2017 Expy Low Voltage Error only in cold temps

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mattjt87

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This is my first post on this forum after joining, I have been a long term follower of the forum but have always been able to find answers that were already being discussed, my current issue I can not seem to find an answer for and am my wits end on trying to trouble shoot.

My 17 expy gives me a low voltage error message only during cold temps (40 and below), depending on how cold it is, I can let the engine run for 5, 10, 15 min etc to warm up and when i restart the truck the message will clear eventually, longer when temps are colder, sometimes it takes 20 min plus of running. The main issue I have is that “for safety some features have been disabled” message comes up and kills the power steering, i could care less about the other features, not having power steering in a vehicle as large and heavy as an expy is virtually disabling the vehicle.

The battery is less than a year old (no corrosion on terminals) and still tests with engine off at 12.4-12.6v depending on temp, ran a simple scan tool test of battery and alternator both check out good, alternator putting out 14.3v at 2000rpm with headlights on, at start up in 20 degree temps the voltage does drop into the 10v range but the engine starts right up, it does not sound slow or weak, but right after startup the voltage returns to normal, I replaced the battery voltage sensor. I added a battery warming wrap last year and it seems to help, with it plugged in overnight the symptoms wont show up unless usually under 20 degrees ambient temp. Im at a loss, the only time the symptoms change is with ambient temperature of the battery, I have searched all over youtube and this forum for same or similar symptoms and can not find much beyond what I have already tried. I live at 7000’ elevation and deal with temps as low as the -30s at times but generally below freezing for at least 4-5 months of the year, parking the vehicle indoors is not an option. This is the newest vehicle we have owned and the one with the most computers, we do not have this issue with any of our other vehicles.
I am assuming that the problem lies within the software at this point and because the voltage does drop so low during startup it triggers the low voltage mode, and is just too sensitive for my conditions.
Does anyone have any suggestions or solutions at this point? I am not against installing a 2nd battery at this point or bypassing the system altogether if that is even possible. Its just frustrating that our newest and what should be most reliable vehicle is forced to stay parked for nearly half the year, because the computer THINKS there is a problem.

Thank you for any help ahead of time, and I will not be offended if Im missing something obvious, I just really want this issue resolved and am usually capable of doing the vast majority of my own work. I do not have forscan but will get it if it means a solution if i can reset the voltage parameters.
 

AWAR

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You need to get the battery tested with a load. If it drops below 10.5 volts with a couple hundred amp draw it is junk.
 

99WhiteC5Coupe

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You need to get the battery tested with a load. If it drops below 10.5 volts with a couple hundred amp draw it is junk.


I agree.

Just because a battery is less than a year old does not mean it is okay, and not defective. It could be weak with the cold ambient air, or have a bad cell.
 

chuck s

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My 2017 does NOT cut the battery when the ignition is Off. Anything connected to any of the ports like a radar receiver or GPS stays powered. Unless I deliberately unplug everything parking at the airport for more than a week is guaranteed to drop the voltage so low it won't start.

On the plus side a portable solar panel plugged into one of the power points keeps the battery charged when parked outdoors.

-- Chuck
 
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