I have a 2005 2nd generation prius. lately the main dash board would start the air conditioner automatically when the car takes a turn. the delaership said its probably a loose connection. then the battery went dead. AAA jump started the battery and car was fine. the dealership says that the main computer needs to be replaced and costs about 1000$. is there a cheaper fix to it. car is drivable now but the automatic air conditioner startup and battery going dead worries me.
If it's still the original 12v battery, replace it. It probably hasn't recharged since boosted and likely won't hold much longer anyway. Then see if all the problems go away (they likely will) before replacing anything else. A low 12v battery causes the computers to act stupid and various odd electrical problems manifest themselves.
Thank you very much. You put some life into my troubled soul. I havent opened anything on the dash board, but is it a regular 12V? any procedures/care?
There are very few 12V that will fit. The easiest and possibly the cheapest is to get one from a Toyota dealer. It pays to call around. The other option is an Optima deep cycle battery, which is a superior product but requires some mechanical work to change the terminals. You can buy a battery and terminal adapter kit from elearnaid.com -- they are in Sylmar. The battery sits in the back passenger side corner of the car, next to the spare tire well, and as such cannot be your typical flooded 12V lead acid battery.
The Optima battery w/kit in question is at Toyota Prius 12 Volt Auxiliary Battery with install kit for 2004 - 10. I did it myself recently. Replacing it with an OEM battery from Toyota would be easier though. The Optima battery won't save you any money though, although there are claims that it's a superior battery.
I agree that you should replace the 12V battery first. Regarding the air conditioner starting by itself, I am wondering whether fixing that is worth $1K to you. I would prefer to keep the $1K in the bank and press the A/C button from time to time, but that's just me.
Dealer testers are too-often wrong about Prius batteries. You can easily test the battery yourself this way: http://priuschat.com/forums/newbie-forum/73400-weird-stuff-happening-mpgs-dropping-test-battery.html If the battery is bad replace it. Then get a new dealer; a dealer that can't diagnose a bad battery and instead wants to sell you a $1000 computer is not worth spit.
