Engine/Transmission (1998.5 - 2002) Push pedal, truck doesn't go!!!

[JWey]

Wondering if you guys might have any ideas here. A friend of mine has a 2002, 3500, 4wd, 6 spd. cab and chassis with about 60k miles totally stock work truck. For the last few months it has been sporadically running a little weird. It will run fine and then all of the sudden cut off when he is driving down the road at 60 or 70 mph. Another thing that has been happening is he will be driving along at a steady speed and notice the truck is slowing down, he hits the fuel pedal and nothing happens, even though the truck is still running. He just replaced the lift pump and it seemed to run fine for a few weeks but now it is acting up again. I suggested it could be bad electrical communication between the pedal and the engine since I think the fuel pedal does not have a cable or linkage, is that correct? I also suggested the next time the pedal doesn't work he should flip on the cruise and see if he can speed up with the controls on the steering wheel. I don't know anything about this stuff since I'm not a mechanic, but just trying to eliminate possibilities. Any help or suggestions you have would be appreciated! Thanks. jwey

 

[Cummins724]

I had the same problem last week with my truck. Does he throw a check engine light? I had a code po121 for the apps sensor [tps]..... truck would act the way that you are describing & sometimes wouldn't want to maintain speed. Then It would run good for a few days before doing it again... . still no codes except po1693 which is a companion code stating that a code is present. Then going down the road & truck went to idle speed cruising down the road & would not respond when I pushed the throttle. I pulled over & checked for codes & got po121... . cleared it & drove home fine. I installed the apps sensor [$398 w/tax] from dealer & problem solved. You should check for codes... . may be the same problem.

 

[Ragain]

If you find it to be the APPS, refer to TDR issue #54 (Nov/Dec/Jan 06-07). An article describes a way to gain access to the potentiometer inside the APPS and clean the contacts w/ contact cleaner. I wish I had that info when mine went out in '04, so I could have saved the $550 they cost then!!!!

 

[JWey]

I don't think he is having a check engine light when this is happening. Sorry to sound stupid, but I don't know what tps or apps means. Thanks for the tip about the TDR issue as well. Any more input is appreciated and I will let you know if he figures it out. Thanks again.

jwey

 

[blacksheepdiesel]

Hey Guys,



To me this sound way too familiar. My experienced guess is the VP44 is on its way out. The APPS (accelerator pedal position sensor) or TPS (throttle position sensor) is the same electrical component, just a different name. It is possible the sensor is causing the problem, but again experience tells me what you are describing is a failing VP44. Mine never set codes, but when replaced it solved the problem.



Godspeed,

Trent

 

[Cummins724]

I don't think he is having a check engine light when this is happening. Sorry to sound stupid, but I don't know what tps or apps means. Thanks for the tip about the TDR issue as well. Any more input is appreciated and I will let you know if he figures it out. Thanks again.

jwey

TPS- Throttle Position Sensor... ... APPS- Accelerator Pedal Position Sensor. I had no check engine light when mine failed until the point where I was cruising down the road & engine failed to respond to any pedal position as if a cable snapped or something. I pulled off the road & then got the code PO121. Before this happened..... I only got code PO1693 which is a companion code meaning that another code is present, but no code came up. My Actron scanner wouldn't pull the code, but luckily I had Smarty with me... . It pulled the code PO121, I cleared it & headed down the road. Another reason that I love Smarty. I would have been stranded..... Thanks Marco!

 

[Warpig]

Hey Guys,



To me this sound way too familiar. My experienced guess is the VP44 is on its way out. The APPS (accelerator pedal position sensor) or TPS (throttle position sensor) is the same electrical component, just a different name. It is possible the sensor is causing the problem, but again experience tells me what you are describing is a failing VP44. Mine never set codes, but when replaced it solved the problem.



Godspeed,

Trent

I agree with Trent here. I have an 02, and at 60000 miles had the dead pedal issue also. It was the VP44 I had the p0216 code, so it wasn't hard to diagnose. Hopefully your buddies truck is still under warranty.

 

[JWey]

Thanks Guys,

It is still under warranty. Will they replace the VP44 under the 100,000 mile warranty? Thanks for the feedback, I passed the info. along to him.

jwey

 

[Warpig]

They should replace it under the warranty, since he doesn't have fueling mods that the dealer would have issue with.

 

[Bulldog80]

You can put as many different vp-44's that you want on there and if it's the apps it will still do the same thing. Do your self a favor and try different apps reset procedures before even considering replacing the vp-44. Mine did the same thing yours is doing and it was the apps. No cehck engine light and no codes either. 60k is plenty of mileage for the apps to go bad.