Mercedes W203 HVAC climate control system explained AC Clicking & Hissing Noisy AC Flaps Actuator

IMPORTANT!!! (PRESS SHOW MORE) see bellow (Especially for M2/15 left/right footwell flap stepper motor and/or lever replacement)
Mercedes W203 463 HVAC climate control system explained
• Identify the climate control system used on W203 & 463
• Locate climate control components and serviceable items
• Describe the function of climate control systems and related components
AC clicking sound issue / Noisy Air Conditioner / Stepper Motor Replacement / Clicking & Hissing
IMPORTANT!!! (Especially for M2/15 left/right footwell flap stepper motor and/or lever replacement)
If you attempt to FIX your problem(s) (replacement stepper motors/plastic parts: lever, etc.) to make your life much, much easier buy a TORX SCREWDRIVER (T20) long or regular length. You need a screwdriver NOT a bit on universal tool because of the thickness of the tool. If you can do it, magnetize the torx screwdriver tip.
Some of the tools used:
10mm socket
ratchet (preferably 3/8")
6-12" extension (for ratchet)
T35 Torx socket (3/8")
T20 torx screwdriver
plastic wedge
Some part numbers:
A2038300033 Operating Parts Kit
A2038300233 Operating Lever Right
A2038300133 Operating Lever Left
A2038300032 Linkage - Parts Kit, Footwell flaps without operating lever
A2038201642 Stepper Motor / flap positioning motor (all same)
A2308216351 Blower Regulator
Item 330 A2038202514 Electric Motor

[@Neradnik1101]

Hi, can I replace c240 with c320. Will it be just plug and play or there will be need for some programming. Is it possible to change it?

[@pepinestacion]

❤ Hello sir, I need help, first of all, excellent video, my problem in my w203 is the following, my manual air conditioning in different zones only cools at maximum low, after just increasing the heat one more degree it comes out quickly, I have changed air conditioning controls and the problem It's still the same, I can't find the fault, could you give me some help with the problem? thanks from Spain

[@Peter-it5ht]

I must complement you on the video, I have a Mercedes s211 om642 engine 2005, do you have a video for this vehicle.

[@lukeduke9304]

Thank you so much!

[@liborlepka4240]

Hello AxBone, My 2004 CLK320 is blowing cooled air on the passanger's side only. The driver's side blows warm(not cool, not hot, just warm) air (everywhere - legs, front, windshield). Hot air works fine on both sides. Could you point me to the right direction? Thanks very much.

[@lujerului]

(Minute 2:00) looks like blending flaps are malfunction (motor / linkage /flaps /etc) You can try to normalize the A/C stepper motors. Hold down the Recirc and Front windshield buttons for about 10 seconds or until they both start flashing back and forth. When they are done flashing and you have confirmed everything is working, you are done.

[@garysondreal5110]

My 2003 c320 only blows warm and hot air. On coldest setting it’s very warm air, when on hot setting it’s very hot air. I’m assuming the blend door is not functioning. Also, at times I get a hissing noise. Is this related? Also has a knocking noise when you first start up car for 20 seconds or so.

[@lujerului]

Is the AC working well? The hissing is typical of a system that is low on refrigerant. However, you should NEVER simply add refrigerant unless you know that the system is, in fact, low. If you can scan the car with a proper diagnostic tool it will tell you if you're low; it's not just codes, it shows lots of things including pressures. As far as what's required/realistic, if you are low and you've never had to add any before, then you may just have a very small leak, so adding some would be all that's needed. (Minute 2:00) looks like top and bottom cold air flaps are malfunction (more/less stuck on close) Knocking sound If is something wrong (Stepper motor/linkage) climate is out of sync and each day when you start the car is running a "self test" (a synchronization of steppers motors). If any part is not working properly (motor / linkage /flaps /etc) the "sync" will stop after a certain time and next time will try again To normalize the A/C stepper motors, hold down the Recirc and Front windshield buttons for about 10 seconds or until they both start flashing back and forth. When they are done flashing and you have confirmed everything is working, you are done.

[@SavedbyHim]

How can I identify which stepper motor/arm is broken on My C209 CLK320? When starting the car I get loud knocking sound for about 20 seconds. It says in the video that air is directed to the footwell on startup. I guess it's the footwell flap motor that is faulty?

[@lujerului]

Usually (depends of your configuration: with or without activated charcoal filters 0:39 ) M2/10 or M2/15 stepper motor/arm is broken 0:54 . It's a laborious work to fix it but doable if you're handy and have patience. Motor part number: A 203 820 16 42 and the operating lever A 203 830 00 33 (cheap parts). Dealer/indies shops are charging a lot to fix it, so live with it. (Mine is stuck open to the floor and in summer time is freezing my foot .)

[@revinot]

Wish i could chime in with help but I also have the same issue on my CLK i think i have multiple as its not just one click its two or three from various parts of the dash :-(

[@SavedbyHim]

@@lujerului Thanks for the info!!

[@lujerului]

With knocking sound (usually) is the plastic lever associated with that flap/motor. The motor is working because you can hear the knocking when is starting to synchronize

[@BorisBidjanSaberi11]

@@lujerului thank you for this video sir

[@povilaszvirblis8593]

Hello. I have 2003 clk270 with simple air control unit (N22 i guess). Problem is when I turn hot air, it is blowing only from driver side vents. From passenger or in the back it is blowing only cold air (im guessing from outside). What stepper mottor/motor arm can be causing this problem?

[@ptabduction]

This is probably coming very late but maybe it will help those that come here after. Have you tried to reset the flaps by pressing the "de-fog" and internal air circulation buttons at the same time for about 5sec? The buttons are right next to eachother. Lights on the buttons will start flashing and the car will go throught reset process of the flaps for about 30sec. If it doesn't stop automatically after 30sec there's an issue with the mechanism, the arms or stepper motor.

[@mahmoudhafez912]

Hello please how can I get training like that for mercedes

[@somathilakeBwm]

my mercedes w203 car .blower runs same fast speed even the key off position .after 2,3 minutes its stops after key off. Cant control with control unit.what is the possible reason ?

[@lujerului]

See owner manual for Residual heat and ventilation Is you air recirculate on? If it is then turn it off and see if it stops (marked "rest" on the console)

[@uasguiasfgjlkagbkl]

Hi Axbone, i have a 07 c180k, w203. While using the AC on cold setting it sometimes blows hot air from driver side and cold from passenger side. Othertimes it works just fine. i have done the HVAC reset and it did not improve. Local mechanic here couldnt figure our the issue so he put temporary hot water stoppers to turn off air in the summers. Please guide me in the right direction.

[@lujerului]

Maybe driver blend air flap is not working properly min 0:59 & min 1:55 ( intermittent stuck flap or/and positioning motor problem or some plastic part cracked).

[@j_zz1452]

What is it 4 minute 0:23

[@lujerului]

On 0:15 Button (tecla) #4 is Air Distribution control switch On 0:18 to 0:23 Button #4 is Activated charcoal filter An activated charcoal filter markedly reduces bad odors and removes pollutants from air entering the passenger compartment. Select activated charcoal filter: The indicator lamp in the button e is not illuminated. Press e button briefly. The indicator lamp in the button illuminates. Switch off activated charcoal filter: The indicator lamp in the button e is illuminated. Press e button briefly. The indicator lamp in the button goes out. The system switches automatically to the air recirculation mode, if the carbon monoxide (CO) or nitrogen oxides (NOX) concentration of the outside air increases beyond a predetermined level. The automatic air recirculation mode does not function if economy mode S is selected or if the outside temperature has fallen below 40°F(5°C). The activated charcoal filter should be switched off when windows fog up on the inside, or if the passenger compartment needs to be quickly heated or cooled down. Switching on the activated charcoal filter and activating convenience closing of power windows and sliding /pop-up roof: The indicator lamp in the e button is not illuminated. Press button e for more than 2 seconds, the side windows and the sliding /pop-up roof will be closed . The indicator lamp in the button illuminates. Switching off activated charcoal filter and activating convenience opening: The indicator lamp in the e button is illuminated. Press button e for more than 2 seconds, the side windows and the sliding / pop-up roof return to the position they were in before closing. The indicator lamp in the button goes out. A window or the sliding / pop-up roof opened manually after convenience closing will no longer be returned to the position it was in before closing when convenience opening is selected.

[@j_zz1452]

En el minuto 0:23 la tecla con el numero 4 para que es?

[@lujerului]

On 0:15 Button (tecla) #4 is Air Distribution control switch On 0:18 to 0:23 Button #4 is Activated charcoal filter An activated charcoal filter markedly reduces bad odors and removes pollutants from air entering the passenger compartment.

[@gbush1620]

My W210 has AC high-pitch noise from cent vent, here is the video captioned. kzbin.info/www/bejne/mXLWoKZtpsmSbKc Is it due to bad flap actuator? Thx.