central locking

Datatek · Feb 27, 2015

wammers said:
The only thing the older RF units can keep awake is the BECM. Locks will not activate unless a genuine code is recieved, the BECM decides what is a genuine code not the RF unit.

Sorry, that is not correct, a failing RF receiver can cause the lock motors to burn, it something that has been well established.
It does not always need a signal from the FOB to do this, the output stage of the receiver appears to fail in a mode that bombards the BECM with signals causing general confusion.

Grrrrrr · Feb 27, 2015

wammers said:
The RF receiver is just that, a receiver, as far as i am aware. Waking up the BECM it can and does do to check if the signal it recieved is the correct code. Until it gets the correct code the BECM will not operate the locks. Maybe the RF reciever loses it's discrimination and spurious signals can mimic the correct code i don't know. Maybe Keith can expand on that, i don't really know enough about electronics and radio.

That was my suspicion, the filtering was so far out a spurious signal(s) was getting through and confusing the BECM causing it to cycle the locks. It won't take a lot to burn the actuator motors out as the brushes are absolutely miniscule.

wammers · Feb 27, 2015

Datatek said:
Sorry, that is plain wrong, a failing RF receiver can cause the lock motors to burn, it something that has been well established.
It does not need a signal from the FOB to do this.

Not saying it's not. But the BECM decides what is a good code not the RF reciever. That is the point being made, the BECM won't drive the locks until it thinks it has received a proper fob code. Or are you saying the RF reciever can cause the locks to burn without receiving any signal at all whether from fob or an outside source?

Datatek · Feb 27, 2015

wammers said:
Not saying it's not. But the BECM decides what is a good code not the RF reciever. That is the point being made, the BECM won't drive the locks until it thinks it has received a proper fob code. Or are you saying the RF reciever can cause the locks to burn without receiving any signal at all whether from fob or an outside source?

Yes. What is more, it is perfectly possible to confuse the BECM into doing things it should not do

The receiver contains an access code plus, I suspect the last rolling code generated, so when it goes berserk it may actually be sending a valid code. Not sure about the last bit yet though.

wammers · Feb 27, 2015

Datatek said:
Yes. What is more, it is perfectly possible to confuse the BECM into doing things it should not do
The receiver contains an access code plus, I suspect the last rolling code generated, so when it goes berserk it may actually be sending a valid code. Not sure about the last bit yet though.

I really prefer oily things.

Datatek · Feb 27, 2015

wammers said:
I really prefer oily things.

It's quite fun playing with FOB receivers in the workshop when I have time, it's cleaner and warmer than the garage/barn

brianp38dse · Feb 27, 2015

So the extra remote is a good shout then

wammers · Feb 27, 2015

brianp38dse said:
So the extra remote is a good shout then

If you live in an area with electric radios, we up here still run ours off gas and steam.

brianp38dse · Feb 27, 2015

Cant get away from rf stuff round here

wammers · Feb 27, 2015

brianp38dse said:
Cant get away from rf stuff round here

Is that ruff females?

brianp38dse · Feb 27, 2015

Plenty of then as well

central locking

Datatek

Well-Known Member

Grrrrrr

Technician, Bodgit & Scarper Ltd

wammers

No longer with us, RIP

Datatek

Well-Known Member

wammers

No longer with us, RIP

Datatek

Well-Known Member

brianp38dse

Well-Known Member

wammers

No longer with us, RIP

brianp38dse

Well-Known Member

wammers

No longer with us, RIP

brianp38dse

Well-Known Member

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