly fuzzy chemicaly treated battery terminal fuzzywuzzys. We'll see. :rolleyes:
 
Not sure

Agades,

I've searched through all the different original softwares I have here. I'm not sure but it could be that there IS a new software for the 2002's like yours. I'd check with a DC dealer...



Marco
 
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