AC one side cold another warm. Please help!
#1
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AC one side cold another warm. Please help!
Hi, my 10 e350 is blowing warm air on the left but cold on the right. She is a right hand drive. AC control sets as 17C without "zone" on. Any advice on diagnosis and repair? Thanks.
#2
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'71 Pinto
Check refrigerant.
#3
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1922 Ford Model T / no OBD
Spend 90 or so seconds on troubleshooting before sledge-hammering the issue.
You will need scanner for W212 to read, but with a dozen of different sensors and sophisticated programs MB incorporate in the system, better do it the right way.
You will need scanner for W212 to read, but with a dozen of different sensors and sophisticated programs MB incorporate in the system, better do it the right way.
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2012 E550 sedan 2019 E63 Wagon
Please for the love of god, someone sticky my fix. I mentioned this in at least in 3 different threads. Cycle the passenger from coldest to hottest in non stop succession for 6 times. LOW to HI non stop, it will dislodge the flap.
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#5
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Thanks all for your help! Unfortunately, the issue cannot be fixed after having serval rounds of HI-LOW rotations in these two days.
Now, I am thinking of getting a scanner. Any recommendations? ICarsoft MB? V2 or 3?
Now, I am thinking of getting a scanner. Any recommendations? ICarsoft MB? V2 or 3?
#6
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1922 Ford Model T / no OBD
Lately Thinkcar seems to be best deal.
https://www.homedepot.com/p/Thinkdia...DIAG/316829802
But the explanation of the subscriptions is murky, so read the fine print.
I bought Autel AH2000 a year ago for $49 and it is excelent scanner. I think it was over a year ago and it still works without additional subscription, but I register it for Sprinter and it will not work on my MB sedan without paying more..
https://www.homedepot.com/p/Thinkdia...DIAG/316829802
But the explanation of the subscriptions is murky, so read the fine print.
I bought Autel AH2000 a year ago for $49 and it is excelent scanner. I think it was over a year ago and it still works without additional subscription, but I register it for Sprinter and it will not work on my MB sedan without paying more..
Last edited by kajtek1; 08-04-2021 at 10:27 AM.
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MY'14 W212 M276 3.5NA @60kMi
mixing flaps
take a look at either side of the central airbox from footwell under the dash.. you'll see control modules for "mixing air vents" .
> Maintenance steps:
Remove one unit from both side, Crack open casing, clean, silicon LUBE, reinstall, clear codes check temps are back under control.... call chiropractor for a spinal adjustment
> Maintenance steps:
Remove one unit from both side, Crack open casing, clean, silicon LUBE, reinstall, clear codes check temps are back under control.... call chiropractor for a spinal adjustment
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S. Madman (08-05-2021)
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#8
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Just checked again with the following specific symptoms :
"Zone" ON
Outside temp: 32C
First, set both side to LOW -> warm air out from faulty side (left), cold air out from the right
Then, turn both sides to HI -> hot air out from both side
Then, turn both sides to LOW again -> warm air out from left, cold air from right.
I am not sure how the mixing flap works. It seems to me that the faulty side could offer warm air normally but can not be able to give out cold air. Is the mixing flap problem?
"Zone" ON
Outside temp: 32C
First, set both side to LOW -> warm air out from faulty side (left), cold air out from the right
Then, turn both sides to HI -> hot air out from both side
Then, turn both sides to LOW again -> warm air out from left, cold air from right.
I am not sure how the mixing flap works. It seems to me that the faulty side could offer warm air normally but can not be able to give out cold air. Is the mixing flap problem?
#10
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I am not a pro and am confusing if the mixing flap (actuator) could still work but only halfway so it can only move to one side (letting hot air in) but not the other!? Any advice?
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2012 E550 sedan 2019 E63 Wagon
Thanks S.Madman. The faulty side could blow hot air when at HI, but could not offer cold air (just give out some warm air) when at LOW.
I am not a pro and am confusing if the mixing flap (actuator) could still work but only halfway so it can only move to one side (letting hot air in) but not the other!? Any advice?
I am not a pro and am confusing if the mixing flap (actuator) could still work but only halfway so it can only move to one side (letting hot air in) but not the other!? Any advice?
I should make a video.
Last edited by S. Madman; 08-05-2021 at 06:46 AM.
#12
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Thread Starter
Something physically is holding it down, you don't have a tri zone w212, so it's not gas, more thank likely that flap is jammed up to a certain point. And just to clarify again, when you go from lo hi lo hi lo hi lo, you are not stopping, correct? You should be doing non stop with no pauses in between.
I should make a video.
I should make a video.
Will do the circles later today to resuscitate the unit again!
#13
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Rounds of HILOWs again. No improvement.. Will probably get a scanner for a test.
BTW, is it possible that the left (faulty side) footwell temperature sensor is not working anymore so it sends wrong message to the control unit for stopping any cold air mixing?
BTW, is it possible that the left (faulty side) footwell temperature sensor is not working anymore so it sends wrong message to the control unit for stopping any cold air mixing?
#14
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1922 Ford Model T / no OBD
Read the reply #3.
With dozens different sensors in the system, reading coffee grinds delivers very low probability of finding the trouble.
With dozens different sensors in the system, reading coffee grinds delivers very low probability of finding the trouble.
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#16
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MY'14 W212 M276 3.5NA @60kMi
minus 50C!! 🤔
well .... you may have found something!
is this OCP module in the weeds?
This may very explain why the HVAC controller is not freezing the driver any further...
I've being up close with the OCP module, it is dependable.
The HVAC logic is not treating -50C as out of range, so you get no code but as a result no heat either.
Pull the fuse and reset things around (OCP, HVAC,...) to get that temperature sensor back online. Definitely a direction worth looking into!
Do you have any other module faults that seem unrelated and may impact the OCP/HVAC CAN-B ??
Do clean your tiny fan up in the OCP... packed with cabin dust!! -50C reading may be a Benz trick to get your attention (ie. $$$$).
is this OCP module in the weeds?
This may very explain why the HVAC controller is not freezing the driver any further...
I've being up close with the OCP module, it is dependable.
The HVAC logic is not treating -50C as out of range, so you get no code but as a result no heat either.
Pull the fuse and reset things around (OCP, HVAC,...) to get that temperature sensor back online. Definitely a direction worth looking into!
Do you have any other module faults that seem unrelated and may impact the OCP/HVAC CAN-B ??
Do clean your tiny fan up in the OCP... packed with cabin dust!! -50C reading may be a Benz trick to get your attention (ie. $$$$).
Last edited by CaliBenzDriver; 08-24-2021 at 12:25 AM.
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1922 Ford Model T / no OBD
I always like to start troubleshooting with sensor calibration test.
Get to the car in the morning before sun can hit it and without starting the engine read all the sensors.
All temperatures should be the same, what should confirm the bad sensor as well.
Get to the car in the morning before sun can hit it and without starting the engine read all the sensors.
All temperatures should be the same, what should confirm the bad sensor as well.
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#18
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MY'14 W212 M276 3.5NA @60kMi
Having done that, do you know what may cause temp. sensors to tell lies to the local controller ??
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1922 Ford Model T / no OBD
Thermistors fail occasionally and since the sensors will not take your mortgage, most of owners just buy new one.
Few years back, Turkish owner of W210 went into measuring thermistor and replacing thermistor only. I remember the fix cost him about 2 bucks, but some time for ordering and soldering.
Few years back, Turkish owner of W210 went into measuring thermistor and replacing thermistor only. I remember the fix cost him about 2 bucks, but some time for ordering and soldering.
#20
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well .... you may have found something!
is this OCP module in the weeds?
This may very explain why the HVAC controller is not freezing the driver any further...
I've being up close with the OCP module, it is dependable.
The HVAC logic is not treating -50C as out of range, so you get no code but as a result no heat either.
Pull the fuse and reset things around (OCP, HVAC,...) to get that temperature sensor back online. Definitely a direction worth looking into!
Do you have any other module faults that seem unrelated and may impact the OCP/HVAC CAN-B ??
Do clean your tiny fan up in the OCP... packed with cabin dust!! -50C reading may be a Benz trick to get your attention (ie. $$$$).
is this OCP module in the weeds?
This may very explain why the HVAC controller is not freezing the driver any further...
I've being up close with the OCP module, it is dependable.
The HVAC logic is not treating -50C as out of range, so you get no code but as a result no heat either.
Pull the fuse and reset things around (OCP, HVAC,...) to get that temperature sensor back online. Definitely a direction worth looking into!
Do you have any other module faults that seem unrelated and may impact the OCP/HVAC CAN-B ??
Do clean your tiny fan up in the OCP... packed with cabin dust!! -50C reading may be a Benz trick to get your attention (ie. $$$$).
A quick test on AC done. Luckily, no issue....
Last edited by My W212; 08-24-2021 at 02:08 AM.
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MY'14 W212 M276 3.5NA @60kMi
ok?
Was this left side vs. right problem fixed by dealing with your OCP Sensor?
BTW in this thread your pressure is shown to climb to 13Bar, which is good sign 👍
BTW in this thread your pressure is shown to climb to 13Bar, which is good sign 👍
#23
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Not yet. More problem to come : (
Last edited by My W212; 08-29-2021 at 02:00 AM.
#24
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Sensor or compressor problem ?
Very frustrated after Googling and reading below....
The above said that the compressor is controlled by temperature inputs from the sensors. If this is the case, the faulty OCP temp sensor should firstly be dealt with in order to avoid sending wrong signal (my case is -50C) to the compressor and asking the compressor to stop producing enough pressure for cooling.
Please help if you have any advice. Million thanks.
The above said that the compressor is controlled by temperature inputs from the sensors. If this is the case, the faulty OCP temp sensor should firstly be dealt with in order to avoid sending wrong signal (my case is -50C) to the compressor and asking the compressor to stop producing enough pressure for cooling.
Please help if you have any advice. Million thanks.