The battery isn't draining when it's cold, when it's cold the internal electrical resistance of the battery increases and the capacity decreases. When the battery warms back up the internal electrical resistance decreases and the capacity increases. If it had to do with contraction, it wouldn't start from the inside. When the truck attempts to start by remote, the BCM sees the voltage drop due to the decreased capacity and won't start. However when you start from inside the cab battery voltage doesn't matter as you are there monitoring it.
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Remote start not working when cold
- Thread starter Hrspwr88
- Start date
Only way to 100% fix the problem would be for the program engineers to lower to voltage threshold down to around 11.5V. I believe that the threshold is probably 12.0V as in the past I noticed it wouldn't start when the battery indicated 11.9V on my multimeter.
I agree 100% but try telling that to the people that believe they're smarter than you and I are. They never want to admit they did something wrong and have to fix it
Chris3058
Ram Guru
Same issues here. Works great in the summer. Gets below -5 and nope. Never starts. I get the one honk FU response from the truck.
Chris3058
Ram Guru
Same boat here. Had the “update” and I find it worse. But my steering wheel gets hot enough to heat a small town. So there’s that.
I had an update done last winter and it didn’t help, got another update done this winter and it seems to have solved the issue.
Mountain Whiskey
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I hear ya! I need gloves on to have my healed steering wheel on. Kind of crazy backwards huh?
Yeah that thing cranks out the heat!
Chris3058
Ram Guru
Remote start wasn’t working? I gotta bring mine in too. Again. Same thing here. +3 C and got the FU single honk.
Yep. They did a few update flashes but said a sensor has failed. They didn't say which one but said it should be in within 3-4 days. Will update once I get the final paperwork.
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Seems like there's lots of things that'll stop the remote start from working properly. Mine wouldn't work at all last weekend. Monday Tuesday Wednesday has been above freezing and it's worked as it should. Tonight it's supposed to drop down and then for the next few days. So I expected to start failing again. We'll see how it goes.
I thought about puttting a small lithium battery in parallel with the battery to see if that would work. The lithium doesn't lose capacity like the AGM batteries do when it's cold and may keep the voltage elevated enough to enable remote start to work.
Fatherof3
Spends too much time on here
I believe you are right . My truck remote starts up here in the great white north in -20 degree temps . They must program them differently for Canadian models ?
Is there anyway you can call them and ask them what sensor failed? I'm curious what the mystery part is that could be causing the problem. Maybe it's the battery voltage sensor.
Could be. Although my truck started this morning at -22 after they did those updates. So maybe it doesn't need the sensor but they are doing it anyways.
I noticed while driving the voltage stays a lot higher and is more consistent. I think part of the update is to the smart charging system.
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Chris3058
Ram Guru
Guess this explains my remote start issue. This is after an hour on the highway. Guess the battery is toast?
