W205 heater wing mirror logic?

[elan362]

Can anyone advise on how the heater wing mirrors work or the logic behind them?
Are they always on? only on when rear demister is on? linket to Temperature and wipers? etc?

on my BMW's, the heated rear view mirror logic was linked to outside temp and wiper operation as follows

With wipers switched off:
Below 5°C = 100% continuous heating
Above 5°C = 0% heating

With wipers switched on:
Below 5°C = 100% continuous heating
From 5 to 10°C = 75% heating
From 10 to 15°C = 50% heating
From 15 to 20°C = 25% heating
Above 20°C = 0% heating

 

[Petrol Pete]

Never thought of this before, but as far as I know every car I have ever had activates the mirror heaters when the rear screen heater is switched on. I will be interested to see what others say on here. A question a bit like 'when do my headlamp washer jets activate ?' . On early some older cars I have had they only spray when the lights are on and the screen washers are manually operated, I now know thats not the case with more modern cars.

 

[elan362]

The BMW heated mirror logic was good as it meant the mirrors dried in rain even if the temperature was >5c, when you are unlikely to use / need to have the heated rear screen on

 

[ernie]

Like others, I've never really thought about it but from observation, my mirror heaters seem to work independently of the rear screen heater. That said, there must be an outside temperature link somewhere but not sure what that criterion is.

Ernie

 

[clk320x]

I’ve never thought about this so whatever way they work must be good

 

[whitenemesis]

Not sure if the same applies to the more modern models but WIS states for the 203 and 219 the door mirror heaters come on below ~12c when the IGN is on. So basically, on permanently in the UK...

 

[Gallon]

From WIS for the w205
Heated mirrors activate when the the heated rear screen is on & will also activate via temperature dependant control as explained below.

 

[elan362]

^^ thanks...
That is really interesting. A bit more sophisticated than simply "always on" or "only on when rear demister on"

 

[rf065]

^^ thanks...
That is really interesting. A bit more sophisticated than simply "always on" or "only on when rear demister on"

I can confirm on mine that they work without the rear screen switched on, but what I'd like to know is why the passenger side always clears the mirror when the drivers side takes twice as long to do the same?

 

[Wabby]

I can confirm on mine that they work without the rear screen switched on, but what I'd like to know is why the passenger side always clears the mirror when the drivers side takes twice as long to do the same?

I'm now going to cause you frustration like you have never felt before. I apologise.

One of the mirrors is 2 INCHES bigger than the other.
Hence the different melting rates.

 

[Gallon]

Funny that my drivers side also takes twice as long to clear & I've tested both the element in the mirror & the power supply both OK. As for mirror size mine are the same on both sides.

 

[rf065]

One of the mirrors is 2 INCHES bigger than the other.
Hence the different melting rates.

Not on mine, nice theory though!

 

[Delderek]

Drivers mirror definitely larger on my w205 se.

 

[elan362]

I am surprised. I thought my mirrors were the same size but no, the passenger mirror is larger than the driver mirror!



Sent from my iPhone using Tapatalk

 

[rf065]

Not much in it though, never 2".

 

[elan362]

Not much in it though, never 2".

Yip, I agree. Not a lot in it.

 

[Wabby]

Not much in it though, never 2".

2" on the C205 - I assumed they would use the same mirrors? Or maybe the driving assistance pack also adds girth to them?

 

[John N]

From WIS for the w205
Heated mirrors activate when the the heated rear screen is on & will also activate via temperature dependant control as explained below.View attachment 84954

Slight Post Highjack!

With all of this amazing wiggly AMP wizardly ensuring that the RH Mirror and the LH Mirror is constantly comparing the Inside and Outside Temperature and comparing both with T=2 C!

The Outside Temperature reading on the Dash STILL can't be engineered to Flash in order to make the Driver aware that the Temperature is at or below Freezing Point!

 

[rf065]

2" on the C205 - I assumed they would use the same mirrors? Or maybe the driving assistance pack also adds girth to them?

Not all W205's, maybe the coupe has a smaller mirror than the saloons or estates?

 

[BMF]

This is something I'd never thought about or questioned...… Now where did I put my tape measure