Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner

No Power at OBD port

32K views 13 replies 8 participants last post by  Glocat24 
#1 ·
SES light has been coming on intermittently, but not staying on consistently. Guy at AutoZone plugged in reader and said there was no power to port. Any idea which fuse to check first? Cigarette lighters all have power. Was told they might both be on same circuit. Any info would be greatly appreciated.

Also, just went through 2 water pumps within a month. Could there be something else making the bearings in pump go bad pre-maturely?

Bob
 
#2 ·
It's fused by the CIGAR fuse #13 under the hood. Must have broken off the back of the OBDII connector if your accy outlets are all OK. Unscrew it from the trim panel and look.

Water pump bearings? Hmmmm, unbalanced fan - unbalanced fan clutch - incorrect (too short) length serpentine belt, replacement water pump made in East Roosterpoot, Banana Republic instead of at a reputable and traceable vendor? How long did the first one last? Are you saying you went through TWO replacements in a month, or the time between the failure of the original to the failure of the replacement was a month? You might have just had one dog of a replacement instead of a vehicle problem.
 
#3 ·
will try to unscrew OBD port and check.

Only had original water pump replaced and 1 new one within last month. So, the replacement didn't last very long. Wifee starting to hear same noise she heard last time before serp. belt shredded, and left her stranded, but only intermittently now. Said it sounds like a jet engine revving-up. Any easy way to check fan balance, clutch, etc?
 
#4 ·
Ok, all 4 wires connected to back of OBD port and #13 fuse ok. Any other ideas why no power to OBD port? I have a Hypertech Power Programmer III for my '99 Blazer; could I use it just to test to see if there's power to the port or not? Any other way to see if there's power at the port without hooking up a reader? I have a multimeter. Thanks for the help.
 
#8 ·
Don't know. Didn't do anything but unscrew port, check wires and put on multimeter. Maybe guy at Autozone had a bad scanner or just didn't feel like helping me. Anyhow, I just called my mechanic to see if he could pull the codes today for me and he said when he replaced last water pump, he heard a noise that sounded like a cracked manifold when engine was cold/warming up. Said it went away when engine got warm probably sealing/closing itself once hot. So, any idea what it's gonna cost to replace exhaust manifold? Any cheap fixes? Any kind of performance manifold I could have installed while I'm getting it done? Should the O2 sensors be replaced? I guess I'm assuming the SES light might be due to the manifold crack.

Geez, one thing after another.
 
#14 ·
Yes I did. #13 fooled me. It corrected it and I pulled a p0300. Leads me to believe a pgr valve.
I have an 06 TB 5.3. The gas mileage is atrocious.

I'm sure with these first years of the TB, it is probably called something different, because no one can order anything like that but a gasket.
Any ideas?
Glo 😉
(Fuel injectors and spark plugs next.)
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top