Actually, you did this correctly be pressing the front defrost/defog button simultaneously with the recirculation button.(the ehow instructions aren't exactly clear on that, as is typical with those articles). If the lights did not stop flashing after 20-30 seconds, then the ACC system has detected a fault, most likely a bad damper control linkage or servo in the dash ventilation system. To know which one, you will need to have the codes read from the ACC module, which can't be done with a generic code reader - you must use SDS (Star Diagnosis) or other expensive, specialty equipment.

 

Great to hear that I didn't screw up the system, but what exactly are the two faults you mentioned? And what do they do?
Also, is it normal to feel a vibration in the steering wheel when the ac starts up, and is running?

 

The ventilation ducts use dampers ("doors") and servos (motors to control those doors) in order to select the desired inputs of air (inside vs. outside and hot vs. cold) and output vents (defog, dash, floor, etc.). When you run the ACC test and the lights don't stop blinking, it means that the system is unable to actuate a damper or detect that it is in the proper position. This can be caused by a bad servo or a broken damper. There are several (10, I believe) in the duct system. To kn ow which are failing, you need to pull codes on the ACC system.

As for vibration from the compressor, I feel that, too, in my CLK. Much more than in my C240. I figure partly it's because of the less rigid chassis on my cabriolet, but also because of using a larger compressor on the CLK vs. the C.

 

Thanks for all your help!

 

AC Issues

hi.

Having issues with 2004 W209 AC. Blower comes on, warm air. I used a freon re-filler pressure gauge and it read in the red/overfilled range. I was able to bleed and now pressure reads in the "Filled" range. Still blowing warm air. I dont think the compressor is engaged...I saw a post it could be the temperature sensor?

I did the AC Reset ... keeps blinking. I know the servos are not working ... but I had cold air coming out before.

Any suggestions?

Thanks,


Tien

 

You need to pull codes from the ACC system. A generic OBDII scanner won't do it - you need a specialized tool. SDS is best, but iCarsoft i980 or MBII, or Autel MS802 Elite would work as well.