When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Okay, here's the question. I know that OBD-II is also known as EEC-V, so is OBD-I the same as EEC-IV? My sister asked me to work on her '93 Crown Vic, and when I went to plug the code scanner in, there was only the one six-pin plug. The single wire that sits to one side with it's own plug is missing, and in tracing the wires back down the harness, I can't find any sign that it was ever there in the first place. My book says that the car should be EEC-IV, and that it should have that wire. The vehicles that used that six-pin plug without the single wire were early to mid '80s carburated MCU controlled vehicles. I talked to a guy I know who used to be a Ford dealership service manager, and he said it's probably OBD-II, which came out in '90 on some vehicles. I looked under the hood, and the sticker says OBD-I certified. It's a California car, if that makes any difference. (It often does) So if it's EEC-IV, I'm back to square one, as my scanner won't pull the codes without that extra wire. Thanks for any help anyone can give me. -TD
The OBD I had a cover on the connector, and from personal experience, a lot of people either leave one of the connectors out or break the clips that hold the terminal to the cover. I have seen the diagnostic hanging on something while the ground was laying there and vice versa. Just a thought.
OBD is onboard diagnostics...systems I and II. System II was government mandated in 96, and I don't believe it was on vehicles earlier than this, they should be OBD-1.
There are OBD-II vehicles that are EEC-IV. The EEC is just the computer EFI system, which has OBD on it. EEV-V is a more complicated EFI system than EEC-IV, it runs most of the new mod motors and the like (it has more parameters for engine control). But the 4.6s used EEC-IV too, as far as I know.
Your car should be EEC-IV and OBD-I...sometimes that 1 wire plug is actually plugged into that six proger.
Some vehicles (not Fords) did get OBD-II prior to 95, but most did not. If it were OBD-II, the DLC test port would be under the dash and would be a 16-pin connector.
According to the EVTM that STI plug *should* be right next to the DLC. There is no difference in CA vehicles.
The wire should be W/P and go to pin 48 of C148 of the PCM.
FWIW, this system can be tested with a paperclip or other short wire jumper if no OBD-1 Ford code reader is available.