OBDII Diagnostic Port - Not working?

[CSVT#49]

So I wanted to run a diagnostic check on my 05. I plugged in my scanner to the OBDII port, turned on the key, and no dice. The scanner powers up but says 'Error' when I try to read the codes. Not having faith in my scanner, I grabbed my SCT X3 programmer and tried using it, same thing with an error message. I checked the fuse, as some have said this can be the culprit, however having power there left me skeptical, but yes the fuse was fine as I had expected it to be. Wiring going to the port looks good. I'm going to disconnect the battery and let it sit for a while and then hook it up and try again, but other then that I have no ideas. Have any of you run into this before and found a solution??

 

[ELVATO]

Does your cigarette lighter/port have power? Both the OBD port and cig lighter share the same fuse. Or, just try swapping a new fuse in there. I have heard of times where a fuse that "looks" fine turns out to be faulty.

If it isn't that, then I'd say it's probably time to start backtracing and seeing if you have a broken wire somewhere.

 

[CSVT#49]

Does your cigarette lighter/port have power? Both the OBD port and cig lighter share the same fuse. Or, just try swapping a new fuse in there. I have heard of times where a fuse that "looks" fine turns out to be faulty.

If it isn't that, then I'd say it's probably time to start backtracing and seeing if you have a broken wire somewhere.

Yea that was the first thing I checked. All of my cigarette lighter ports have power as does the OBDII port. There is just no communication. I noticed there is a 4-pin gray connector taped back behind the OBDII port and was wondering if something needed to be plugged into that as well to enable the reader to read the codes from the PCM. I've seen some adapter harnesses before used in parallel with the OBDII port, but have not yet ever used one myself.

 

[CSVT#49]

Well I hate wiring... but at least I understand it and can read schematics pretty easily. After chasing through pages upon pages of schematics and checking continuity of connections across the truck I found no problems.

However as it turns out Ford decided not to support the standard ISO 9141-2 and ISO 14230-4 signals nor did they support SAE J1850 PWM for engine and vehicle diagnostics. Instead they moved forward with using CAN bus signals (ISO 15765-4 and SAE-J2284) communications for OBD II diagnostics. Looking through the schematics the standard SAE connections only sync with my Navigation module, but nothing on the PCM. The ISO dedicated pin outs are not fully functional. Only the K line ISO pin is connected and not the L line ISO pin. The only thing connected to the K line ISO pin is the Restraint Control Module and the Parking Aid Module again not the PCM.

Then the problem... the scan tools that I was using Innova 3100 (older model series then the current 3100) and the SCT X3 only support the ISO 9141-2, ISO 14230-4, and SAE J1850 PWM. So I am shyt out of luck with the scanners I have. I'm going to have to go into an Autozone or O'Reilly auto parts store and see if there scanners support CAN bus signal OBD II and then see if I can connect up with my PCM.

05 Expedition OBD II port pin out

 

[dvandoormaal]

Another issue solved!

Another very helpful thread.

Went to scan the truck after replacing the fuse box, plugged in the scanner and nothing...

Saw this thread and threw my USB dongle in the power outlet and presto, no light.

Checked fuse 41 (2003 EB 5.4), a 20A fuse. There it was, Blown...

Gonna replace it when I get home and hopefully should be good.

Thanks a bunch!