MY truck does not want to go into overdrive or cruise control . This started 2 days ago. It will go into O.D. sometimes and when it does the cruise control will work until O.D. drops out again. I did a search and read about the brake switch, I thought for sure that was the problem but after putting in a new brake switch I still have the problem. I did notice that the tc was unlocking inadvertently the last month or two. I put a new TPS in about 2 years ago because the converter was doing the same thing. I only have about 15k miles on this TPS . Can the TPS make the O.D. not kick in? Or does it just lock up the tc. I also read a little about the temp sensor possibly doing these symptoms . I have a 97 and could not find good info on how to install the 1k ohm resister on it since it is inside the trans. Does anyone have any other suggestions? Infidel?

 

Might not see it, but have someone follow to be sure the brake lights are behaving.

 

Here you go.

https://www.dieseltruckresource.com/...-317131/page2/

For grins, when this is happening, your tach isn't dropping out or bouncing around, is it?

 

The tach works fine. I do not think it is the speed sensor. I did read that thread on the temp sensor . It states to put the resister in line with the temp sensor. This does not make sense to me, I would think you would wire it in place of the temp sensor by soldering one end of the resistor to the violet wire coming from the transmission control modual and the other end to ground. To me putting it in line would still keep the temp sensor in the circuit. I am assuming the control modual talked about is the large aluminum case with 3 large wire loom terminals connected to it on the passenger side fire wall. If I am following the info correctly it would be the violet wire in the middle connector on that modual. I will check my brake lights but It is doubtful that a new switch would be faulty. Plus the drop out circuit for the trans and cruise is a seperate set of terminals on the brake light switch . The internet here is horrible so it hard to answer questions so if I do not get back to you speedily , please be patient.

 

Yes, you put it inline, basically to keep the OHM reading above the point where the temp sensor can drop out OD, hope that makes sense.

And yes, the PCM is what we are talking about, mounted on firewall. The middle one should have a white connector.

 

Thanks patdaly , The diagram cleared up some doubts. I will put the resister in line and see if that does the trick. If not the only other thing I can think to do is replace the tps but I believe it only controls the tc lock up clutch.

 

One other thing, check your throttle linkage bellcrank for slop. Goerend transmissions website has an excellent video showing the problem, and how to fix it for cheap ( tear apart and replace the plastic bushings )

That is yet another possibility.

 

Well the resistor fix did not fix it. It made it to where when the trans fluid warmed up the trans temp light came on and then it locked out O.D. at the switch. I will look at the georand brothers site. I have his transmission in it anyway but when I called them they did not mention the cable.

 

I could not find the article on the georand site. I believe it is the TPS now after reading another thread on the subject here. I am going to put in the 5k resistor fix . I ordered the parts and am waiting for delivery. The one I have has very few miles on it but the after market ones seem to be junk . I should have changed it first but with so few miles I did not want to accept that it failed. I will have to say that I was very disapointed with the georand tech line. Jeff was very little help and seemed to be more interested in me getting a scan and pressure tests to rule out a trans failure than he was in helping me narrow it down.

 

Here you go, I couldn't find it on his website now either.

 

An 11.99 analog volt meter is cheaper to test a tps than buying a new one on a "maybe its bad".

 

OK, Iam finally able to get on the internet. I installed the 5K reastat in place of my TPS. The truck shifts into OD and the TC locks up as it should now. Just to recap for others that might have this problem sometime. My truck would shift speraticaly in and out of OD, the TC would not lock up at all and at low speeds like 10-20 mph the trans would try to shift in and out. I thought the low speed shifting problem was in the lower gears but what was happening was that the OD was kicking in and out a sometimes so fast that it would just go in and out of gear.

 

Can someone please point me toward to thread that discusses details of replacement of the TPS with a rheostat? I am running out of things to check, fix and replace on our 96 with no OD and trans temp warning light on startup......

It is a BRAND NEW trans, with new servo etc....

OD issues are compounded by DTT's hack job on the PCM wiring to install their controller box that failed and started this whole cascade of bad events. So very sorry we spend over $8k with them in the first place to replace tired original transmission!

 

Ask and ye shall receive......

https://www.dieseltruckresource.com/...t-point-42003/

https://www.dieseltruckresource.com/...ce-tps-142641/

 

(bowing and scraping!)
Many blessing upon you PatDaly!