Thank you, ricebubbles - this is definitely going into the W220 S-Class Encyclopedia. Very nice work!

 

Simply amazing! Great work! Your work will be a great addition to Skylaw's wonderful encyclopedia.

 

The problem i'm having is that when i come to a stop with my heat on that my heat starts to blow cold air instead of continuing to stay warm air. I checked for error codes by pressing the res and charcoal and didn't see any codes. When i push the increase and decrease up and down i don't get anything all it says is searching and nothing pops up, not sure how many times i have to go up or down, is there a certain amount of times to go either way?

 

As I explained in my attached document above there are three hidden menus available in the W220 Auto Climate Control (ACC). These are used to:
Hidden Menu 1. Access/Review/Read Auto Climate Control (ACC) Actual Parameter Values,
Method: Press Residual Heat and Ventilation (REST) button alone for greater than five seconds with ignition on (position 2) or with engine running.

Hidden Menu 2. ACC Flap/Vent, Engine Fan and A/C Compressor Test,
Method: Press the Residual Heat and Ventilation (REST) button and Recirculate Air Button for greater than five seconds with ignition on (position 2) or with engine running.

Hidden Menu 3. access/review/read and clear/reset ACC Fault/Error Diagnostic Trouble Codes (DTC).
Method: Press Residual Heat and Ventilation (REST) and Activated Charcoal Filter Buttons simultaneously for greater than 5 seconds with ignition on (position 2) or with engine running.

You may not be getting any fault codes produced. I suspect that you have a problem with the water circulation pump. I would be testing the pump function using the tests in Hidden Menu 1 above. Record the heater core temperatures for various settings of the ACC. That is parameters NR.03: and NR.04: Plus record the engine temperature and anything else you think relevant. You can also do this whilst driving. Just have someone else to help scroll through the parameters and record the values. This may help diagnose what is malfunctioning.

There was nothing special about accessing Hidden Menu 3. It can take many seconds for the searching to complete. If you don’t have any faults or you have cleared/erased them you should see the ACC display screen showing "DIAGN. ERROR ----".

Best of luck!

 

Thanks this is very useful!:bowdown:

 

Hi

New to this site but wanted to say thanks for the aircon info.

Any ideas on the following codes cost-wise?


Ok so:
B1000
AAC Pushbutton Control Module (N22) is defective.

B1268
Communication fault of A/C Bus with Centre Vent Control Module (N18/4).

B1271
Communication fault of A/C Bus with Stepper Motor Control Module (N22/5).

Thanks,
Adam

 

My center vents seem to blow harder than my side vents, is this common?

 

A/C Compressor Valve DC Current error code 98

My AC stop blowing cold air , I checked the AC diagnostic menu and on
NR.98: A/C Compressor Valve DC Current (mA) Value: 0 mA
Can anybody tell me what this mean , Do I hae to replace the Compressor?


Thanks

 

....
Can anybody tell me what this mean , Do I have to replace the Compressor....

The current is equivalent to a pulse modulated voltage which comes from the SAM left side. The signal uses only one wire. You can see it if you have a look on your compressor. There is a plug on top. If the wire or its connections has broken or are corroded the current is 0. So not only a bad compressor can show this fault.

The SAM only generates the signal, if it gets infos from the a/c controller over CAN. Lack of communication between this devices can also be responsible for missing voltage.

 

CLK320 AC

Would this work for a 2000 CLK320 ac system, as well ?

 

Thank you for the excellent document. I believe the term "Heissland" means "Hot Countries" Mercedes make different national versions for some countries that have unique or extreme operating environments. For example vehicles sold in the Middle East and North Africa have higher capacity radiators, vehicles sold in South Africa have different ride heights, springs, shocks and tires. Some of the S-class models sold in the Middle East have dual air conditioners, one for the front seats and another for the rear seats. Another issue is for countries with high sand content in the operating environment the recirculating flap does not close all the way as the excellent passenger compartment sealing will result in sand being drawn into the car. I used the sight glass on the receiver drier on my other cars to determine when the air conditioner was fully charged with Freon, the sight glass shows bubbles initially which turns clear when the system is full. The W220 does not have a sight glass so I use the hidden menu to access the high side pressure sensor reading to determine when the system is fully charged, around 14.5 Bar at idle.

 

Yes this is normal