tps

[WBerry]

where is the tps located on these trucks?ive had a scan done on transmission and it says the tps is bad. ive went to three different dodge dealers trying to get this tps and they tell me there isnt one on these diesels. what does it look like?does anyone have a picture showing this or a part number and where to get it?with overdrive off it only shifts 1st,2nd,3rd,with overdrive on it still only shifts uput 1st,2nd,3rd,but will shift up to 4th at app. 65mph but not into lockup. anyone got any ideas? thanks,lightfoot

 

[shendren]

i can tell you that i just went thru this. the dodge dealers are !@#$ing IDIOTS!!! there is a throttle position sensor on the 96. it is on the front port side of the injector pump. black and square. the throttle linkage needs to be adjusted so that the tps is at 1. 0v +/- . 01 and over 3. 5v. see the adjustment at the end of this link... .



http://dodgeram.org/tech/tsb/recalls/970/repair.htm

 

[shendren]

i forgot. i was told by cummins that the tps rarely goes. it is almost certainly the adjustment is out of whack. good luck.

 

[Joe G.]

Before you mess with it try hoseing it down with contact cleaner. Then work the throttle linkage back and forth a few times. That may just cure it. They get dirty and coroded inside so the electrical contact is not good. Then if the voltage is not correct adjust it.

 

[shendren]

where do you spray this part? it is sealed.

 

[shendren]

p. s. please take a print of my link and take it back to all 3 dealers and tell em to hire a diesel mechanic. incredible... ... .

 

[Joe G.]

Not quite sealed. On the back side where it connects to the linkage it will soak up some of the cleaner. I also give the connector a good dose.

 

[WBerry]

thanks guys for the info. now that i know whatit is,where it is and what it looks like. ive thought on this the day the trans started acting uo i had washand degreased the engine on my way to work i had driven it about 25 miles after that and then it set till i got off of work and then is when the trans started acting up,is it possible that washing off the engine shorted out this unit? thanks,lightfoot.

 

[Joe G.]

AHA!

I think you have it. Get it all cleaned up. Use some dialectric (sp?) grease on the connector. Take it for a ride and see if that helps. Might just be water in the connector.

 

[WBerry]

WELL THIS MORMING I CLEANED UP THE TPS WITHOUT TAKING IT APART FIRST,WENT FOR A TEST DRIVE,NO CHANGE. SO I TOOK IT APART,THERE WAS SOME CRUD ON THE INSIDE ON THE SILVER DISK,CLEAN IT AND PUT BACK ON. NOW WITH O/D OFF STILL WILL ONLY SHIFT UP TO 3RD,TURN O/D ON AND IT WILL SHIFT ANOTHER GEAR DONT KNOW IF THIS IS 3RD GEAR LOCKUP OR 4TH GEAR ENGAGING. WHAT DO I DO NEXT,SHOULD I GO AHEAD AND GET A NEW TPS AND WHERE DO I GET ONE?DC OR CUMMINS? THANKS, LIGHTFOOT

 

[Joe G.]

If you took it off and put it back without adjusting it that can cause problems. The first thing that has to be correct is the throttle rod adjustment. The measurement is from the back of the bracket that mounts the throttle linkage to the center of the ball the cable attaches to. This measurement should be 5".





Quoted from my '95 manual:



INSTALLATION

(1) Position the TPS to the mounting bracket. The electrical connector should be facing downward. The TPS is spring loaded. After positioning the TPS to its mounting bracket, rotate the TPS on the bracket in a counter-clockwise direction until the two bolt holes align.

(2) Install and tighten the two bolts.

(3) Connect the electrical connector on bottom of TPS.

(4) Operate the throttle by hand to check for binding.

(5) The TPS voltage must now be tested and (if necessary) adjusted. Refer to the following: Throttle Postition Sensor Testing.



THROTTLE POSITION SENSOR TESTING

CAUTION: Before testing the TPS, verify that the engine is set at correct low idle speed.

(1) After confirming the correct linkage adjustment in idle speed, proceed to the following:

(2) Attach a paper clip into the center terminal of the TPS connector. Do not remove the connector from the TPS for this test.

(3) Attach the positive lead of a voltmeter to this paper clip and the negative lead to a good ground.

(4) Turn the ignition to the ON position. Do not start engine.

(5) The voltage at the TPS center terminal should be 1. 0 volt (+- . 2 volt) with the linkage at idle speed. At wide open throttle (WOT), the output voltage must be 2. 2-to-2. 9 volts higher than at idle speed. If voltage is not correct, proceed to adjusting linkage.

(6) The linkage rod connecting the throttle lever to the fuel injection pump lever is adjustable. To prevent damage to the ends of the linkage, attach locking-type pliers to the flat located on the linkage rod before loosening locknuts.

(7) Loosen the right-handed-nut.

(8) Loosen the left-handed-nut.

(9) Slowly rotate the flat on the linkage rod (lengthen or shorten) to achive 1. 0 volt (+-. 2 volts) on the voltmeter with the linkage in the idle position. At WOT, the output voltage must be 2. 2-to-2. 9 volts higher than at idle. Do not lengthen or shorten the linkage rod more than 1 mm from 5". If voltage requirements cannot be met by linkage adjustment replace the TPS.







The manual continues about final testing of the voltage. If you did not adjust the TPS then you really don't know if it's bad or not.

 

[WBerry]

JOE G. THANKS FOR THE INFO,AS I DONT HAVE VOLT METER,ETC AND IT LOOKS A LITTLE ABOVE MY SCOPE I THINK I HAVE THE CUMMINS SHOP DO IT IN THE MORNING,ALSO IF ITS BAD THEY SHOULD HAVE IT SHOULDNT THEY?ILL SEE IF THIS CURES IN THE MORNING,WAS SUPPOSE TO WORK BUT ILL TAKE THE MORNING OFF. THANKS LIGHFOOT

 

[WBerry]

got tps changed and adjusted yesterday,now trans. is operating great and like it should. got the tps from dc there cost for it is $103. 00 and they retail it for $172. 00,they gave me a discount on it i guess,i paid $133. 80 plus tax. took about twenty minutes to change it,i think i got in the correct volt range. trans. is shifting like almost new. happy thanksgiving everyone. lighfoot

 

[Dave Fritz]

TPS noise filter

I received this tip via email from Steve C. (Gemcuttr1), a former TDR member (temporarily due to his job) .



=============

I have had two bad TPS's on my 95 2500 4x4, and when the last one got to the point of not responding to cleaning, I sure didn't want to pay DC $200!



I did some experimenting and found that an electrolytic capacitor (440 microFarads, 35 Vdc) with the negative side connected to the SIG RETURN wire and the positive side hooked to the TPS SIG wire gave me absolutely *troublefree* operation! Even though my TPS is basically trashed, the capacitor filters out almost all of the electrical noise, and my auto transmission once again shifts like factory-new!



I dug into the wire bundle coming out of the PCM and soldered the capacitor as close to the plug as I could manage - thinking some "TPS problems" may actually be wiring/connector problems in disguise.



Results with other values were:

220 mF, 35 Vdc - too little filtering. transmission a little flaky.

1000 mF, 35 Vdc - far too much filtering, and a 1. 5 second delay in transmission shift response crept in.



BTW, I might add that since I added the capacitor, my cruise control hasn't dropped out even once in 15K miles - usually a twice-per-week occurence (I drive 1500 miles a week). What I believe is that the dropout problem is caused by an electrical noise spike from the TPS - which is *exactly* what the capacitor filters out.



Please consider this tip a free gift for all oilburner fans! The capacitor costs just 40 cents, and I hope it will save TDR members and others lots of money! After all, you can by a lot of #2 diesel for $200!

=============



In theory, this will work well for a noisy TPS. While it can't fix a TPS with a big dead spot somewhere in its range, a capacitor and a couple of clip leads could get you down the road if you were having trouble with a noisy sensor on a dark night a long way from help. Steve also noted that a manually operated potentiometer can serve as a TPS for emergencies and diagnostic purposes.



I will be posting more details about TPS filtering and bypassing on my TPS adjustment page , but it may take a few days. - Dave

 

[Hummin Cummins]

I am currently attempting adjustment on my 95, have seen several different procedures and specs for adjusting tps. When linkage is at the 5" length i get . 78v at idle. If i try to get the 1. 0v, i move the linkage outside the 5" range by 1/4". Is my . 78 acceptable or will the adjustment on the tps itself get me where i need to be Trying to get truck back to specs before bombing, previous owner was not very perticular about things like that.

 

[Joe G.]

According to the service manual you are supposed to replace it in those circumstances. Another thing you might check is to see if you are getting full throttle at the adjustment where the voltage is 1. 0. Probably not. I have somewhat the same problem on mine now. I'll replace mine when I can afford it. In the mean time I have adjusted it so that it barely gets full throttle. It's still a little low like that but it will have to do for now. My OD and lockup shift points are not quite right for light throttle. If I stand on it there does not seem to be a problem. A little tip: remove the two nuts that fasten the master cylinder and lean it toward the fender. Then you can see the throttle stop. My "helper" for checking full throttle is a long stick and the power seat.

 

[Hummin Cummins]

Joe,



Thanks for the assist, guess i better move my puter to the garage, save me trips in and out of the house. Final settings... . . 72v at the 5", went to 1. 0v still had WOT, went to the 1. 2v and still had it, linkage adjustment was about 3/16 shy of 5" and still had WOT.

 

[Cooker]

With everything adjusted correctly, the most I can get mine to is . 89 volts. I suppoes I could adjust it higher, as losing full throttle wouldn't be that big of a deal As I understand this is acceptable, but I would like to adjust it a little higher and see how the transmission responds to different TPS voltages. Will replacing the TPS cure this? Other than the adjustment, the TPS acts fine. It just doesn't seem like replacement will cure this if it acts fine otherwise?



Thanks.

 

[Joe G.]

Hummin Cummins, It sounds like yours is just fine. The TPS is not so important for those of us with a 47RH trans ('94 & '95).



Cooker, I don't see a sig so I don't know what sort of beast you have. The 47RE I believe is a little bit more sensitve to the TPS then a 47RH. As long as the thing is behaving itself you should be ok. It mainly affects shift points for OD and TCC lockup. Bill K. described the affect in a recent post. I've printed that thread for future reference.



Dave's post about the capacitor sounds like a great idea. I had a ratty TPS once and it tore things up. The capacitor should prevent that if my TPS gets that way again. It hammered the flex drive plate until it failed. Big bill at Dodge to get it fixed so I've learned to overhaul these things since then.

 

[Cooker]

Thanks Joe,

Sorry I forgot the sig.



I am trying to delay OD and TCC lockup just a little bit. At the moment it's not to early IMO, I just would like it a fuzz later. Without more adjustability I can't go past . 89. Maybe I'll have to double check the linkage adjustment, hopefully I can gain a tiny little bit there with sacrificing WOT.



Do you have a link to Bill's post. I'm sure I must have seen it, but I don't remember the post you are speaking of.



Thanks,

Ryan