• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

pcm or ecm trouble on 98 6.5l 3500hd

Hopefully, they did not charge you a whole day of work? and you get your truck back.

The fact is that stealership does not train or have a trained mechanics at the shop anymore.
They may claim they know but the market is so small for them so they would not care anymore.
 
need that a soon as possible made two recovery today on in the ditch and the other one a roll over lucky for me i had a guy pressing the feeder to gave me more winching power but i dont undersatant why the high idle wont engage with that pcm but monday morning i m calling heath diesel
 
ok so who ever bought from them never receved the money for the core just to expect what i m gone a pay and not spending more money to ship the a core
 
can someone help me in the mean time to maje my high idle work again do you thing it s because i have the wrong pcm install but what bug me is what evev 6.5 you got you can make them work
 
i thinking removing the modul on my wreck truck tap the wire to mine and install some kind of lock on that one at 1300 rmp and wire a switch to it
 
cause it aint working anymore with b7 and b8 and it might take a while ordering from heath diesel since i m from canada i would say a good 2 weekdu to custom clearence
 
ok finally found a pcm from a junk yard today it was on a 98 true 3500hd standard like mine truck is working awsome but still have no high idle when we are doing the high idle it must go somewhere a relay a sensor or something my probleme have to be there now
 
congrats on finding an identical PCM!! the only possible change is the rear end ratios, 4.63 vs 5.13. otherwise, if it was a factory 5 speed, you got yourself a perfect match!! boy, a HD specific manual trans., PCM is kind of a needle in a haystack!


as far as the high idle, check the grounds.

does anyone have any idea if a PMD on its way out affects high idle? I know cruise control is affected, but otherwise IDK.

also dakota, do you have cruise on that thing? If not, you are in for a real treat. 6.5ls are plug and play! :)
 
no cruise it s a manual 5 speed he has the hole truck for sale 1000$ but i only bought the pcm 25$ haha lucky me drove it about 30 mile today no check engine light nothing running strong but the freeking high idle now i did rewired evrything even change the pin in the harness nothing but it must activated a selenoid or something in matter to raised the idle like that .pmd maybe
 
the high idle is simply a signal sent to the inj system from the pcm any selenoids would be in the inj pump, I don't believe there is one
 
well, I havent done it, but supposedly all electronic 6.5L trucks have the wiring plug under the dash allready for cruise. all you need to do is take apart the column and install the multifunction lever with the cruise on it. this requires a new or junkyard multifunction stick.

I wish I new more about this high idle to be of help.
 
funny that you guy mention a selenoid in the fuel pump cause with my original pcm the fault was fuel pump and when the gm dealer did program the new pcm again same error code what was buzzing the mechanic is it was working with the pcm i had from my junk 2500 if i remember he mention something about a selenoid giving him a 0 and when he was installing the one from the 2500 i remenber the reading was varying between 5 and 8 so he said the selenoid has to be fine it s working with that one but by the reading he had he was more suspecting something wrong in the fuel pum at first he was confused he said if i would not try the pcm from my 2500 he would a change the fuel pump in reason of that reading
 
i have another pump in my 2500 how hard is it to swap maybe he was right about the selenoid in the pump but even now with the pcm i got yesterday from the 3500hd the truck work awsome beside the high idle would you try swaping the pump if you were me
 
You must log in or register to reply here.
Back
Top