Auto Dim for Passenger? W212
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2010 e350
Auto Dim for Passenger? W212
Hey guys,
So a few days ago, I managed to hit something, and my mirror has shattered for my car. I know that my car has auto-dim for driver (right) and rearview mirror, but unsure if my passenger (left) has auto dim. I have searched the VIN and has come up with the following:
249 - IINTERIOR AND EXTERIOR MIRROR, AUTOMATICALLY DIMMING
For reference, my car is an Australian model, not sure if that makes any difference.
The part number of the current mirror is A2128102121, but, does not come with auto dim
Any help is appreciated,
Thanks,
zain.arsh.04
So a few days ago, I managed to hit something, and my mirror has shattered for my car. I know that my car has auto-dim for driver (right) and rearview mirror, but unsure if my passenger (left) has auto dim. I have searched the VIN and has come up with the following:
249 - IINTERIOR AND EXTERIOR MIRROR, AUTOMATICALLY DIMMING
For reference, my car is an Australian model, not sure if that makes any difference.
The part number of the current mirror is A2128102121, but, does not come with auto dim
Any help is appreciated,
Thanks,
zain.arsh.04
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Joined: Apr 2019
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From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
SHATTERED OUTSIDE MIRROR
Hey guys,
So a few days ago, I managed to hit something, and my mirror has shattered for my car. I know that my car has auto-dim for driver (right) and rearview mirror, but unsure if my passenger (left) has auto dim. I have searched the VIN and has come up with the following:
249 - IINTERIOR AND EXTERIOR MIRROR, AUTOMATICALLY DIMMING
For reference, my car is an Australian model, not sure if that makes any difference.
The part number of the current mirror is A2128102121, but, does not come with auto dim
Any help is appreciated,
Thanks,
zain.arsh.04
So a few days ago, I managed to hit something, and my mirror has shattered for my car. I know that my car has auto-dim for driver (right) and rearview mirror, but unsure if my passenger (left) has auto dim. I have searched the VIN and has come up with the following:
249 - IINTERIOR AND EXTERIOR MIRROR, AUTOMATICALLY DIMMING
For reference, my car is an Australian model, not sure if that makes any difference.
The part number of the current mirror is A2128102121, but, does not come with auto dim
Any help is appreciated,
Thanks,
zain.arsh.04
The passenger side mirror does not dim.
While in there, you may be interested to unplug the mirror HEATER that I understand is always active.
Goo'Day
Last edited by CaliBenzDriver; Oct 15, 2025 at 05:23 PM.
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Posts: 33
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W212 facelift
Yes the mirror heater is always active but very small current and depend on the outside temp. So can unplug or not if you want.But I'm very interested in how to make the side mirror auto-dimming. I tried to look in the coding section of the passenger side mirror control module, it can activate the auto-dimming feature. However, I could not find the wiring diagram for the dimming-line out from control module to test. If you have the wiring diagram of the door control module, please show me the location of the auto-dimming supply so I can test and report back.
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From: Southern US
2010 E550, 273 Engine: 2012 S550, 278 Engine
Hi CaliBenz,
Yes the mirror heater is always active but very small current and depend on the outside temp. So can unplug or not if you want.But I'm very interested in how to make the side mirror auto-dimming. I tried to look in the coding section of the passenger side mirror control module, it can activate the auto-dimming feature. However, I could not find the wiring diagram for the dimming-line out from control module to test. If you have the wiring diagram of the door control module, please show me the location of the auto-dimming supply so I can test and report back.
Yes the mirror heater is always active but very small current and depend on the outside temp. So can unplug or not if you want.But I'm very interested in how to make the side mirror auto-dimming. I tried to look in the coding section of the passenger side mirror control module, it can activate the auto-dimming feature. However, I could not find the wiring diagram for the dimming-line out from control module to test. If you have the wiring diagram of the door control module, please show me the location of the auto-dimming supply so I can test and report back.
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Joined: Apr 2019
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From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
mirror heaters
How did you come up with the concept mirrors are controlled by the rear windows defrost?
It sounds like a good idea to have mirror heaters not always ON.
Last edited by CaliBenzDriver; Oct 16, 2025 at 12:58 AM.
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Joined: Apr 2019
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From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
CUSTOM MIRROR DIMMING
Hi CaliBenz,
Yes the mirror heater is always active but very small current and depend on the outside temp. So can unplug or not if you want.But I'm very interested in how to make the side mirror auto-dimming. I tried to look in the coding section of the passenger side mirror control module, it can activate the auto-dimming feature. However, I could not find the wiring diagram for the dimming-line out from control module to test. If you have the wiring diagram of the door control module, please show me the location of the auto-dimming supply so I can test and report back.
Yes the mirror heater is always active but very small current and depend on the outside temp. So can unplug or not if you want.But I'm very interested in how to make the side mirror auto-dimming. I tried to look in the coding section of the passenger side mirror control module, it can activate the auto-dimming feature. However, I could not find the wiring diagram for the dimming-line out from control module to test. If you have the wiring diagram of the door control module, please show me the location of the auto-dimming supply so I can test and report back.
There may be ways to...
-- purchase a dimmable US driver side mirror to use as your Australian passenger side
-- AND wire it to the DCU module comparing with the other side.
-- AND custom code the DCU function to enable passenger-side dimming.
Last edited by CaliBenzDriver; Oct 16, 2025 at 01:35 AM.
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MBWorld Fanatic!
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From: Southern US
2010 E550, 273 Engine: 2012 S550, 278 Engine
If my own MB has it ON at all times the power is extremely low as it does not do anything before I press the rear defrost.
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From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
AUTO DEFROST FEATURES
Every car I have driven so far has had mirror heaters working with rear defroster. And I have driven lots of different make rental cars in Canadian and up state winter conditions to find this out.
If my own MB has it ON at all times the power is extremely low as it does not do anything before I press the rear defrost.
If my own MB has it ON at all times the power is extremely low as it does not do anything before I press the rear defrost.
I haven't bothered too much documenting these DCU settings as I seldom defrost in mild California weather. There's something of interest in these settings (JR).
Have you seen how our WINDSHIELD glass features a built-in wipers defrost heater ?
I have seen it on my US car but don't know too much about its circuit activation: Auto or manual?
Last edited by CaliBenzDriver; Oct 16, 2025 at 02:14 PM.
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From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
it's easy to recognize a dimming mirror vs. non-dimming by looking at the glass for built-in pattern all around near the edges.
I've also wondered why Mercedes 2014 mirrors don't AUTO FOLD ... I rationalize the harness should last longer.
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From: Baltimore County, MD
'13 s212 63 p30. '06 LX470
I've wondered the exact same things about non-dimming passenger side...
it's easy to recognize a dimming mirror vs. non-dimming by looking at the glass for built-in pattern all around near the edges.
I've also wondered why Mercedes 2014 mirrors don't AUTO FOLD ... I rationalize the harness should last longer.
it's easy to recognize a dimming mirror vs. non-dimming by looking at the glass for built-in pattern all around near the edges.
I've also wondered why Mercedes 2014 mirrors don't AUTO FOLD ... I rationalize the harness should last longer.
Out Of Control!!
Joined: Apr 2019
Posts: 11,923
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From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
I shied away from fancy mirrors after having issues with convenience tilt colomn and sunroof plastics.
So far my basic mirrors can still reverse-tilt ok after visiting them for initial grease inspection.
MBWorld Fanatic!
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From: Southern US
2010 E550, 273 Engine: 2012 S550, 278 Engine
For me it says that the mirrors heaters come ON when the rear window defrost if activated AND it is cold enough temperature. It does not say how cold it needs to be but the heaters work from the button that activates the rear defrost.
MBWorld Fanatic!
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From: Baltimore County, MD
'13 s212 63 p30. '06 LX470
This is the way it’s always worked for me on any Mercedes. However, the old LX I drive as well has independent buttons for all of these features we’re talking about… I’m allowed to defrost the rear independently from the side mirrors :-)
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W212 MY'14 M276-3.5NA @75kMi
LOST IN TRANSLATION...
Look what I saw...
The setting PERMANENT (default) threw me off
It should read "UNLIMITED" or "Rear-Defrost"... since we know mirror defrost is not actually permanently powered ON.
DCU can shut off heater after time out
MIRROR HEATER TEMPS
Temps optional settings
Icant make sense of this setting besides Temp3 = (Temp1 + Temp2)
driver-side active options
There are available options to time out mirrors independently of the rear-defrost control.
mirror heater mode... PWM: YES. (DE translated EN)
Top level menu: modules selection
DCU Menu : Variant Coding
Variant menu: "Ext mirror"...
personalized options saved ... All set!
Last edited by CaliBenzDriver; Oct 18, 2025 at 12:15 AM.
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From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
CUSTOM CODED OPTIONS
I did this using the LAUNCH cReader MB Elite
acailable around $125 or so.
Both SAM's, NTG, IC-Display... modules can be Variant coded.
Be sure to backup your own module before trying new settings. Every car use slightly different config.
acailable around $125 or so.
Both SAM's, NTG, IC-Display... modules can be Variant coded.
Be sure to backup your own module before trying new settings. Every car use slightly different config.
