my 2004 burb recently (recently as in it was 3 years ago) suffered a very short (time wise) engine bay fire. I was taking the trash to the dump and I'm assuming because the car was sitting idle the rats nest on the exhaust manifold got hot enough and combusted. luckily, I was walking back to my car and witnessed it combust. I ran and grabbed the fire extinguisher on the office building at the dump and quickly put it out. fire lasted for around 5-7 seconds. back to now when I am in shop class and wanted to scan my car and I plug the scanner in and nothing. I wiggle it, unplug it plug it back in and still nothing. I want to assume it's because of the engine bay fire but if anyone has any other insight let me know. thanks!

 

All I can share is what happened on our 2005 Yukon XL.

Mrs. Cusser took it in for Arizona emissions inspection, test site could not get OBD2 signal. She brought the Yukon home, and I searched online, found that the OBD2 circuit was shared with the cigarette lighter circuit, labeled "CIGAR" in the fuse box. Nowhere in the owner's manual did information about this exist. I tested the CIGAR fuse and it was blown; I went to parts store and bought replacement fuses, and even the guy behind the counter was familiar with this scenario. Anyway, I replaced the fuse and parts guy confirmed he could now get OBD2 signal, and Mrs. Cusser took it back to the test station and passed.

Just try to tell me that the test station folks had never heard of this before !!!!! To really lower emissions they could've popped in a fuse and saved all that extra driving/pollution !!!

 

Wait, my Cigarette lighter doesn't work. where is that fuse? you may have just solved my problem

 

I cannot remember exactly, maybe here in the engine compartment; could be labeled CIGAR or CIG LTR

 

do you remember the amps of the fuse?

 

Sorry, don't remember, if you locate the fuse the color and amps will be evident. Also, there are multiple sizes of fuses used on vehicles, compounding confusion. Actually - I cannot be sure it was the 2005 Yukon or the 1994 Suburban that had this happen!!!

 

yup. Cig lighter fuse for OBD port power.
I believe it is a 15 amp fuse. Lower right corner of fuse box under the hood. the fuse on the top of two rows.

 

Found the fuse (it was blown) replaced it, then found out that the cig lighter works (burnt my thumb) and I'm going to see if I can scan it today.