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2002 ML-320
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Discussion Starter #1
For the last couple of years the blower speed has been unpredictable. On a hot day when the car has been baking in the sun it might blow like a hurricane upon starting the car. Other times it will blow meekly. Setting the fan to MAX from AUTO would have no effect on the blower speed. I've been living with it.

This week the air conditioning is no longer blowing cold. I used the EC button to determine if the compressor was running (cycling it off and back on) and it appears to be running.

So I followed the instructions from this post to gather the data from the system. I took the reading two times about 90 minutes apart.

Code:
Bank   Read1   Read2
--     ------  ------
01     85       92
02     103     145
03     88       96
04     87       97
05     89       96
06     198     203
07     11       13
08     98       113
09     11       7
10     3.2      4.9
20     0        0
21     6        6
22     0        0
23     100      0  
24     14       14.2
40     8        8
41     5        5
42     248     248  
43     14       14
The biggest difference I notice is that 23 (Percentage of Batt voltage at 58d) drops from 100% to 0%.

Lastly, I tried the instructions found here to "test/reset/" the a/c air condintioning control panel. Nothing happens when I press RECIRC and FRONT DEFOG simultaneously - other than the car getting really hot inside since the defrost comes on.

So, is the end game simply that my air conditioning control panel is shot and I need to replace it? Or is it more complicated than that?

Thanks in advance for your asistance.
 

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2000 CLK430 2010 S550 4matic
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First you only have part of the diag done. Set the left temp to hi and the right to low. Car should be off but in the second key pos. Press both the ec and rest buttons. Screen will go blank. Press the right auto button. If you throw a code or codes it will show here. If not youll see a ff.

Doubt the controller is shot.
 

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2004 CLK 240 Coupe
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11,377 Posts
Hi - the whole box of tricks is a bit of a mystery to me really.

stim is right - there is possibly more that can be done. (I don't have an EC button on my W209, so I don't think I can do this diagnostic error test. :confused:

Here are the details from my notes:

Part 2 — Collect Trouble Codes

Now that we have all the sensor values, let’s check the computer for malfunction codes. Read this carefully, because you have a 20 second window after switching on the ignition to load the trouble code display mode.

Ignition must be switched on. 20 second timer starts.

Increase the left side temperature (left red arrow) until left side says “HI.”

Decrease the right side temperature (right cold arrow) until right side says “LO.”

If your 20 seconds passed, switch off the ignition and switch it back on.

Your HI/LO settings will be preset. Timer restarts.
Press and hold the “EC” and “REST” buttons simultaneously for at least five seconds.
The screen will go blank.

Load the first code by pressing the right side “AUTO” button.

If you have any error codes in memory, the screen should look like the figure on the right. The ‘E’ stands for “error.” In this case, we have error code B1234.

Write down each error code. To cycle through the codes, press the right side “AUTO” button.
When you finish, press the “REST” button to exit.

Error Codes:

Error B1226 - In-car Temperature Sensor Malfunction
Error B1227 - Outside Temperature Sensor Malfunction
Error B1228 - Left Heater Core Temperature Sensor Malfunction
Error B1229 - Right Heater Core Temperature Sensor Malfunction
Error B1230 - Evaporator Temperature Sensor Malfunction
Error B1231 - Engine Coolant Temperature Sensor Malfunction
Error B1232 - Refrigerant Pressure Sensor Malfunction
Error B1233 - Refrigerant Temperature Sensor Malfunction
Error B1234 - Sun Sensor Malfunction
Error B1235 - Emissions Sensor Malfunction
Error B1241 - Refrigerant Low
Error B1416 - Coolant Circulation Pump Malfunction
Error B1417 - Left Duovalve Malfunction
Error B1418 - Right Duovalve Malfunction
 

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2000 CLK430 2010 S550 4matic
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Thanks for the assist Keyhole, was pretty difficult to type on my Android phone this afternoon to give a proper response.

The blower issue is separate. You have a bad motor regulator. Thats an easy if not cheap replacement. Its a simple unscrew, unclip, unplug and reassemble. They go from the heat. The electronics in the regulator are crap and the residual heat under the dash does something to the circuitry. In the 12 years I've own my CLK430 its been replaced about three times.

Your sensor data looks ok, nothing obvious but you need to get the diagnostics. The reset you tried is a flap reset and basically it zeros out the flap actuators. It will work only on some cars - not all. Mine doesn't work and I know the controller is fine. The last two values on the sensor readouts pertains to the electronic coding - if its coded a certain way certain functions may not be available. I don't want to get into it because changing those values is possible - for instance you can show the fan speed even though the car is set to automatic. When purchased the car - new - it was set this way - when they replaced the unit the coding was different and only displayed the temps and AUTO when in auto - no fan bars. When you take it out of auto it will display them. Coding also allow for convertible - when the top is down fan speeds are different.

****When looking at the sensor temps again it looks like there is some heat in the heater box core being released. BUT you'll have to tell me if the car was cold (sitting for a while with TEST 1 ***** If it was the temps of the heater box shouldn't being going up - that high compared to the ambient temp sensor. ******



Last, if the compressor is indeed working and not cutting out at speeds or after a few minutes of use you could have a stuck DUOVALVE which controls the hot coolant into the car. If its stuck open hot coolant is flowing into the heater box and will mix with the cold air giving you dehumidified HOT air. They do go and get stuck. There is a way to take it apart and clean it. There is a DIY in the forum. You can test it - sortof by turning off the car - keeps the windows shut, radio off and park in a quiet area. Press the REST key and LISTEN CAREFULLY. You should hear a thump thump at the upper right (LEFT HAND DRIVE). Thats the valve cycling.

Do the diags if you can then report back - I'll work it out. Forget about replacing the climate control unit. I'm nearly 100% sure its fine. There are SEVERAL other things that can be wrong. They rarely go wrong and if they do its generally the buttons that fail not the electronics.

Although the AC system seems complicated it really isn't. What matters is the pressure, a good flow of air over the condenser, ZERO air in the system and a functioning set of flaps. The DUOVALVE operation is crucial as it controls the heat entering the heater core. Also sensors are also crucial as faulty sensors will shut down the AC system. Engine speed/tach sensors will also shut down the system if they are bad. When you stomp on the throttle the system shuts off. If the sensor indicates that even through you aren't it will shut the system off.

The compressor and clutch are also very important but from your 7 sensor it looks like you are compressing something and have gas in the system. The number if the temps are hot and the car is running should be a bit higher though. Mine reads about 16 when the car is running idle and its about 90F At highway speeds it drops and fluctuates to about 14 or so.

The front fans play a major role in getting the coolant pressure correct. Bad flow will jack the temp of the coolant AC and you will get very poor cooling or the compressor will shut off.

Most independent shops that do not have experience with MB's will gas them properly but have ZERO clue about the electronics. Its pretty crucial.
 

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2002 ML-320
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Discussion Starter #5

****When looking at the sensor temps again it looks like there is some heat in the heater box core being released. BUT you'll have to tell me if the car was cold (sitting for a while with TEST 1 ***** If it was the temps of the heater box shouldn't being going up - that high compared to the ambient temp sensor. ******


***Also the Sensor 7 if the car was running of sitting after the second test shouldn't be that low this indicates there is freon in the system the compressor IS NOT RUNNING!!!! If it is running the value should be in the 12+ range it its working properly!
The first set of numbers came after driving the car for 15-20 minutes at about 88F with high humidity (love DC in the summer). The second set of numbers were about the same amount of time on the return trip. The first set were taken outside in an open parking lot. The second set were taken in a parking garage under a building - where it was surprisingly hot.

I'll try the other diagnostics in the morning. However, if the compressor isn't running is there something specific I should focus on?
 

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2000 CLK430 2010 S550 4matic
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If the compressor shuts down you should throw a code in the diag. See what happens when you run it. It should. Next stage if it doesn't throw a code is to have the system evac'd/recharged to get a baseline fill. Then the $$$ will start to add up if that doesn't help.
 

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Discussion Starter #7
Here is what I got:

Error B1227 - Outside Temperature Sensor Malfunction
Error B1416 - Coolant Circulation Pump Malfunction


The first one may be residual. I replaced the sensor a few months ago. Or the new one could be bad.

I have a feeling that the second code is bad news. Usually I am sitting down when using the computer, so I won't fall far if I faint.
 

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First try to clear the codes then drive the car for a little while and recheck. To clear the codes enter the diag . Press and hold both AUTO buttons for a few seconds - you'll see a d when they are cleared.

The coolant error relates to the DUOVALVE - it may be stuck open giving you heat to the heater box when you don't need it. The duovalve is pretty expensive but can be (sometimes) cleaned/opened to unstick it.

Try the clearing of the codes to see if they come back.
 

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Discussion Starter #9
I don't think that I will be able to clear them. The left AUTO button appears to be broken. Pressing causes nothing. No "click" like I get with the right AUTO button. So when I got the sensor readings I just scrolled through the list backwards.

Is there any other way to clear the codes? I have the tools to pull the command panel out of the dash. Would disconnecting it for some period of time clear it?
 

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2004 CLK 240 Coupe
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For the last couple of years the blower speed has been unpredictable.
A few late comments about your first post.

1. You can safely disregard #23. Circuit 58d is the voltage for the variable instrument/switch lighting, ie, the setting of your dimmer control for the panel lighting. Were the panel lights on for one of the measurements? I'm not sure why it is in this a/c diagnostic list anyway.

2. stim makes a good point about your duovalves, which show different temps left/right. Maybe they need attention.

3. I discovered that you can continue to read these values while the car is moving (ie, until you reset the display) so that you can monitor # 6 the engine coolant temp as is rises, or #7 the refrigerant pressure on the move - which is interesting.

4. I don't think that #20 should be zero.

5. #2 (read 2) seems very high. But when parked the hot engine can affect this reading. It only makes sense when the car is moving, or if the engine has cooled down.

6. Your W208 a/c system also uses your pneumatic system - to control the flaps I believe, so that must always be considered when fault-finding.

This is a WIS page on the a/c, when used with the MB testgear. This conforms my previous post.
 

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Is there any other way to clear the codes? I have the tools to pull the command panel out of the dash. Would disconnecting it for some period of time clear it?
Doesn't pressing REST clear the codes when you exit?
 

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2000 CLK430 2010 S550 4matic
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No - REST will not clear the codes when you exit. They are preserved in nonvol memory until you press both the AUTO buttons at the same time. Removing the power for any length of time won't clear it as a the chip is written and saved. No power to the chip but the data is still saved. I'm pretty sure this is the way it works.

If his right AUTO button is broken - he has a problem but I'm pretty sure the codes can be cleared with the STAR diagnostic system which means a trip to the dealership for about 150-200 just to clear and diag the system.

If you don't clear the codes the system will definately not work as it doesn't self correct when you replace a defective component. Its not that smart - it will just keep them in memory and if there is a serious code it will shut off the system and keep it off until the code is cleared. 80's computer programming - as the climate system has been around in various forms for years. It works but the programming is very slow and super basic.

The only thing he could do is remove the climate control unit and attempt to remove and fix the button. I bet if you are patient and have small plastic wedges and small jewelers screwdrivers you could take the face/switches off and maybe fix them. Or have the thing redone - because the part is insanely expensive. Mine was replaced twice under an extended warranty and the repair bill was nearly 2000 USD for each time.

Because the units were pretty much model specific - ie E class units won't be the same as a C or CLK, etc. finding one used for a decent price is impossible. Tried Ebay - nothing.

What you could do is just replace the button by purchasing one cheap - the auto buttons are the same and if you are skilled remove it and do a swap. The unit looks like its fairly easy to remove just the button bezel.

I'd do it but I am VERY detailled oriented/careful and have a delicate touch. Its not something someone with zero patience should attempt.
 

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Discussion Starter #13
Guys,

Thanks so much for the assistance. Unfortunately, I need to place this project on hold. I was rearended this morning on the way to work. Top was down on a beautiful morning. The back is all crumpled on the passenger side. Top is inoperable. Can't even close it manually because the deck lid is pushed forward preventing the cover from lifting to expose the top. I strongly suspect that my baby will not survive this event. Probably won't hear how bad it is until early next week.

TriscuiT
 

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2000 CLK430 2010 S550 4matic
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Sorry to here that - more than likely the insurance co will total it. A rear end collision in one of these at this age is done. Have seen way too many in salvage that looked great except for rear end damage - and the damage really wasn't that bad. The cost to repair the rear quarter is insanely expensive if its the hardtop. They have to cut out the rear quarter and do some major welding. With the convertible due to the chassis complexity and top parts its about even with rear end repairs. Depending on the mileage if you are below 70K there might be a chance if the pre-accident condition was way better than average. If the airbags went off or you have major subframe damage - its done unfortunately.

I worry about mine every time some idiot in a enormous SUV pulls up behind me on the highway and tailgates.
 

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Discussion Starter #15
It has about 97k miles. Body was fairly clean. Wheels not so much. We'll see what happens. I am sure it will be next week before I hear anything. Maybe it is time to upgrade to a newer model. Maybe a 2009.
 

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Discussion Starter #16
Well, clearly I was hoping to be able to fix this and share the knowledge for others who followed. Unfortunately, the damage estimate on my car is just shy of $14kUSD. So I am now looking for the next car. Thanks for all of the help. I think that we would have solved this problem with just a little more work.
 

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What kind of numbers did they give you for the collision / total claim? Did you have full collision?
 

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Discussion Starter #18
I had a small (well LARGE) typo in the message above. It is almost $15k not $14k.

Numbers broke out as:

Parts 10,205.00
Parts Discount $ -445.63
Body Labor 75.7 hrs @ $ 40.00 /hr 3,028.00
Paint Labor 19.3 hrs @ $ 40.00 /hr 772.00
Frame Labor 3.5 hrs @ $ 40.00 /hr 140.00
Paint Supplies 400.00
Miscellaneous 44.00
Other Charges 316.00
Subtotal 14,459.37
Sales Tax $ 10,193.37 @ 5.0000 % 509.67
Grand Total 14,969.04
Deductible 250.00
CUSTOMER PAY 250.00
INSURANCE PAY 14,719.04


I have full coverage. However, the other driver is 100% at fault so their insurance company has to swallow the whole pill for the claim. I am going through my insurance company because it is easier for me. They will subrogate the claim to the other company. When they get their money from the other company they will reimburse me for my $250 deductible.

Today I officially heard from my insurance company that the car was a total loss. They are giving me just shy of $12kUSD for the car.
 

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Thats not too bad for the age and the mileage. Actually surprised they gave you that much. Normally they go through hoops to lowball. Kelly Blue Book listed it at about 10.5 and thats as a private sale retail. So you actually made out because if you tried to sell it in pristine condition it would have been much less then the Book Value at the dealer it would have been worth maybe 8 or 8.5K
 

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Discussion Starter #20
I'd still rather have my car. But I do understand that this is better than I would have gotten in most attempts to sell it. Apparently the price is influenced by recent sales of the model in this area. Being in the DC Metro area means that everything is on the high-side price-wise. That also means that anything I get as a replacement will also be on the high-side unless I travel to buy it. I have no idea what I'm going to get. So many options - even when limiting the search to convertibles. It may be sacrilege on these forums, but anyone have any experience with the Infiniti G27 convertible?
 
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