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AC

Thanks for your response Kajtek1.

My mistake in referring to the AC refrigerant as Freon. I actually meant 134. I don't believe I could even get Freon without a license. But good to not assume I know what I am doing.

The "7-02 14-17 Freon level normal" means that #7 of the codes reads 02 (low) and that the normal range (R134) should be between 14-17. Indicating my refrigerant level is way too low and likely keeping my compressor clutch from engaging.

I DID reset the codes, read, reset and then read again as has been instructed several times in the many posts I read before making my post. However, I will do as you request and post again.

My concern is the error code referring to the Clutch. I am not sure if the clutch is bad OR that error code is caused by the low 134 level.

I understand that the only 'sure' way would be to apply 12V directly to the clutch and see if it engages. I plan to check that today.

I've looked everywhere for the smog sensor. Unable to find. Seems odd that they would call a smog sensor an emission sensor. I thought everything to do with the word emission related to what was coming out of the exhaust.

How can I find the definitions/descriptions for the various items referenced by 'B31' (for example)?

I really appreciate your input.
 

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Applying 12v to the clutch would be the last thing to advise.
Those are digital cars and lot of things on them run on different voltages.
cdi engines for example do have injector fired at hundreds of volts.
I would consider 2 ways
1. measure clutch resistance
2. add refrigerant and see if the clutch will kick in. Full can has about 4 bars in it, so if the clutch will not kick in, you will end up with partly filled can, so you need a setup with valve to hold it in case the clutch will not kick in.
I would not worry about pollution sensor. The only time I heard report the warning come on was from guy driving in Warsaw- Poland. Pretty polluted city and it was only once it happened to him.
Series interface coming back would probably require visit on SD.
 

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Thanks for your response.

The magnetic clutch error code (I would think) would not register unless there was a problem with the clutch. I wonder if low 134 pressure switch keeping it from engaging would cause the error code.

I remember AC takes a few horsepower and that an electromagnetic field is a product of current and voltage. If you reduce one you have to increase the other. So for a given power grip, it would be in your best interest to use the highest voltage because current causes heat and requires a larger wire (costly). It makes sense to use the highest voltage. I will check the resistance either way.

I am hesitant to just add more 134 due to the possibility I might have to replace something.

I could not find a 'smog' sensor but when I searched for emission sensor with 235 it came up with oxygen sensor.. Apparently, my car has 4 and just to purchase is over $400!?!?

I've decided to ignore (for now) everything but the AC. I will get a definitive answer on the clutch/compressor.

Do you know where I can get information on the rest of the DTC codes?
 

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Need help, I ran the DTC codes and everything is looks good except #7 was at 07. I did a full vacuum an recharge at a local garage/auto parts store and the mechanic said my coolant was at about 650g but was now back up to 1000g after the recharge, however #7 still reads between 06-09, so nowhere near 14-17 as it should. The only DTC error I have is Eb 1416 (coolant pump). I cleared the codes and that one remains, however when I turn off the engine and press the REST button it comes on and blows warm air.... feeling the pump wile REST is "ON" and the pump seems to be working.

Symptoms:
on LO, full fan, warmer than ambient air coming out all vents. EC button works fine and I hear it turning the compressor on and off. I feel my dash lights 'dim' ever so slightly when the comp kicks in.

What I've done:
-Full Recharge
-Cleaned Duovalves (they were clean and didn't seem stuck) solenoids click when disconnecting/reconnecting the lead.

-Checked compressor clutch and it is engaging and disengaging.
-Compressor not making any strange noises.
-Evaporator temperature sensor #5 stays within 1 degree of #3 and #4 (seems correct)
-New cabin filters and carbon filter
-CCU seems to be working correctly.
-Blower works fine.

2001 W210 E320 V6 wagon.

What gets me is the #7 not changing after a recharge.... could it be that the compressor, though seemingly working fine and not throwing codes, is not pressurizing the system?

I don't think there were any leaks, 14 year old car with 650g coolant left and just recharged 3 days ago to 1000g.

What am I missing?
thanks.
 

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What you are missing is that the compressor is variable displacement and that #7 will never be a fixed value when working, as the displacement and pressure are controlled by the expansion valve at the evaporator.

Example, car not running after sitting all night, outside air temp 72* all cars temp sensors agree 72* (#1, #2 , #3 , #4 , #5 ) #7 should be in the range of 5-7 in this condition.

Now car running in city traffic, stop and go, 95*OAT your number #7 will be in a range 14-19

Now car running on the highway 70 MPH 95* OAT your number #7 will be in the range 8-12

If you compressor is engaged and no change of pressure is noted at #7


Thats bad news.
 

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Lets start with clearing that coolant is in radiator, while AC system holds refrigerant.
Static pressure of liquefied gas does not change much with % of fill.
That is why pressure gauges used to check propane fill are not working.
What you need to do brinaddison is to bring us 3 sets of readouts per stickies.
 

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Forgive my ignorance - new to this forum - but I cannot find the "3 readouts as per stickies" however I imagine they are sensor readings done "cold" (EC on), "warm", (Compressor on) and "warm" (Compressor off)?

What I can say, because I've been checking the sensors the last couple of days is that all #1- #8 stay pretty consistent with what seems to be good values that change according to how hot the car gets (I'll try to write them down today but from what I've read on the forum, nothing stands out as being a red flag). Yesterday morning when I first checked #7 "cold" it was at 10... that's the highest I've seen it. After driving for a bit, (10min mix of highway and town) #7 read between 08-09 with EC "off" and between 06-07 with EC "on" ...air coming out vents was ambient and gradually got warmer than ambient, this with controls on "LO" and highest fan setting, EC off. With EC on it was maybe closer to ambient temp but not by much.... hard to tell.

This is what I can't wrap my mind around, that the only fault code I get is the Eb1416 (aux water pump, or coolant pump) which, from what I understand, would not affect AC cooling... though I may be wrong? Everything just seems to check out fine except I've never seen a "very high reading" for #7 (10 is the highest so far).

It must be noted that I was getting a slight smell though the vents at "start" last season, when I turned the AC for the first time and the windshield blower (de-fogger) seemed to fog up the windshield more than normal at first. I chalked the smell up to old cabin filters. I changed them all and that seemed to fix that problem though I do still get that very faint odor, occasionally, when I first turn on the Climate Control but almost unnoticeable now. It wasn't a musky or moldy "organic" smell, hard to describe but I'd have to say it was more of an "industrial" smell... if that makes any sense?
 

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ok, ran the sensors as per the 1), 2), 3) as you recommended in the stickies, here are the results: (the car is set in degrees Celsius) ...3rd test, with engine running, the EC was disengaged (compressor ON)

1) Car OFF cold in the morning:
1-25
2-25
3-24
4-23
5-23
6-24
7-05
8-22

2) Car OFF warm in direct sunlight:
1-45
2-32
3-26
4-25
5-25
6-25
7-06
8-27

3) Car ON after 3 minutes at idle:
1-42
2-32
3-32
4-31
5-32
6-72
7-07
8-29

I hope this is correct and thanks for your help.

Brin.
 

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btw, all fault codes cleared.

The only one that was present before clearing was Eb-1416, after clearing and cycling the power/re-running the fault codes everything was clear, no faults recorded.
 

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Your cabin sensors look good, with the exception of refrigerant sensor, that sitting next to 72C engine is showing 29C. I think it is secondary issue to be recheck later, but your compressor during the test 3 is not pumping.
So check wire connections on the compressor and repeat test #3 displaying sensor 7 before engine start and see how it changes right after.
 

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So I checked the compressor wire (blue wire going into black socket) unplugged it, plugged it back in and made sure it was seated correctly, I have no way to check the current at the moment and not sure how to though I do have a multimeter.

Like I said in my first post the clutch is engaging and disengaging correctly. Ran the sensor numbers again, first cold - engine off:

1-37
2-34
3-48
4-47
5-44
6-38
7-08
8-35

Then again after engine on for 5 min.

1-37
2-35
3-45
4-45
5-43
6-82
7-09 (EC off) -08(EC on)
8-35

That refrigerant sensor is certainly not working correctly.

Still blowing warm air....
 

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5 minutes after start in not telling whole story and observing the pressure right after engine start would answer if the compressor is cutting in and later out, or is not coming on completely.
That test takes 20 seconds and sure beats getting your hands dirty under the hood.
If you see compressor turning and no pressure change, that means you need new compressor.
 

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oops, ok... will do the test again in the morning when the car is cold. Sweltering hot in Brussels today and the merc is in direct sunlight. :(

I had imagined it was the compressor but it's good to see my diagnosis confirmed by an expert. Thank you for taking the time to analyze my codes and give me your input, I certainly appreciate it.

Didn't want to change out the compressor if that was not the problem. This is my first AC issue... I guess we all have to tackle it at some point.

About that refrigerent temperature sensor... I gathered it's connected to the dryer... but for the life of me I cannot locate the dryer, seems like it may be under the left headlamp?
 
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