Sevice Engine Soon Light...
 

So about 3-4 times per day, my truck will accelerate very quickly with the slightest touch of the gas pedal, then followed by the service engine soon light...I checked for any codes to see what I may need to fix, but no codes are found. Any suggestions on what this could be??


I am also having issues to where I a few times per day I have to put my truck in neutral to get it to start instead of in park...could the two be related?

Throttle position sensor. What year? You will either have to to with aftermarket(and most suck) or OEM and there are several different ones, depending on your year. Even better, ford does not sell just the sensor, only the whole pedal assembly for around $400.

Safooma, my truck is a 99. Any recommendations on the best one for the lowest price??

I got an oem one from a ford dealer on ebay for $220.

The first thing to do is to take the pedal assembly out(it's only 3 bolts and two connectors) and clean the switch and the sensor with some contact cleaner. This worked for me for over a year.




While you have the assembly out, check the part number of the TPS thingy. If it is PN - F81Z-9F836-AB, then you can get an oem ford one(the entire assembly) here:


http://www.ebay.com/itm/231269309848?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Looks like the price has increased since i purchased mine, but this is still the best deal going on the OEM parts. I just swapped out the entire assembly, took the old sensor and IVS out, cleaned them up and tossed them in the glove box along with my extra cps and clutch pedal bushing.

Note that you can buy the position sensor from napa/dorman/etc, but I found nothing but negative experiences when i was researching.

Good luck!

What are you using to read codes? The generic scanners only pull generic OBD-II codes from these trucks, not the many proprietary codes that can be present. If the MIL came on, there's a code stored. I wouldn't throw parts at it just yet.

I went to an autoparts store and had them check for codes...don't have a scanner of my own. Where would be the best place to get this checked out that wont cost too much?

I would hold off on spending any $$$ until you have done some more troubleshooting.

If you're not retrieving a Hard or Soft Code Stored in the PCM, it's most probably the PCM itself.

The PCM will log events from the field but has no way to log anything occurring to itself (it doesn't monitor itself).

A problem with the PCM can cause the symptoms (amongst others) you speak of.

As Pikachew eludes to, you may require a Bi-Directional Scan Tool for Pulse With Modulation Systems to see what, if any Code is logged. Perhaps the one your using is not retrieving a Stored Code. The Auto Parts Stores while helpful, don't generally use top of the line Scan Tools to assist their customers - Just my observation.

Cheapest way to pull your codes is to get a bluetooth adapter and TorquePro app for your smart phone. Or you could hit up one of us close by to help you out. Where are you located?

I will look into that! Thank you. I live in western Colorado