Engine/Transmission (1998.5 - 2002) TCC not unlocking when coming to a stop

[dodger22]

I posted earlier complaining that my ABS was kicking in when I slowed to a stop. After further investigation I have now determined that the Torque Convertor does not unlock and at about 12 - 18 mph I feel this washboard effect. When I slip the truck into neutral just before that speed it feels normal. I replaced the governor solenoid and sensor because of problems with shifting back and forth between 1st and 2nd.



The code with the key-on key-off trick showed P1693 which basically means "you have a problem". I borrowed a friend's scanner which showed a code for coolant temperature exceeded - which I can understand as the fan clutch does not work and I have to replace. The PCM showed it was clear but the scanner could not establish a link with the ECM and was asking if the ignition was turned on.



This is driving me crazy, can someone help please?



Thanks and regards,



Richard

 

[barryg41]

Before I did my complete changeover on my transmission with DTT products. I would have the same problem. For some reason my truck eats batteries. 4 sets since new. But the problem of not unlocking when coming to a stop was one of the batteries was bad or going bad. It would also hunt in and out of lockup in OD or out of OD. New batteries always fixed my problem.



My transmission mechanic, James Northum of Dallas, said the alternator was pulsing the bad battery trying to keep it topped off, which in turn was causing spikes that the pcm saw. He also told me to wrap the ground cable that runs behind the alternator with tin foil, then wrap with black tape. So far no problems, but I have new batteries and transmission also.



I am sure others would tell you to make sure all ground connections are tight and clean. There are quite a few under the hood in the engine bay.



Hope this helps!

 

[THoltz]

Make sure your battery cables/terminals are clean and corrosion free. If you need to clean them, but a spray can of battery termianl cleaner at Auto Zone or other parts store, it work pretty good.

 

[dodger22]

Thanks for your suggestions guys! I took the truck to a transmission shop today and they are having trouble determining what the problem is. They are waiting to hear back from "their Tech guy". They think it is an electrical issue and suggested I might want to take it to a dealer.



When/if we can figure out the problem i will let you know.



Richard

 

[JJPage]

dodger22



I know I have a 3rd Gen, and different electronics, but I was experiencing similar problems. Shuttle shifting back and forth, TC not locking up all the time, throttle actually hanging up, I traveled over 2 miles surging down the road with my foot off the throttle, applying brakes did not stop the action, putting the truck in neutral did.



I found the plug going into my transmission was saturated with fluid, leaking out of my front band adjustment locknut/stud. Cleaning that up and repairing the leak helped the TC locking/unlocking issue, but the upshifting not happening until I would lift the throttle, and just plain erratic behavior still existed.



I ordered a new governor solenoid, transducer/pressure sensor, and an APPS. The APPS I purchased from Tim @ TMB Mechanical. I installed the APPS this last weekend, and LO and BEHOLD, all my issues are solved. My truck shifts better than ever, all the annoying action my transmission was throwing at me is non-existent. I will still install the other trans components, but not until I service it next.



I understand this may not be your issue at all, but with an engine mounted APPS, it is certainly something to consider... . best $160. 00 I have spent on my truck in a long while.



Jess

 

[dodger22]

Thanks Jess for your input. I will likely get the truck back tomorrow and start trouble shooting myself. It had occurred to me that the problem might be in the APPS but the scanner is not picking up on any codes. Did your truck throw any codes to indicate the APPS? I don't want to throw money at the problem if I can't be sure it will fix it.

You mention that the APPS cost $160. I have been checking on prices thru' the internet and found the cheapest complete unit was around $550.

I will check out the link you mentioned, thanks.

Regards,

Richard

PS I could not find a link for Tim@TMB Mechanical. Have you got a more definitive website - thanks.

 

[JJPage]

No, I was not getting codes to point out the APPS, but I was getting trans codes, P0700,P0743,P0753.



here's a link for Timbo: Home



You can also google "timbo apps", lots of examples on different forums.

 

[Beach]

Does the TC stay locked up all the time? What happens if you don't shift to neutral when coming to a stop? I had an issue with mine this winter where the TC wasn't unlocking and would stall the motor unless I shifted to neutral before I stopped. Turned out to be a bad valve body! It was like driving a manual with out a clutch.

 

[dodger22]

Beach, the torque convertor did not stay locked. After some shuddering it would release and thus prevent the engine from stalling out. I got a call from the transmission shop today to say that the TC was the problem. There was some evidence of wear material in the pan which has likely got into the TC.



I called DTT today to get a new TC shipped to the shop. The bad news is it could be 3 weeks before they ship as they are on back order. The good news is they now use a billet cover with triple disk clutches.



I drove the truck home rather than have it sit on their lot for 3 weeks. The transmission shop should never have let me leave with it because it would not shift out of 1st gear, so I was doing 25 mph at about 2700 rpm on the freeway with the 4-ways on.



Hopefully this is the answer to my problem. Time will tell!



Richard

 

[ChrisOlson]

Hello

My transmission Was having Lots of TCC locking issues I did 2 things
TIMBO APP great product great guy to deal with.
and
The NO BULL technical service noise eliminator. from no bull technical services
this eliminated MY unwanted Locking and un locking problem
another great product and great service

Chris

 

[dodger22]

update on T/C not unlocking when coming to a stop

Today I got my truck back from the transmission shop. The only wear really evident was the low/reverse band. I also had the DTT triple disc billet T/C installed. Driving home from the shop everything seems to work as it should so whether it was the T/C or the band I guess I won't know for sure until I ship the T/C back to DTT and have Bill K. look at it.



Richard