Can you operate the 'AC/Rest' feature on the W166s after the car is shutdown?
Thread Starter
Senior Member
Joined: Aug 2012
Posts: 318
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From: Melbourne, Australia
'24 GLB250. Previously '23 GLB250 '17 GLS500 '14 C250 '13 ML500 '12 C250 '08 ML500 '07 E500 '03 A160
Can you operate the 'AC/Rest' feature on the W166s after the car is shutdown?
Hi guys, again just curious about something ...
On my W164 after I'd turned the car off and removed the key I could then press the 'AC/Rest' button and the system would blow out cool(ish) air for I think 30 minutes. Was a great feature to help keep the car cooler when parked on those hot days. My old E-Class used to do it also, but our new C-Class doesn't. Both my old ML & E-Class had THERMOTRONIC 3-zone climate control but the new C-Class only has THERMATIC dual-zone climate control so I'm guessing that is why. Can anyone shine any light on this? And if the new W166s with THERMOTRONIC have this feature too?
Thank you!
On my W164 after I'd turned the car off and removed the key I could then press the 'AC/Rest' button and the system would blow out cool(ish) air for I think 30 minutes. Was a great feature to help keep the car cooler when parked on those hot days. My old E-Class used to do it also, but our new C-Class doesn't. Both my old ML & E-Class had THERMOTRONIC 3-zone climate control but the new C-Class only has THERMATIC dual-zone climate control so I'm guessing that is why. Can anyone shine any light on this? And if the new W166s with THERMOTRONIC have this feature too?
Thank you!
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Joined: Oct 2009
Posts: 315
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From: Sweden
W166 ML350 BT
Mine can. But I actually think the function is there for heating the vehicle with "REST" heat from the engine. Maybe they have built in temperature limit for when the function is active or not. We have -6C at the moment so it's very nice to come to a not so cold car after a stop.
Thread Starter
Senior Member
Joined: Aug 2012
Posts: 318
Likes: 2
From: Melbourne, Australia
'24 GLB250. Previously '23 GLB250 '17 GLS500 '14 C250 '13 ML500 '12 C250 '08 ML500 '07 E500 '03 A160
Mine can. But I actually think the function is there for heating the vehicle with "REST" heat from the engine. Maybe they have built in temperature limit for when the function is active or not. We have -6C at the moment so it's very nice to come to a not so cold car after a stop.
Oh, I never considered the heat side of things. It doesn't get that cold here in Melbourne in winter, well it does to us, but not below freezing like you guys haha. I've only ever used the function as a cooling/ventilation feature when I've had to leave the dog in the car while darting into a shop in the warmer months. It works really well in temperatures up to mid to high 20s (celcius) for short periods of time. Good to hear it seems to be a feature on W166s too. Can't wait until mine arrives!!
Last edited by Benz Werd; Dec 12, 2012 at 09:49 AM.
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From: Seattle, WA
99 ML430, 01 CLK55, 07 R63, 15 E63 Wagon
The system just uses the residual hot/medium/cold air that's in the system before you turned the car off. So it will blow out whatever temp you had set when you were using it before the car turned off.
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From: Lake Oswego, OR
2020 GLE 450; 2023 BMW M2 Coupe
"Residual Heat"
Hi guys, again just curious about something ...
On my W164 after I'd turned the car off and removed the key I could then press the 'AC/Rest' button and the system would blow out cool(ish) air for I think 30 minutes. Was a great feature to help keep the car cooler when parked on those hot days. My old E-Class used to do it also, but our new C-Class doesn't. Both my old ML & E-Class had THERMOTRONIC 3-zone climate control but the new C-Class only has THERMATIC dual-zone climate control so I'm guessing that is why. Can anyone shine any light on this? And if the new W166s with THERMOTRONIC have this feature too?
On my W164 after I'd turned the car off and removed the key I could then press the 'AC/Rest' button and the system would blow out cool(ish) air for I think 30 minutes. Was a great feature to help keep the car cooler when parked on those hot days. My old E-Class used to do it also, but our new C-Class doesn't. Both my old ML & E-Class had THERMOTRONIC 3-zone climate control but the new C-Class only has THERMATIC dual-zone climate control so I'm guessing that is why. Can anyone shine any light on this? And if the new W166s with THERMOTRONIC have this feature too?
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From: Australia
X350d GLE500e 2017, ML350 BlueTec 2012(sold), A200 2013, ML350CDI 2009(sold), Aston Martin DB7 2003
Residual heat/ventilation can be turned on just like the W164, simply by pressing the AC/Heat button after the motor is shut off.
Funny thing. Last night I parked the car in the garage, and as I walked away I heard a noise.
Checked up and it was the heater fan running, so the residual heat/ventilation feature came on automatically, without touching the AC/Heat button. I did have the system set to Auto prior to shutdown.
Its little things like this that make an MB worthwhile.
PS: I have Thermatic on the 166, and the ambient temperature last night was 30C.
Funny thing. Last night I parked the car in the garage, and as I walked away I heard a noise.
Checked up and it was the heater fan running, so the residual heat/ventilation feature came on automatically, without touching the AC/Heat button. I did have the system set to Auto prior to shutdown.
Its little things like this that make an MB worthwhile.
PS: I have Thermatic on the 166, and the ambient temperature last night was 30C.
Last edited by iankayem; Dec 12, 2012 at 08:56 PM.
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2013 ML BLUETEC JULY 31
Its for cold climates so some states may get it. Local marketing.
I think u will find its more than residual heat. I believe there is an extra tank and a circulating pump. Whatever coolant is in the heater coil goes cold fast so it must circulate thru block. Not sure on tank sorry.
For summer it simply does not circulate just fan blows. High tech stuff like the cold climate electric/ceramic heater for instant heat on start up
I think u will find its more than residual heat. I believe there is an extra tank and a circulating pump. Whatever coolant is in the heater coil goes cold fast so it must circulate thru block. Not sure on tank sorry.
For summer it simply does not circulate just fan blows. High tech stuff like the cold climate electric/ceramic heater for instant heat on start up
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From: Lake Oswego, OR
2020 GLE 450; 2023 BMW M2 Coupe
MBWorld Fanatic!
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From: Lake Oswego, OR
2020 GLE 450; 2023 BMW M2 Coupe
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From: Australia
X350d GLE500e 2017, ML350 BlueTec 2012(sold), A200 2013, ML350CDI 2009(sold), Aston Martin DB7 2003
Its for cold climates so some states may get it. Local marketing.
I think u will find its more than residual heat. I believe there is an extra tank and a circulating pump. Whatever coolant is in the heater coil goes cold fast so it must circulate thru block. Not sure on tank sorry.
For summer it simply does not circulate just fan blows. High tech stuff like the cold climate electric/ceramic heater for instant heat on start up
I think u will find its more than residual heat. I believe there is an extra tank and a circulating pump. Whatever coolant is in the heater coil goes cold fast so it must circulate thru block. Not sure on tank sorry.
For summer it simply does not circulate just fan blows. High tech stuff like the cold climate electric/ceramic heater for instant heat on start up
