Hi, Sorry it took so long for me to get back to you! I changed the Expansion Valve and the Compressor still didn't turn on. After researching the problem so more I found someone who had a Lexus who had the same problem and also got the B1479 code. Toyota has a TSB about it T-SB-0084-13. The Flow sensor has to have 3.8v with the AC OFF in order to have the amplifier tell the compressor to kick in! (mine was 3.59v) Toyota recommend changing the compressor because they don't sell the Flow sensor! I was able to find the Sensor on ebay for $50 and decided to try and change it myself!
I had to take off the front bumper, ac condenser(replaced drier) and radiator to get easy access to the Flow sensor on the compressor ( you may be able get to the sensor by just taking out the radiator) . I took the snap ring off the sensor and tried to lift up the sensor but it was frozen and broke off when I pulled up on it. I had to use a chisel to get the rest of it out. I noticed there was a lot of what looked like white rust or corrosion there so I scrapped out what I could and sanded it down so the new one would seat properly ! ( maybe The white rust was making the sensor not read correctly?). I got the new one in and put the snap ring on and then I checked it with Techstream and got a reading of 3.86v.(above the 3.8v min needed)! My old one was 3.59v!
I put everything back together and charged the system and the AC works now. A lot of work for such a simple part! I read the problem is with many Toyota models and years starting in 2009! Crazy how they let the problem last so long without addressing it and making people pay for a new compressor!
I just thought I would let you know in case someone else runs into the same problem!
Here's a couple of pictures of the before and after Techstream Flow sensor readings!
Images (Click to enlarge)
Thursday, July 26th, 2018 AT 7:59 AM