Tahoe Problems Whats wrong when the "transaction active" comes on

it could be a lot of things I would check the u joints on the drive line I would also check the transmission mount as well the break pads could be sticking to the rotors too where is the clicking noise coming from front back in the middle

Transaction? I never seen that. When do you see this come on?
Does it go off or stays on all the time?
I can only think of 2 things:
Traction as in traction control unit goes active meaning it wont slide the rear end under power on rain or snow etc...
Or I have seen an option for towing a trailer where there is a button usually at the end of the shifter lever.
Both of them are ok to have a lite on, if you were to have a problem with transmission you would have the check engine light on and maybe the transmission switch light blinking.
Check you owners manual for a reference of this light.

Find an owners booklet on web or ebay?
Find a neighbour with one, ask him?

secrity light on?securt system wont let it start.

is the transfer case shifted into neutral?what if you move it down to low gear?is there fluid?

examine, the box for fuse, normally inside of the vehicle, They have name for any circuit. In front of the vehicle is for mayor fuse, a.c.+fan, etc.

Proceed, sincerely. God bless you

sounds like you have a electrical isssue, you possibly have a bad alternator the car is drawing too much voltage to stay running check battery and charging system

There is a possibility that the A/C compressor clutch burned up or got disconnected. Try investigating the wiring for the clutch.

have your cars computer codes read at a parts store. there is something wrong with your vehicle that it is retarding the ignition and doing other things to protect itself from damage due to some problem with engine....your codes should give you specific details on whats wrong.

throttle position sensor