More 47RH problems...kicking out of lockup and overdrive randomly

stubz616

stubz616

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Oct 28, 2008
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OK, just read a bunch of threads and found some similar stuff but nothing exactly like what mine is doing now. Its a Goerend trans and my TPS failed a while back so i did the POT mod and never had any problems at all until now. with o/d off it always locked in third about 36mph, with overdrive on it always shifted to overdrive at 36 and locked at about 46mph. lately if i take off with overdrive off it will lock normally at 36 like it use to but kick out like 2-3 seconds after hitting lockup. same story with overdrive... it will shift into o/d at 36 and kick right back out 2-3 seconds later, a couple hundred yards down the road it may try to go in again and kick back out, or it may not try again at all until i stop and speed back up to where it wants to be in again.

Here's the kicker... I checked the POT and found a broken pin on the harness, fixed it, still has the problem. checked all the wiring and its all good. (5V ref is good, good ground, and the signal wire only has .2ohms to the PCM) everything plugged in, the POT varies the voltage fine when tuning the knob, no dead spots, and i set it while backprobing at the PCM.

If i have my lockup switch on though while driving it will hold lockup fine and shift to overdrive and hold it fine so all the wiring to my trans and the solenoids should be fine, correct?

This truck is driving me crazy right now:bang:what:... any help would be appreciated. Thanks
 
Our '99 dodge did this, fixed it with a $20 part from Hendrix diesel it something to do with static electriclty.
 
I remember something about wrapping the alternator leads in foil and grounding the foil on both ends to cut down on the electrical noise.
TPS is a pretty crappy setup. If you saw how cheap they were inside, youd be boiling mad after you shelled out 200$ for one.
Theres a signal for lockup and one for OD as well. If you can figure out what pin you could do it manually, worst case.
Theres also a temp sender that can kick you out of OD.. and the speed sender on the rear diff.
 
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Set you TPS voltage to 1 volt with key on.. You may have to drill the factory bolt holes
 
I had the same exact problem and believe it or not it turned out to be my tranny temp sensor was shorting out. replaced it with a resistor and problem solved.
 
Olee Poole said:
Set you TPS voltage to 1 volt with key on.. You may have to drill the factory bolt holes
Click to expand...

I have a POT in there now which is set to 1.5V i believe

RDPsmoker said:
I had the same exact problem and believe it or not it turned out to be my tranny temp sensor was shorting out. replaced it with a resistor and problem solved.
Click to expand...

I'll have to try this... or get a new sensor.
 
Mine had similar symptoms some time back. I put in new battery terminal cables as the ground terminal on the batt end started to warm up. Got better but not perfect. Cleaned the ground conns and it got better again.

Then the weirdest thing, power supply of the trans computer obviously has something to do with the park lights since after providing better voltage to light switch input voltage for park lights the problem vanished completely.

I soldered one thick extra jumper cable from heavy gauge Red/Green stripe input wire to milder gauge Pink/Red stripe Parklight input voltage wire. Maybe I was only lucky and the power to trans computer and OD switch only got re-routed but all these actions resulted a perfectly operating truck.
 
Still having problems with this... gotta get it hooked to a scanner again and see whats going on... any other ideas? I think i'm about to see if a 30-06 will fix it....uggghh
 
A few things you can try 1)cycle the pot back and forth, 2) unplug the PCM and wait 10 minutes or so and then plug it back in, 3) get under the truck and make sure all is well connection wise.
 
be sure to check ckp, ive seen that to cause them to kick out of lock up, o/d, and cruise control
 
I changed the CKP to a known good one with no difference. and tried cycling the POT. Ill try leaving the PCM unplugged tonight for a little while
 
What are you doing when it kicks out? steady speed cruising on a flat road?
If its not electronics that are involved, wonder what it is in the valve body that decides to downshift under load.
Checked TV cable adjustment?
 
Just cruising at 45mph it'll kick in and out. If i accelerate harder than I normally would it will hold overdrive until I let off. Don't get it, because it was fine one second driving down the road then just started acting up
 
mine had the same problem and the POT fix worked for me, i think it was about 12 bucks for everything at radio shack. they had to order the pot swich though. theres a writeup on here some where i belive. thats if your tps is faulty
 
97coalroller said:
mine had the same problem and the POT fix worked for me, i think it was about 12 bucks for everything at radio shack. they had to order the pot swich though. theres a writeup on here some where i belive. thats if your tps is faulty
Click to expand...

POT time, chased a TPS issues for ever....PITA!

Jim
 
My failed brake switch caused the same symptoms. I also have had cheap radio shack pots go bad and seemed to have to replace them every other year. I have a 5 turn from Mcmaster in there now that has lasted at least three years. I also have a digital voltage gage just to monitor the pot voltage because I change it when I lock out OD and it makes it easy to set.
 
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