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A/C Rest Light won't turn off?

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Old May 12, 2023 | 09:27 PM
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16' E250 Bluetech W212
Exclamation A/C Rest Light won't turn off?

Hey everyone!

I just picked up a 2016 E250 Bluetech today in Canada. It's a fantastic car I must say.
I just have a small question, the A/C Rest light appears to always be on. I believe this means the A/C is on at all times as well. I can definitely feel cooler air. How do I turn it off? Doesn't work when I press it as you can see in the video provided.
I was reading up on the Rest feature it and seems neat but it should still turn off when I click it, no?
Thanks!

Link to vid:
https://imgur.com/a/6pZn9r9
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Old May 14, 2023 | 04:19 AM
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2011 E350 CDI 4Matic, Rover 75, Chevy K2500, 2 motorcycles
Originally Posted by ThatGuyM
Hey everyone!

I just picked up a 2016 E250 Bluetech today in Canada. It's a fantastic car I must say.
I just have a small question, the A/C Rest light appears to always be on. I believe this means the A/C is on at all times as well. I can definitely feel cooler air. How do I turn it off? Doesn't work when I press it as you can see in the video provided.
I was reading up on the Rest feature it and seems neat but it should still turn off when I click it, no?
Thanks!

Link to vid:
https://imgur.com/a/6pZn9r9
These systems work differently and even the HVAC panels can be different in the same cars in different markets. That said, it seems to me that the Canadian cars are more like the Euro market cars than the USA market cars.

Mine is a 2011 and has a different control panel than your facelift, BUT I'm sure mine only works - or is meant to - when the car is completely off. In your video it seems that your car is either on or in the "accessory" mode. In mine I turn the car off - I have to confirm whether off or accessory - then press the Rest button. It lights up and the system comes on, but I don't think it is fully functional for making adjustments.

I'll try to remember to try a few things today.
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Old May 15, 2023 | 02:28 PM
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So, with the car OFF I push the REST button and the HVAC comes on at the previously selected temp. Obviously, no AC for cooling, but fan for ventilation. The only things that are on are the REST button LED and the temperature selected. I can turn it off again by pressing the button again.


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Old May 17, 2023 | 11:40 AM
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Originally Posted by slovcan
So, with the car OFF I push the REST button and the HVAC comes on at the previously selected temp. Obviously, no AC for cooling, but fan for ventilation. The only things that are on are the REST button LED and the temperature selected. I can turn it off again by pressing the button again.

The REST function is for the short stops during your drive, It uses the engine heat or cooling coil cool when the car is stopped, and you initiate the rest function. This is very nice feature especially in cold weather as when you stop to fill up for 10-15 minutes your car is still warm when you come back to continue your drive. This works the same way for the AC. I can drive my car 8-10 minutes with the AC compressor OFF and it still blows cool so the REST function work for cooling also for about 10 minutes, but I think for heating it works longer.
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Old May 17, 2023 | 11:45 AM
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Originally Posted by Arrie
The REST function is for the short stops during your drive, It uses the engine heat or cooling coil cool when the car is stopped, and you initiate the rest function. This is very nice feature especially in cold weather as when you stop to fill up for 10-15 minutes your car is still warm when you come back to continue your drive. This works the same way for the AC. I can drive my car 8-10 minutes with the AC compressor OFF and it still blows cool so the REST function work for cooling also for about 10 minutes, but I think for heating it works longer.
Yes, agreed. GREAT feature. I was just highlighting how mine works as the OP's doesn't seem right.
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Old May 17, 2023 | 12:01 PM
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I remember from W210, that REST on would indicate low refrigerant, or other malfunctioning.
Do full AC test. Start with measuring the pressure and all temperature sensors on cold morning before engine start.
Post the values here and we can help with interpreting.
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Old May 17, 2023 | 12:46 PM
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Originally Posted by kajtek1
I remember from W210, that REST on would indicate low refrigerant, or other malfunctioning.
Do full AC test. Start with measuring the pressure and all temperature sensors on cold morning before engine start.
Post the values here and we can help with interpreting.
That could be the answer the Original Poster is looking for.
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