The module with the button is your Keyless Entry System (KES), just as everyone has been describing, and it was made by SCS-Frigette who is no longer in business...and it's garbage. But the good news is that your coach probably came with a front door auto lock and maybe your cargo doors also have an auto lock?
* When you bought your RV did they tell you it came from the factor with a KES?
* Do you have the option of opening and locking your cargo doors with one switch... usually located by the entry door? If so you can install a new KES and with a new fob your can Open and lock your front door, but because you are using a car alarm system that is only designed to unlock the trunk... you can use this button to unlock your cargo doors and to lock the cargo doors you will push 2-buttons on the fob at the same time to lock the trunk... which is no big deal, but it's not intuitive.
This is also a good time for you to learn more about your Trimark door lock adjustments, and to help you with that you should visit this thread:
https://www.irv2.com/forums/f258/tri...le-479375.html
And this thread...
https://www.winnieowners.com/forums/...re-330834.html
And if you want to get your Keyless Entry System (KES) working again, all you need to do is buy the Avital 300xl on Amazon and a few relays and fuses.
The total cost to get your KES working about is about $50 if you do the work yourself; and take it from me, you love having your fob operational again!
For more information on how to remove the wire harness from your old SCS control box and re-wire your auto locking system, you just need to go to this thread... and there you will find a wire conversion diagram I created that will make cutting your old wire harness easy to understand and connect to your new Avital KES.
https://www.irv2.com/forums/f101/scs...ls-451241.html
As for calling Trimark... don't bother. They will give you bad information and their customer support is run by a few sour grapes. However, their technical support is nice and knowledgeable if you ever need to talk to them.
Trimark customer service will try to up-sell you on their wire harness conversion and new Trimark control box for ~$400 in parts only; and then you will pay $200- $250 in labor; or you can learn how to do it yourself for $50 and install the Avital KES.
Note: I also elected to install a siren that Winnebago conveniently left out and now if I push the "panic" button on the fob the siren will go off. ...Note also, this is not the same as the chirping sounds you are familiar with a car. That's another horn, but you don't need this since you can hear the door plunger lock.
The siren is also useful to scare away skunks that happen by your campsite, and it will also will give you peace of mind if you ever spend the night in a Wallmart parking lot and you think you hear something outside your coach and need to sound the alarm.
ANOTHER TIP: I found LED lights placed under your coach are a good deterrent for mice and unwanted guests too! Just run a 40' strand of LED Rope Lights under your coach and zip-tie as necessary... and then cut a hole in the back wall of your inverter bay... where you can then access the switch power outlet your engine uses for the block heater.
You can also use a mechanical, 24 hour timer that flashes the LED light every 30 minutes all night long for added effect if you want; and since the engine block heater switch is conveniently mounted inside the RV, you can easily switch the LED lights on-and-off when you want to scare off those unwanted critters too.
In summary: If you have a little handyman experience and the desire to get your KES working again; the Trimark door adjustments are almost sure to fix your intermittent door locking problems. And with some determination to learn about KES systems, because their manuals are so poorly written, you too can follow the wire conversion chart I created, and in ~2-4 hours you should be able to fix your KES yourself for $50... and $75 if you want to add a siren to make the panic button functional.
...And as always, I highly recommend you hide a spare set of keys outside your RV for those times when you lock yourself out by mistake.