Interference stopping my remote locking working

A battery powered AM radio is an excellent cheap RF detector that can help you find many problems. The typical internal ferrite bar antenna is very directional, which really helps you locate the offending noise source fast.

Of course there are lots of fancier gadgets which draw a graphical spectrum for visual analysis, but they tend to cost more.

Dimmable LEDs are a very common culprit these days. Many car owners have found that changing the interior lights to LEDs will cause the remote locks to be inoperative for a few moments while the car is actively dimming down the lights, which is coincidentally when some drivers are walking away and trying to click the lock button.

If you have some LEDs being driven by a dimmer in or on your house, they would be among the first things to check.

 

Check for 315 MHz RFI from a neighbor
Key Fobs and Garage Doors Stopped Working in a Cleveland Suburb - Here's Why

 

And you are not having your battery and it's connections tested.......why exactly ?
Could be door actuators failing too......with a "coincidence" factor thrown in.

 

I had exactly this and verified it was only a problem on my driveway. As soon as I moved 5 m or more away the lock/unlock returned to working perfectly.

I check all usual suspects and checked the fob and 12 V battery voltages (and 12 V connections) and found no problem there. I don't have any frequency analyser equipment so couldn't check that.

After a few days, without doing anything else, it started to lock again on my drive and hasn't happened since.

I concluded it must have been something transmitting a radio frequency that interfered with the door lock frequency. 5G wasn't even a thing then, but I did wonder if it might be a 4G tower. Looking back I discounted that as a cause due to the relatively few days it happened.

Also of note, it only happened to a non-SKS Prius. The SKS Prius had no issues during this time.

For me it was just one of those mysteries of life.

 

A military connection would be no surprise to me. Near here, decades ago, many people (including a coworker) living close to Naval Station Everett experienced failure of garage door openers and other radio devices for a couple weeks, while certain big ships were in port. The issue did appear in some local news, along with a statement that it was related to naval operations. The RF emissions from certain equipment caused interference, and it was not expected to clear until those ships left.

 

And sometimes that is done on purpose.
I found that my Garmin GPS became erratic and totally inaccurate every time I came close to Regan National airport in DC.
I suspect that happens close to other major military bases too.

 

With this military stuff, it would definitely be on purpose. They have priority use, other users of the same bands have no choice but to accept the interference.

 

That's not quite what I meant.

The "civilian" GPS system is good enough to be used to "target" a military strike on the cheap, if you are a terrorist for example.

The system that the military actually uses likely is NOT "on the same bands".

The civilian system is intentionally scrambled to prevent it's use to direct a strike against a military base......or the airport that the President uses.

 

I was referring to interference in the band that resulted in OP's loss of remote car locking, and an Everett neighborhood's loss of remote garage door opening. At least in the later case, the military was deliberately using that band for other purposes. It is not a GPS band.

Military GPS is a multiband system, civilian GPS is a subset of that. The non-civilian side is always 'scrambled' to keep them off, the civilian-accessible side is adjustable to limit accuracy, and *.gov has additional tools to further degrade or block it in zones of interest (e.g. battlefields) as needed. *.gov also has websites announcing when and where larger scale tests will be interfering with GPS on large scales of interest to aviators.