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Discussion Starter · #1 ·
Page 127 of the 2019 Ascent manual touches on something called the "Power saving function". Manual says this saves the fob battery and the vehicle battery. Apparently there are two cases where this kicks in.

Case 1: If the car has been sitting unused for two weeks, and neither the keyless access function or remote keyless entry function has been used, and the car is locked.

Case 2: The fob is within operating range for 10 minutes or longer and the car is locked.

This power saving function is apparently separate from turning off the key fob, described on page 128.

Is anyone familiar with the power saving function described on pg. 127? Does this turn off the whole car, or just some parts? Our car sits for weeks at a time, and it's been dead 3X now when it was time to go. Since we keep it in a garage I've never locked it. Would/should this function help?
 

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The Ascent groups on Facebook believe you have to lock it and keep the key at least 20 feet away to stop the 'background electrical systems' from running.

I've moved my key rack from next to the garage door.
 

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Lock the car, and keep the FOBs out of range of the car. If it's on the edge of the range, the car may think the FOB is coming in and out of range, which will keep it awake. If the car isn't locked, it won't go into power save mode, as @Q-Man13 mentioned above.
 

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Discussion Starter · #4 ·
Thanks for the replies.
The Ascent is in the garage, which is separate from the house. The fobs are in a kitchen drawer. Straight line from car to kitchen would be about 70 feet and at least two walls.
That should be enough.
Apparently this "power saving mode" is not absolute. It's not like a cut-off switch at the battery. Touching the door handle or using the fob takes the car out of the mode, so there's still some electrical activity when the rig is in the mode.
So, I'm still curious to hear any details about what is turned off? How many gizmos have power to them in "power saving" vs. just parking the car and walking away? Somebody must have some measurement of current draw in or out of power saving?
 

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Since we keep it in a garage I've never locked it. Would/should this function help?
Well, first, remember to lock the doors, because as noted, power saving mode doesn't engage if you don't.

Parts of the BCM are always active and aware. This allows the car to wake up when it detects a FOB, or a touch on a handle sensor.

IIRC, parts of other systems are always awake to one extent or another, such as the telematics and head unit, to allow responding to vehicle pings, remote commands or to send updates to the head unit.

Power draw during "mostly asleep" mode is milliamps. I've left mine locked and off for almost two weeks without issue on my 59,000 mile old OEM battery.
 

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maybe not all car programmed same ?
i have my unlocked for over 2 weeks and the keys only 8-10 feet from the trunk ... it still started up fine ...
touch on a handle sensors are only 3-4 feet
i not sure if unlocked car doing long range scan , as the lights on the mirror and interior light stays off if car is unlocked and you go next to it , but if car locked its turns on with in 10-15 feet away
 

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Also 2020 will shutoff if keys in or next to the and car is unlocked and trunk or doors are open in 20-25 minutes , i just test it it right now
 

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Lock the car, and keep the FOBs out of range of the car. If it's on the edge of the range, the car may think the FOB is coming in and out of range, which will keep it awake. If the car isn't locked, it won't go into power save mode, as @Q-Man13 mentioned above.
We didn’t know about power save mode. Thanks. We keep it unlocked while in the garage since we’ve owned the car. When we read about the FOB being in constant contact with the car we bought the special pouches and now a box to block the signal because we store the keys within 3 feet of the tail end of the car.
 

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We didn’t know about power save mode. Thanks. We keep it unlocked while in the garage since we’ve owned the car. When we read about the FOB being in constant contact with the car we bought the special pouches and now a box to block the signal because we store the keys within 3 feet of the tail end of the car.
I am curious what tweaks to code they've made over the little ECU and BCM revisions that happen over time. I've always locked my car, out of habit, and out of parking situation, my FOBs have always been a couple dozen feet away or more, so, I've never experienced the negative effects of keeping something in the car awake because my situation is different.

But, it definitely can't hurt to do what you did or try what's in the manual, that's for sure.
 
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