Engine/Transmission (1998.5 - 2002) transmission jump.

[Rockcrusher]

Between 45-50 mph, easy on the throttle, either overdrive or converter lock up, jumps in and out causing short surges. Kind of like ingnition cutting in and out on gas burner.

Any ideas?

 

[bgwhtjp33]

Had the same prob. 01 1500... . changed the L/U sol. and cured the prob. Hope this helps

 

[Tom W]

Do search on converter locking and unlocking. A very common problem with several causes, usually electrical noise spikes. Clean the battery terminals and see if if goes away temporarily. If it does, get a noise filter from DTT ( 1 866 504 4002 toll free ) Also do the APPS reset procedure.

 

[Rockcrusher]

Thanks for the input. Always get best answers on TDR. Dealers charge big for wrong answers.

 

[JBrownlow]

Have had the same problem for about two weeks, with the problem getting worse each day. Went to the transmission shop and had things checked. Not a transmission problem. Truck is a 1998. 5, 3500, auto.



Went to the dealer today and told them that the transmission folks said it is a TCC lock/unlock signal from the puter.



After much checking, the final outcome was determined to be a "very high amperage draw" at the lift pump. Causing a spike to the puter. Had to go for the new "in tank" kit as that is now all that is offered.



Fixed the problem (at the cost of $976. 39 out of my pocket).



In the last six months (8250 miles), I have now spent $3329. 78 for repairs out on the road (VP-44, lift pump, filter, labor & tax), and now another lift pump upgrade at $976. 39.



Problems started at 109347 miles and am now at 117560. Had one pump changed under warranty at about 55000 miles.



Not a very good track record in my estimation.



Nor are the dealers doing anything to make "on the road repairs" affordable.



Am still paying for Chryslers mistakes... ... ... jb

 

[Will Manchester]

I am sorry to hear about your $1000 bill to fix the surging problem!



This is a very common problem on the ISB. Basically, the PCM is getting a noisy signal from the APPS/ECM (signal passes through the ECM). The surging problem occurs when the PCM is seeing either 0 throttle (forces converter unlock) or very high throttle (somewhere above 70-80 percent throttle causes the TC to unlock as well) when you are crusing down the road at a constant throttle, for some reason it is typically at very light throttle. If you were to put a scope on the APPS input to the PCM you would see a very irratic voltage @ constant throttle instaed of a flat line. There is a very simple fix: http://www.atsdiesel.com/PDF/APPS - TPS Fix A1.PDF Notice that this is a Chrysler bulliten, you may want to take this to your dealers attention!



Basically what you are doing here is feeding a signal directly from the APPS to the PCM instead of passing through the ECM. One other helpful fix (not shown in the link above) is to add a redudant ground from pin 4 (APPS sensor ground) of the APPS to your battery ground. Sometimes it takes both steps to resolve the issue.