Engine/Transmission (1994 - 1998) pcm, tps, tv cable problem.

[Ahopper]

ok i have been searching everything under the sun to find out whats wrong eith my truck. here is what i have going on:

last november i hade a full rebuilt dtt tranmission put in. scince then i have had to replace two govener pressur silinoids in the transmission. now i think i am having the same problem but the symptoms are a little different. i can shift to all gears perfectly fine at 1700 rpm the whole time. if i mash it any more and hold it it wont shift into thrird. if i then let off a little bit it will shift and it will shift into fourth fine also and lockup. i have a tc lock up switch. when i use it in second it will lock it up but still doesnt make any difference to shift into third. my first to second shifts are fine. i turned the voltage up on the dtt trans control to 4. 57v dc and it made it worse and then i went to 4. 37 volts and no change either. now that i have tinkered with it its getting worse. i cleaned and greased all electrical plugs that i know of that goes to the transmition including the middle computer plug.



here is my conclution.

1. it shouldnt be the tps because it mainly controls lockup. right?

2. the tv cable only controles down shift right? or does it help all shifts?

3. trannie fluid is good.

4. the only thing i can think of is the pcm is buring out the govenor silinods in the trannie. really hope this isnt the cas but i dont know.



sorry this is so long i just am stuck, and suposed to go on vacation with the trailer next weekend

 

[tp0d]

tps shouldnt control your third shift, but this -is- an electronic-controlled transmission, so dont quote me on that.

Sounds like your TV cable is too tight, and/or the dtt trans control is doing something weird. Have you tried running with the transmission control disconnected? Also, have you tried running with the tv cable popped off the throttle linkage? It should shift into all gears that way, but probably pretty sluggish, and it wont kickdown at all.

Have you either used the 3 key-on sequence to look for codes, or used a scanner on it? Only other thing I could see causing a problem could be the vehicle speed sensor, does that work ok?

good luck

-j

 

[Ahopper]

i dont see any codes. i just replace the liilte $70 dollar sensor when my abs was acting up. i cleaned and greased those connections as well. i talked to dtt and they gave me the same advice on the tv cable. i will remove it tonight and see what it does. they are ordering me a new govener silinoid. (im havin a hard time spellin today) its still under warrenty. i know someone who has an extra 97 pcm also so when i change the silinoid out i will change the pcm too. to see if that is what the problem is.

 

[Ahopper]

Help!

ok i have replaced my silinoid in the transmition and repaced the pcm with another 97 unit (used but was wirking when taken out). the truck has not changed at like all the other times it did when it was replaced. i checked the tps. it was at 1. 0 volts. the dtt controller is at 4. 62. i had it at 4. 47 but it started off in second that way. im lost now. if i slowley start off i still have to comleatly let off for the trannie to shift into 3rd. and then if i give it too much gas it will down shift.

 

[Ahopper]

i took off the tv cable. it ran twice as good as it did befor. it will atleaset shift reasonable now. i cant get into it though untill overdrive. if i leave this off will it hurt the trannie for now? i have a trip planned to leave in about five hours.

 

[Ahopper]

can anybody help?

 

[BTanzini]

If your transmission is the same as a 96 there is a sensor on the driversside of transmission about midway, when I had shift problems I replaced that sensor and it took care of the problem. ther is also an output sensor that you might have to replace, these sensors report bact PCM if I remember correctly,this was 2002 when I had problem. Also check your connectors.

 

[Dieseldemon]

If you leave the TV cable unhooked it will lower the pressure in the transmission and might slip and burn up the clutches. If you hook up the cable and have a friend push the throttle to the floor get under the truck and push the TV lever all the way back and adj the cable so it will just go on the lever