QuestionQUESTION: I have a 2000 300M that was brought to me for non functioning AC. The system had been serviced for a leak and recharged by another mechanic and ran for 2 days before failing. When I checked it, I noticed the display is blank but the temperature and fan appear to be working and you do get a confirmation beep when you push the other buttons. All fuses in the main panel have been checked and are good. Is there anything else I can check with regards to the climate control panel without substituting? I read on a previous post there is a procedure to check for climate control trouble codes but the link provided does not seem to work, could you re-post the information?
Thanks in advance.
ANSWER: need a new ac control head for the display not working.
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QUESTION: I ordered a replacement.
I read on a previous post there is a link for climate control trouble codes but the link provided does not seem to work, could you re-post the link\information?
ANSWER: it wont do u ne good if the display does not work.
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QUESTION: I understand that I can't read the code if the display/control is non-functional, I was hoping to have the information in advance so when I put the new unit in, I can check codes.
AnswerTROUBLE CODES FROM THE ATC CONTROL
The trouble codes can be checked with the ATC control if a DRBIII® scan tool is not available. The control head can only be placed into the diagnostic mode while the engine is running and the vehicle is not moving. Set the control to a 75° F setting (so there is no confusion with the 23-51 Diagnostic Trouble Codes (DTC's)
To place the system into it's diagnostic mode, press and hold the Floor, Mix and Defrost buttons (at the same time) The ATC head display will begin to blink. Release the Floor, Mix and Defrost buttons. Once the control head enters the diagnostic mode, the display on the control head will continue to blink. This occurs until it completes its tests and climate control unit door/actuator calibrations. Then it will display any diagnostic trouble codes that are present in the BCM. If there are no diagnostic trouble codes, the system will return to its normal operation as indicated by the temperature symbol (a C or a F) Diagnostic trouble codes related to the ATC and climate control unit will appear on the display in numerical form. The diagnostic trouble codes are stored in the BCM and can range between 23 and 51. The ATC control can only show one diagnostic trouble code at a time. Under certain circumstances, more than one diagnostic trouble code could be in the memory. To scroll through any additional diagnostic trouble codes, press the Panel Mode button on the ATC control. It is important that no other knob or button is pushed until all codes are read. Pushing any button except Panel Mode or turning a knob will end the diagnostic test without showing the rest of the trouble codes. There also may be other trouble codes stored in the BCM not related to the Climate Control System. These codes can only be found using the DRBIII® scan tool. Entering Self-Diagnostic Mode
ATC AND MANUAL A/C DTC's
CODE DESCRIPTION
23 BLEND DOOR ACTUATOR FEEDBACK FAILURE
24 MODE DOOR ACTUATOR FEEDBACK FAILURE
25 AMBIENT SENSOR
31 RECIRCULATION DOOR ACTUATOR STALL FAILURE
32 BLEND DOOR ACTUATOR STALL FAILURE
33 MODE DOOR ACTUATOR STALL FAILURE
35 EVAPORATOR SENSOR FAILURE
37 BLEND DOOR ACTUATOR OUTPUT SHORTED TO BATTERY
38 BLEND DOOR ACTUATOR OUTPUT SHORTED TO GROUND
39 MODE DOOR ACTUATOR OUTPUT SHORTED TO BATTERY
40 MODE DOOR ACTUATOR OUTPUT SHORTED TO GROUND
41 RECIRC DOOR ACTUATOR OUPUT SHORTED TO BATTERY
42 RECIRC DOOR ACTUATOR OUTPUT SHORTED TO GROUND
43 COMMON DOOR OUTPUT SHORTED TO BATTERY
44 COMMON DOOR OUTPUT SHORTED TO GROUND
51 SYSTEM VOLTAGE TOO LOW FOR DOOR CALIBRATION
