Hello,

Recently my "Service Engine Soon" light came on. The vehicle appears to still be running fine, although I must admit I have noticed a significant increase in fuel consumption over the past months.

My brother-in-law went to Autozone to use their scanner [he has done this many many times on his various vehicles] and when he attempted to use the scanner to determine what codes were showing up, apparently there was no power to the diagnostics port.

An Autozone guy was helping him with it and the Autozone guy tried numerous times and also noted that there was no power to the OBD-2 port. He suggested to my brother-in-law that it was probably a blown fuse.

Can anybody tell me what fuse on a 2002 Tahoe handles the OBD-2 power?

Something I should mention is that at some point early on my brother-in-law installed a remote start unit to my Tahoe. Last year we removed that after I had other problems. ( This remote start unit was talked about in another thread I posted some time ago... https://chevroletforum.com/forum/general-tech-10/2002-tahoe-starts-then-immediately-shuts-off-24401/ -- thanks to the guys who provided me with the solution!) I'm not sure what he happened to tap into as far as wiring when he had originally installed the remote start unit. It's possible that if he tapped into some wire that also uses the same power as the diag port, then perhaps I have a shorting wire somewhere that caused the fuse to blow [I'm assuming that the fuse is blown].

But before I proceed further, I'd like to know what fuse would likely be the culprit fuse if a fuse were blown, so I can work on that as the same time I attempt to track down the wiring to make sure there are no shorts.

Thanks

mike

 

15 amp fuse under the hood labeled "CIGAR"

 

Thank you!

Mike

 

I pulled that fuse, and it definitely was blown. I also realize fuses don't blow for no reason at all. I'll pick up another one tomorrow for it. I'll look over the wiring where the old remote start had been patched into things under the dash, replace the fuse, and then hope for the best. Hopefully I'll be able to then see what's going on with the Service Engine Soon via the diag port.

I really appreciate your help! Thanks again.

Mike

 

Along these lines, checking fuses, with everything in place, can anyone think why after installing a new fuel pump, all of the gauges don't work unless you plug in an OBD reader?