'06 Envoy base 4.2. Greetings, I'm here not because I really want to be. Celebrating New Years Day getting my "new" Envoy out of repo after our deadbeat employee lost it. It'* pretty nice with 87k. On the way home, the CEL came on (of course). I plugged in my Actron CP9135 code reader and it didn't even come on. I tested it on another car and it works. I have no owners manual or records.
The timing is not that bad and we plan to keep the Envoy for a while. Thanks in advance for any help. I do all my own work and hope to contribute in the future.
Happy New Years, C.

Check to see if your cig/lighter fuse is blown. Usually power is provided by this fuse to the OBD port.

agree with mike on the obd being powered by the cig fuse.

i used to work by lake george, quite a beautiful place

I did a little searching before posting but didn't land on that fuse 13 cig lighter powering the OBD port. Now I've seen it covered in many posts.
It'* worth mentioning for us new to GM that the fuses are minis. I didn't have any spares so I took the 20A from the aux socket in the rear fuse box and put in #13 under the hood. I had 4 codes for secondary air issues of a couple types: 0411, 2431, 2440 & 2444. I'll start digging. Thanks for the help.

walmart has a pretty decent deal on a multi pack, good to keep in the car because you cant always find that type

u can always cut the power line on the back of the plug and run a jumper wire to the battery as well

Let'* not go that far. Typically the only thing that kills a cig fuse is the lighter itself. Keep the lighter out and never use it. Far too often the lighters fail and never pop back out and end up overloading the circuit.