this might sound like a noob questiong but i as wondering if thee is a way to pull the codes on a 94 f250 4x4 351, i had a doge daytona all i had to do was tun the key back and forth 3 times and the check engine lie would flash the codes out to me and i was wondering if this truck has some thing like that.. thanks for all the help..

 

Go to Ford Fuel Injection and read up. Lots of good info there. You have 3-digit codes in your '94, and, while it's not as easy as turning the ignition on and off a bunch, it's not difficult, just a jumper wire between two harnesses under the hood.

Jason

 

thanks for the info man, i read evry thing that they had there about oing the selftest and im confused about groundingout the self test out put is there a ground screw or bolt?

 

On the driver's side fender, right in front of the hood hinge, there are two wiring harnesses under a plastic cover. Pull them both out, then, using the diagrams at http://www.fordfuelinjection.com/?p=13 either connect STO and STI with a jumper wire (like a paperclip), or connect the STI (single wire harness) to a good chassis ground. Then you turn the ignition on and start counting CEL blips.

Jason

 

The STI should be jumpered to the SIGRTN pin on the 6 pin connector, not the STO. STO is the same circuit as the check engine light (Self Test Output) and is not a ground source. Fordfuelinjection.com does a poor job explaining the jumper hookup, which is why I usually link here instead: EEC IV Self Test hookup . Just leave out the pictured analog voltmeter or test light and watch the check engine light blink instead.

 

Hmmm...I was just re-explaining what FFI has on their site, but I had never actually done it that way--I just ground the single-wire harness, and my CEL blinks away...

Jason

 

I usually ground directly to the battery, works every time.

 

Yes, any ground will work, but why go all the way to the battery when a ground is provided for you in the diagnostic connector right next to the wire you have to ground? A paperclip won't reach that far .
Regardless of where the STI is grounded, this statement is incorrect.

 

forget if its either autozone or advance but one of them should be able to pull the codes for ya with a scanner for free...

 

They only do that on '96 and newer OBD-II vehicles. These trucks, other than '96 F150s, are all OBD-I, which AutoZone doesn't know how to scan properly.

Well, shoot, I already said I was just parroting what fordfuelinjection.com said--I had never done it before that particular way. Now I may have to go out and try it one of these days, just to see if it's true or not.

Jason

 

That's fine as long as the harness ground point is intact and there isn't a heavy rust problem, if it isn't then it may present problems.

 

i was always told they could do them on all of them.. but ehh ohh well... ive just always had my own scanners so i never much worried about it...

 

They must sell those scanners for 5 bucks now wouldn't they? I paid 50 for mine many years ago, but I would think they'd be fairly cheap now, since there's really nothing to them. The reason I'm asking is, it's nice to have one when pulling codes as you can write while listening to the beeps instead of having to watch the cel while trying to write.

 

dunno... walmart still has them in their automotive section... i could look next time im there... usually every friday...

 

If the signal return wire doesn't make a good circuit directly back to the computer, there are bigger problems than just checking the codes (all sensors using the signal return for signal ground would likely not work either). Grounding through the signal return wire is the most direct ground path to the computer.