Hello everyone, The AC for 2010 Prius has been experiencing the following. This seems odd, not logical: • On normal days (70's-80's, warm days) AC seems to be fine. Not freezing, but you can feel cold air. • On hot days (85+) the AC air seems tepid, not all that cold. You can feel it, a bit, but not really. • On any day, the air for the driver is colder than passenger. • AC seems to make a louder pitch engine sound when AC is running. Turn AC off, sound goes away. ---- • Temp coolant was recently replaced (unrelated) ~ symptoms the same before and after. We have a 2012 Prius, and the AC will dang near cause frostbite. So curious now what is happening w/the AC of our beloved 2010.
I have experienced the same issues with my 2011 since about 130K. The system was evac’ed and recharged by the dealer with minimal improvement. I suspect a failing compressor. Due to cost (and also, lack of time), I have not addressed the issue.
If the compressor is the issue, what do you expect those to run? --- For DIY'ers out there, can this be a part pulled from a yard and self installed? What would these generally run?
My compressor seized in August 2015 at 81K miles and was replaced by my Toyota dealer service guys for $1383.75. My service writer was able to track down a used compressor from a 2013 wreck which cost $650. It has worked just fine, in Arizona heat, ever since. There is a self test of the HVAC system you can run. The keystrokes for this test are start from ACC mode (power on without brake), hold down AUTO and Recirculate/Fresh Air buttons, and press START again. Should see A/C LCD and all LED lights blink 4 times at 1 second interval followed by a code displayed where the preset temperature (digits on left side of LCD) are normally displayed. A 00 code means no problems. Then press OFF to escape. If it says there is an A/C Inverter Load System Malfunction (code 76), this can be caused by a refrigerant leak or overfill, a problem in the condenser fan circuit, or lastly a compressor lock. There are codes for other conditions in the maintenance manual which you might find in various other air conditioner threads.
Looked it up, which always takes some time. If you haven't used any Toyota Maintenance Manuals before, they are rather difficult. Anyway, code 43 is listed in the DTC column as code B1443/43, the next column over is Detection Item where it lists Air Outlet Damper Control Servo Motor Circuit, then it lists Trouble Area where we have three entries: 1. Air outlet control servo motor 2. Air conditioning harness 3. A/C amplifier So, the assumption is the problem for that code could be any of these three items. Later on in the manual there are four pages with a wiring diagram and inspection procedures for that code. The first thing to check is for a mechanical malfunction, and I'll quote the instruction: The air outlet control servo motor sends pulse signals to indicate the damper position to the A/C amplifier. The A/C amplifier activates the motor (normal or reverse) based on these signals to move the mode damper to any position, which controls the air outlet switching. The A/C amplifier communicates with the servo through a communication/driver IC and wiring assembly called the air conditioning harness. HINT: Confirm that no mechanical problem is present because this DTC can be stored when either a damper link or the damper is mechanically locked. So I would check that first, if you know where it is. I have not dug into my dashboard much, and can't really direct you further, but you can see quite a few mechanical links and wiring if you remove the lower glove compartment drawer. The remainder of the diagnostic is through using the Techstream computer. Good luck!
