Warning & Check Engine Icon

I own a 1996 Toyota Avalon. I changed a rear brake bulb when the light icon came on the dash. But, now when ever I put the car into reverse the little car icon pops on and stays on. And since that happened, the check engine icon has popped on. When I had that checked it showed Error P0773, which is the Shift Solenoid and a short. What is the cause of the car light icon (where might the short be located) and where is the shift solenoid located on my 1996 Avalon. Can and how much should it cost to replace? All answers you provide will be extremely helpful. Thank you.

You probably need to change the solenoid, which can be tested. The code you’ve asked about indicates the entire circuit, but that doesn’t mean you have a short in this circuit, just a bad switch, which is your solenoid. The failure of this part will cause an error code.