Computer communication body control error, and transmission issue

Previous owner, my brother replaced computer, and transmission couple years ago. It went down with bad fuel pump sat for 6 months before being fixed and givendors to me.

Is the gear indicator flickering?

None of the lights on the shifter work.

If not it could be a ground wire on the body control module

Today input it all the way into first at stop sign and my doors inlocked. They lock once in drive and unlock usually only in park.

It sounds like it is your ignition switch. The wires from the gauge cluster and lights all come from the igniting switch not the lock cylinder. You might have to change the ignition switch but first I would search on Google for the body control mod and find out where that ground is and trace all the wires that won't you cost you a dime to do it yourself

And if that does not work look under your blazer and look for the plug going into the transmission see if it is dirty I have a leak on my truck and everytime it's gets fluid in it it will stay in 2nd and shift out so I have to unplug the battery to reset the computer and clean it

Fluid in the terminals on the connector that plugs into trans

CAN-BUS telling you a module is GAME OVER Call around locate a shop that has the old GM tech2 scan tool and know EXACTLY what that issue is $100 fee You can guess along time and not discover the correct answer...

Thank you guys. I am going to trace wires I have time for that as stay at home mom.