I have a 2007 Dodge Dakota Quad Cab SLT and when it is cold in the morning ~ 40F degrees or less the remotes won 't unlock the doors. If I unlock the door manually with one turn or even rapidly turning the key back and forth the alarm sounds. 90% starting the truck will shut the alarm off; however, there are times where I have to start it two or three times to shut the alarm off. The colder it is the worse this gets.

There was a similar thread https://dodgeforum.com/forum/3rd-gen...rangeness.html but there is no solution.

After the truck warms up everything works fine, or if the tempature gets above 40 before I leave I do not have any problems.

I have tried both keyfobs and both keys with the same results. I don't think it is RF interference because it has happened at my house or after an overnight stay away from home. Plus it works every other time at home. Just not when it is cold.

 

It sounds like you're receiver (the keyless entry system part in your truck) is having trouble when it's cold.
I'm not even sure that could happen, but I've never of that before.

A lot of electrical issues can be solved by removing the battery cables for a while (like 30 minutes), and then hooking it back up.
That is the first thing I'd try.

We'll help you out as best as we can here. Welcome aboard.

 

Well I gave it a shot when I got home from work. I disconnected the battery and left it off for about an hour while I took care of some chores. I reconnected it and of course it worked then because it was warm.

It is now 30F out and it is not working.

 

what about the actual truck battery? had it tested? or maybe the lock plungers need lubricating?

 

I just took a reading now and it had 12.4 volts. There is never any problems starting the truck.
As far as the lock plungers the truck doesn't even respond to the remote. No light flashes or horn chirps even tried the panic button and nothing happens.

 

Have you pulled the cover off your keys to see if the connections are intact?

 

The connections are intact. I know I am asking for help, but I am trying to understand this latest train of thought.

Let me restate the facts.
When the temperature outside drops below 40 degrees and the truck is cold, the keyless entry does not work. And I mean nothing at all. The truck has no response to the keys no light or horn acknowledgment.

When the cab of the truck gets back above 40 degrees everything works fine. Now the keys this entire time are stored inside my 68 degree house.

I think it is safe to assume that it is not the keys that are the problem.

Thank you everyone so far for the ideas but it still doesn't work.

 

hmmm I wonder if the RF transmitter is weak... but I couldnt imagine both keys doing that at the same time, so scratch that. Do any of your gauges act funny or not work at all when this happens? Do you have an OBDII scanner? I am not certain if this issue would necessarily illuminate a CEL, but I am curious if there are any codes sitting there. The FCM or front control module controls the keyless entry as well as a bunch of other things such as lights and so on. If you have a code maybe we can narrow it down. I'd almost bet there is a code from the FCM that woudl start with a "U"

 

Is the battery original to the truck? Just because youre reading 12.4 volts doesnt mean its still good because a voltage rating is worthless if no amps are being drawn, not to mention when its colder, the amps the battery can handle drop. It sounds like an electrical problem in the truck, and most problems start with the battery. And problems with the battery normally start when the temperature drops.

 

Oops I missed that post... lol

Did you do a complete battery test then, like reng stated.

Any little issue with the battery power and these things are practically useless.