I have a 2006 CLK 500 and recently, while driving with the A/C on (3 bars), I noticed that my A/C will stop altogether. More exactly, there will be no air blowing, while the system is on. I immediately try to adjust the A/C power and strength but pushing the power or the strength adjust buttons don't do anything. I can turn the A/C off and when I turn it back on, I can't adjust the strength (it is stuck on 3 bars). The reading gets stuck on 3 bars and I cannot adjust it to more or less, all with no air blowing. I can turn the system off and on but the problem persists in that no air is blowing when the system is on. WHat troubles me even more, is that I can't adjust the strength (it is also stuck). In order to get things back to normal, I have to pull over and restart the car. Upon restart, the A/C unit returns back to normal and I can feel the A/C and adjust the strength of the fan. Has anyone else had this problem or know what could be causing this? This will happen about once a week. HELP!!!
rleeclk55
With no replies I guess that nobody has had this exact fault as you described it. Anyway, intermittent faults are the very worst to diagnose, as it could be anything....
In this instance it really seems that your a/c unit is faulty, and not any of the external sensors or a refrigerant issue. You will have to do some more investigation, or remove the entire unit for repair.
In this instance it really seems that your a/c unit is faulty, and not any of the external sensors or a refrigerant issue. You will have to do some more investigation, or remove the entire unit for repair.
I have read that the CLK a/c has its own diagnostic feature. I've never tried it out myself. Clearly you need the a/c version that has a display panel.
Here is something from my notes for your interest. :thumbsup:
The "REST" Menu Feature of the Climate Control
These are for the W208/209, other models may differ. After you get home from a drive (20 minutes or longer), let the car idle for 60 seconds while in park with the AC on. Press and hold the "REST" button on the climate control. After approximately 5 seconds, the display will change. You can now release the REST button. The left "auto" button will allow you to scroll through the menu. Here are what the codes mean:
01 The in-car temperature sensor.
02 The bumper temperature sensor.
03 The temperature of the left side heater core.
04 The temperature of the right side heater core.
05 The temperature at the evaporator sensor.
06 The engine coolant temperature.
07 The barometric pressure of the Freon.
08 The Freon temperature.
09 Blank.
10 The voltage at the heater blower control (normal is 08-6.0, which is .8 to 6 volts).
11 Emissions sensor voltage (to detect atmospheric gases and recirculate interior air). W209 only
12 Sun sensor voltage (to shift airflow in car). W209 only
20 The current at the auxiliary fan (the electric fan on radiator, in milliamps or mA).
21 Engine speed (x 100 RPM).
22 Vehicle speed (km/h or mph depending on installation).
23 The percentage of battery voltage at terminal 58d (a percentage of total voltage, 99.0 = 99%).
24 Battery voltage (e.g. 12.8 = 12.8V).
40 The climate control software version. - V8
41 The climate control hardware version. - V5
Either turning the car off or pressing the REST button again will take the HVAC out of diagnostic mode.
Some notes.
Common problems that can throw the Electronic HVAC for a loop are bad temperature sensors.
Naturally, if the in-car temperature sensor (#1) is broken and reads low, the AC will cycle off early while in auto mode. If it’s broken and reads high, you may freeze to death while in auto mode.
The evaporator sensor (#5) should be close to the in-car temperature sensor while the A/C is off, and a lot lower while the A/C is on.
The Freon pressure sensor (#7) is a good way to determine whether the Freon is low. Low refrigerant pressure commonly causes the left side to blow warmer air than the right side. Of course, the logical question is, "What’s normal?" My Freon pressure sensor (#7) reads as follows - when the car is started, and the AC is turned on, without touching the gas, it’s as high as 15. It drops to 7 while driving, and is commonly at 11/12 while waiting at lights.
Here is something from my notes for your interest. :thumbsup:
The "REST" Menu Feature of the Climate Control
These are for the W208/209, other models may differ. After you get home from a drive (20 minutes or longer), let the car idle for 60 seconds while in park with the AC on. Press and hold the "REST" button on the climate control. After approximately 5 seconds, the display will change. You can now release the REST button. The left "auto" button will allow you to scroll through the menu. Here are what the codes mean:
01 The in-car temperature sensor.
02 The bumper temperature sensor.
03 The temperature of the left side heater core.
04 The temperature of the right side heater core.
05 The temperature at the evaporator sensor.
06 The engine coolant temperature.
07 The barometric pressure of the Freon.
08 The Freon temperature.
09 Blank.
10 The voltage at the heater blower control (normal is 08-6.0, which is .8 to 6 volts).
11 Emissions sensor voltage (to detect atmospheric gases and recirculate interior air). W209 only
12 Sun sensor voltage (to shift airflow in car). W209 only
20 The current at the auxiliary fan (the electric fan on radiator, in milliamps or mA).
21 Engine speed (x 100 RPM).
22 Vehicle speed (km/h or mph depending on installation).
23 The percentage of battery voltage at terminal 58d (a percentage of total voltage, 99.0 = 99%).
24 Battery voltage (e.g. 12.8 = 12.8V).
40 The climate control software version. - V8
41 The climate control hardware version. - V5
Either turning the car off or pressing the REST button again will take the HVAC out of diagnostic mode.
Some notes.
Common problems that can throw the Electronic HVAC for a loop are bad temperature sensors.
Naturally, if the in-car temperature sensor (#1) is broken and reads low, the AC will cycle off early while in auto mode. If it’s broken and reads high, you may freeze to death while in auto mode.
The evaporator sensor (#5) should be close to the in-car temperature sensor while the A/C is off, and a lot lower while the A/C is on.
The Freon pressure sensor (#7) is a good way to determine whether the Freon is low. Low refrigerant pressure commonly causes the left side to blow warmer air than the right side. Of course, the logical question is, "What’s normal?" My Freon pressure sensor (#7) reads as follows - when the car is started, and the AC is turned on, without touching the gas, it’s as high as 15. It drops to 7 while driving, and is commonly at 11/12 while waiting at lights.
Thanks, in general, for posting the above information keyhole.
It'll come in handy for all of us at some point, I'm sure.
It'll come in handy for all of us at some point, I'm sure.
Good - I really don't know why I have never given that saved routine a dry run before. So after posting today, I tried it out on my CLK a/c system, CODE 581b (C-AAC). It worked for me, and I listed the 8 temp/press readings, which made sense generally.
A few points to note for anyone who tries it out.
a) Only readings #1 to 8 are sensors that affect the air conditioning system.
b) Press the left Auto button to move the sequence forward. Press the right Auto button to move the sequence backwards.
c) #7 above should read refrigerant pressure (we don't use Freon any more!). Mine showed a reading of 9 when the car was parked.
I also have a diagnostic sequence to try out later that will provide error codes on some MB a/c units, but without a fault on mine I'm not sure how that might work out.
A few points to note for anyone who tries it out.
a) Only readings #1 to 8 are sensors that affect the air conditioning system.
b) Press the left Auto button to move the sequence forward. Press the right Auto button to move the sequence backwards.
c) #7 above should read refrigerant pressure (we don't use Freon any more!). Mine showed a reading of 9 when the car was parked.
I also have a diagnostic sequence to try out later that will provide error codes on some MB a/c units, but without a fault on mine I'm not sure how that might work out.
We have a 2000 CLK 320 with the EC light illuminated on the Climate Control Unit, I have run the diagnostics and found that I have two codes that were not in the error code list: 42 and 43. The values are as follows 42 = 232 and 43 = 14. This past summer I filled the system with R134 refrigerant as the system has a front seal leak in the compressor and I have not replaced it yet. Within hours of recharging the system, it no longer blew cold air and the EC light came on. I have yet to purchase the service manual simply because MB wants too much for it.
Thanks in advance for your help.
Rick_V
Thanks in advance for your help.
Rick_V
Try putting the A/C in AUTO mode and see if the A/C starts working... if so, then it's one of the sensors... works for me!
Also check out this thread on the w210 forum... might get some ideas here:
http://www.benzworld.org/forums/w210-e-class/1265436-ac-quits-blowing-cold-air.html
Also check out this thread on the w210 forum... might get some ideas here:
http://www.benzworld.org/forums/w210-e-class/1265436-ac-quits-blowing-cold-air.html
Thanks Keyhole!
Your "REST" menu and info below helped me tremendously!! Mine was at 2.... LOL ....Soooo I found a guy in my little town that works on Mercedes and recharged it and the total bill was $61.37 ) It works great, and at 92 degrees here today I needed it! Thanks again!! :thumbsup:
"The Freon pressure sensor (#7) is a good way to determine whether the Freon is low. Low refrigerant pressure commonly causes the left side to blow warmer air than the right side. Of course, the logical question is, "What’s normal?" My Freon pressure sensor (#7) reads as follows - when the car is started, and the AC is turned on, without touching the gas, it’s as high as 15. It drops to 7 while driving, and is commonly at 11/12 while waiting at lights."
Your "REST" menu and info below helped me tremendously!! Mine was at 2....
LOL ....Soooo I found a guy in my little town that works on Mercedes and recharged it and the total bill was $61.37 ) It works great, and at 92 degrees here today I needed it! Thanks again!! :thumbsup:"The Freon pressure sensor (#7) is a good way to determine whether the Freon is low. Low refrigerant pressure commonly causes the left side to blow warmer air than the right side. Of course, the logical question is, "What’s normal?" My Freon pressure sensor (#7) reads as follows - when the car is started, and the AC is turned on, without touching the gas, it’s as high as 15. It drops to 7 while driving, and is commonly at 11/12 while waiting at lights."
Good to know that the a/c diagnostic information was useful.. (Why isn't is in the Owner's manual?)
Also good to see that newbies are using 'Search' to look up old threads on previously discussed topics. That's much better than starting a new thread on a topic that has been thrashed out earlier!
(Why isn't is in the Owner's manual?)Also good to see that newbies are using 'Search' to look up old threads on previously discussed topics. That's much better than starting a new thread on a topic that has been thrashed out earlier!
Can anyone please tell me what I should be looking to do next based on these numbers. From what the info chart explained my r134 appears to be normal. This is after 30 minutes of driving
1 - 111
2 - 124
3 - 98
4 - 102
5 - 94
6 - 210
7 - 13
8 - 122
. . .
10 -5.1
20 -0
21 -6
22 -0
23 -0
24 -13.8
40 -8
41 -5
42 -248
43 -158
This is after a cold start in the morning
43-158
42-248
41-5
40-8
24-12.0
23-0
22-0
21-0
20-0
10-1.4
9-0
8-94
7-8
6-97
5-95
4-96
3-96
2-95
1-261
1 - 111
2 - 124
3 - 98
4 - 102
5 - 94
6 - 210
7 - 13
8 - 122
. . .
10 -5.1
20 -0
21 -6
22 -0
23 -0
24 -13.8
40 -8
41 -5
42 -248
43 -158
This is after a cold start in the morning
43-158
42-248
41-5
40-8
24-12.0
23-0
22-0
21-0
20-0
10-1.4
9-0
8-94
7-8
6-97
5-95
4-96
3-96
2-95
1-261
HELP!!! HELP!!! HELP!!! i got a 2002 clk 55 amg and i had it for a few months and the ac worked fine. then about 1 month later it stopped working and all of the buttons stopped working and the ec light came on. i have looked all over the internet and found nothing. the only thing that works is the defrost for the front and the back thats all nothing else works.i dont want to spend alot of money trying to fix it. i got antifreeze and the guage said it was full.if there is anyone out there that is or hade this problem please send me a message.
First step - try the A/C system test/reset procedure - press and hold the RECIRC and FRONT DEFOG buttons simultaneously until their indicator lights blink. They should stop blinking after 20-30 seconds. If this doesn't do anything, then your A/C control panel is bad. If the lights don't stop blinking, then you have a damper control problem (bad damper linkage or servo under the dash). If the lights stop blinking but the problem isn't solved, then it's in the refrigerant system - bad compressor, low/high pressure valve, etc.
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