A/c Issue / Diagnosis Help

[tjmc11]

Today my a/c light began to blink (did not run through water which is a common cause). The A/C then suddenly quit cooling. This happened suddenly. I hooked it up to my A/C machine and tested the vaccuum which held fine. It had 1.50 lbs of freon in it. Which to my knowledge is close to the correct amount (1.54 I think is reccomended).

Other info: The Clutch engages for about 2 - 3 seconds and then kicks out / off.

Does anyone have any ideas of what this could be. Is my compressor going out or is this a possible over-heating clutch relay going bad? Or possibly a switch/control issue? Please advise.....any help is graetly appreciated.

[blk_on_blk]

Your "A/C machine"?? What's that? Is that like a professional A/C machine where you can check pressures on the high and low side of the system? If you can, then you can check to see if you might have a blockage. We had a blockage and our A/C just stopped working. That meant a replacement of the compressor, drier, condensor, and expansion valve.

It could also be that your cabin filter is clogged. If you don't get enough airflow through the ventalation system, it will shut itself off (or so I've read).

There is also a discussion of a bad A/C relay on the ES models. Since the RX shares so much with the ES, it might be the problem. They have an upgrade A/C relay that is the replacement.

It could also just be a stuck expansion valve, which always seem to go out at some point.

[blueridge]

Push and hold the AUTO button and the Recirculation button at the same time for 5 seconds. Place the key in the ignition while holding the buttons down. Turn ignition so ON and release the buttons. On your display screen you will see numbers flashing, they will cycle through and repeat. Post those numbers you see, hit the Recirculation button again and the AC system will run through a diagnostic test. Hit the OFF button to cancel everything out.

[blueridge]

More info on the test:

SELF-DIAGNOSTICS

An Electronic Control Unit (ECU) within A/C-heater control

panel monitors system circuits and stores trouble codes in memory if

problems are detected. All codes, except Codes 22 and 23, are stored

in memory. Malfunction is current if Code 22 or 23 is displayed. To

retrieve stored codes, see RETRIEVING CODES. Codes are displayed at

temperature display. See Fig. 2.

RETRIEVING CODES

1) Simultaneously press and hold AUTO and recirculated air

switches. See Fig. 2. Turn ignition on. All indicators will flash 4

times, at one-second intervals. Tone will sound when indicators flash.

2) A/C system will enter self-diagnostic mode. To end

indicator check, press and release OFF switch. Read codes at

temperature display.

3) If trouble code is displayed, proceed to appropriate

trouble shooting procedure. See DIAGNOSTIC CODE IDENTIFICATION table.

Codes are displayed in ascending order. To slow rate at which codes

are displayed, press fresh air button to change display to step

operation. Each time fresh air button is pressed, display changes by

one step.

4) If tone sounds as code is displayed, problem currently

exists. If tone does not sound as code is displayed, problem occurred

in past and does not presently exist.

Code Diagnosis

00 ...............Normal

11 (1) ..........In-Vehicle Temperature Sensor Circuit

12 (2) ..........Ambient Temperature Sensor Circuit

13 ...............Evaporator Temperature Sensor Circuit

14 ...............Coolant Temperature Sensor Circuit

21 (3) ..........Solar Sensor Circuit

22 (4) ..........Compressor Lock Sensor Circuit

23 (4) ..........Pressure Switch Circuit

31 ...............Air Mix Door Position Sensor Circuit

32 ...............Air Inlet Door Position Sensor Circuit

33 ...............Air Outlet Door Position Sensor Circuit

41 ...............Air Mix Door Servomotor Circuit

42 ...............Air Inlet Door Servomotor Circuit

43 ...............Air Outlet Door Servomotor Circuit

(1) - If in-vehicle temperature is -4 F (-20 C) or less,

Code 11 may set even though system is normal.

(2) - If outside air temperature is -58 F (-50 C) or less,

Code 12 may occur set though system is normal.

(3) - If testing is done in a dark area, Code 21 may set

even though system is normal. Shine a light at solar

sensor and recheck codes.

(4) - Malfunction is current. Code is not stored in memory.

ACTUATOR CHECK

1) Perform step 1) of RETRIEVING CODES. When system enters

self-diagnostic mode, press recirculated air button. Each mode door,

motor, and relay will operate at one-second intervals. Press fresh air

button to display codes one at a time, and perform step-by-step

actuator check.

2) Check airflow and temperature by hand. Tone will sound

each time display code changes. Each display code is associated with a

system operating condition. Press OFF button to

cancel actuator check mode.

[tjmc11]

Push and hold the AUTO button and the Recirculation button at the same time for 5 seconds. Place the key in the ignition while holding the buttons down. Turn ignition so ON and release the buttons. On your display screen you will see numbers flashing, they will cycle through and repeat. Post those numbers you see, hit the Recirculation button again and the AC system will run through a diagnostic test. Hit the OFF button to cancel everything out.

The code I received was 00. This tells me that there was no issue with the pressure/temp/ vent position/ cabin temp sensors. I am afraid I have a compressor issue. Purchased a compressor and will be installing it today.

[tjmc11]

Update: Tested all sensors and they were fine. Clutch relay was fine as well. Replaced compressor and got cold air blowing again.

[Gibbie]

I've encountered the same problem (flashing AC indicator on climate screen) a couple times. Turning off the AC and then back on has resolved the problem in both cases. I had Lexus service check but they couldn't find any problems. I'll check the codes next time it occurs. This is on a 2005 RX.

Both times were at initial startup in the morning. Ambient temperature was in the upper 70's F.

[cyberdiver]

I'm having similar issues with my 03 ES. I ran this diagnostic and it is alternating "21" "24". I don't see a 24 listed?

[tjmc11]

Update: Tested all sensors and they were fine. Clutch relay was fine as well. Replaced compressor and got cold air blowing again.

You may have an expansion valve issue OR your belts could be slipping due to water or looseness of the belt. IF your a/c works and then begins to blow warmer air, BUT AFTER you turn the a/c off for a while it begins to work again, it is more likely the expansion valve.

If it suddenly blinks and you turn it off and on again and it works, I would bet it is an issue with belt slippage or looseness OR a clutch relay issue.

[tjmc11]

I've encountered the same problem (flashing AC indicator on climate screen) a couple times. Turning off the AC and then back on has resolved the problem in both cases. I had Lexus service check but they couldn't find any problems. I'll check the codes next time it occurs. This is on a 2005 RX.

Both times were at initial startup in the morning. Ambient temperature was in the upper 70's F.

[/quote/]

You may have a compressor issue. Have someone start the engine with the A/C off. Look at the a/c compressor and clutch assembly. Havesomeone turnt he a/c on and see if the clutch engages. IF the clutch does not engage, I would first guess yoru compressor is locked up.

Please post your results once you do this.

[tjmc11]

I'm having similar issues with my 03 ES. I ran this diagnostic and it is alternating "21" "24". I don't see a 24 listed?

You may have a compressor issue. Have someone start the engine with the A/C off. Look at the a/c compressor and clutch assembly. Havesomeone turnt he a/c on and see if the clutch engages. IF the clutch does not engage, I would first guess yoru compressor is locked up.

Please post your results once you do this.

[david panama]

OK. SORRY FOR THE BAD ENGLISH. THE SAME HAPPENS TO ME. I NOTICED THAT THE AC CONTROL BLINKS WHEN THE COOLING TEMP SELECTED BY USER IS HIGHER THAN THE EXTERIOR TEMP. JUST SELECT A LOWER COOLING TEMP AND PUSH THE BLINKING AC BUTTON AGAIN.O OFF AND ON AGAIN. IT WILL STOP TO BLINK AND COOL AGAIN.

IF IT DOES NOT FUNCTION, YOUR COOLING SISTEM MIGHT BE FROZEN. WAIT A WHILE UNTIL THE TUBES DEFROZE.

[soda]

Having troubles with a/c as well. No power to a/c compressor and lcd display is burnt out. Where's the first spot to trubleshoot appreciate any input.

[Tana]

21,33,41,43 are the codes that popped up for mine... now what?