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1997 (I-6) E320
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Discussion Starter #1
I have searched the threads and the internet and called the dealer, no help, so please dont dismiss this with a "use the search feature"

I have a 97 E320 (with the inline six) that needs a recharge on the A/C. the system keeps the "EC" button lit that keeps the compressor off because the line has a low charge. I cant charge the line without turning on the compressor. I cant turn on the compressor without charging the line... HELP! what do I have to do to get the compressor running so I can charge the line?
 

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210.065
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2,947 Posts
Matt once said he can for sure (recently), I will try to search the forum for you.
 

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1996 210.020
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3,972 Posts
It takes energy to move refrigerant into the car, because you want to boil the refrigerant out of the can and condense it in the car. The compressor supplies this energy if it is running. Without the compressor, you need to supply the energy in another form.

If you immerse the refrigerant can in hot water (not so hot that you can't put your hand in), that will supply the energy needed.
 

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1997 (I-6) E320
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7 Posts
Discussion Starter #4
Tried the hot water thing. Did not work... Isn't there any way to over ride the system and get the compressor working?
 

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Dallas, Texas
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Tried the hot water thing. Did not work... Isn't there any way to over ride the system and get the compressor working?
EC light may be on because of faulty refrigerant temperature sensor. Have you read codes? Have you looked at actual values using ACC panel? You can pull plug at compressor and apply 12V directly to the clutch coil.
 

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1997 (I-6) E320
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7 Posts
Discussion Starter #6
Nope, the sensors are all fine, the only code it gives is for low refrigerant pressure... which I already knew. Nothing wrong but low line pressure, which wouldn't let me turn on the compressor to re pressurize the line. I think that is incredible. nothing more than a way to get you into the dealer. I found the procedure to bypass the lock out to get the compressor started again, so for the record:

"(Your A/C compressor has its own pressure switch, so overriding the 'EC' light will not compromise this safeguard.) Switch the ignition on (position 2). Set the left temperature to 'HI' and the right temperature to 'LO'. Switch the ignition off. While holding the 'REST' button, switch the ignition on (position 2). On the left side, 'P1' will flash and on the right side, a code will be displayed. Press the 'EC' button twice so that the left side flashes 'P2'. Using the right side red temperature increase button, add 16 to the value. Press the 'EC button again to store the updated code. Turn the ignition off."

I found this in the AC diagnostics in the DIY stickies, it was hard to find because there is no direct link to it.

Thanks everyone, I can tell this forum has some great members. It has already saved me well over $100.:)
 

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1996 210.020
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Tried the hot water thing. Did not work... Isn't there any way to over ride the system and get the compressor working?
There is not any way to override the system, other than to wire 12V directly to the compressor clutch and I strongly recommend against that due to various hazards, both to the equipment and your body.

Warming the can will work, but you'll have to be patient. You will have to keep reheating the water as evaporating refrigerant in the can cools it off. Perhaps a hair dryer aimed at the can will do it faster.

I use a heated cylinder to charge the car, which takes the place of the warm water. But whatever you do, it takes energy to get the refrigerant into the car.
 

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1997 (I-6) E320
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7 Posts
Discussion Starter #8
Hmm, perhaps you missed my post directly above yours Matt; There is a way to over ride the system. I found it, used it successfully and posted it for the record.
 

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1996 210.020
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That procedure won't work in all cases, Rankel. It does not dismiss the pressure reading entirely; it just seems to make it less sensitive. On the other hand, a heated charging cylinder does work in all cases (all brands and models of cars).
 

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1997 (I-6) E320
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Discussion Starter #10
Worked for me! Before telling people there is no way to do something and use a hair dryer instead I suggest telling people try to override the sensor first. submerging the can in hot water did nothing but make the valve on the pressure gauge start to leak... overriding the sensor... well, it worked.

Don't insist there is no way to do something when there is very obviously a way to do it. Even if it wont work in every single situation it is better than suggesting to everyone with a charging difficulty that they do something that seems to me to be potentially dangerous. Go legit first, use duct tape and hair dryers when all else fails.
 

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1996 210.020
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The reason that I suggested using heat is to prevent wear on your compressor. But it's your compressor; treat it how you will.
 

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E320/E250 Bluetec Ford F350 6.7l
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I can't make a sense from the situation above.
The low refrigerant switch is about 30 psi, the full can of R134 gives over 100 psi.
Once you statically pump 100 psi into the system, the low switch will activate the compressor and will keep it running as long as low pressure is above 30 psi.
It always worked like that for me.
 

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1999 E430
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22 Posts
THIS IS WHAT MOST PEOPLE ARE LOOKING FOR!

I found the procedure to bypass the lock out to get the compressor started again, so for the record:

"(Your A/C compressor has its own pressure switch, so overriding the 'EC' light will not compromise this safeguard.) Switch the ignition on (position 2). Set the left temperature to 'HI' and the right temperature to 'LO'. Switch the ignition off. While holding the 'REST' button, switch the ignition on (position 2). On the left side, 'P1' will flash and on the right side, a code will be displayed. Press the 'EC' button twice so that the left side flashes 'P2'. Using the right side red temperature increase button, add 16 to the value. Press the 'EC button again to store the updated code. Turn the ignition off."

I found this in the AC diagnostics in the DIY stickies, it was hard to find because there is no direct link to it.

Thanks everyone, I can tell this forum has some great members. It has already saved me well over $100.:)
I searched all over for this air conditioning compressor bypass economy mode procedure because I was tired of paying $100 per year to a mechanic for recharging. As usual the system loses just enough refrigerant through the winter to go into Economy mode. All it takes is 1 $7.00 can of R-132 to return everything to normal. Now it is done with $11.00 spent on the hose and $7.00 on the freon. TYVM
 

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W210
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13,885 Posts
Nope, the sensors are all fine, the only code it gives is for low refrigerant pressure... which I already knew. Nothing wrong but low line pressure, which wouldn't let me turn on the compressor to re pressurize the line. I think that is incredible. nothing more than a way to get you into the dealer. I found the procedure to bypass the lock out to get the compressor started again, so for the record:

"(Your A/C compressor has its own pressure switch, so overriding the 'EC' light will not compromise this safeguard.) Switch the ignition on (position 2). Set the left temperature to 'HI' and the right temperature to 'LO'. Switch the ignition off. While holding the 'REST' button, switch the ignition on (position 2). On the left side, 'P1' will flash and on the right side, a code will be displayed. Press the 'EC' button twice so that the left side flashes 'P2'. Using the right side red temperature increase button, add 16 to the value. Press the 'EC button again to store the updated code. Turn the ignition off."

I found this in the AC diagnostics in the DIY stickies, it was hard to find because there is no direct link to it.

Thanks everyone, I can tell this forum has some great members. It has already saved me well over $100.:)
I had to do this about 2 years ago and it worked for me also. Question is, after the recharge, do you have to go back and subtract 16 (to put it backj to factory setting) or will it reset it itself? Also, if you had added 16 to that number, will it cool less or more? Do you have to go back and subtract the 16 to put it back to the way it was?

Does adding 16 have an effect on the cooling? Does it make the compressor, compress less? What is the default value of this?

My AC now cools like anything, however unlike Nissans, it takes several MORE minutes to achieve it. Does the adding 16 have anything to do with that?
 

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1996 210.020
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There isn't a "default value" for all cars, CR. There's one value for your car.

Convert the number to binary and look in the 16's column to see if the bit is set. Adding refrigerant won't reset it. Adding 16 again will reset it (and set the 32's bit).

This doesn't affect cooling capacity. It only prevents compressor shutdown under certain circumstances.
 

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W210
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There isn't a "default value" for all cars, CR. There's one value for your car.

Convert the number to binary and look in the 16's column to see if the bit is set. Adding refrigerant won't reset it. Adding 16 again will reset it (and set the 32's bit).

This doesn't affect cooling capacity. It only prevents compressor shutdown under certain circumstances.
Thanks Matt:)
 

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1997 E300D
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71 Posts
EC Light

I think if you read the MB release notes, by adding 16 you disable the double redundancy? This should make the EC light from coming on and forcing your compressor off. It will still shut down if it needs too. but not via the Forced EC light.

Thats what I read from the bulliten below.

Here it is:

37/99-2 GROUP 83 - MODEL 210, CLIMATE CONTROL "EC" LAMP ON: *** UPDATE TO MB-NET MESSAGE NO. 220 DATED APRIL 16, 1999, DTB 17/99 ***: If you receive client complaints on model 210 of "the EC lamp on", please check the system according to the published diagnostic and service procedures. Check if the version coding is correct. Replace the refrigerant temperature sensor in every case. If the refrigerant quantity, temperature or pressure sensors are within the specified values, the low refrigerant level indication should be switched off via the HHT or via the on-board diagnostics (P2 value) as described below. Do not replace AAC push-button modules for this complaint.
Please note that "EC" lamp low refrigerant indication is a redundant feature. Disabling this feature does not compromise the safety of the AC system, because the AC compressor will switch off if low refrigerant (level) pressure is detected.
Switching of the "EC" lamp low refrigerant level detection via the AAC Push-button Control Module can be accomplished as follows:
Switch ignition to position 2.
Set the left temperature to "HI" and the right to "LO"
Switch the ignition off.
While holding the "REST" button, switch the ignition to pos. 2. On the left side of the display, "P1" will be blinking and on the right side, the version code is
displayed. Press the "EC" button, no change is needed for the P1 value.
Press the "EC" button again. "P2", will be blinking on the left side of the display and the value on the right side.
Record this value. Using the right side temperature (red) button add 16 to the displayed value.
Press the "EC" button to store the updated version code.
Turn the ignition off and on again. Reset the left and right side temperatures to 72?F (by pressing the red and blue buttons at the same time).
For warranty, please use Damage Code 83752 04.

57/99-2 GROUP 83 - MODEL 210, CLIMATE CONTROL "EC" LAMP ON: *** REPLACES MB-NET MESSAGE NO. 461 DATED AUGUST 25, 1999, DTB 37/99 ***: On Model 210, for conditions of the EC LED lamp on although the button has not been pressed, please replace the refrigerant temperature sensor to resolve this condition. The refrigerant temperature sensor may absorb moisture may cause incorrect values to transmit to the control module causing the air conditioning system to switch off. For warranty, please use Damage Code 83752.
 

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1997 E300D
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71 Posts
This form is the bomb. Saved me thousands. Every gremlin the E300 w210 has had > mine has been there. The blower regulator, the Car dying without any reason (K-40 Relay mod) has not died since replacement, Resonance flapper transducer, Car rattling like SH t, Motor mount replace, belt tensioner shock replaced.

And now my wife went a couple of hours out of town, and is now in Tucson without A/C and it's 108 deg. She tells me the EC light is forced on. A quick search, of this site will save me another 1K as she would have taken it in to get serviced and got hosed.
Thanks for everyone's postings and Stickys. I do all my own work and use all the information I can Find via the internet.
 

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1996 210.020
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3,972 Posts
The bulletin is essentially correct, Mr. Billy, but it does leave out a very important detail. Do not do this twice.

If it's done once at the dealer, they'll know that they did it and so will any other dealer. But you won't know (unless you happen to know the default coding).

To tell if it has been applied, convert the number to binary and look at the 16's bit.
 
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