HVAC 'rest' function on a 2016?
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MBWorld Fanatic!
Joined: Dec 2005
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From: SoCal. Desert
'16 E350, gone: '03 c230k
HVAC 'rest' function on a 2016?
My old W203 had a 'rest' function with the climate control, where after shutting the car off you could hit the A/C button and the car would circulate the warm coolant and put the fan on low for the occupants of the car. I don't have this on my 2016 nor have I seen it on any other 2016/facelift W212's. I'm wondering if this feature was only available thru a specific option package, if it was discontinued, or if there is some hidden way of activating it?
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From: V E G A S
1922 Ford Model T / no OBD
REST become rare option on W211 and completely deleted on W212.
My only guess is that too many owners had "battery problems" due to it.
On other hand, electric cabin heaters become standard for cold climates, so owners of those can get the cabin cozy very fast once they start the engine.
For those who really want the car warm - Chinese make decent clones of Webasto. I just bought $100 unit for my Sprinter, where installation is a breeze.
A bit more work to fit it on sedan, but keeping your behind warm in snow storm -PRICELESS.
My only guess is that too many owners had "battery problems" due to it.
On other hand, electric cabin heaters become standard for cold climates, so owners of those can get the cabin cozy very fast once they start the engine.
For those who really want the car warm - Chinese make decent clones of Webasto. I just bought $100 unit for my Sprinter, where installation is a breeze.
A bit more work to fit it on sedan, but keeping your behind warm in snow storm -PRICELESS.
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From: Dallas-Ft.Worth,TX
2016 E350 Sport
On my older MB (W203), "Rest" function was/is the only way to turn off the A/C in the Spring/Fall months. 99% of the time, I used Rest for that purpose, rather than to keep the cabin warm with residual heat.
In the Winter, I found that cabin heat worked as well in Rest mode as it did in AUTO mode. So, in general, I've kept it in Rest mode 7 months of the year (Oct--Apr), using AUTO mode only in the heat of the Summer... here in the hotter Dallas TX area.
The W212 has a proper "Off" button, so that works well for me.
BTW, it's funny to me that in 2001, the buzz here was focused on how to turn the system off. Now, some miss it...
In the Winter, I found that cabin heat worked as well in Rest mode as it did in AUTO mode. So, in general, I've kept it in Rest mode 7 months of the year (Oct--Apr), using AUTO mode only in the heat of the Summer... here in the hotter Dallas TX area.
The W212 has a proper "Off" button, so that works well for me.
BTW, it's funny to me that in 2001, the buzz here was focused on how to turn the system off. Now, some miss it...
Last edited by DFWdude; Mar 18, 2020 at 07:44 AM.
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MBWorld Fanatic!
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From: Dallas-Ft.Worth,TX
2016 E350 Sport
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From: V E G A S
1922 Ford Model T / no OBD
You'd be amazed how much drivers who do have AC in Germany are using it. Bare in mind that humidity plays huge role how human feel the heat.
I grew up in Poland, where 25C/77F was heat wave. Years in California and 77F become sweater weather.
Now 3 years in Las Vegas, where people wear hoodies at 90F.
Than sun is additional factor. Quite often we go with dogs on desert, when morning temperature is 50F. With clear sky, the sun makes me sweating in T-shirt. That's huge difference even to California who is famous as sunnystate.
I grew up in Poland, where 25C/77F was heat wave. Years in California and 77F become sweater weather.
Now 3 years in Las Vegas, where people wear hoodies at 90F.
Than sun is additional factor. Quite often we go with dogs on desert, when morning temperature is 50F. With clear sky, the sun makes me sweating in T-shirt. That's huge difference even to California who is famous as sunnystate.
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From: Southern US
2010 E550, 273 Engine: 2012 S550, 278 Engine
My car has the pump right in front of the coolant reservoir but I don’t have any way to turn it on. I would like it to circulate the coolant after engine is shut off just to eliminate the coolant boiling in the hot spots of the engine until it has cooled down.
The Audi Q7 I had in the past had this feature and I was told it was for the health of the engine but perhaps it was for the cabin heating at the same time?
The Audi Q7 I had in the past had this feature and I was told it was for the health of the engine but perhaps it was for the cabin heating at the same time?
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Joined: Mar 2020
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2010 E350
New owner of a Canadian 2010 E350. Between the heated steering wheel, the 'rest' function and heated seats that stay on when the engine is off its the best winter optioned car I've had. (not to mention the rear wheel biased awd). The rest function works so well I usually turn it off after 5mins or so.
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From: V E G A S
1922 Ford Model T / no OBD
My car has the pump right in front of the coolant reservoir but I don’t have any way to turn it on. I would like it to circulate the coolant after engine is shut off just to eliminate the coolant boiling in the hot spots of the engine until it has cooled down.
The Audi Q7 I had in the past had this feature and I was told it was for the health of the engine but perhaps it was for the cabin heating at the same time?
The Audi Q7 I had in the past had this feature and I was told it was for the health of the engine but perhaps it was for the cabin heating at the same time?
Per my experience MB engines are much more efficient than Audi engines, so less heat produced to start with.
MBWorld Fanatic!
Joined: Jan 2009
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From: V E G A S
1922 Ford Model T / no OBD
New owner of a Canadian 2010 E350. Between the heated steering wheel, the 'rest' function and heated seats that stay on when the engine is off its the best winter optioned car I've had. (not to mention the rear wheel biased awd). The rest function works so well I usually turn it off after 5mins or so.
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From: Southern US
2010 E550, 273 Engine: 2012 S550, 278 Engine
They made "hot spots cooling" program on SUVs, where those engines work harder, but MB engineers figure out 200-300 HP engines in sedan work very light, so no need for extra cooling.
Per my experience MB engines are much more efficient than Audi engines, so less heat produced to start with.
Per my experience MB engines are much more efficient than Audi engines, so less heat produced to start with.
I know 99.9% (or more) of world's cars don't have any hot spot cooling but as my car has the hardware for it why in the hell is it not used?
I'm seriously thinking of installing a timer that would run the pump for 5 or so minutes after every time I stop the engine. I cannot see any harm coming from this.
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From: V E G A S
1922 Ford Model T / no OBD
As I said, the hot spot cooling is not needed on sedans.
I drive Ford Powerstrokes for years and since I was using my trucks for hauling 30,000 lb rigs, the engines did have hot spots.
But Ford never installed any aux coolant pumps on them. I had to observe idling the engine for couple of minutes before shut down each time I hauled.
I drive Ford Powerstrokes for years and since I was using my trucks for hauling 30,000 lb rigs, the engines did have hot spots.
But Ford never installed any aux coolant pumps on them. I had to observe idling the engine for couple of minutes before shut down each time I hauled.
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From: Jakarta-Indonesia
2014 - W212.065 - E400 ( M276.820, 3 liter Turbo) RWD not Hybrid
Dang...what a coincidence this post is.
I just discovered today that, after running on the highway at good speed for 20+ miles and almost zero traffic ( due to Covid-19 semi or soft lock down of my city ), my evaporator blower unit actually run as low speed
for +-30 minute after engine shut down. Its consuming about 4 amps, that is a whopping 48 watts. Car doors are locked, hood open.
I did not hear any electric pump noise though... but will investigate next time. There is only 1 electric pump, but it is for the turbo coolant which has its own baby reservoir.
I also did not check if the HVAC control is ON or not.... but will investigate next time. I stumbled upon this post when the blower is already off and my W212 is totally sleeping already.
NO, my W212 does not have rest function, I am in the tropics and do not need heating up the car interior.
Is the the way MB W212 face-lift dry out the evaporator core to prevent mildew/smell growth ? Perhaps.
I just discovered today that, after running on the highway at good speed for 20+ miles and almost zero traffic ( due to Covid-19 semi or soft lock down of my city ), my evaporator blower unit actually run as low speed
for +-30 minute after engine shut down. Its consuming about 4 amps, that is a whopping 48 watts. Car doors are locked, hood open.
I did not hear any electric pump noise though... but will investigate next time. There is only 1 electric pump, but it is for the turbo coolant which has its own baby reservoir.
I also did not check if the HVAC control is ON or not.... but will investigate next time. I stumbled upon this post when the blower is already off and my W212 is totally sleeping already.
NO, my W212 does not have rest function, I am in the tropics and do not need heating up the car interior.
Is the the way MB W212 face-lift dry out the evaporator core to prevent mildew/smell growth ? Perhaps.
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Joined: Jul 2008
Posts: 8,384
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2019 G70 6MT & 2022 Ford Maverick XL
Dang...what a coincidence this post is.
I just discovered today that, after running on the highway at good speed for 20+ miles and almost zero traffic ( due to Covid-19 semi or soft lock down of my city ), my evaporator blower unit actually run as low speed
for +-30 minute after engine shut down. Its consuming about 4 amps, that is a whopping 48 watts. Car doors are locked, hood open.
I did not hear any electric pump noise though... but will investigate next time. There is only 1 electric pump, but it is for the turbo coolant which has its own baby reservoir.
I also did not check if the HVAC control is ON or not.... but will investigate next time. I stumbled upon this post when the blower is already off and my W212 is totally sleeping already.
NO, my W212 does not have rest function, I am in the tropics and do not need heating up the car interior.
Is the the way MB W212 face-lift dry out the evaporator core to prevent mildew/smell growth ? Perhaps.
I just discovered today that, after running on the highway at good speed for 20+ miles and almost zero traffic ( due to Covid-19 semi or soft lock down of my city ), my evaporator blower unit actually run as low speed
for +-30 minute after engine shut down. Its consuming about 4 amps, that is a whopping 48 watts. Car doors are locked, hood open.
I did not hear any electric pump noise though... but will investigate next time. There is only 1 electric pump, but it is for the turbo coolant which has its own baby reservoir.
I also did not check if the HVAC control is ON or not.... but will investigate next time. I stumbled upon this post when the blower is already off and my W212 is totally sleeping already.
NO, my W212 does not have rest function, I am in the tropics and do not need heating up the car interior.
Is the the way MB W212 face-lift dry out the evaporator core to prevent mildew/smell growth ? Perhaps.
MBWorld Fanatic!
Joined: May 2018
Posts: 6,646
Likes: 6,595
From: Jakarta-Indonesia
2014 - W212.065 - E400 ( M276.820, 3 liter Turbo) RWD not Hybrid
If I did not open the blower water separator box which is on top of my battery approx 20 minutes after engine shut down, I would not realize the blower is spinning.
It was practically noiseless due to low speed. You must see the blower phsically spinning....I doubt you can hear it.
I will check again next time if this occurence is ALWAYS or some other condition/s of HVAC system must be met.
It was practically noiseless due to low speed. You must see the blower phsically spinning....I doubt you can hear it.
I will check again next time if this occurence is ALWAYS or some other condition/s of HVAC system must be met.
MBWorld Fanatic!
Joined: May 2018
Posts: 6,646
Likes: 6,595
From: Jakarta-Indonesia
2014 - W212.065 - E400 ( M276.820, 3 liter Turbo) RWD not Hybrid
I also do not know which version of headlight get such cooling down. Logic says it must be the LED type as LED module itself is poor with temperature exceeding 65 Celcius.
What kind of headlight/s on yours with the auto cooling down ?
My headlight is this type :
MBWorld Fanatic!
Joined: May 2018
Posts: 6,646
Likes: 6,595
From: Jakarta-Indonesia
2014 - W212.065 - E400 ( M276.820, 3 liter Turbo) RWD not Hybrid
Interesting guys, well noted..... I must investigate if mine which is NOT a USA version with the *orange ( *signal light or reflector ? ) on the side , has a fan or not.
