Last Fri. I was driving home in 2005 F250 Diesel truck and experienced a weird problem. Everything was fine until I stopped for a light and when I went to accelerate, nothing happened! No matter how hard I pressed or pumped the accelerator, the engine RPM would not move off the idle speed. It was like the linkage between the accelerator peddle and the engine was disconnected! I was lucky enough to be on a slight grade and I coasted the truck into a parking lot. I called a tow truck and my F250 is now sitting at the garage who won't open till tomorrow AM.

I'd appreciate any wisdom and assistance.

(Story continues in Post #3.)

 

The engine 'throttle' input is electronically controlled by the Accelerator Pedal Position (APP) sensor, which is build in the to pedal assembly. The PCM uses the signal from the sensor, there is no mechanical link between the pedal and the engine itself.

 

My truck was returned to me on Wed. The shop could find nothing wrong. They drove it but the truck functioned normally. There were no codes in the computer which the shop could relate to the problem. They returned my truck and on the way home from the shop, the exact same thing happened. I stopped for a stop sign and went to accelerate and there was nothing. The engine RPM would not move off idle speed no matter how I pressed or pumped the accelerator. I pulled off the road and turned the engine off, thinking that just might reset the problem. When I tried to start it, it wouldn't start. I tried to start it twice and neither time it wouldn't start and I had it towed back to the shop.

They had cleared all codes from the computer before returning it to me. When they got it back the second time, the was only one error code in the computer which was from the turbocharger and was related to the vehicle not starting.

The disconnect between the accelerator and the computer doesn't leave an error code in the computer so does anyone know or have an idea what is going on? The shop is still driving the vehicle but everything is working normally. My wife has lost total confidence in the vehicle and is pushing to get rid of it.

I'd appreciate help or assistance.

 

As Texastech Diesel has said, it is most likely the APP is bad. Not to uncommon, had a Kenworth with a similar setup that acted up for 2 months before it finally went out, it was a 10 minute fix on the side of the road. Your SD is a little harder to do, but not much. As the APP is the only connection between the foot pedal and the engine/PCM I would just replace it. I believe the Ford part #'s are 8C3Z9725A without adjustable pedals and 5C3Z9F836CA with adjustable pedals.