2004 Pontiac g6 3.5.

On the diagram I have a 5 volt ref to and from TAC Module and Accelerator pedal sensor. I don't see 5v ref to and from the computer to the TAC, only the high speed data wires. The 5v ref are both around 3v. I have a code for ecm no com to TAC. Powers and grounds for ecm are good. But I have codes for memory and processor error for the ecm. I'm stuck on the 5v ref thing, I don't understand how its only between the TAC and Accelerator Pedal Sensor. At first I had no com to the ecm but I cleaned grounds and I have com now. I also have intermittent no com with power steering module but I can get readings from all sensors when I have com and they agree, have steering torque readings and angle etc. I'll attach a picture of the codes. Any explanation is greatly appreciated!!

I had to look up a 2005 G6, 2004 doesn't list aG6 in Shop Key.
It looks as if the TAC supplies the 5v ref for both legs of the accelerator pedal sensors. If you have only 3v coming out of the tan and white and black wires at the throttle body, then you need to verify power and ground at the throttle body.
Pin 8 and 17 are grounded at g105 (under coolant hose on transmission stud).

Key on power is supplied to the pink and black wire from ETC fuse 2 via power train relay 33 (both in under hood fuse box).

What OBDII type of device are you using? Just curious as I use several and not to surprise me I haven't seen that but there's tons of them out there. Always like to hear about other brands. Example this past week I picked up a bluetooth OBDII MX+ & USB OBD Link EX FORscan which I have to get the latter up and running on a ford to see what it's all about. I have other way more powerful scan tools, scopes just decided to try something simple and review it eventually.

Bought this car a couple weeks ago as a mechanics special. I unfortunately didn't take notes when I checked powers and grounds at TAC. I will redo that today. For some reason I had it in my head only PCM supplies 5v ref. That was really throwing me off! Thought I had a missing diagram lol. Thank you for taking the time to reply!

Its a Thinkdiag dongle. I bought it to keep in my vehicle. I'm pretty amazed at everything I can see with it and it has some bidirectional capabilities and resets. For $119 and a year of all makes and models included I had to try it out. I'm supposed to be picking up a Snapon from a local guy soon, really looking forward to having a scope!

Was the computer long story short. Thanks again for the help. Was a little nerve racking making the call lol.