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Remote start not working when cold

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Truck is back at the dealer for remote start issues when cold. They checked the logs and surprise surprise each fail is because low battery voltage!! BUT when they test the battery it says pass so they told me everything is ok, come get my truck.🤣

They agree it needs a battery and they are happy to install a new battery if I foot the bill but can't warranty it since the tester said pass. Amazing.

FCA Canada is now dealing with my concerns. Lol
Thanks for sharing, this is exactly why I avoided my dealer with this issue (at least so far). Hard to fault them though since the battery does start the truck normally, even though the voltages are lower than they should be (in my case anyway). Sounds like they need to change some programming for the remote start. I'm sure when I install the new battery the issue will disappear (at least for a bit). Still need to determine if there's abnormal power draw when the vehicle is off.
 
Thanks for sharing, this is exactly why I avoided my dealer with this issue (at least so far). Hard to fault them though since the battery does start the truck normally, even though the voltages are lower than they should be (in my case anyway). Sounds like they need to change some programming for the remote start. I'm sure when I install the new battery the issue will disappear (at least for a bit). Still need to determine if there's abnormal power draw when the vehicle is off.

Apparently there is a recall/update for battery draw. They performed it on mine but didn't solve anything. They mentioned if you haven't noticed your radio staying on its likely not applicable to your vehicle.
 
Apparently there is a recall/update for battery draw. They performed it on mine but didn't solve anything. They mentioned if you haven't noticed your radio staying on its likely not applicable to your vehicle.
Okay, good to know. My radio does turn off everytime I shut off the truck, at least it looks that way.
 
In Texas of all places, I woke up this morning to the same problem. Temps dropped to 28F last night - now no remote start. Like the rest, starts fine manually. I will call the dealer, but expecting to get the same runaround as the rest of you. My guess is, they are using cheap batteries in these things. I mean think about how many times during a city commute the engine starts and stops. That has to be hard on the battery. And if the manufacturer puts a mediocre battery in at assembly, it makes sense that they are drawing down when it gets colder out. My truck is not even 5 months old yet - this should not be happening, and FCA should make it right. I'll reserve judgement until I talk to the dealer, but my hopes are not high.

Next day update: So, this morning it was 3 degrees colder than yesterday, 25F, and the truck started fine using my remote key FOB - go figure?!
 
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I've started my 2021 every day over the past week with remote start. It's been -1 to -15F every morning. No issues but good to know about the low battery issue.
 
I have a 2020 Ram with an Ecodiesel and last weekend it was cold out, before I attempted to start my truck I measured the battery, the battery measured 11.9V. I tried to remote start with the FOB and the truck honked once and failed to start. I then started my truck manually and moved it to the street so that I could remove the snow off my driveway, while removing the snow I left it running. I moved my truck back on to the driveway once I was done and shut if off. I was in the house for maybe 2 hours and decided to take my truck to Autozone to test the battery, I drove there and they tested it and told me that the battery had 74% charge and that the battery was good, which I thought was odd that the charge was that low. I then drove it home and once there I shut the truck off and measured the battery and it measured 12.29V, which to me indicates a bad battery as it should be 12.6V and above when at rest. I then put a battery tender on the battery and left it on over night and the next morning even though it was colder, the truck started just fine with the FOB. I took it to the dealer and they tested the battery, which took several hours, and they told me that my battery was fine and the performed an update to the BCM, which is supposed to correct this problem, we shall see soon enough as it's supposed to get cold again this weekend. If it didn't get fixed, I guess I will be out sever hundred for a new battery as the dealer will more than likely not replace it as it passed their test.
 
Dealer finally replaced the battery. I'll keep you guys posted to see if this solves the issue.
 
Dealer finally replaced the battery. I'll keep you guys posted to see if this solves the issue.
I'm willing to bet that it will, at least for a time. All modern day vehicles will have some daily battery drain. Here's what I recently noticed (at least with my truck). If you start it at least once daily it seems to be ok, as others reported as well. For example, if you read my above posts with the issues I experienced I was able to remote start the truck yesterday when I got home from work, I had it running the day before. It seems if I go 2 days or more without starting the truck the drain on the battery is too much to remote start it (which sucks). I guess that's a better temporary fix vs using a trickle charger.

In the meantime, I came across this video yesterday which I'll link below. It's not specific to our trucks but for those who don't want to watch it the guy mentions about keeping a keyfob too close to the vehicle which causes the communication module to not "sleep" and cause a little extra battery drain. This got me thinking because about 2 months ago (roughly) I installed a small safe in my garage and one of the items I placed in there was my spare keyfob. I would guess that it sits roughly 15ft away from where I park my truck. I'll be doing a test this weekend when I'm off. I will place my meter in series with the truck battery and measure the current when the truck is off. I will than remove the keyfob from the garage to somewhere far away and see if my current drops. I'm kinda hoping at this point that this is what might've caused my issue to begin with. Maybe someone out there knows the exact range our fobs need to be away from the truck to prevent this?

 
Ya I assume it'll be fixed for as long as the battery stays healthy. Interesting find about the fob proximity, let us know what you find. Its not my issue but it may help others a bunch.
 
Ya I assume it'll be fixed for as long as the battery stays healthy. Interesting find about the fob proximity, let us know what you find. Its not my issue but it may help others a bunch.
Yes I absolutely will! I'm not totally convinced yet that was my issue but it's interesting info for sure. More info: got home from work today and attempted a remote start and it failed. Manually started ok. This time I let it warm up and took it for a little drive. Got back home and grabbed my meter and put it on. Shut the truck off and after several minutes my voltage settled out at 11.6 volts this time (it was 12.3 last time). My voltages are all over the place so I have no doubt my battery is not good. Glad I was proactive and ordered a new one.
 
Below is a cut and paste from the manual. My guess would be that your battery may have low voltage when it's that cold due to a bad cell or something. When you start it normally on the cold mornings is it a bit sluggish to start? These trucks are fidgety when it comes to batteries.

All of the following conditions must be met
before the engine will remote start:
 Gear selector in PARK
 Doors closed
 Hood closed
 Hazard switch off
 Brake switch inactive (brake pedal not
pushed)
 Battery at an acceptable charge level
 PANIC button not pushed
 Fuel meets minimum requirement
 System not disabled from previous remote
start event
 Vehicle security alarm not active
 Malfunction Indicator Light is not illuminated

Had a similar experience after my battery fully died in the -9F high this week and the check engine light came on and stayed on after recharging the battery.
 
FCA products (and many others) have been finicky for a long while now when it comes to almost-dead batteries, due to all the electronics. This (and midwest winters) are why I generally replace the batteries before they are completely bad, roughly every 4 years.

Based on the battery quality I'm reading about recently with our 5th gens, I'll be keeping a close eye on mine.
 
Well, Just what I thought, after sitting at the dealership for a couple of hours last Monday to test the battery only for them to tell me that the battery was good, for the past 2 mornings my truck failed to remote start when it's cold out. This morning the battery voltage measured 11.9V, which makes the BCM think that it's a dead battery and won't start through the remote. There must be different criteria that must be met when starting the truck normally inside the cab.
 
Well, Just what I thought, after sitting at the dealership for a couple of hours last Monday to test the battery only for them to tell me that the battery was good, for the past 2 mornings my truck failed to remote start when it's cold out. This morning the battery voltage measured 11.9V, which makes the BCM think that it's a dead battery and won't start through the remote. There must be different criteria that must be met when starting the truck normally inside the cab.
Sounds like you're in the same boat as me and that's exactly why I never wasted my time going to the dealer. Our batteries are bad. As to why a manual start works vs a remote start I have a few guesses but can't say for sure.
 
Ok, I just recently experienced some karma with my remote start after previously stating in this thread that I had no issues yet (go figure). I had a 2014 Ram 1500 sport for over 6 years and never experienced any issues whatsoever with the remote start. The truck was traded in with the original battery still going strong.

I use the Uconnect app to remote start when I'm at work as the truck is far away and I can't see it and I usually use the keyfob when I'm home cause I can hear the truck start but on occasion I use the app at home. My issues with the remote start on my 2020 Rebel started about 2 weeks ago. At the end of my shift one day I opened the app and gave it the start command. A minute later I received the "Remote start failed" message. I tried again and same thing. I started walking toward my truck and when it came in sight I used the keyfob and it remote started no problem. I thought that was rather weird. For the next several days I never had any issues remote starting with the app or fob. Actually, at this point in time I never had a remote start fail with the fob so I started to think maybe it was a software issue with the app until recently.

Temperatures really took a dive here over the weekend. On Saturday morning it was in the -40's (celcius). I went outside and plugged in my truck and my wife's van. About 5 hours later I attempted to remote start the truck via the app when I was in the garage. I could hear the horn beep once and I received the message that the truck started (when it didn't). Weird. I than attempted to start with the keyfob and same thing (one horn honk and no start). I than went out and started manually. The truck started fine (no sign of struggle). After about 10 minutes I went out and about (groceries and stuff) and kept the truck running the whole while I was out. When I came home I let the truck sit for a few hours (plugged in) and attempted the same process as before (app followed by fob) with the exact same results as before.

Grabbed my multimeter this time and low and behold: 11.66 volts. Odd thing the truck manually starts with no issues at all even at that voltage. That's where I'm at right now. It was too cold to do any further troubleshooting and it's Monday so I'm back to work. Luckily I carpool with someone and they offered to drive all week. This is driving me crazy though. We spend all this money on these trucks only to have certain features not being reliable. Remote start is pretty much mandatory where I live! I plan on digging into this further this weekend. Right now it's looking like my battery is causing the issue. I plan to check the battery current when the vehicle is off in case I have excess draw. One thing I won't be doing is taking the truck to my local dealer. I'll update this thread when I get some more info this coming weekend.

The attached image below is from the Challenger forum. I thought it was rather odd as they state that remote start battery range is between 11-15 volts. First I heard of it. I was always under the impression that a normal battery voltage is around 12.6 volts. 12.4 is acceptable but anything under 12v was an indicator of a bad battery. Maybe someone out there can shed some light. Did batteries change that much over the last few years and I'm out of the loop?

Sorry for the long post I wanted to include as much significant information as possible.

View attachment 82132
There must be different criteria in the BCM in regards to remote start vs normal starting. My battery measured this morning at 11.9V and wouldn't start but did start normally. Last week when it was a few degrees cooler I put a battery tender on it and it started just fine. Dealer tested the battery and said it was ok. Who knows what the problem is?
 
Sounds like you're in the same boat as me and that's exactly why I never wasted my time going to the dealer. Our batteries are bad. As to why a manual start works vs a remote start I have a few guesses but can't say for sure.
I wonder if anyone has gone out and bought a non-OEM battery and tried that avenue.
 
I wonder if anyone has gone out and bought a non-OEM battery and tried that avenue.
I ordered an Odyssey 94R agm battery and according to my tracking info it should arrive today. If it does I'll put it in right away. I'm sure that will cure the problem, at least for now. I need to check my current draw to see if I have a parasitic drain. I want to do that today but it's hard to get the motivation when it's extremely cold outside!

And yes there must be something in the programming that prevents a remote start when battery voltage is low. Maybe a manual start doesn't care? I know one place I won't get the real answer is from the dealer!
 
Update: The first time I took mine to the dealership on 1/12 they reprogrammed my key fob. Again, my remote start working the very next day, 1/13, but not 1/14 or 1/15.

1/15 I took it back and the mechanic said he reconfigured the vehicle with Chrysler files which resets everything. He asked me how I lock my truck when I park it. I told him that I pretty much 50/50 use the fob or the buttons on the inside the truck. He told me that this "confuses" the programming and I should ONLY use the fob from now on and when I use the fob I should always double hit the lock so it honks. I thought this was strange but I'm not a mechanic. He also said that before I remote start it in the mornings, I should always lock it this way as well.

Also, he said when he looked at the logs, he did not find any errors for remote start failures.

Morning of 1/16 it was about 32F outside and I did as I was told - locked the truck and tried to remote start. Remote start did not work. To be fair, when they reconfigured my truck I did not think to look at my settings to be sure that the truck would not honk when remote starting. I usually have this setting off as I live in a neighborhood and I actually like my neighbors so I cringed and panicked a bit when it was honking with the remote start attempts. I didn't try more than twice so this could've been user error tbh.


Morning of 1/17 it was about 41F outside and did the same thing as the previous morning but this time the remote start worked. Could've been the increase in temp.

The lowest it is supposed to get this week in my area is 51F so I guess when it's colder again I will report back.
Since my previous update almost a month ago, my remote start has worked every morning. The temp. has varied from high 20s-60s F. I have not followed what the mechanic said in my previous post about only locking it with the fob and locking it prior to remote starts.

It is supposed to be 18F Sunday and 8F Monday morning. I've never been outside below 23F so if I don't report back then I probably froze in time.
 
Since my previous update almost a month ago, my remote start has worked every morning. The temp. has varied from high 20s-60s F. I have not followed what the mechanic said in my previous post about only locking it with the fob and locking it prior to remote starts.

It is supposed to be 18F Sunday and 8F Monday morning. I've never been outside below 23F so if I don't report back then I probably froze in time.

It's -5F you have to worry about, that's when your snot freezes
 

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