2006 Prius - AC Not Working Suddenly

2006 Prius with 254k. No previous AC issues AFAIK. I have owned my Gen2 for 2 years and 54k miles. AC has always been ice cold until yesterday. I took a look this morning and had the following observations:
1. Sight glass shows no flow in it;
2. High pressure charging port with Schraeder valve has pressure when I depress schraeder valve momentarily.
3. Turned AC onto coldest temp and high fan (in manual setting). I then heard fan (number unknown) spinning (unable to determine air flow direction) until I remove plastic panel at front of engine bay. I disconnected the AC pressure switch adjacent to the sight glass. When pressure switch was disconnected, the fans turned off. However, when pressure switch was disconnected/reconnected I did not hear a clutch engaging sound from the compressor.
4. I tried to obtain AC codes a number of times. I pressed and held "A/C AUTO" button and "Recirculate" button on steering wheel while car was off then pressed start button twice with foot off brake pedal. Also tried same routine with foot on brake pedal and one push of start button. Codes never came up.

Any assistance would be greatly appreciated.

 

I just got back from a drive in my Gen2. I tried using the Recirculation button on the steering wheel with fan on low, medium and high. Also, tried using Recirculation button with, and without, AC on. My best guess is that clock spring is bad. Thereby, preventing Recirculation button from working. Which in turn is preventing me from obtaining AC codes.

Before today, I never used the Recirculation button on the steering wheel.

 

Only fault code found was P0420 O2 sensor ( which had been on for several months). Therefore, the P0420 is unlikely to be related to the AC blowing warm.

 

Yesterday, when AC prroblem began I checked the temperature (F) of: i.) MG1 INV TEMP; and ii.) MG2 INV TEMP. My high temp yesterday for MG1 INV YEMP was about 138F. And, MG2 INV TEMP had a high of about 132F. Finally, engine coolant temp was in the range of 183F to 187F yesterday (after watm-up).

I used my Torque Pro with custom Gen2 PIDs to get these readings (described above).

 

Onto AC fuses and removing black panel at front of engine bay: later today.

 

According to my Toyota wiring manual (referenced in item "c") there are five ("5") fuses associated with the AC system as follows:

a. Dome 15A: BAT (based on p.447-8 of owner's manual) is fuse 39 in engine compartment fusebox;

b. Gauges 10A: IGN (based on p.447-8 of owner's manual) is fuse 8 in IP fusebox;

c. BAT 40A This fuse appears to be adjacent to HV battery. As a result, fast test should be BAT supply at relay7 in engine compartment. See p.22 of book entitled "TOYOTA PRIUS ELECTRICAL WIRING DIAGRAM 2006 MODEL" published by Toyota with ID: EM01R0U;

d. AC (HTR) 10A: IGN (based on p.447-8 of owner's manual) is fuse 17 in IP fusebox); and

e. CHS W/P 10A: BAT (based on p.447-8 of owner's manual) is fuse 44 in engine compartment fusebox.

Let me know if I missed any.

Edited to add: three ("3") pictures from pages 350-1 of "TOYOTA PRIUS ELECTRICAL WIRING DIAGRAM 2006 MODEL" referenced above in "c."

 

I am attempting to get my v13.00.022 of Techstream up and running again. Apparently, the original key expired. I separately posted a request for assistance regarding a new key for v13.00.22. Hopefully, I can get this cleaned up and read the AC codes.

BAD (original) key: 1111111111111111111111111111111150001511111111

Link to PC request for help with v13.00.022 key: Techstream 13.00.22 Key Needed | PriusChat

 

Techstream v13.00.022 is up and running. I found the following codes in the AC section of TS:

a. 1421 (current) -solar sensor circuit passenger side;
b. 1423 (current) Open in Pressure Sensor Circuit; and
c. 1433 (history) Air Outlet Damper Position Sensor Circuit.

 

Anyone have a part number for the AC pressure switch?

 

AC pressure switch has four wires. My chart for AC only shows two of the four wires as follows: pin1: red wire - power in; and pin4: white with black tracer which provides ground. My understanding is that pin 1 and pin 4 are connected by the pressyre switch when pressure is in normal range.

 

Sounds like I need to do the following:

1. finish testing fuses applicable to AC system (so far "DOME" and "GAUGES" fuses have been inspected and found to be good);
2. test for voltage at pin4 of AC pressure sensor with AC turned on;
3. test for ground at pin1 of AC pressure sensor;
4. purchase new R134a AC manifold (so as to not contaminate the Prius system); and
5. test for pressure on both high and low sides of Prius AC system using new R134a manifold.

 

Tested pin4 (red wire) of the AC pressure switch with AC "on" with fan at maximum and vehicle in READY mode. Test was done with a test light. Result is no power at pin4. I will do test again with multimeter and also test ground circuit of pin1 (white with black tracer).. According to wiring diagram the red conductor travels to a connector identified as IA2 which connects engine harness to the interior harness. After connector IA2, wire color changes to green and travels to a junction block 5B/5J and then onto the AC Control Assembly.

 

Ordered brand new gauges and manifold to be exclusively used on the Prius. They should here in three or four days. Upon receipt of new gauges/manifold, I will provide pressure readings.