AC is dead

I have been reading all the threads I can about this particular problem. It seems it can get expensive in a hurry!! Luckily I have 2 prius and can do an apples to apples comparison's. From comparing them I know that the compressor is not turning on for the 2005 that the AC is not working on. It was cooling fine the day before. Then today when I started the car, no cool air so I do not think it is a gradual leak. I will check the pressure of both cars to confirm though tonight. Also looking at the condenser there does not look to be any rock damage. I ran the AC self diagnostics and here is were the questions start? In several threads it is stated that a DTC error will be read out if any of the tests show a fault. From what I have read it appears that I will need a newer OBDII reader to see the AC error codes if there are any present? If this is true what reader would you recommend? They all say they read the legistrated ODBII codes but I am sure I will need one that can interpret the AC amplifier error codes. I have also checked the AC/HTR fuse under the dash and it is good. I should also like to point out that the radiator fan does not come on either when either of the AC buttons are pressed. This makes me think that it is probably something holding off the whole AC systen rather than the 206V AC inverter not providing juice. Any advice would be appreciated.

thanks

 

Update on this:

Both of the Prius have the same pressure readings so its probably not refigerant low. I jumped across pressure sensor and still no compressor turning on. Running the on board AC diagnostics I get a difference between the working Prius and the no AC one. For the working one I just get a 12 then a 21 when it steps through the Sensor check. On the no AC one I get 00, 21, 64, 73, and 11. Does anybody know if this is trying to tell me something? I have the list of DTC codes and I don't really see how these correlate to any of the supposed DTC AC failure codes. BTW the working one is an 04 and the broken one is an 05. Any info would be appreciated. Also it appears that Autointegrity may support AC code extraction. ScanguageII emailed me that they do not support anything past the standard ODB11 functions.
thanks[/QUOTE]

 

Sorry, I should have elaborated. Everything is working except that I get no cold air. I have compared the operations of the working car versus the broken one and have concluded that the compressor is definitely not being turned on. I have a manual (I think from the tech info on the Toyota site) on the AC system and it would appear that I will need to measure the resitance of either the compressor connector or the A/C inverter. My conclusion to this is from looking in the manual at the possible DTC codes and seeing which ones could cause the compressor to not start. Of course if I had a reader that could access the DTC's from the hybrid side and thus the AC ecu I would have a better chance of quickly finding the issue. Has anybody had either the compressor or the PSU replaced because of no cold air?

 

Vertex, Having had a chance to look at the AC documentation I have, I see that the listing below is from the Problem symptoms table on page AC-28. The AC- numbers listed in this table are incorrect for were the actual debug is located. Apart from that the AC chapter is very informative. I am still trying to see if the autointegrity software will list AC DTC's so that I can possibly use the debug flow listed in the AC manual to pinpoint the problem.

I will keep updating this as I make progress.

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Vertex,
Thank-you for checking this. I may now have to seriouly think about getting the Autoenginuity scanner. I also have a Lexus that is supposedly able to be read as well.

Thanks.