This car has been stored for a while, and we recently had the main battery replaced. Everything works fine now except one thing: The MAX button, next to the A/C button on the dash used to cause the gas engine to run to run the compressor, but now, nothing happens. Any suggestions for the reasonably compentent home mechanic?
The AC and MAX buttons won't work unless the rotary dial is set to Auto or something other than off. The MAX button won't turn green unless the AC button is green also. Is that how you tried it?
No, the AC does not come on at all. It used to. In fact when the engine is warm the Prius will turn off the gas engine (provided the hybrid battery is charged up), and you could force the gas engine to start by pressing the AC button and then the MAX button to force the gas engine to turn the compressor. But now: even with both buttons press AC green and MAX green, the gas engine stays off. Does anyone know under that conditions the green LEDs turn on (i.e. does that indicate that the computer has seen the button pushed? Now, this car had been stored for a while, and it wouldn't surprise me if there is a connection not being made between the button and the computer that tells the system to turn on the gas engine to run the compressor..... Have have checked all the easy stuff like the fuses and the relays that would pretain to the AC system.... Im still very open to suggestions here.
If you want to fix the problem yourself you are probably going to have to examine the wiring, and I suggest you subscribe to techinfo.toyota.com so you can obtain the electrical wiring diagram for your model year and see how the system is supposed to work.
+1. Many useful things on techinfo. You'll also be able to find diagnostic decision trees for the heat/AC in volume 1, and disassembly for the center panel in volume 2. Perhaps you have something as simple as oxidized connections from the button board to the hvac "amplifier" (quaint old name for what's now just another ECU). It would be the first I've heard of it happening, but I've just had to deal with such a problem on another vehicle I've had sitting for some years. Checking that would require removing your center finish panel, which could be very brittle by now and at risk of breakage, so if I were you I'd look at any other diagnostic avenues in the manual before getting the tools out. If you do need to get to the pushbuttons, it's not hard, just sort of tedious. They are about the last things left on the center panel once you have removed the rest of the car. (The silver lining is if you happen to bust the panel, it will be very little additional work to transfer everything to a new one.) -Chap
There was a great drawing entitled "The Exploded Beetle" Exploded Bug by Peter Aschwanden in the classic "The VW Idiot Book". It came to mind when I read Chap's sentence "They are about the last things left on the center panel once you have removed the rest of the car."" I thought of a GEN1 instead of a BUG! Read more: http://priuschat.com/threads/my-2002-prius.128503/#ixzz2YxENPocV Follow us: @PriusChat on Twitter | PriusChat on Facebookthat was of a beetle all taken apart with the all the parts laid out on the floor
