The AC diagnosis algorithm is hibernating for the winter to provide better answers in the summer.
In the meantime, use the comments box on the previous page to provide background info on the problem, sensor values, and error codes. I’ll take a look at them personally.
yes got error codes Eb1 234
Eb1 416
Eb1 241
E FF
what should I do next
Hi Jim, Thanks for sending the trouble codes (part 2). I'll also need the sensor values from part 1 above. Thanks.
Robbie,
It's hard to tell why you're A/C is not working based on the numbers.
Sensor #7 measures the pressure in the system. Mercedes was inconsistent with units of measure. Some cars report in pounds per square inch (PSI); others in bar. 1 bar = 14.5 psi. Your reading of 44 could be either very low or very high depending on whether it's reporting in units of bar or PSI.
If very low (measuring in PSI), you need a recharge.
If very high (measuring in bar), it means there's an obstruction in the high pressure side of the system, such as the evaporator expansion valve.
Recommend that you get a set of A/C gauges to measure the actual pressure in the system. Also, you should verify that the compressor is engaged (you'll see the compressor shaft turning, not just the pulley wheel.) Let me know what you find out.
Doug,
A couple follow-up questions:
1. Is your EC light stuck on?
2. Can you eyeball the compressor to make sure it's engaged?
3. Did you ever hear a “hissing” noise from behind the center vents?
4. Did you ever notice a temperature difference between the left center vent and the right center vent?
Please also send the numbers from the early mornings when the AC seems to be working.
I have a 98 that blows cold air for anywhere from 30 seconds to a few minutes than the a/c goes warm. Have an error code of eb1419 and the following values:
1=80, 2=60, 3=86, 4=86, 5=153, 6=129, 7=5, 8=76
I have a 02 E320. 1-75, 2-73, 3-60, 4-58, 5-42, 6-138, 7-08, 8-96. Error codes – b1234, b1416. Thanks for any help.
Symptoms…EC stuck on, needs recharging..(this happens about every 2-3 years or so, no one can find a leak…recharge it and good to go) problem is that I cannot get the compressor to engage so I can recharge it.
1=94 2=69 3=78 4=78 5=87 6=114(kept rising) 7=03 8=64
Error Codes B1- 416, 234, 416 and 241
Greg,
You have an error code for your refrigerant pressure sensor. When that sensor is bad, the climate control computer won't send power to the compressor. There is a backup sensor in the compressor. Follow these instructions to disable the primary (malfunctioning) sensor:
1. Switch the ignition on (position 2).
2. Set the left temperature to 'HI' and the right temperature to 'LO'.
3. Switch the ignition off.
4. 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.
5. Press the 'EC' button twice so that the left side flashes 'P2'.
6. Using the right side red temperature increase button, add 16 to the value.
7. Press the 'EC button again to store the updated code.
8. Turn the ignition off.
The compressor may engage at that point. It's difficult to recharge the system when the compressor is off since you need the compressor to suck the refrigerant out of the can into the system. Sometimes immersing the can in warm water while recharging will increase the pressure in the can enough to push the refrigerant into the system.
Andrew,
Don't know any of the history, but my guess is that you're having trouble with the left side vents being considerably warmer than the right. That is caused by a stuck duovalve. See the instructions here for leaning the duovalve:
http://www.benzworld.org/forums/w210-e-class/13...
You also may need a recharge.
See my reply above.
Error code B1241 indicates that you need a recharge. Probably developed a leak somewhere. The receiver-dryer canister, followed by the compressor itself and the evaporator at the most common sources.
The other error codes are inconsequential.
On the off chance that your problem is caused by a bad sensor, try these instructions to bypass the primary refrigerant pressure sensor:
1. Switch the ignition on (position 2).
2. Set the left temperature to 'HI' and the right temperature to 'LO'.
3. Switch the ignition off.
4. 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.
5. Press the 'EC' button twice so that the left side flashes 'P2'.
6. Using the right side red temperature increase button, add 16 to the value.
7. Press the 'EC button again to store the updated code.
8. Turn the ignition off.
Hi Rebecca,
Is your EC light on?
What pressures were you getting on the low side as your added refrigerant? Are you the refrigerant transferred out of the cans?
Can you send me the error codes also?
Is your EC light stuck on?
I think your problem is due to one or two bad sensors. Error code B1233 indicates the refrigerant temperature sensor has malfunctioned. Your evaporator temperature sensor may also be fried since it's reporting a temperature (136 degrees) that is implausibly hot.
Jeff,
It's difficult to add refrigerant with the compressor off. Are you certain all 4 cans emptied into the system? Try this to override the light and give the compressor the best chance to turn on ASAP:
1. Switch the ignition on (position 2).
2. Set the left temperature to 'HI' and the right temperature to 'LO'.
3. Switch the ignition off.
4. 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.
5. Press the 'EC' button twice so that the left side flashes 'P2'.
6. Using the right side red temperature increase button, add 16 to the value.
7. Press the 'EC button again to store the updated code.
8. Turn the ignition off.
Your problem is caused by a bad evaporator temperature sensor (#5). The air coming in from outside is not 153 degrees. That sensor is critical to ensuring that the evaporator core does not freeze and crack. When the sensor malfunctions, the compressor shuts down to protect the evaporator.
Brian,
What problem are you experiencing? Your numbers look great and there are no major error codes.
Tim,
The most common leaks are the receiver-dryer, the compressor, the condenser, and the evaporator (in roughly that order). It's hard to pick up the tracer dye when you have a very slow leak.
Try this to bypass the primary pressure switch:
1. Switch the ignition on (position 2).
2. Set the left temperature to 'HI' and the right temperature to 'LO'.
3. Switch the ignition off.
4. 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.
5. Press the 'EC' button twice so that the left side flashes 'P2'.
6. Using the right side red temperature increase button, add 16 to the value.
7. Press the 'EC button again to store the updated code.
8. Turn the ignition off.
You need the compressor engaged to draw refrigerant out of the can. If the above doesn't work, you could try immersing the can in warm water to increase the pressure inside the can (but not too hot so that the can explodes). Worst case you'd need to jump the compressor clutch to force it to engage.
sensor data
01 9
02 89
03 85
04 80
05 129
06 175
07 E
08 87
09 148
Error codes
Eb1 232
235
419
422
E FF
Help please. Readings: 1=46 2=26 3=41 4=40 5=38 6=46 7=00 8=25.
Error codes: E61=226, 227, 232, 234, and 422.
p.s. one thing for me that improved air flow was changing the cabin filters (4) on my 1997 e420.
pps. If you got paypal I can pay for a brew.
Hi, just picked up a nice w210 1998 TurboDiesel. Seems in great shape and well taken care of. AC seems to work OK, but warm (almost hot) air sometimes blows out of the driver side AC vent, when all the others (middle and passenger side) are blowing cold. Then sometimes when I start it up, it works fine, and then goes back to blowing hot air! Would appreciate any insight and guidance.
Here are my codes:
1-30, 2-37, 3-43, 4-9, 5-49, 6-82, 7-21, 8-59
Error Code: Eb1 – 231
WOOOOW, thanks sooo much Blake!! followed your directions to a tee….I might add that you should be patient once you enter the new code/value for the pressure switch. Nothing happened for about 30/45 seconds…. the ec light stayed on and no cold air…then when I was about to give up, I hit the ec button and heard a click…then it went off and ta daaa ice cold air. dont know if it was coincidence that i hit the button and it went off or if it just finished cycling to the new switch in the compressor. Either way, you got us a/c again, “bought ya a beer” too. Greg W
Hello, my 2000 E320 has a hissing sound when the A/C is operational. There is little if any cold air blowing. Here are the following codes: 1=85, 2=75, 3=87, 4=89, 5=85, 6=181, 7=06, 8=82. My error codes are as follows: Eb1=234, Eb1=235, E=FF
Thanks…not really a mechanic…but can fog a mirror. Attempted to get 2 1/2 or 3 cans into the system. New numbers are 1-82, 2-84, 3-164, 4-100, 5-105, 6-211, 7-17, 8-118. Only one error now…416.
I drive an 01 clk430
About a week ago I had my ac recharged. Yesterday it stopped blowing cold air. I think I have a major leak but am not sure where.
My codes are as follows:
1-84
2-90
3-87
4-88
5-85
6-171
7-6
8-86
e1 227
e1 231
e1 232
e1 416
e1 422
I'd appreciate your opinion, thanks a lot!
I drive an 01 clk430
About a week ago I had my ac recharged. Yesterday it stopped blowing cold air. I think I have a major leak but am not sure where.
My codes are as follows:
1-84
2-90
3-87
4-88
5-85
6-171
7-6
8-86
e1 227
e1 231
e1 232
e1 416
e1 422
I'd appreciate your opinion, thanks a lot!
Hi, sent you some codes yesterday and bought you a beer. wondering if you received or I didn't click right. Name was DieselDogGP, email was gt_hummel@comcast.net.
Hi,
You have at least two problems going on.
Problem #1 — Malfunctioning refrigerant pressure sensor. The sensor needs to be replaced. The sensor is showing zero pressure, but hopefully that reflects a problem with the sensor rather than an empty system. No doubt your EC light is on as a result. Follow these steps to bypass the pressure sensor and hopefully get cold air.
1. Switch the ignition on (position 2).
2. Set the left temperature to 'HI' and the right temperature to 'LO'.
3. Switch the ignition off.
4. 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.
5. Press the 'EC' button twice so that the left side flashes 'P2'.
6. Using the right side red temperature increase button, add 16 to the value.
7. Press the 'EC button again to store the updated code.
8. Turn the ignition off.
Problem #2 – In-car temperature sensor. The climate control has no idea how hot/cold the interior of the car is. Consequently, it doesn't know whether to send heat or air conditioning. The sensor needs to be replaced. In the meantime, set both sides to LO to force cold air.
You have at least one, maybe two, problems.
Numero uno: Malfunctioning refrigerant pressure sensor. The sensor needs to be replaced. The sensor is showing zero pressure, but hopefully that reflects a problem with the sensor rather than an empty system. No doubt your EC light is on as a result. Follow these steps to bypass the pressure sensor and hopefully get cold air.
1. Switch the ignition on (position 2).
2. Set the left temperature to 'HI' and the right temperature to 'LO'.
3. Switch the ignition off.
4. 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.
5. Press the 'EC' button twice so that the left side flashes 'P2'.
6. Using the right side red temperature increase button, add 16 to the value.
7. Press the 'EC button again to store the updated code.
8. Turn the ignition off.
Second (?) problem is the electromagnetic clutch on the compressor. This could indicate a serious problem with the compressor, but it's hard to tell since the refrigerant pressure sensor is bad. Try bypassing & replacing the sensor as described above before worrying about the compressor clutch.
Hello Blake,
I “Bought You A Beer” just to thank you for maintaining this resource, regardless of whether we get to the bottom of my a/c issues!
1998 E300 TurboDiesel, 199,700 miles. Was cooling some, but hot on left center vent (my reminder to add refrigerant every year or so). Hooked up manifold gauge set this afternoon and found just under 100 psi on high and low side. Engaged a/c and compressor clutch did not engage, therefore pressures did not change and of course, no cooling whatsoever.
Tonight I found your site, so please help me if you can!
Sensors: 1-26, 2-23, 3-28, 4-28, 5-27, 6-63, 7-05, 8-28
Ambient Temperature tonight was 57 degrees F (14 C)
Temp was higher this afternoon when gauges were checked.
Error Codes: Eb1419, Eb1231, Eb1234, Eb1419, Eb1459
Unless I wrote something down wrong, it gave Eb1419 twice.
Thanks in advance!
David
PS: I suggest checking refrigerant levels before replacing the Duovalve. Anybody need a perfectly good, but used Duovalve, (since I replaced mine a couple of years ago when the left center vent was hot and the right one was cold)!!
DieselDog,
Is sensor #4 really 9? Or is it 49?
There are two major causes of the left-to-right temperature differential: not enough A/C or too much eat. Most commonly, the “not enough A/C” problem is caused by low refrigerant and can be fixed by a recharge. Often with low refrigerant you'll hear a “hissing” noise coming from behind the center vents, particularly a slow fan speeds. Less commonly, the evaporator expansion valve can clog and mimic low refrigerant by restricting the flow of refrigerant into the evaporator. On the “too much heat” side of things, the heater valve sometimes sticks open on one side. I'll need you to confirm sensors #3 (left vent temp) & #4 (right vent temp) along with #5 at the time to tell if this is a problem.
Since your temperatures appear to be reported in celsius, I'm assuming the pressure (#7) is in units of PSI. If so, 21 PSI is too low. Most likely you need a recharge. I'll be more confident if I can get clarification on #3-5.
Greg,
Glad I could be of help. Thanks for the beer!
Bryan,
Looks like you need a recharge. Your refrigerant pressure is lower than expected and there are no signs of any other major problems. Can't guarantee that a recharge will solve everything — you could have a leak somewhere. But I think low refrigerant is at least the proximate cause of your problem.
Alex,
You have an error code for your refrigerant pressure sensor. Is your EC light stuck on? Can you verify that the compressor is engaged? Usually the compressor won't activate with a defective refrigerant pressure sensor. Your pressures look low but if the compressor is not engaged that is expected.
David,
Thank you for the beer! You are absolutely right about digging deeper before replacing parts!
You are on the right track about the refrigerant being low. I imagine your EC light is off — if so, here's what I envision happened.
At some point in the past, the refrigerant pressure sensor (#7) was bypassed. That sensor frequently causes trouble and can be bypassed as a short-term measure since there is a backup pressure sensor in the compressor itself.
Because the climate control computer is ignoring that pressure sensor, it relies on the compressor's built-in sensor to disengage the clutch when your refrigerant charge drops too low. The compressor refuses to engage, and the climate control computer has no idea why. Hence error code B1419 (compressor clutch). You have two B1419 codes because the first one is more recent.
You'll need to recharge. Easier said than done if the compressor won't engage. The compressor drops the low-side pressure, which is essential for sucking the R134a out of the can. Sometimes placing the can in warm/hot water will boost the pressure inside the can just enough to push a little refrigerant into the system and reactivate the compressor. The risk of course is that if the pressure in the can gets too high it'll explode. The safest alternative is to disconnect the compressor clutch lead and connect it to a 12V battery to force the compressor to engage while you inject the R134a.
I have a 1997 e320. Problems with a/c for several years. What does the hissing noise behind the vents indicate?
1–22
2–26
3–23
4–16
5–04
6–82
7–12
8–38
e61–227
“–234
“–235
“–239
“–ff
Vent to the left of driver blows heat while others blow cold. Other vents may be intermittant.
Thanks for your help. ( 1997 e 420)
97 E420
1-28,2-32,3-24,4-20,5-25,6-85,7-14,8-54
E61 – 227
E61 – 232
E61 – 234
E61 – 235
E FF
Driver side vents blow warmer than passenger side, both with EC On & Off
Thank You !
Hello,
I have a 2000 CLK 430 and the charge was low and the EC light was on. I replaced a hose and recharged but I need to reset the EC light. If I turn the ignition on and press the EC button, turn ignition back on and then push the EC it turns off and the AC works great. How do I reset so the EC will stay off.
1 82
2 100
3 60
4 60
5 38
6 181
7 14
8 122
Codes are Eb1 232, 233,241,416
Thanks,
kurt
Hello there! First of all, this is really some amazing info You are sharing with us! Thanks a million!
Bought recently a 290 TDT -97, EC light stuck on, no soothing cool air for anyone in the vehicle.
Values: 1:27. 2:16. 3:31. 4:33. 5:14. 6:80. 7:03. 8:36.
Error codes: E61: 227, 231, 234, 416, 459 and 241.
Btw after reading the error codes, pressing “rest” did not do a thing. Switched off the ignition and switced on, everything back to “normal”.
According to former owner, everything was working perfectly well, suddenly, when driving, “EC” light came on and that was the last time the interior temperature in the vehicle was lower than the ambient one.
outside temp was 70F, sunny day, windows were closed. Inside temp was around 95. Opened windows to cool down
here are the readings (in F )
1 = 103 (dropped to 87 after windows opened), 2 = 67, 3 = 84 (rose to 105 when eng hot), 4 = 84 (rose to 107 with eng hot) , 5 = 120, 6 = 118 (rose to 182), 7 = 04, 8= 67 (rose to 75),
error codes = E61 234/235/241/FF
I plugged a freon bottle with a gage to the low pressure port yesterday and it was reading in the overcharged zone around 50PSI. Today is a bit warmer and I left the engine run longer. When I plugged the gage again the pressure read 90 PSI (RED zone). The a/c clutch is not engaging so that maybe normal with a system when not operating.
Can this be a faulty Freon pressure sensor?
I did hear some hissing sound coming from the center vents some times in the past years. It seemed that loading up more freon reduced that sound.
Your help is appreciated. Thanks
Hey everyone, just returned from a trip — will work this evening on answering the backlog from the past couple days!
First of all a big thank you for writing this how-to and helping many of us.
I have a 02 W208 CLK 320, the airco unit should be identical (afaik)
It is stuck on the EC button
Sensor readings:
1 – 29
2 – 16
3 – 41
4 – 41
5 – 19
6 – 63
7 – 4
8 – 17
Error codes:
Eb1241
E FF
Looking through the other cases, I probably need a recharge or it's a faulty sensor.
If it is a recharge, how do i do this myself? (because Mercedes charges a bit too much for this)
And how does one replace the sensor? Is bypassing it a safe option?
The weird thing is that my Mercedes garage did a full refill less than 9 months ago and they put in the fluorescent colorant so that they could see potential leaks. after a month I went back and they couldnt see anything fluorescent, so the system is OK, or so they said…
I'm just worried that this is going to cost me a lot of $$$
First of all a big thank you for writing this how-to and helping many of us.
I have a 02 W208 CLK 320, the airco unit should be identical (afaik)
It is stuck on the EC button
Sensor readings:
1 – 29
2 – 16
3 – 41
4 – 41
5 – 19
6 – 63
7 – 4
8 – 17
Error codes:
Eb1241
E FF
Looking through the other cases, I probably need a recharge or it's a faulty sensor.
If it is a recharge, how do i do this myself? (because Mercedes charges a bit too much for this)
And how does one replace the sensor? Is bypassing it a safe option?
The weird thing is that my Mercedes garage did a full refill less than 9 months ago and they put in the fluorescent colorant so that they could see potential leaks. after a month I went back and they couldnt see anything fluorescent, so the system is OK, or so they said…
I'm just worried that this is going to cost me a lot of $$$
I have a 99 E320 and the EC is stuck on. My codes are as follows: 1=82, 2=73, 3=87, 4=91 5=107, 6=175, 7=06, 8=85 and the error codes are Eb1 234, Eb1 416; Eb1 426: Eb1 426: Eb1 241 and E FF. Please let me know if you might know what's wrong.
Thanks. The problem ended up being a leak in hose. Had the hose replaced, a recharge, and am now back in business!
Hi Blake,
My S320 (1999) A/C seems to not blow much air out of any of the vents with the exception of the rear vent located between the two front seats. I also noticed that hot air comes out of the defrost area near the windshield when the A/C is set for cooling. Ambient temperature was 57 F on the day this data was taken.
Here are the readings from the sensors:
1 75
2 64
3 69
4 71
5 38
6 145
7 11
8 114
error codes:
Eb1 425
Eb1 424
Thanks for your help.
Regards,
David
First of all a big thank you for writing this how-to and helping many of us.
I have a 02 W208 CLK 320, the airco unit should be identical (afaik)
It is stuck on the EC button
Sensor readings:
1 – 29
2 – 16
3 – 41
4 – 41
5 – 19
6 – 63
7 – 4
8 – 17
Error codes:
Eb1241
E FF
Looking through the other cases, I probably need a recharge or it's a faulty sensor.
If it is a recharge, how do i do this myself? (because Mercedes charges a bit too much for this)
And how does one replace the sensor? Is bypassing it a safe option?
The weird thing is that my Mercedes garage did a full refill less than 9 months ago and they put in the fluorescent colorant so that they could see potential leaks. after a month I went back and they couldnt see anything fluorescent, so the system is OK, or so they said…
I'm just worried that this is going to cost me a lot of $$$
Hi,
I'll get you a beer, you can be sure. If you only can help me out of this.. Going on now for months and years. First with the old compressor that finally completely died, now with a new compressor, dryer and completely cleaned and recharged system. As I found your article here, A/C started working for 2 days ! I thought – imposssible, but now it just does for 5 minutes at max and shuts off while driving. Here are my sensor values from 2 following days:
1 – 38/39 38/39/37/36/35/34/35/34/33/34/36/37/36/35 changing in 1 sec intervall
2 – 40/41/42/43 40/41
3 – 03 07/06
4 – 04 06
5 – 59 59
6 – 83 84
7 – 10/09 10
8 – 40 41/42/41/42
Error codes weren't there. I got just E – FF and any attempt to switch to the next one was like blocked. It just clicked, blinked and stayed in this E- FF.
Thanks in advance
Alex
direct email: info@al-dorado.com
Jools, As far as I can tell there is no rhyme or reason for the units variation. Haven't noticed any pattern to it.
In many cases, a bad sensor will cause the EC light to stay on. Not always though. You can still have a bad sensor if the EC light is off.