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wont connect to OBD

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Old 10-31-2008, 11:50 AM
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wont connect to OBD

hi i have a 03 f-150 triton 4.6 2 wheel drive crew cab, went to get it inspected this afternoon and it passed mechanically but the truck wouldnt respond to the obd emissions test, it simply wouldnt give a signal back to the computor, i have 60 days to fix it but id like to get it done soooon please help, what could it be and where should i start??? thanks alot
 
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Old 10-31-2008, 12:53 PM
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Check Fuses

I would start by checking fuses. I believe the Cig lighter or 12V Power point fuse is the one the obd port is powered from.
 
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Old 10-31-2008, 06:36 PM
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ok so i read the rejection report, and it turns out that everything passes except for the MIL inspection (malfunction indicator light) (check engine light), the light isnt on, no trouble codes come up, ive taken it to 2 seperate places and nothing comes up its all clear. could this have been tampered with by the dealer to sell this vehicle quick and get rid of it?? what else should i look for, the dealer said they would look at it but theyre an hour away and like everyboody else on here i work all week long crazy schedule no time for that. If i have to i will take it back for them to look at but im trying to avoid that as you can see. the truck is mint, and im just hoping its something stupid and small but we all know what happens when we hope for a quick fix.

thanks for all the help guys,.
 
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Old 10-31-2008, 06:51 PM
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Sometimes they need to be driven around for a week or two for the correct parameters to reset on the PCM. Your CEL could be burned out too possibly.
 
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Old 10-31-2008, 07:26 PM
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ok so put it so a diesel guy can understand please lol what is the pcm and whats the cel is it expensive??? what would have caused this the vehicle has passed inspection every year up to 07 is this common?
 
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Old 10-31-2008, 08:01 PM
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Originally Posted by 6.9 Diesel
ok so put it so a diesel guy can understand please lol what is the pcm and whats the cel is it expensive??? what would have caused this the vehicle has passed inspection every year up to 07 is this common?
PCM is the computer, CEL is the check engine light
 
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Old 10-31-2008, 08:41 PM
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does the cel come on when the key is turn on. i think the truck won't run if the bulb is out. had that trouble one time liked to never firgured it out
 
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Old 10-31-2008, 10:24 PM
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Originally Posted by todd31277
does the cel come on when the key is turn on. i think the truck won't run if the bulb is out. had that trouble one time liked to never firgured it out
LOL! The bulb won't stop the engine from running.

However, if the bulb is burned out, missing, or otherwise does not come on during the bulb prove-out, you will never get past an OBD based emissions test and you won't be getting your new plates.

Steve
 
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Old 11-01-2008, 08:47 AM
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the light comes on when the key is turned on, but quickly goes out so i kniow its working, now if i had a computor issue wouldnt the truck run like crap???? people are telling me it was a bad connection with the inspection computor...
 
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Old 11-01-2008, 02:51 PM
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Originally Posted by projectSHO89
LOL! The bulb won't stop the engine from running.

However, if the bulb is burned out, missing, or otherwise does not come on during the bulb prove-out, you will never get past an OBD based emissions test and you won't be getting your new plates.

Steve
had a 93 f150 i was working on. they had pulled the bulb out for whatever reason. would not start until i put it back in.
 
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Old 11-01-2008, 07:27 PM
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Originally Posted by 6.9 Diesel
the light comes on when the key is turned on, but quickly goes out so i kniow its working,......
How can they fail if for not working when it works? Obviously, it's a problem for their computer communicating with the truck's computer. As already pointed out, the power to the computer port runs off the same fuse as your cigar lighter. If your cigar lighter doesn't work due to no circuit power, you also cannot pass an OBD-based inspection on one of these trucks. Fuse # 3 in the under-dash box.

had a 93 f150 i was working on. they had pulled the bulb out for whatever reason. would not start until i put it back in.
Ford never has done such a thing. Coincidence.

Steve
 
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Old 11-03-2008, 06:42 PM
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well the fuse is fine im begining to believe that its something to do with the machine that they used to inspect the truck because like i said everything else that had to do with the computer inspection portion passed, it was just the MIL that wasnt reading in the machine they used, ive gone through the truck over and over again nothing broken no wires stripped spliced everything looks fine like new, i need some help should i take it somewhere else and have them try to inspect it and bite the 45 bucks if it fails or what, im reluctant to return to the dealer and have it serviced they were kind of rude, but i dont want to throw money at somehting that needs professional attention, i appreciate it thatks alot.
 
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Old 11-03-2008, 06:56 PM
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ok so once again i have the inspection report in font of me under the emissions portioon of the test which failed it states: KOER*** KOEO*** MIL status: rejected unable to communicate Readiness monitors: unknown Diagnostic trouble codes: unknown

now i also noticed that under the vehicle description where it states how many cylinders the engine has it says 6 not 8 its a tritonV8 so would this set something off in theyre computor and automatically reject it?????i have the feeling that im on to something or maby not but its something new that i probally should have stated in the first post sorry and thanks alot guys...
 
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Old 11-04-2008, 06:19 AM
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You're on to nothing.

Power to the OBD port is on the same circuit as the cigar lighter. MAKE SURE IT WORKS.

If it does, take the truck to a shop to have the port problem diagnosed and fixed.
 
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Old 11-05-2008, 11:28 AM
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You post is a little confusing. If they tell you the MIL is "ON" when it isn't yet it comes "ON" at KOEO that doesn't make sense. They tell you you don't have any DTCs on the report so why don't you just show them that the MIL illuminates at KOEO? That way they'll know the lite works. It sounds like you have a network problem, but in order for their computer to figure out what type of vehicle you have and how many cylinders it has their computer had to connect to the vehicle network via your DLC.
 
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