Hey all, Thanks in advance for any help you guys give and I apologize if I missed the thread, if it's out there, that may have the answer to my questions. I bought a gen 2 recently and the a/c was shot. Damaged condenser and fried compressor. I took the car to a shop that works on prius's and they fixed it all up. New compressor, condenser, whole system flush, the works. A week later I took the car out in the morning. A/c worked fine. Later that day (a very hot day to boot), after the car had been sitting for a few hours I went out again, but this time the a/c blew hot air. I don't think the compressor came on, but I don't quite remember. Since I was in the car already, I decided to take it back to the mechanic who worked on it. When I parked there, I decided to turn the car off and on again to see if the compressor would come on. This time it did and it blew cold! The mechanic told me he could look at it tomorrow so I took off. So far, it's done it about three times and all I had to do was turn the car off and on again. I checked the a/c codes on the MFD a little later and found two: 12 and 76. I kinda went through the troubleshooting for 76 and I think it MAY be overcharged, but it's kinda hard to tell with that sight glass. 12 is a little more involved. Has anyone here had those codes? What was your experience? 12 involves the ambient room temperature sensor; if that goes bad, will the compressor not turn on? If these codes were there before the A/C was refurbished could that cause problems now? Is it possible that clearing them would fix this? Last, but not least, how DO you clear A/C codes? Thanks guys!
Are you sure it was 12 and not 21? Also, when the charge was done did s/he add the specific weight of R134a refrigerant?
Thanks for your reply! Yeah, it was 12. 21 came up later this evening when I checked again, but I'm guessing that's because it got dark right? Between the time I wrote the OP and now, I managed to get my mini vci up and running. What a PITA! Anyway, I hooked it up and ran the code checks on the a/c system. It was already dark so it showed 21 as current and the other two, 12 & 76, as history. I wonder if the codes were there from when the system was jacked up before. I assume they added the right amount, but I guess I shouldn't, huh? Lol. Since I got connected to the car through Techstream, I went ahead and cleared the DTC's in the A/C system. Maybe that'll clear up any issues. I was thinking I'd wait and see. Do you think I should take it back to them anyway? It's got a 3 year warranty after all.
If you used Techstream, the codes should be in Annnn format where A = B, C, P, or U. n can be any digit 1 -9, or letters A - F as nnnn represents a hexadecimal number. Are you sure the 12 code was on the A/C screen or was it blinked out on one of the lights on the dash. A/C shortcodes are not very well or completely detailed in the repair manual so the full Techstream DTC is preferable.
I checked the codes the manual way initially. Using the steering wheel buttons. The two alternately flashing numbers on the top right of the mfd were 12 and 76. That's when I wrote the OP. Sometime after I wrote the post, I got Techstream working and got the same 2 codes plus the 21, but by that time it had gotten dark. 21 is normal when it's dark outside right? Yeah, in Techstream they were four digit numbers plus a preceeding letter.
Yes, you are correct. That's what it means and is nothing to worry about. So, do you have the full codes from Techstream, then?
Not all of the systems in the car have a simple correspondence between the two-digit codes and DTCs, but AFAIK the HVAC codes do line up nicely: code xx shown on the MFD corresponds to B14xx as a DTC. Also, you don't face the possibility of getting the digits swapped because you're not reading blink codes, just a number of the MFD (or off the LCD control display in a Gen 3). So B1412 is about the ambient temperature sensor (not the room temperature sensor; that would be B1411). There is a copy-pasto in the summary table of codes (where for B1412 it says "ambient temperature sensor" for the detection item but "room temperature sensor" in the trouble-item column, copied from the row before). The actual workup pages for B1412 don't have that mistake. The ambient sensor isn't inside the cabin, it's out behind the front bumper, ahead of the condenser. It is connected to the engine controller (ECM), not to the HVAC controller; the ECM reads it and sends data to the HVAC controller. B1476 involves the electrical load of the compressor turning out to be greater or smaller than expected, which could implicate refrigerant volume, compressor mechanicals, or the effectiveness of condenser cooling.
Thanks Chapman. The 12 code hasn't come back since I cleared the codes, but 76 has. I took it back to the mechanic who "fixed" the a/c and they're telling me there are codes pointing to a bad inverter. There weren't any when I checked. I think they're trying to screw me out of a thousand bucks. I'm not sure how to approach this. At the least I'm going to the shop tomorrow with Techstream to check the codes myself. From what I've seen in the repair manual, code 76 isn't related to the inverter at all, like you said in your comment.
Also, I just remembered that only one fan came on when I turned the ac on. I wanted to see if both would, but only one did. Hmmm. This is when it was working. Now it doesn't work at all.
Hey guys, Been a while, but I have some news. I ended up going to another shop to fix the a/c. They told me the compressor used by the original shop was a dud. They replaced it and now it seems to be working fine. I do have a question or two though. Which fan is the radiator fan and which is the condenser fan? The only one that runs when I have the a/c on is the drivers side fan. Both the CDS and RDI fuses are good. I have never seen the passenger side fan turn on since I've got the car. Thanks again guys.
Your ac is still messed up. Both fans should run when engine reaches op temp.. The passenger side fan should run at high speed the ac is tuned on. Its a screamer. Like just about every other car out there. My guess is you have low refrigerant. There's a refrigerant level sensor in the passengers side of the condenser. It detects frig level low frig no high speed fan. Whoever is working on your ac doesn't know jack about it. Let me see if i can find the last post about this nonsense.
Ok, Just took a look at the fans. I made a boo boo when I installed them lol. I just discovered that I didn't fully insert the harness for the passenger side fan. All is working fine now. Omgsh I'm so happy. Thanks for your responses guys. I really appreciate your help!
The drivers side seemed to be turning faster than the passenger side one after I plugged in the harness. Before that, just the drivers side fan was running. I'll check the link you posted.
Anybody looking at the wiring diagram can plainly see that it is not possible for one fan to be on high speed and the other one on low. Low speed is achieved by making a series circuit through both fans. Either they are both on low, or neither is. As for high speed, it is possible to have one fan on high while the other could be off (but not on low speed). That is not part of the documented control strategy, but it physically can happen. As for the terms "radiator fan" and "condenser fan", I advise just not using those terms. They may have some basis in Toyota design history, but in this car they are side by side, equally behind both the condenser and the radiator, and the distinction is more likely to increase confusion than to decrease it. What I'd recommend is just saying "the one with the blue wire" or "the one with the green wire" because that's something you can see under the hood just by looking, and it clearly identifies which fan is which in the wiring diagram. Sometimes when both wires are old and road-crusty, you'll need to take a wet rag to both of them before you decide which one is bluer and which one is greener.
