Hi, I bought an eec diagnosgtic tool for my f150 1991 4.9 inline 6 pick up. I plugged it in and it just does a constant beep and flash of light. I can't get it to quiet down so it can do it's thing. Its an actron cp9015 scanner.
any help ?
thanks
rich

 

Unplug the scanner.
Ground the STI wire (the single wire you pluged into the scanner).
Turn on the key.
Does the CEL on the dash do a constant flash?
Does the fuel pump run all the time the key is on and the engine is not running?
If yes to the above I would say you have lost the EEC Computer.

 

O.k.
I did as you instructed and the check engine light comes on and the relay is making for the fuel pump.
If i've lost the eec computer. What now?
Where is it and is it expensive to replace?
Thanks for help

 

You have to replace it.
It is in the drivers kick panel (see link below) and is about $30 - $50 at a salvage yard and $150.00 to $200.00 at an auto parts store.
Most say that Ford tells them that they are not available from Ford.

Location:
http://i54.photobucket.com/albums/g9...CMlocation.jpg
/

 

Subford,
I look at the location of your picture and i see wires on my truck but no computer. could it be located somewhere else? like under the radio area.
Also, to be clear, when i ground the single wire from the eec test area the check engine light comes on but does not blink. and the fuel pump relay is active. If the computer was healthy....what would be happening?
thanks
rich

 

No but I know on a 1990 after you take the plug off from under the hood you have to take the computer out from the drivers kick panel. A 1991 might be the same but on a 1992 it has to come out from under the hood. Please let me know about the 1991.

The light should blink when you ground that wire and the fuel pump should come one for one second and quit.

If the light does not flash and the fuel pump does not quit after one second I would say the computer is bad.

Or if the fuel pump runs all the time the wire is not grounded and the key is on with the engine not running but goes off when you turn the key off I would say the computer is bad.

Does this truck run??

 

Hi,
i tried to reply and couldn't get through.
The truck runs just fine. Just a gas hog. 9 miles to gal.

 

I would still say you have a bad EEC Computer.