I've attached a few pictures below as a step-by-step guide on checking your codes/problems with your car. Here is a tutorial showing how to check wiring:
You are going to need a professional style scanner to help with the transmission code diagnostics.Hope this helps and thanks for using 2CarPros.
Danny-
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.