When replacing a fob battery, "GENTLY" brush the battery contacts with a pencil eraser. This will clean surface corrosion which could cause a voltage drop and reduce the transmitters output. Cost plays a huge role here, but even with all of the tools and equipmnent that I have I do not and cannot reasonably afford to purchase the additional equipment that would recieve signals from a key fob to measure it's output and attempt any servicing for many of those systems. We truly are limited to dealing with the components onboard the vehicle, following any appropriate service bulletins, and then if unsuccessful either leave it unrepaired, or go into parts swap mode. (Which I HATE doing, and usually would turn the vehicle away) In order to protect vehicle security it is necessary to make purchasing the things needed to perform this kind of service expensive, that's why a dealer will have the equipment for the brands that they sell, but it is not reasonable for someone like me to get involved with beyond the level that I do. Keep in mind some systems use the vehicles radio antenna for the key fob reception. (The radio in this case IS the reciever and communicates the command signal to the BCM). One thing that I can do with my scan tools is watch for the communication to occur between the modules. If I don't see the communication, which if the system does not unlock the doors is quite likely the result I would then do testing to confirm that the modules can and do "wake-up" with certain commands. Then from there attempt to be certain that the antenna system is working correctly, even if that means pull the radio and use a substitute antenna. In the event the car works for a while like Jems, but does not work after a specific period of time I would suspect there is a vehicle problem where the BCM deliberatly shuts the system down to protect the vehicle battery. I would be testing that car to make sure modules eneter sleep mode at the right times, and then of course wake back up when commands are given. A radio reciever that does not wake up to the fob transmission can never send an unlock command to the BCM, likewise even if the radio does send the command, if the BCM cannot or will not follow the command, the result is the doors don't unlock. Keep in mind, the problem could easily be a door lock solenoid failing, as well as the latch simply stiffing up and requiring to much power for the solenoid to operate.

A number of Dodge cars have had some form of automatic door locking feature since at least 1989. Usually, after a front door has been opened, all four door locks are activated upon passing through 15 mph. This doesn't hamper the front passengers since their doors will unlock upon moving the inside door handle, however, the rear passengers may find themselves locked in depending on the setting of the rear door child locks. Even when the child lock has not been set, the rear passengers may find that they have to manually move the lock button to the unlock position before the door handle will unlatch the door. There are many variations on this theme. For Dodges, there is a routine of on-off-on cycles executed through the ignition switch that can activate or de-activate the auto-locking feature. I suspect you vehicle also has a similar method that won't require a trip to the dealer. However, I have never de-activated this feature in my car since it does not cause an inconvenience and the procedure is not intuitive; 6 mo later, I won't remember the sequence and would have to look it up again. However, in your case, unlocking all doors upon key removal could get to be a nusiance. If you can't find the arm/disarm procedure in your 3rd party repair manual, you may be able to find it on-line at your local library.

Our last house had locking hardware with a keypad on the garage side for ease of getting in and out. We always kept it locked as an extra precaution, not just for extra security in addition to the garage door, but also to provide barrier in the case we forgot to close the garage door for the night when coming home late (happened more than I'd like to admit). The keypad allowed the door to always be locked, but we didn't have to worry about locking ourselves out if we didn't bring the key and it was slightly easier to unlock while holding onto our things. I guess I would also judge your exposure to break-ins in your area. Where we live we have a greater likeliness of a burglary than the typical suburb so we have put as many impediments to getting into our house as possible. In some areas that may be overkill. But even then there is a definite advantage to being slightly more secure (and visibly so) than your neighbors.

Once I had an aluminum storm door. I stuck the spare key to the door closer thingy with duct tape, which matched the color of the door. So well, in fact, that when I needed the key I first thought someone had taken it! It took me a few minutes to remember where the duct tape was. Another time, I lived in a three family house with a shared basement. My spare key was taped to the back of my dryer with duct tape. Of course, this method depended on someone else being home to let me into the basement. Currently, there is a mail slot in the front door. So the key is taped to the inside of the front door where I can reach it through the mail slot. I rely on duct tape a lot!