tmacie

OK heres the situation. Crusing down the interstate at 70 I can go up the grades in cruise no problem, TC locked. If i drop the speed to 60 or 65 the TC randomly unlocks going up the slightest of grade and sometimes stays unlocked for a while. There is not much of any load on the engine when this happens. The funny part is, I can be on a secondary road at 55 not on cruise and the TC will NOT unlock unless I push the pedal past the kickdown point. Anyone with a little more Auto tranny and lockup TC experience care to chime in?

Truck (just incase sig doesnt show): 94 CTD Reg cab, auto, 4x4, 3.54 gears, only mods are stacks and silencer ring removal.

Thanks for the help,
Travis

Lil Dog

I would do a search on TPS..Throttle Position Sensor. There were some good posts on how to clean, adjust and test your TPS before spending $$$ on a new one.

It sounds to me like you have a dead spot in the TPS where the majority of the driving is done. Take your time and scan those threads for instructions on cleaning the units by drilling a hole in it. Lots of good info here if you take your time on the search.

tmacie

Thanks for the info....forgot about the TPS.


Travis

iaddiesel

My 95 3/4 ton 4x4 diesel automatic acts the same way to the "T"
Let me know if you get a good fix on it.

johnsjas

I had a bad TPS and replaced it fixing the problem. It costed me $130.

tmacie

I'm gonna try re-setting it, and the 440 uF cap filter. I'll let everyone know how it goes.


Travis

Lil Dog

It may need to be cleaned as well.. I know there was a post and some pictures of how to drill a hole in the TPS casing in order to get a good shot of electronics cleaner in there. there was a good debate about whether you could get any cleaner in there from spraying it around the input shaft due to the seal on the casing.

Cleaning may help as well.. Might delay the $130 bill..

Sidewinder

I did the cleaning thing twice before the TPS quit completely. It' a good start for a free confirmation of the TPS as the problem BUT I would replace it if you find out it is the problem or you might have the same luck as me and it will fail in the middle of a 1200 mile trip.

Don't say you weren't warned.

abbeyinc

I had this very problem this fall. Turns out it was related to charging problems. Low batteries and a failing alternator caused it to happen. New alternator, charged batteries, and the PCM reflash outlined at dodgeram.info took care of it.

The problem was exactly as you describe it, but it would gradually go away with extended highway driving...batteries charged and low alternator load...but if I did several days of in-town-errand-running the problem would resurface.

Do cheap and easy stuff first. Check your battery condidtion, then your alternator output.

tmacie

Matt,
It actually happened opposite what you said, in town driving is fine, but highway driving is affected. Either way, its due for new batteries.


Travis

mr T

the first thing that ever went on me was the tps...i carved the top out, cleaned it, adjusted it and all that and it just didnt do it...i had to be a pricey new one...been 3 years since...no problems....do a search on TPS and try the adjustment procedures available first before coughing up the 200$ in some cases

abbeyinc

Yeah- I wasn't very clear. What I meant was: around town running (multiple stop/start) drains the batteries with a bad or weak alternator, then the symptom shows up on the highway. Anyway, you get it.