1994 F250 7.3 Diagnostic connector issue

[Verlyn Foster]

I've done a lot of diagnostic work on this 1994 F250 and have discovered a short to ground in the right bank under the valve cover. But, after all the testing and narrowing down of the short, I still can't get the self test output terminal inside the eec test plug to test 0 volts with the key on and no self test engaged. I'm pretty sure the IDM is going to need to be replaced because of the short and I would like to be able to pull codes on this truck, but, can't get the scan tool to do any type of tests. I've tried my MT2500 as well as an OTC Read only scan tool. I have also attempted to pull the codes manually with 0 success. Can anyone tell me the origin of the STO wire? Does it come from the main PCM?

 

[79jasper]

The powerstrokes needs a special reader. J1850 is the protocol.
The pcm can actually be flashed to be obd2 compliant.
I've never attempted the EEC method. https://www.troublecodes.net/ford/
Check the pcm fuse and relay. Unplug the fuel heater on the fuel filter bowl first.

Sent from my SM-N960U using Tapatalk

 

[greenskeeper]

IDMs rarely fail on the OBS trucks, slightly more often on the SD trucks due to water infiltration.