04.5 throttle not responding correctly

[befrazier]

Here is what I have done. I changed out a plug that is inside the bed for my fifth wheel. Then I changed out my transmission fluid on my nv5600. Then I changed out my belt and started it up and the engine light came on. I checked things out and belt is routed correctly. I then installed the brite box. Then I unhooked mileage max. The engine light was still on. Checked the code on the odometer and it is p2121. Truck ran fine untill I got on gravel road and then the throttle was not responding correctly. It would speed up and I would let off the throttle just a little and it would fall off completely. I turned the truck off and started it again and it ran fine for about 5 miles then did it again. I unpluged battery and got the engine light to go off. I ran the truck for about 200 miles and no problems. I had my batteries tested at napa while they were still in the truck and they said they are fine. I cleaned the connections real good and hooked them back up. They are the factory installed batteries so they are now exactly 6 years old. I needed to test my camper lights with the new plug and something is going on with it that is not right. I changed plugs again and same thing. The factory plug is working correctly. I think I am getting a short somewhere from where it has been spliced in to the factory wiring and the plug in the back of the truck. I hit a bump in the road and the engine light came on again and the throttle did not react correctly for just a moment and went back to normal. Could my problem be just the wiring to the plug in the back of the truck? If not what could be the problem and where is it located on my 04. 5 nv5600 6-speed. Any help would be greatly appreciated.

 

[p-Bar]

Don't know if you looked up the code here it is : P2121 Pedal Position Sensor 1 Performance / Rationality. hope this helps

 

[CPittman]

Could just be your TPS or APPS (throttle position sensor) or (accelerator pedal position sensor) failing. What's the mileage on the truck?



I have had two 2004 Cummins trucks - replaced the first one's APPS at 191,000 miles and the second truck's failed at 181,500 miles. So, if your mileage is getting up there you may need this MOPAR part number: 53031575-AH



On edit: that part number is for trucks with the automatic transmission.

 

[befrazier]

Truck has 88,000 on it. Is there a difference in a TPS and APPS? And where are they located? I fixed the electrical problem with the plug in the bed and I still have the same problem. I guess that eleminates that question. I think I found the APPS under the drivers side battery box. I had to take the front drivers fender well out to get to it. Is this actually what I found (APPS)? I called the dealer and they priced the APPS at $280 bucks. Have not bought it yet or been able to compare parts to see if I have the same thing that I found on the truck. I only have the one code showing on the odometer

(P2121) so I hope I have identified the correct part.

 

[CPittman]

TPS and APPS are the same thing. It's not located under the battery box, that's part of the cruise control. The APPS is located at the front of the engine on the driver's side at the top and it's under a large black plastic cover.



It's too early mileage-wise for your APPS to be failing. I would look elsewhere for the problem.

 

[stick]

I'd just buy a new truck!!



Sorry, i'm looking.



Stick

 

[befrazier]

Very funny Stick. I saw a picture on this site that showed the throttle cable going into a black box with a cover on it. I thought that they were saying that this is the APPS. I thought I understood that on older models it was mounted on the engine and what I found looks exactly like the picture that I had seen but mounted under the battery box. Now I am getting confused.

 

[p-Bar]

Ya 05 or 06 it disappeared confusing

 

[befrazier]

I went down to the dealer and looked at the actual part and it matched up with the part that I have been describing. I replaced the APPS and put everything back together. When I started the truck the engine light was still on, so I started the truck up eight times and the engine light went off. I had a friend delete the code and everything is running great but I need to drive it plenty of miles to be sold on it.



Just some info for anybody that may have to replace this part on a 04. 5. The throttle cable runs from the pedal to a black box under the drivers side of the battery box. This is the APPS. The easiest way to get to it is to take the plastic fender well out. There is about 10 screws to remove and a plastic holder that you just push back through the fender well. This is holding the throttle cable. The fender well will pop out and just set it on your tire. The APPS will be in front of your face at this time. There are 3 screws on the underneath side that you will remove and then it will be in your hand. The electric plug is the tricky thing. There is a red tab that slides to release the plug. There are 2 tabs that let you open the box and there is the sensor and where the throttle cable hooks up. Just pop the the throttle cable off easy like, no problem. Then all you have to do is replace the part and put everything back together. I bought the part at the local dodge dealer. You might want to unhook your battery cable just in case before you start. I hope this will help someone in the future.



This site has been very helpful and I do appreciate all the help and info that I have found and recieved here.



I am going to Colorado in 3 weeks so when I get back I will let everyone know if the truck is running fine or not. Need to put some miles on it.



Thanks again

 

[cerberusiam]

Up to 04. 5 the apps is mounted on the left front of the engine for automatic trucks, under the driver side battery for manuals. TV cable is needed so its on the front of the engine. IIRC, the cruise is divorced so the cable is still needed to activate it.



In 05 the APPS was moved to the top the accelerator pedal under the dash. The TTVA motor replaced the TV cable so APPS is now located out of the harsh engine compartment environment. Cruise control is now integrated into the ECU no cables needed.

 

[befrazier]

It's back!!! I drove the truck only about 100 miles and went through some road construction in front of the Dodge dealer. Go figure. There happens to be a drop off on the asphalt, the engine light came on and the truck lost where the foot pedal was for about 100 feet. It ran fine the next 4 miles home. I checked the code, p2121, again. I don't know what to do at this point??????? may just take it to the dealer.

 

[p-Bar]

I think their is a calibration that has to be done by cycling the accelerator pedal . Will do a search and see if I can find the post.
Also found out that the APPs is self calibrating.
Try reading this post
https://www.turbodieselregister.com...s-2003-2007/215978-need-help-apps-please.html

 

[befrazier]

I called the dealer and they can't get me in untill Monday. If there are any suggestions from anybody I have the weekend to figure it out. Otherwise she is going to the dealer. I can't seem to find any wiring issues anywhere but I am not a wiring guru. I am getting more convinced that this is what it is because sometimes when I hit a rough spot in the road it will act up but not everytime. There has been a few times that it has acted up as soon as I started the truck with the old APPS on. The new APPS has only acted up the one time I hit the change in asphalt levels so far. I will keep driving it just to try to get more info of when it reacts badly. Any info will be greatly appreciated and I will try anything that I am capable of to get her fixed. (I may need detailed info if you have any)

 

[p-Bar]

Sounds like a wiring problem clean all the contacts on any plug you had to disconnect . The going over the bump makes me think that

 

[befrazier]

After some thinking and alot of it I decided to take the batteries out of the truck and get them tested again. This time, load tested not with a cheesy hand held unit. One battery tested out bad. I bought two new batteries and installed them. Time to drive the truck some more before Monday, when I am suppose to take the truck to the shop, and see if everything is working well. I am feeling better about this that anything else so far. The bad battery was probably shorting out my system and sending low voltage to the APPS causing it to fail. I will report my findings later. Thanks for the help.

 

[stick]

So, what happened??



Stick

 

[befrazier]

I have been driving the heck out of it since Friday and no problems so far. I am more and more convinced that the one bad battery was the problem the whole time. Now I have an extra APPS on the shelf. Never check the batteries in the truck with a hand held unit. Take the time and take the batteries out and get them load tested.

 

[SShafranko]

Where can you go to get the batteries load tested? Napa?

 

[befrazier]

I would assume anywhere that sells them. The guy at Napa just brought the hand held unit out and I did'nt know any better. I had them tested at Walmart.

 

[SShafranko]

Ahh OK Thanks