So I've been battling a bad ECM for a while or at least what I am assuming is a failing ECM. For quite some time now I've had a map sensor voltage to low to long and air intake temp sensor voltage to low to long....the truck has been running fine other than it won't idle properly(touch the throttle or brake peddle and it levels out, until it warms up then she'll idle fine for any period of time) although this time last year it did the same thing....either way just drove it from pa to nc to sc to fl back to sc to pa over the course of a week and a half ran great not one single starting issue (sometime it won't crank on the first try, turn the key off try again she'll start) got in it the other day started right moved it over shut it down 5 min later to go to the store it won't start.....ran codes got the normal map and AIT along with p0232 fuel shutoff I assume is why it's not starting.....so on to the question should I spend the 1300-1600$ on a new ECM or save my money and get a p-pump kit? If I p-pump it does that totally eliminate the need for an ECM ? This truck has about 100k on the Bd 100hp injection pump that's had an ad150 lift pump it's whole life but I kno I'll be replacing that before to long. Any advise will be greatly appreciated


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Ok so p-pumping is not as easy as it sounds and there is alot of tuning involved with it alnog with the 3000-4000$ have you took the MAP and the AITsensors and replaced them if your geting codes for those sensors it means there bad from what i understand dirty ones wont throw codes and if you were to p-pump your truck you also will still need you pcm and ecm as they control your gauges you cant take it all the way off unless you plan on runing standalone gauges it doesnt sound like a ecm issue i strongly suggest spending the money on a couple of sensors befor what your planing to do.

 

Think I'd diagnose the issues instead of wasting my time and money! Instead I'll bet my money it's not the ecm

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Thanks lilmike1540, Yes replaced those two sensors already but it never changed anything (codes lights all the same with new sensors) ....I did some diagnosis with the help of moparmans forum....my voltages are good to the sensors....could it still be a ground issue if my voltages are cgood to the sensors


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Could be a bad ground, Could be a wiring issue on signal back to the ecm.The list of it could be's is huge, Need to find a good shop and let them diagnose it!
Used to try and teach people how to diagnose a issue but that's not possible. It takes years of experience and training to understand automotive powertrain controls. No offense but it's not a skill that can be learned in a forum! Find a shop!

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Thanks mysterync !!! got one more for y'all so if I have a friend with a good ECM can I try that or will I have to reflash it for my truck then reflash it to put it back in his ?? Finding a trustworthy shop in this day and time is like finding a needle in a haystack !!!!


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Understand that. Yes you could install a known good. It might throw a code but it should run fine.

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afternoon guys...Mysterync....

I have a 99 2500 Auto 4x4...recently my tach has started jumping irradically at between 1500-2300 rpm....first noticed it pulling a grade has been progressively getting worse, thru a CPS code, I replaced that.... I have a 2001 motor in my 99 with all my 99 wiring and ECM...I have my CPS out front on the crank pully using a Tone wheel I bought and made work....I had the infamous53 Water jacket crack on my 99 block, thus the new 2001 motor....

My truck seems to be running fine otherwise, It will randomly fuel cut if I hold the tach over 2200 rpm pulling grade....I just did a trip from Oregon to Montana and back over several passes towing my car trailer...this is when it started. If I backed off the throttle a bit, and held 1900rpm or so at 55-60mpr over the pass, no issues....even though the tach was jumping and dropping off to 0...

Any ideas on where to chase....? I am a Tech on cars, just a greenie on these Diesel pigs...

thanks for any info in advance, John.

 

Well just to give an update it was the ECM replaced it 1500 dollars later she's running good as new !!!


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