Hoping someone can help. I have a 99.5 F-250 with 7.2 liter powerstroke. Yesterday I was "setting in" a new set of rotors and braking hard from 60 down to 20 when the truck shuttered a little and the service engine light flashed. It then ran fine. Today, when I went to start it, the service engine light stayed on and when I try to give it throttle, it continues to idle. It will shift into drive and reverse and will move under idle but no throttle response at all and the service engine light stays on. I tried unhooking the battery to reset the engine but no dice. Any suggestions would be most appreciated.

 

Try unplugging the wiring connector that hooks onto the go pedal. Check for any signs of corrosion and plug it back in. Sounds like a TPS or IVS issue.

 

I think you mean a 7.3. I have heard of this before but cant remember the cause sorry. I will give you a bump and maybe you will get a good answer soon.

 

Sorry. You are correct, 7.3.

 

Chris is dead on as usual, the throttle position sensor on the pedal has a metal tab, check it.

 

There is a microswitch on the throttle pedal that must work or you end up with the problems you describe.

Check to be sure you hear the Idle Validation Switch (IVS).

If it gets dirty, it can become intermittent. Then, the Powertrain Control Module (PCM) thinks the pedal has no foot pressure and remains at idle.

It's just a small microswitch mounted in the Throttle Position Sensor (TPS).

You should be able to hear it "click".

Also, if fuse 45 is blown, you are not supplying voltage to the Idle Validation Switch (IVS), and thus the Powertrain Control Module (PCM) is not seeing it when the pedal is fully released at start-up. This means "idle only" until the PCM does see the voltage.

Find out where the short (usually a chafed wire) is, as that's likely to be what it is. It can be on either side of the switch's wiring in this case.

Red wire with a yellow tracer, according to the PDF.

Pop

 

I can add nothing more,These guys are right on !

 

Thanks to you all. After I saw the advice from Chris I went out and looked at the throttle. I first hooked up a code reader I purchased at Autozone but no codes were present. When I looked at the throttle, I was a bit lost. There seemed to be more than one connector going to the throttle. One looked to be 2 wires coming from my Edge module on the dash, and there also appeared to be a larger one going into the back. Which one should I be looking at for a lose connection? It was odd because I had not had any issues until I hit the brakes really hard. I felt around the wires for a loose connection or chaffing but didn't feel anything. I tried starting it again and the problem stopped.

 

Be careful on what code reader you use. Many will not read Powerstroke codes (especially soft ones that do not illuminate the SES light). Many die-hards use the Auto Enginuity software which is really good, but not cheap. I have an Actron code reader that I bought on sale at Pep Boys that will read codes (hard codes that light the SES at least, I don't know about soft ones). I don't know what other brands will read our codes, but just because the reader doesn't see any doesn't mean that there aren't any.

 

X2 on the code reader ... and if u moving the wires around made it work that would point to a loose connectuion or chaffed wire to me ... dig deeper u don't wanna loose that throttle again at high speeds or something

 

I was using a Actron model CP9180 I got at Autozone. I'm beginning to think after reading other post that I should get a new pedal assembly. The thought of it failing crossing a highway causes me to think this isn't something "half way" fix. Thanks for the help and I'll let you know if it fixes the issue.

 

You don't have to replace the whole assembly, they sell just the TPS.

http://www.dormanproducts.com/docume...s_Sensors2.pdf

 

I thought I'd finish the story in case it might help someone else. I decided to get a new pedal assembly but they are not available. The dealer said they are on National Backorder and the ETA is late Spetember. I found a used one and purchased it from Truck Parts Unlimited. The guy I talked to said they are getting a lot of inquires from dealers about parts they need. When I got home and tried to test it the truck wouldn't turn over. I thought the batteries may have went down but it wouldn't even jump start. I noticed the amp needle didn't move when I tried to start so thought the starter was bad. Pulled it and took it to Autozone where they checked it an dsaid it was good. I decided to put a new one in anyway as this was the original and my truck has 113,000 mile. Put it in and the truck fired right up.The throttle worked fine as well so I tried swapping the harness back and forth and both pedals worked fine. Weird bunch of issues but it's working now. I'd also say trust yourself when you think something is wrong or I'd still be trying to figure out was wrong. The starter just decided to die at the same time the other issue started.

Thanks all for the input.

 

I am currently down with a bad Go Pedal. Yes, it is on National Backorder. From the reading that I have done, the Dorman part will not work. The tabs are in the wrong spot. I have not been able to verify this as no parts house around me stocks it.

 

On EDIT: Ed found me a pedal and it is on the way. I knew that I could count on him.. Once I get it in, I will be checking out the old one to see exactly what went wrong with that sensor. When tested on the truck it was only reading a max volt of about 3.8 and was only showing a 75% open on WOT. It should read 4.5 and 95% from what I have read.

I will let you know!