The factory "perimeter alarm system" which is what ford calls it, will sound (horn and lights) for 30 seconds and then flash the hazards for an additional 3 minutes. The only way to bypass or silence the alarm without a valid fob or key is by removing the horn OR fuse, which you'd notice. Even if the battery is disconnected and then reconnected the system will revert back to the previous state (armed, disarmed, triggered). SO, if you've tested functionality of the horn and factory alarm system then it's definitely getting triggered the second any door, hood or liftgate is opened. Either your asleep or maybe just don't hear it at the time it's sounding. Again, the horn sounds for only 30 seconds which isn't the longest but sadly that's the duration for most vehicle's alarm system regardless of the make or model.
it is strange to require a new RDU (Rear Differential Unit) at 100K. Maybe your Edge went in deep water.
I cannot comment on the labor required for changing the RDU, but the programming part is simply a code that needs to be entered into the PCM. The code would be on a sticker on the Active Torque Coupling (that is attached to the RDU). This can be done with ForScan, might need to email the developers to add it for your year if it is not their by default.
It's my bad for believing the online sites that show a particular bulb as an appropriate replacement without examining the vehicle. I also saw a number of YouTube videos that purport (incorrectly) to show changing bulbs in a 2017. Lesson learned.
17Sport, that's not a bad idea but I'm not sure if I want to muck around with that. I'll keep looking though; I'm just really surprised to not see others complain about it. The bulbs themselves work and are pretty bright when you're standing and looking at them, but they seem to be in a lousy position to actually light up the surface/area that you're driving on.
Anybody have any experience with a rear differential replacement? I have a 2013 with about 100k on it and dealer says rear diff is bad. It has a growl like a wheel bearing coming from rear of vehicle. Dealer wants around $2k to for parts and install. I was thinking of buying parts, roughly $900 and installing myself. It doesn't look that difficult but I have heard that the computer may need reprogrammed once the new diff is installed? I know this is the Edge forum but mine has been a total disappointment. 2 major drivetrain failures (PTU and rear differential) within 100k miles......this will be my first and last Ford vehicle.
Its a very common mistake to interpret an error code as a failed sensor - the sensor code is an alert that something is wrong related to the signals received from those sensors, but to identify what is actually wrong requires diagnostics, not throwing parts at it.
What is your mileage?
What is the service history - oil change intervals, what oil?
These engines have Variable Valve Timing (VVT) and poor service intervals is the main culprit for the servo valves that control this getting fouled and that leads to incorrect valve timing, and the crank and cam sensors being out of synch.
An OBDII diagnostic scanner (no, not a code reader) should be used to diagnose this.