Car alarm interference?

Jesh1

Guys, I went out to the car a few days ago and the thing would not unlock for me. I pressed the unlock button a good few times but got response at all. I assumed my battery in the key fob is on its way out so grabbed another set of keys, no response at all. Tried with the third set and nothing again.

The same thing happened to me about two years ago one evening but everything worked fine later that day! However, now the problem is still ongoing.

Later that evening the car eventually opened with the set of keys I normally use. I’m fairly perplexed as to what is going on here. Is it a faulty receiver in the car alarm or radio frequency interference?

My main problem is the car cannot be unlocked with the key. When I unlock it, it triggers the alarm for 15secs but will not let me inside the car………:mad: madness .It’s a factory fitted alarm.

Has anyone ever experienced anything like this and what was the outcome.
I really dont want to be throwing a wad of cash on it.

Atlantic Dawn

Does this just happen when parked outside your home or all locations?

Jesh1

All instances have happened outside my house. I have yet to test it away from home.TBH, I'm afraid to lock it somewhere else in case it won't open again!

coolisin

Does your set of keys have the disarm key?

It might be the alarm is on its way out depending on year or it maybe the battery in the car is low.

Depending where you are there maybe something on a similar frequency to the alarm fob and is stopping your alarm from noticing the signal coming to it.

Redisle

Yeah there could be outside interference as mentioned above but that would be hard to determine. Most of them would operate at 433.92Mhz which is ISM band and is basically a free for all. Lots of things like wireless weather stations, electricity monitors, wireless doorbells etc use this frequency.

Just something to bear in mind it's generally not a good idea to keep pressing the key fob if the key fob is working but the car isn't picking it up. These keys usually use a rolling code system and will lose "sync" with the car if you press it too many times without the doors actually opening. They key(s) would then need to be recoded to the car (just the remote/alarm bit) which may be easy or hard, depending on the car!

Jesh1

Cheers lads, some interesting responses.
Coolisin, no disarm key I’m afraid. Totally snookered here, it also has a battery backup for the alarm. Worst case if something goes pear shaped I will have to wait for the battery backup to die…Can’t even disconnect it. The battery is reading 14.8v as normal.
Redisle,
I‘ve read about the rolling code before, completely forgot about it.
For RF interference my theories are
· Airport nearby.
· Next-door neighbor just had a kid. Baby monitor possible?
· My doorbell is wireless

Clearly clutching at straws here! It's time for some more research.