My a/c clutch is not engaging, and the EC light is lit always, except when I put the controls into Defrost, but, the a/c clutch still does not engage.

I found this thread C230 A/C Diagnostic display (Climate control)--How to use

I pulled the codes. Now bear in mind, I have lost some pixels on the pax side, so my numbers may be wrong. I pulled 416, 231, 235, and 234.

Just before I noticed I had no a/c, I did seize the belt tensioner pulley, melted the belt at the pulley right after a cold start in the winter, the car backfired, the engine quit, I was able to start it right back up, quit again without backfiring, and then I was able to restart it and drive a couple of blocks to get off the road.

I am guessing that's why I have codes 416 and 235, because the belt seized. I do not know what an ECT(231) sensor is nor a Sun sensor(234). As a side note, I occasionally set an EGR code, but the valve has been replaced. I do not know if this plays into the CCU. I did clear a set code before pulling these CCU codes.

How do I clear the codes and start over? I can't seem to find out how to clear them here.

I did hook up a gage on just the low side and I do have refrigerant pressure.

I also have a Snap-On Mt2500G, but no S-33 key, which is the one for the ac system. I just ordered an S-33 and a S-34 key so I have all the keys for my car. Will the scanner clear the codes so I can start over once I get the personality key?

Any help would be appreciated.

__________________
Thank You!
Fred
2009 ML350
2004 SL600
2004 SL500
1996 SL600
2002 SLK32
2005 CLK320 cabrio
2003 ML350
1997 C280 Sport

Anybody?

__________________
Thank You!
Fred
2009 ML350
2004 SL600
2004 SL500
1996 SL600
2002 SLK32
2005 CLK320 cabrio
2003 ML350
1997 C280 Sport

There should be a "b1" before each of those codes.

Is one of those a code for the electromagnetic clutch? It sounds like yours has failed due to the belt slipping. This warms a heat-sensitive fuse in the clutch, disabling it permanently. The only fix is a new clutch coil. It is assumed that this is due to compressor damange; the FSM says to replace the compressor, and that's probably what you need.

You can clear these codes from the pushbutton unit. No scanner is necessary if you have this in your car.

ECT sensor is engine coolant temperature. There may be a problem or may not. Can you read the engine temperature from the unit? Ignore the sun sensor code. They all do this, and it isn't important.

Yes, they all have b1 on the left side.

None were for the clutch.
When I checked, coolant temp was ok.

How do you clear the codes with the CCU?

__________________
Thank You!
Fred
2009 ML350
2004 SL600
2004 SL500
1996 SL600
2002 SLK32
2005 CLK320 cabrio
2003 ML350
1997 C280 Sport

Shoot, I knew that you were about to ask that.

Rather than type it again, I give you this link:

http://www.benzworld.org/forums/w210-e-class/1384396-automatic-climate-control-diagnostic-trouble-code.html#post2947104

OK
I cleared them, but still no clutch. Crap, maybe I need a clutch. Damn that's stupid - a belt breaks and I need a compressor clutch.

As for the codes listed in the link in my first thread
1. In-car termperature sensor (with aspirator blower)
2. Outside temperature sensor
3. Heater core temperature sensor
5. Evaporator temperature sensor
6. ECT sensor (Coolant temp.), e.g. 12*5 = 125C
7. Refrigerant pressure in bar, e.g. 12*8 = 12.8 bar
8. Blower control voltage, e.g. 16*5 = 1.65 volts
9. Software status of A/C pushbutton control module
15. Selected in-car temperature
20. Version code
21. Engine Speed (RPM), e.g. 6*0 = 600 rpm
22. Terminal 58d (Bat. Volt.), e.g. 99.0 = 99% of voltage
23. Vehicle speed (Kilometers Per Hour)
50. Not used – 00
51. Number of current slip recognition (poly-V-belt)
52. Number of stored slip recognitions (poly-V-belt)


- my car in question is a 2001 E430. I have more codes than listed - is there a list someplace for my car's CCU?

Thanks!

__________________
Thank You!
Fred
2009 ML350
2004 SL600
2004 SL500
1996 SL600
2002 SLK32
2005 CLK320 cabrio
2003 ML350
1997 C280 Sport

Unplug the connector at the compressor, and check for continuity to ground. It should show just a few ohms. That will tell for sure if your clutch is bad. Squealing the belt on the pulley is a really bad thing. Can you turn the compressor shaft easily by hand?

I'm not sure where you found that list of sensor values, but the 210 does not have slip recognition as used in the older platforms. There is no compressor speed sensor, just the heat-sensitive fuse in the clutch coil.

I'll check the clutch resistance tomorrow. Do you have to do this from undreneath, or is there some other convenient place to check it?

Thanks for your help

__________________
Thank You!
Fred
2009 ML350
2004 SL600
2004 SL500
1996 SL600
2002 SLK32
2005 CLK320 cabrio
2003 ML350
1997 C280 Sport

The connector is on top of the compressor; one wire. It's a bit tight down there, but removing the window washer reservoir gives you a lot more room.

OK, now, is there a law against being stooopid?

Or how about a/c for dummies.

To refresh - first I seize the idler puller bearing, then the ac no longer works, EC light on. I press the EC button way too many times, turn it on off, lo, hi, all to no avail. Then I remember reading about pulling up values, do a search, find that thread. See that some of the numbers seems to apply, but not all. Find the thread that indicates the fault codes. Pull up mine. They all seem to be related to the fried belt.

Someone is nice enough to point me to the thread on how to clear them, ah, but I get them cleared, but the EC light is still lit. So now I resign myself to buying a new clutch coil and tools to do that job.

Wife wants to go out for a quick bite instead of cooking something. Jump in the car, the EC light is on, so now I depress the EC button (I did not do this after I cleared the codes), and the EC light goes off. Hahaha! The a/c now works!

Thanks Matt L for guiding me through this!

__________________
Thank You!
Fred
2009 ML350
2004 SL600
2004 SL500
1996 SL600
2002 SLK32
2005 CLK320 cabrio
2003 ML350
1997 C280 Sport

Hah! Well, good to hear that it isn't terminal. Still, I would be wondering about that belt problem. Is your compressor noisy?

No, it was not the compressor pulley bearing, I may have not stated the problem well enough; it was the idler pulley bearing on the belt tensioner that went bad on me, seized, and melted the belt.

There's no noise in front right now.

__________________
Thank You!
Fred
2009 ML350
2004 SL600
2004 SL500
1996 SL600
2002 SLK32
2005 CLK320 cabrio
2003 ML350
1997 C280 Sport

Oh good.

I have yet to hear of anyone here or on BW that has needed a new compressor for their 210. Sitting low in the car probably helps it survive, since it doesn't seem to have a problem with corrosion destroying the body seal.