Electrical shorts, 12 V battery, evaporative emission control system vent circuit, ecu communication

Hi. I have been having all sorts of issues with my 2004 toyota Prius with 200000 miles, and I would like to know what I should get fixed. I don't want to take it to the dealer for the actual repairs/maintenance, although I took it in and paid for a diagnostic. For a couple of years, the display lights for gas and speed have been occasionally working. Some days they work, others they don't display my gas, mileage, speed, ect. However, my check engine sign remains on. At first, they would work about 3/4 the amount of time, now they only work approximately 1/4 of the time. Also, now the tape player and cd player is recognized 3/4 the time. The information screen would stay on when the car is powered off and the car no longer recognizes when the key is inside of the car. The head and tail lights randomly don't work. The horn has completely stopped blowing. I believe the display and airbag remaining on ultimately killed the battery. Also, the airbag signal stays blinking when the car is off. I knew I was in for some major issues when the car wouldn't accelerate on the highway, and completely died while I was driving. I replaced the 12 volt battery, which stopped the random display system from coming on in a powered off car. The airbag on the dash remains to flash with the power off. Also, I am having problems at some gas stations with the pump thinking my gas is full. It pumps fine when I turn the nozzle upside down. I don't want these issues to completely kill the car. I have previously taken the car to the dealer twice with these electrical issues, once for the headlights. They told me to replace the headlights. I did. It never fixed what is causing it to occasionally break. The engine also doesn't sound the best and my check engine light is on, after an oil change. The same thing happened before and I replaced some other part that didn't fix the original issue when this originally started. At first it was hard to get a diagnostic as these issues would only randomly happen, but now the issues are happening most of the time, so my current diagnostic codes came back as powertrain P0446. Electrical B2775, B1271,B1801, B1811. When I ran the diagnostic, it said my evaporative emission control needed to be replaced. When I did a self-check there were memory codes 58-43, 63-44, 63-51. I'd like to buy the parts I need and pay someone for the labor I cannot do myself. I don't want to pay someone for unnecessary work or part tax when I can get it myself, as Im pretty broke and cant get a new car any time soon.

 

I live in Lakewood Ohio. Darn it. Thank you so much for the offer.

 

Hi. I have watched youtube videos on how to take the car apart. I do have the tools for the display. Garage, check. I rigged my car to pass emissions test and got it in on the line before the computer signaled the code. I agree with the order of operations, and the largest problem is the unfortunately te emissions control system, as I do believe it is what killed my battery, and will ultimately kill the hybrid. I agree they must be related. That short with the horn, I watched someone take apart, and it is located right next to the airbag. So, I can do it at the same time. I was wondering if the headlights and tail lights are all connected to the drivers side somewhere, as I have a short in the drivers side. Also, I was wondering if there could have been a leak causing all this? I have fixed the lights before, but I believe the short causes them to randomly work.

It sucks when you cant find a good mechanic. There are only 3 dealerships around here. Two fixed the "problem", but the same issues keep happening after replacing the head lights. It has to be in the wiring somewhere, and no one wants to test all the shorts for under a g.

 

Rebuilt or should i just buy a new combination meter? what about the fact it sometimes works?