No Communication?

[t_mccu]

I Just Cannot Get My Truck Inspected!!!!!!!!!! Another Post On Here Tells Of My Problem With My P0420 Code. I Thought I Had Gone To Get The Inspection With It Worked Out. I Have No Light On Right Now And I Drove It At Least 50 Miles. Aparrently He Said Now His Computer Would Not Communicate With Mine. The First Thing He Said Was My Cigarette Lighter Fuse Is Busted. I Checked And That Is Not It.




Please Help Me If You Have Any Idea!!!!!!!!!

[mike2004tct]

What does a cigarette lighter fuse have to do with an inspection?

Check your ECM fuse, perhaps that's the problem.
Are you talking about an emissions test?
I know of a person here in Wi. who had his car fail the test because he disconnected his battery right before going in for the test, and the ODBII
didn't communicate with testing facility computer. He was told to come back the next day (he did,and his car failed because of a gas cannister recirc. problem that caused the SES light to go on after a day of driving)

[t_mccu]

The cigarette lighter on most vehicles is tied into the Data connection port. This means if that fuse is blown they cannot communicate....

You mentioned your friend disconnecting his battery...I did disconnect mine but I drove it about 50 miles before going in. Maybe I didn't drive quite enough. I didn't think that would cause no communication at all?

I am going back up there at lunch and I will post whether or not I get communication or not

Thanks

[blazes9395]

I don't know how exactly each province or state,that has emissions, conducts their testing, but here in Ontario, when a OBDII vehicle goes for testing, if a person has disconnected thier battery, they loose certain information that onboard testing the computer has perfomed on the systems. When this information is lost, the computer needs to go through the cycle to preform a test on that system. If this information has been lost, you usually get a fail on your emission test.

As for the actual communication between the inspection computer and the vehicles computer, that doesn't amke sense, there should be communication even right after a battery disconnect, that doesn't make sense. Maybe blazee is on to something when he mentioned wiring problems as a possible problem.

[ZL1power69]

here in md, in the past if i had someone come to me and say their check engine light was on but they need to go to emmisions, i would grab a scan tool and about a block or so away from the test station i would clear the codes and it would pass. now if they see that the computer has been reset, you fail right away. the reset period for computers is usually 15 miles.
now the lighter may be tied into the same power feed as the diagnostic port so if the fuse blows then the computer may not be able to be reached. when i was looking for a new truck, i looked at 2 98 blazers and on both of them, i plugged in the scan tool and nothing. the diagnostic port is suppose to have power all the time but i tried using the adaptor to draw power from the lighter and also nothing. at the time i was clueless because it was the same problem occured on 2 trucks of the same year.

[t_mccu]

Thanks for the input guys! I went back today and everything went fine. I don't know what happened. It may have been a loose connection or something. I have never been so happy to pass an inspection. He kept saying that it should communicate even if the battery has been pulled. I am in NC and it was at an NC Inspection center where that is all they do. He had some sort of headlight machine I had never seen before. I think that is how he makes a few extra bucks but I didn't argue. I was afraid if I left that place again my light would come back on.

Thanks again guys!!!!!!!!!