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confused transmission

Discussion in 'Ram Trucks' started by GrissOm Bro's, Jun 1, 2003.

  1. GrissOm Bro's

    GrissOm Bro's Junior Member
    Messages: 12

    I got a 99 dodge cummins but there is a problem with the tranny i think.

    when im goin down the high way at about 65mph my tranny cant make up its mind whether to stay in overdrive or 4th gear and it jumps back and forth is this normal at this speed or wat would cause this to happen



    Jeremy
     
  2. John DiMartino

    John DiMartino PlowSite.com Veteran
    Messages: 2,154

    Jeremy,there are a couple of things that could be wrong. I think your truck is going in and out of lockup,thats how it sounds. This could be caused by your TPS sensor(mounted on the throttle bell crank on the engine). Before i replaced it I would try the following,which costs very little,just your time and a few bucks.Remove the PCM connectors (3 of them on pass side behind airbox,put a little bit of dielectric grease on the connectors and reinstall. There is a TSB for this problem(ill find it for you later),you can perform the APPS reset. This is the accelerator pedal position reset. The truck will run better after doing this,even if it doesnt fix it.remove battery neg terminals for a minute,reconnect,turn ign key to run,but do not crank,now slowly press throttle to floor, and let up to idle position,do this 3 times ,Turn off key then start engine and road test it again,see it if helps. I have heard of bad batters causing the lock/unlock to happen also.If you batterys are original,they may be causing it as well.
     
  3. John DiMartino

    John DiMartino PlowSite.com Veteran
    Messages: 2,154

  4. GrissOm Bro's

    GrissOm Bro's Junior Member
    Messages: 12

    Thank ya

    John, Thanks for all the advise i am hopin this will work but above when you said to disconnect the neg terminal is that on both batteries or just one

    thanks

    Jeremy
     
  5. wyldman

    wyldman Member
    Messages: 3,265

    You need to remove the ground on both batteries to do the APPS reset,or any procedure that requires disconnetion of battery power,
     
  6. John DiMartino

    John DiMartino PlowSite.com Veteran
    Messages: 2,154

    Your welcome, my truck is doing the same thing as yours right now,its cycling in and out of lockup.I dont care only because i have the DTT smart controller and it captured the lockup signal and keeps it locked,I only noticed it because i had the controller turned off the other day and i felt it doing it. I think it may be time to replace my batterys anyway,they are original and 4 yrs old in october,they get worked hard plowing,and with my stereo system. It will be interesting to see if replacing the batterys fixes it.I will probably replace them before powing season unless one fails sooner.
     
  7. wyldman

    wyldman Member
    Messages: 3,265

    John

    Don't forget when you replace those batteries,bomb them :D

    2 Interstate Group 31's fit real nice
     
  8. John DiMartino

    John DiMartino PlowSite.com Veteran
    Messages: 2,154

    Chris, I am bombing my truck as we speak,I spent too much on the NX nitorus system,so batterys have to wait:D .This should be a BIG BOMB when i unleash the new power:drinkup: ( I see broken parts in my future:) )
     
  9. wyldman

    wyldman Member
    Messages: 3,265

    Well,make sure I get an update when it's all back together.Maybe my tranny will finally let go,and I'll have to make the trip down for a tranny bomb and a test drive :D

    I also picked up a spare P7100 pump,which came off a real hot truck.Should be good for well over 450 HP in my truck,just need a bigger turbo,and the time to put it all together.Trying to see if I can get 400,000 out of this tranny first,as we both know it won't hold it now.I should hit 400,000 by this summer.

    The Interstate 31-MHD's are only a 100 or so,my cost,so I'm sure they are cheaper down there.
     
  10. griffithtlc

    griffithtlc Senior Member
    Messages: 213

    Hey guys, i noticed that my new truck has the problems described in the TSB http://dodgeram.info/tsb/1995/21-04-95.htm. This is just the converter locking in and out, right? How much is this going to hurt my tranny, if I avoid going that speed as much as possible, or if I just get out of OD at that speed? Also, does anybody know how much a new pcm is for a 94 diesel? I just don't have the money to deal with it right now if it is expensive, however if it is going to hurt my tranny, then I will fix it right away. I figure I can just stay out of OD until I hit 50, and then pop it back in.
     
  11. John DiMartino

    John DiMartino PlowSite.com Veteran
    Messages: 2,154

    Your 94 doesnt have a PCM. If your having that problem the most likey coause is the TPS sensor. You can remove it,and clean it up real good,and reinstall it(thats what I would do),or pay over 100 bucks for a new one.Clean it first,the problem should go away. I think the voltage should be 1.0-1.2 volts at idle,ill try to find the info for you.
     
  12. griffithtlc

    griffithtlc Senior Member
    Messages: 213

    John, It does have the PCM. Basically, it is the same problem in the TSB, at 43-46 MPH, in OD, it shakes a little, not tires out of balance shaking, but in the driveline. It acts confuesed, but the RPMs don't fluctuate. So, I have just been out of OD until I hit 50 MPH, and it doesn't do it. Does the APPS work on this model, also? I noticed that sometimes at highway speed, I am cycling in and out of lockup. I am going to clean the TPS tonight.
     
  13. wyldman

    wyldman Member
    Messages: 3,265

    You still should have a PCM on your truck.I'd clean the TP sensor and contacts first,then adjust it to spec.The APPS they use on the newer trucks is different.
     
  14. griffithtlc

    griffithtlc Senior Member
    Messages: 213

    Holy smokes! I talked to Dodge about the problem, and they said a new PCM would be 500 bucks. they said it won't hurt it to switch out of OD, so it will have to wait a while, at least until next summer. I am going to see if I can get an updated one out of a different truck.
     
  15. John DiMartino

    John DiMartino PlowSite.com Veteran
    Messages: 2,154

    its probably not a PCM,the TPS just needs to be cleaned. Go clean it and set the voltage and go from there.
     
  16. wyldman

    wyldman Member
    Messages: 3,265

    Listen to John,clean and adjust the TPS first,it's free.You probably don't need the PCM.

    Could it also be a torque convertor shudder,or maybe it's slipping.The power of the Cummins loves to burn them up.:D
     
  17. griffithtlc

    griffithtlc Senior Member
    Messages: 213

    well, I took off the sensor, cleaned the connections, and adjusted the voltage. While I was down there, I noticed that the Trans valve cable had a lot of slop in it (enough to use 2 zip ties as spacers), so I adjusted that. I got the voltage up to about 1.2. It didn't seem to go up after I reached that point, so I am going to borrow a buddies digital volt meter tomarrow (his is better). After the test drive, It still shakes a little bit at 42-48, but not as bad. As far as the TC wandering in and out, it doesn't do it as often. I think tomarrow I am going to crank it up to 1.4, and see how that does.