A/C system diagnostics- Need codes.
10-10-20, 04:42 PM
#62
Driver School Candidate
I was having trouble at first too. Make sure that you press the RECIRCULATION button and AUTO button, THEN turn the ignition to ON. The original post is a little confusing as to the order in which you are suppose to do the setps. Here are the full instructions:
TROUBLE SHOOTING
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. See Fig. 3 or 4. Press OFF button to
cancel actuator check mode.
TROUBLE SHOOTING
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. See Fig. 3 or 4. Press OFF button to
cancel actuator check mode.
Thanks
10-11-20, 12:14 AM
#63
So i got code 41. If i replace the AIR MIX DOOR POSITION SENSOR OR “THE SERVO”, my problem with the delay of my ac turning on would fix the problem?? Cause my ac on my 2011 LS460 would turn on 30-45 seconds after i start the car and my temp setting would not save the previous temp it goes back to 75 degress.
Thanks
Thanks
With these older A/C Air Mix Door servo units there is the option of replacing with a known good used unit (if no new ones are still available) and there is also a procedure out there pioneered on a GS300 that shows how to carefully recondition one of these servos.
10-11-20, 03:38 AM
#64
Driver School Candidate
Kingrb18, is this in reference to an A/C Error Code 41 for your SC300 or SC400 or are you asking in reference to a 2011 LS460? This thread is specific to SC300/400's.
With these older A/C Air Mix Door servo units there is the option of replacing with a known good used unit (if no new ones are still available) and there is also a procedure out there pioneered on a GS300 that shows how to carefully recondition one of these servos.
With these older A/C Air Mix Door servo units there is the option of replacing with a known good used unit (if no new ones are still available) and there is also a procedure out there pioneered on a GS300 that shows how to carefully recondition one of these servos.
Oh its for my LS460. Do you think this might be the same?
Thanks
10-11-20, 07:47 PM
#65
No, the system, model specific A/C component designs and climate control unit will all be completely different between a 1992-2000 SC300/400 and a 2011 LS460.
Only the general theory of how a common car A/C system is designed will be a commonality. Even then an SC uses a thermal expansion valve setup on its evaporator which is old technology that was not manufactured with a much newer LS460.
The LS460 has multi-zone climate control with a different number and design to each servo unit behind the dash. A 92-00 SC has three servos behind the dash and a single zone climate control computer.
The error codes *may* be similar between Toyota/Lexus models of the SC’s vintage and your 2011 however.
The good news is that if one of your A/C servos actually is bad it will still be available as a new replacement part from Lexus.
I suggest posting the same question again in the LS460 sub-forum where there is much more familiarity with your specific model to help diagnose your issue.
Only the general theory of how a common car A/C system is designed will be a commonality. Even then an SC uses a thermal expansion valve setup on its evaporator which is old technology that was not manufactured with a much newer LS460.
The LS460 has multi-zone climate control with a different number and design to each servo unit behind the dash. A 92-00 SC has three servos behind the dash and a single zone climate control computer.
The error codes *may* be similar between Toyota/Lexus models of the SC’s vintage and your 2011 however.
The good news is that if one of your A/C servos actually is bad it will still be available as a new replacement part from Lexus.
I suggest posting the same question again in the LS460 sub-forum where there is much more familiarity with your specific model to help diagnose your issue.
Last edited by KahnBB6; 10-14-20 at 02:13 AM.
10-13-20, 07:17 AM
#66
Driver School Candidate
No, the system, model specific A/C component designs and climate control unit will all be completely different between a 1992-2000 SC300/400 and a 2011 LS460.
Only the general theory of how a common car A/C system is design will be a commonality. Even then an SC uses a thermal expansion valve setup on its evaporator which is old technology that was not manufactured with a much newer LS460.
The LS460 has multi-zone climate control with a different number and design to each servo unit behing the dash. A 92-00 SC has three servos behind the dash and a single zone climate control computer.
The error codes *may* be similar between Toyota/Lexus models of the SC’s vintage and your 2011 however.
The good news is that if one of your A/C servos actually is bad it will still be available as a new replacement part from Lexus.
I suggest posting the same question again in the LS460 sub-forum where there is much more familiarity with your specific model to help diagnose your issue.
Only the general theory of how a common car A/C system is design will be a commonality. Even then an SC uses a thermal expansion valve setup on its evaporator which is old technology that was not manufactured with a much newer LS460.
The LS460 has multi-zone climate control with a different number and design to each servo unit behing the dash. A 92-00 SC has three servos behind the dash and a single zone climate control computer.
The error codes *may* be similar between Toyota/Lexus models of the SC’s vintage and your 2011 however.
The good news is that if one of your A/C servos actually is bad it will still be available as a new replacement part from Lexus.
I suggest posting the same question again in the LS460 sub-forum where there is much more familiarity with your specific model to help diagnose your issue.
Thank you so much Kahn. Im new in the forum and i dont see a detailed post like yours with for LS’s.
10-14-20, 02:24 AM
#67
Thus the A/C controller and A/C dash servos in 92-00 SC's are very electrically simple designs compared to what you have in your LS460.
Again, I do not know how much the old 90's Toyota/Lexus A/C trouble codes line up with an LS460's trouble codes. What I'd guess is that an LS460 may use many of the same codes but have even more of them since it's a dual zone climate system. I'm not sure honestly but apart from the forums there is one other resource that can help:
Get a 2-3 day account for the Toyota/Lexus TIS (Total Information System) website and you can access pretty much any U.S. spec model Toyota or Lexus ever sold and download the factory technical service manual pages for any sections that you will need to review for your model, make and year. It's only a few bucks and if you can get access to the same service manual pages that the technicians have, including the official troubleshooting order for all of the car's systems... such as the A/C system.
Again, I'd still urge you to direct LS460 related questions into the appropriate model sub-forum because it's not something we're as familiar with here in the 1st gen SC section but I hope this helps a little bit!
Last edited by KahnBB6; 10-14-20 at 02:30 AM.
10-26-20, 01:41 PM
#68
Driver School Candidate
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Does anyone know if there’s is a self diagnostic feature for a 2008 is250 with navigation? My motor blower is not turning on and was replaced and still not working, worked prior to going out. Fuses and relay have been changed.
05-22-22, 12:20 PM
#70
Driver School Candidate
Time to resurrect this thread again it’s summer time and my ac is being odd. CODES 21 and 43
Looking into the thread it seems code 43 really doesn’t matter because i can still change the location of where the ac blows. Although i must say when i put it in the face position or any other it will only blow in bi direction (face and foot).
The ac never really blew cold just air. I checked freon levels and it’s in the green. Now when i turn on the ac button the ac button blinks (that’s why i’m here) and when first turning on the ac it will blow icebergs for 1-3 seconds the rpms will drop anywhere between 900-400 and the sc compressor will make a odd metal on metal sound (hard to explain) Previously in the winter the ac blew hot air but i never pressed the ac button only the level of air being put out.
Before all this happened i’ve pressed the ac button the compressor would kick up but no icebergs only ambient air going into the cabin.
Edit: i would like to mention i just changed my throttle body gasket and valve cover gaskets. Although this shouldn’t have any sense in the coldness but possibly the new “metal on metal” like symptom that has just arised.
Looking into the thread it seems code 43 really doesn’t matter because i can still change the location of where the ac blows. Although i must say when i put it in the face position or any other it will only blow in bi direction (face and foot).
The ac never really blew cold just air. I checked freon levels and it’s in the green. Now when i turn on the ac button the ac button blinks (that’s why i’m here) and when first turning on the ac it will blow icebergs for 1-3 seconds the rpms will drop anywhere between 900-400 and the sc compressor will make a odd metal on metal sound (hard to explain) Previously in the winter the ac blew hot air but i never pressed the ac button only the level of air being put out.
Before all this happened i’ve pressed the ac button the compressor would kick up but no icebergs only ambient air going into the cabin.
Edit: i would like to mention i just changed my throttle body gasket and valve cover gaskets. Although this shouldn’t have any sense in the coldness but possibly the new “metal on metal” like symptom that has just arised.
Last edited by jadesc4; 05-22-22 at 03:14 PM.
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