I have 2001 CLK430, the econ light is on and the A/C doesn't work. Also the auto switch on the left (drivers) side doesn't work but the passengers side does. Any ideas?

 

Turn econ off. A/C "will not work" with it on. Your switch is broken, it's old plastic. Use the one on the passengers side. No big deal.

 

List what you see when you put the AC in diagnostic mode. This link will explain how to put it in diagnostic mode.


www.marcusfitzhugh.com/CLK/DIY/acdiag.html

 

The econ light does not go off when i push the button. How do I put the A/C in diagnostic mode?

 

Post 3, the post just before yours says, "This link will explain how to put it in diagnostic mode." That statement is followed by a link - www.marcusfitzhugh.com/CLK/DIY/acdiag.html

Go to that link. I built that webpage after repeatedly answering the question you're asking. That page states how to put the HVAC system in diagnostic mode. Once you put it in diagnostic mode, write down what you see and post the figures in this thread. Specifically, items 1 through 8 are important. If you post what you see in items 1 through 8, myself or someone else can typically tell you why the air from the vents isn't cold enough to freeze you out of the car.



The attached photo shows my evaporator sensor's temperature is 37 degrees F. My vent temp shows five point five degrees F. I know the value of a good AC system, but I will need the diagnostic info to help.

If the answer isn't obvious from the readings in diagnostic mode, I'll then tell you how to list the AC fault codes.

 

If the EC light is on and you can't turn it off its more than likely the result of a VERY low charge. Lets face it these cars are getting pretty old and they will perpetually leak if components and seals are not replaced. My system was running perfectly (37F with temps in the high 90's to 105F even at idle) until this spring and I think I have a low charge - no codes or EC light but mine is a 2000 with 81K and I'm sure its leaking somewhere. I had to get it charged by a 1/4 LB last year. It also could mean one of your AC components has failed and threw a code which is stored the in climate controlller. These can be pulled by setting the left side to HI and the right side to LOW. You may have a problem because one of your buttons is broken. Its also a problem because you can't clear the codes to get the system to work. If the codes are stored and retained the system will shut down because the stored code. There are procedures to fix the buttons either in this forum or www.benzworld.org. I would personally fix the button or ebay another controller because its important to get the diag codes and clear them when the components are fixed.

NEXT when the button is fixed or the system has been replaced:

Don't just get a can of freon and attempt to fill it because you probably have a very large leak. The system won't work because of the stored codes anyway. Your best bet to preserve some pretty expensive components is to take it to someone who just does heating and cooling. They will first check for any leaks by a UV light if the system has tracer dye that was inject before. Then they will fill the system under a vacuum which is important for a good charge as well as to remove any air in the system which can cause internal corrosion which is very bad for aluminum. They will add the freon based on weight according to ambient temps and humidity. This is crucial for a good charge.

 

My EC light came on last year just before Winter and the AC stopped blowing cold. Heat, etc worked perfectly, and AC worked perfectly up until the point the light came on.

I did not worry about it because Winter was coming and I knew I would not need the AC in Winter so I saved my cash and waited until Spring. So 2 weeks ago I went to have my AC serviced as the weather broke. They reset the computer (with a machine, not with manual combos on the ac unit) loaded more freon and I have been blowing cold every since.

Last time the ac was charged was in 2009 so I'm fine with that time span. As for your auto switch, probably just went bad. Shouldn't be a big deal for a new switch.
Me- CLK 430 Coupe w/ approaching 150k and still my baby!

 

I ran the diagnostics and here are the results #1-78, #2-68, #3-77, #4-77, #5-73,
#6-198, #7-1, #8-76 (checking later 81), 10-3.3. The econ light was on, but i lowered the temp on both sides to 63 degrees F. Can you tell from these numbers if it just needs a freon charge or if something else could be an issue. I have had the car about a year and last summer the A/C worked fine.

 

I had a slow A/C system leak that triggered my econ light when the coolant level dropped to a certain point.

I went the rout of using UV dye and searching with very little conclusive evidence if where the leak was coming from. Seals were replaced and the problem returned. The compresseor was removed and a part was replaced. That too failed to solve the problem.

I bought a used compressor from a 208 part out that another member had listed in the for sale section and with that installation, the AC has worked perfectly for the last week. I hope the issue is resolved.

To go back to the beginning, I would have bought new or used replacement components before trying the less costly fix of new seals and rings.

 

According to #7, you have no Freon.

 

I brought it to my local guy and he gets about 125.00 to evacuate & recharge system and clear the codes. Does this sound resonable?

 

Dependiing on how much was added. Cost of freon is always going up - so its probably a decent price. Let you know tomorrow - having the same thing I HOPE! I had a 1/4 pound last year about the same time - so there is either a very small leak at a fitting or at the o rings from the expansion and contraction in the wild swings we had over the past year. OR my compressor is staring to get weak but my car only has 82K miles and last summer with temps in the upper 90's to 103 I would get evap temps at 37-38 at idle with the fan on 4 or 5 bars which is excellent and doesn't show that the compressor is getting weak.

 

Sounds right.

 

Got mine back this afternoon - said he had to add .5 lb to the system. Total cost was 115.00 which included a full check out inside cabin and out. Suspects a leak at the hose between the condenser and drier. Said the job would be about 290 to replace the hose, fit new o rings to the sensors at the drier and evac and recharge. Sort of a little miffed because there was dye in the system - added by him last spring. Should have looked first before recharging the system. Now have to do it a second time if the pipe is replaced. Said should be fine for the summer because the sniffer couldn't find anything once the system was recharged - so it must be VERY small. Could also be that the hose or connections leaked due to severe changes to temps I had in the winter. I wiped everything clean to remove any traces of residual dye and will check it periodically with a uv/yellow glasses in the next month.

My evap temps are in the 38-39 range with outside temps in the low 70's which is normal. Fan at 4-5 bars. Cooling drop when car is sitting in the sun from 80 at evap only takes a couple of minutes to get into the lower 40's. The drop time is important to determine if the compressor is still working efficiently. A slowing dying one will take more than 15 minutes of driving to get the temps to drop - and in the heat will never get that low.

On the upside I guess is that the cost so far wasn't bad considering the age of the car. At least the evap, condenser and the compressor are working fine. Replacing the compressor I can live with since a new one (DENSO - AMAZON.com) is cheap enough but if the evap goes during the summer it would be a killer due to the time to pull the dash.

 

had the system rechared for about 135.00, there was also a fault code for the ambient temp sensor that would not let the compressor on because the outside temp was too low. That was also abou 135.00 parts and labor. All working fine now.

 

Is there a way to test the compressor ? My ac is blowing hot air and I've been told 3 different things. It's going to cost at least $500 to get it repaired. I want to make sure it's the correct diagnosis.

 

Yes a compressor can be tested with a pressure gauge. Alternatively, the ac can be put in diagnostic mode and the pressure can be tested without a gauge.

Rather than going down that rabbit hole, let's try something else. Like I tell every Benz owner with AC issues, put the system in diagnostic mode and list the codes. That will tell you valuable information about what's wrong.

 

Ok, I printed off your instructions on diagnostic mode. Just makes me mad because I am a female....but NOT stupid !

 

I didn't mean to imply that you're stupid. No one here is born knowing how to put the AC in diagnostic mode or what the codes mean. However, with a little help most of us can do our own diagnosis and get cool air.

 

Oh no, I wasn't referring to you. I was referring to the mechanics I've been to and paid money to.

 

Most mechanics who haven't worked on MB's in the past have no idea how to give a proper AC diagnostic. As Marcus has said please post you codes 1 through at least 7. Also you need to get into the diagnostic mode which is separate. Here are clear instructions:

Get the active codes 1-7:

Turn car off
Turn key to position 2, press the REST button a few seconds until you see 01 then a number, write down then press the right AUTO button and do the same through code 7. Write all down and then post here.

Get diagnostic error codes:

This is different than the last procedure because it will list in sequence the fault codes that may or may not exist with your car. If you have certain codes present THE AC SYSTEM WILL NOT ENGAGE and this is more than likely whats going on with your car when the mechanics did the initial diagnostic. If it didn't engage they would not get a proper pressure reading because the compressor did not turn on. If you have a code present it can be cleared. The AC system will engage briefly for a cycle or two then the code will come back and stop the system.

To first get the codes you have to turn the car off.

Turn it on to the second position. Jack up the left side temp to you see HI on the display. On the left side drop it to LO. Turn off.

Turn on to second key position and within 10 seconds press and hold BOTH the EC and REST buttons at the same time for at least 5 seconds. The display will blank out and the RECIRC LED will flash. Press the AUTO button on the right. The fan will run high for a second and flash a code if one exists. If not a FF will show meaning its finished. If a code shows up it will look like a "b" then the code. Write it down and press the AUTO (RIGHT) again - another code or FF will show up. Turn the car off when done.

REPORT everything back here and someone will give you an answer. You can clear the codes that get displayed by pressing BOTH AUTO buttons at the same time when the code apprears. You will then see a dd when it clears.

A compressor to go can happen (if gas was overcharged or undercharged with too little oil) but its pretty rare for them to "just" go. They would get weak first in most cases. Or if someone just added gas from a can without evac'd the system of moisture this would and can cause the system to corrode pretty quickly.

More than likely you have a leak somewhere, more than likely pretty large but maybe not and the system just turned off the compressor. A proper gas up FROM A PROFESSIONAL that does AC systems will help determining that problem by injecting a dye into the system. Costs can either be pretty high depending on where the leak is. An evaporator leak more than likely will break the bank because the entire dash has to be ripped out and the labor hours to do that is 14-17. At 140 (dealer) + the part you are about 2500 unless you do most of the work yourself. A condenser which is at the front of the car behind the grill isn't that bad. Hoses and fittings do leak esp at this age. Mileage doesn't matter - rubber just ages by time. Some hoses are expensive but the labor isn't bad. Example an independent AC guy would charge 275 for the hose from the compressor to the drier, replace all the o-rings at the drier and do a regas. Not too bad.

Consensus from the my dealer is that over time the system will leak gas. Slowly at the fittings from expansion/contraction and the age of the rubber. Normal is 1/4 lb or less if you have a severe winter or rapid changes super cold then warm then super cold again.

My AC last year needed a 1/4lb and it cooled as low as 37 in 100+ weather at idle which is excellent (in less than 10 minutes). This year again it needed more gas - didn't throw a code but wasn't that cool. Again less than 1/4lb - same cooling.

 

Ok, my codes are as follows:


1 - 101
2 - 106
3 - 101
4 - 102
5 - 97
6 - 198
7 - 10
8 - 115

 

I didn't see your response. Let me do this diagnostic test and I will post codes.

 

Second mechanic ran dye and found no leak. He said the expansion valve was closing up (?) or "maybe" a leak in the dash which won't show up on the dye test. Third mechanic said compressor was dead. First mechanic said must be a leak somewhere but didn't want to mess with it.....WTH am I supposed to do with a bunch of "maybes" ??

 

Ok, here are codes:


1 - 89
2 - 8
3 - 85
4 - 112
5 - 83
6 - 133
7 - 6


I never got a B code and the Recirc light didn't flash.