1994 F250 7.3 DI, How to read codes - Diesel Forum

nobull56 · 07-11-2009, 06:23 PM

Have a 1994 f250 7.3. Truck quit, have been trying lots of fixes, none work. In one thread I was told that 94 could only be read with OBD 1, unless some magic thing allows OBD 11. I have followed the directions of by ‘Autoray 2000 (with upgrade) & only get ‘Eng not responding’. Any Ideas??

chuckster57 · 07-11-2009, 06:54 PM

First thing to determine is if it's OBD I or II. Since '94 is the year of change IIRC, do you have the trapazoid connector under the dash or the other one in the engine compartment. You might have the OBD II connector and OBD I protocol.

nashvillebill · 07-12-2009, 03:14 AM

Mine's the '94 and it's got an OBDII connector--but the PCM wasn't flashed for it, and the AIC didn't work. I had the PCM reflashed and the AIC now works, but my scanner (Actron) still doesn't work. The Ford protocol just doesn't follow OBDII protocol.

nobull56 · 07-12-2009, 10:18 AM

my truck has both, OBD 1 under hood & OBD11 in the cab. It has a tag under the hood that says 'PCM reprogrammed, Modal #F5TF-12A650 BTE' then a autharation # 95-11-9. does this help?

chuckster57 · 07-12-2009, 06:30 PM

It should be OBD II then. The only other problem is that PSD's don't follow "normal" OBD II protocols. They have there own, and you need the right reader or software to see if any codes are stored. Auto Enginuity is the software of choice here. I don't have it cause mine is OBD I.

Just for fun: here is a link to retrieve codes using the OBD I connector and an analog volt meter, can't hurt to try

Troublcodes.net Trouble Codes OBD & OBD2 Trouble Codes and Technical info & Tool Store. By BAT Auto Technical