Some of you may be familiar but searching on google has yielded nothing for me.

Background: 2 weeks before I plan to take my 1999 f-150 to get inspected my check engine light comes on. I take it to autozone to see what the issue is and they aren't able to get a reading. Drive to another mechanics shop and they also aren't able to get a reading.

Currently: the truck runs fine with no issues, the check engine light is even gone away. However I don't want to take it get inspected without knowing why it couldnt connect to any of the programmers previously, because i figure if they couldnt connect the machine at the inspections station probably wont connect either.

Anybody have any idea what could be causing this?

 

That sounds like something that would happen to me...seriously..

 

My Mustang did that when I didn't secure the fuel cap. The fuel cap light would come on as well, but turn off once secured. Then the check engine light would stay on till it was warmed up, shut off and started again.

Can't see it being serious otherwise I'm sure it'd throw a code.

 

I have had a ABS light do the same thing to me before, was a wire that had rub wear on it and when I would turn the wire would short, turn the light on and end up going away a short time later.

 

Thats the thing, even if it stayed on, (which it hasnt been on since) I cant connect a programmer to it to read the code. When i take it to autozone, my vehicle isn't detected. It didn't look like it was even on. Could it be a fuse? does anybody have any ECU wiring diagrams I can look at? Any ideas or Anything?

 

if the scanner won't make contact with the car, check the fuses under the dash. more than likely thats why it wont connect. it could rarely be a fuse in the underhood fusebox.

 

I checked all the fuses that said PCM, on it, nothing, even the fuses under the hood, still nothing The guy at autozone said it may be the cigarette lighter fuse. Ill check all the ones under the dash later and let you guys know what I found

 

the fuse for one of the cig lighters/power outlets also powers the obd2 port. The 2 power ports are on different fuses, that threw me off at first because my phone charger was still on.

 

Not sure what state you live in but a vehicle inspection should not require anybody to plug into your on board system, they should make sure the check engine light comes on and goes off, inspect to see all emision control devices are attached and have not been tampered with and probe the tailpipe for emisions. Call first to verify.

 

Lot of inspections now a days do require a plug into the OBii to scan the vehicle for codes