automobile remotes...

Rich D · Nov 21, 2021

A question concerning the car remotes; door lock, headlights, etc.

Each car/handset must be a matched pair, regarding the ID
and security codes. Obviously only one car in the parking
lot ought to respond.

Are the ID codes determined by each manufacturer, as
they choose? Or is there an intern\'l body which allocates
them, such that each is guaranteed unique, just as
every telephone has a unique number?

Additionally, anybody know anything about their modulation
methods, or FCC regs? i.e. simple on/off key?

--
Rich

Jon Elson · Nov 21, 2021

Rich D wrote:

A question concerning the car remotes; door lock, headlights, etc.

Each car/handset must be a matched pair, regarding the ID
and security codes. Obviously only one car in the parking
lot ought to respond.

Are the ID codes determined by each manufacturer, as
they choose? Or is there an intern\'l body which allocates
them, such that each is guaranteed unique, just as
every telephone has a unique number?

Well, they have a chip that is programmed at the factory, probably with a
sequentially-incremented number. The car is then trained to accept several
key\'s serial numbers. The all-in-one keys/fobs have two chips, one operated
by pushbutton with a coin cell for door unlock, and one RF-powered by the
engine computer through a coil near the ignition lock, for immobilizer.
So, in theory, there should be no two cars anywhere that respond to the same
code.

Jon

Jon Elson · Nov 21, 2021

Rich D wrote:

A question concerning the car remotes; door lock, headlights, etc.

Each car/handset must be a matched pair, regarding the ID
and security codes. Obviously only one car in the parking
lot ought to respond.

Are the ID codes determined by each manufacturer, as
they choose? Or is there an intern\'l body which allocates
them, such that each is guaranteed unique, just as
every telephone has a unique number?

Well, they have a chip that is programmed at the factory, probably with a
sequentially-incremented number. The car is then trained to accept several
key\'s serial numbers. The all-in-one keys/fobs have two chips, one operated
by pushbutton with a coin cell for door unlock, and one RF-powered by the
engine computer through a coil near the ignition lock, for immobilizer.
So, in theory, there should be no two cars anywhere that respond to the same
code.

Jon

Jon Elson · Nov 21, 2021

Rich D wrote:

A question concerning the car remotes; door lock, headlights, etc.

Each car/handset must be a matched pair, regarding the ID
and security codes. Obviously only one car in the parking
lot ought to respond.

Are the ID codes determined by each manufacturer, as
they choose? Or is there an intern\'l body which allocates
them, such that each is guaranteed unique, just as
every telephone has a unique number?

Well, they have a chip that is programmed at the factory, probably with a
sequentially-incremented number. The car is then trained to accept several
key\'s serial numbers. The all-in-one keys/fobs have two chips, one operated
by pushbutton with a coin cell for door unlock, and one RF-powered by the
engine computer through a coil near the ignition lock, for immobilizer.
So, in theory, there should be no two cars anywhere that respond to the same
code.

Jon

Rich D · Nov 21, 2021

OnFebruary 18, Jon Elson wrote:

A question concerning the car remotes; door lock, headlights, etc.
Each car/handset must be a matched pair, regarding the ID
and security codes. Obviously only one car in the parking
lot ought to respond.
Are the ID codes determined by each manufacturer, as
they choose? Or is there an intern\'l body which allocates
them, such that each is guaranteed unique, just as
every telephone has a unique number?

Well, they have a chip that is programmed at the factory, probably with a
sequentially-incremented number. The car is then trained to accept several
key\'s serial numbers. The all-in-one keys/fobs have two chips, one operated
by pushbutton with a coin cell for door unlock, and one RF-powered by the
engine computer through a coil near the ignition lock, for immobilizer.

So, each manuf\'r has its own allocation of ID numbers. And, presumably, its own
RF format. Are there FCC regs on that?

So, in theory, there should be no two cars anywhere that respond to the same
code.

Well, no. There\'s no intern\'l body allocating the codes, so in theory, there
could be duplication.

Whereas, in the phone network, you dial a number, it\'s guaranteed to ring exactly
one target device.

--
Rich

Rich D · Nov 21, 2021

OnFebruary 18, Jon Elson wrote:

A question concerning the car remotes; door lock, headlights, etc.
Each car/handset must be a matched pair, regarding the ID
and security codes. Obviously only one car in the parking
lot ought to respond.
Are the ID codes determined by each manufacturer, as
they choose? Or is there an intern\'l body which allocates
them, such that each is guaranteed unique, just as
every telephone has a unique number?

Well, they have a chip that is programmed at the factory, probably with a
sequentially-incremented number. The car is then trained to accept several
key\'s serial numbers. The all-in-one keys/fobs have two chips, one operated
by pushbutton with a coin cell for door unlock, and one RF-powered by the
engine computer through a coil near the ignition lock, for immobilizer.

So, each manuf\'r has its own allocation of ID numbers. And, presumably, its own
RF format. Are there FCC regs on that?

So, in theory, there should be no two cars anywhere that respond to the same
code.

Well, no. There\'s no intern\'l body allocating the codes, so in theory, there
could be duplication.

Whereas, in the phone network, you dial a number, it\'s guaranteed to ring exactly
one target device.

--
Rich

Rich D · Nov 21, 2021

OnFebruary 18, Jon Elson wrote:

A question concerning the car remotes; door lock, headlights, etc.
Each car/handset must be a matched pair, regarding the ID
and security codes. Obviously only one car in the parking
lot ought to respond.
Are the ID codes determined by each manufacturer, as
they choose? Or is there an intern\'l body which allocates
them, such that each is guaranteed unique, just as
every telephone has a unique number?

Well, they have a chip that is programmed at the factory, probably with a
sequentially-incremented number. The car is then trained to accept several
key\'s serial numbers. The all-in-one keys/fobs have two chips, one operated
by pushbutton with a coin cell for door unlock, and one RF-powered by the
engine computer through a coil near the ignition lock, for immobilizer.

So, each manuf\'r has its own allocation of ID numbers. And, presumably, its own
RF format. Are there FCC regs on that?

So, in theory, there should be no two cars anywhere that respond to the same
code.

Well, no. There\'s no intern\'l body allocating the codes, so in theory, there
could be duplication.

Whereas, in the phone network, you dial a number, it\'s guaranteed to ring exactly
one target device.

--
Rich

Rich D · Nov 21, 2021

OnFebruary 18, Jon Elson wrote:

A question concerning the car remotes; door lock, headlights, etc.
Each car/handset must be a matched pair, regarding the ID
and security codes. Obviously only one car in the parking
lot ought to respond.
Are the ID codes determined by each manufacturer, as
they choose? Or is there an intern\'l body which allocates
them, such that each is guaranteed unique, just as
every telephone has a unique number?

Well, they have a chip that is programmed at the factory, probably with a
sequentially-incremented number. The car is then trained to accept several
key\'s serial numbers. The all-in-one keys/fobs have two chips, one operated
by pushbutton with a coin cell for door unlock, and one RF-powered by the
engine computer through a coil near the ignition lock, for immobilizer.

So, each manuf\'r has its own allocation of ID numbers. And, presumably, its own
RF format. Are there FCC regs on that?

So, in theory, there should be no two cars anywhere that respond to the same
code.

Well, no. There\'s no intern\'l body allocating the codes, so in theory, there
could be duplication.

Whereas, in the phone network, you dial a number, it\'s guaranteed to ring exactly
one target device.

--
Rich

Rich D · Nov 21, 2021

OnFebruary 18, Jon Elson wrote:

A question concerning the car remotes; door lock, headlights, etc.
Each car/handset must be a matched pair, regarding the ID
and security codes. Obviously only one car in the parking
lot ought to respond.
Are the ID codes determined by each manufacturer, as
they choose? Or is there an intern\'l body which allocates
them, such that each is guaranteed unique, just as
every telephone has a unique number?

Well, they have a chip that is programmed at the factory, probably with a
sequentially-incremented number. The car is then trained to accept several
key\'s serial numbers. The all-in-one keys/fobs have two chips, one operated
by pushbutton with a coin cell for door unlock, and one RF-powered by the
engine computer through a coil near the ignition lock, for immobilizer.

So, each manuf\'r has its own allocation of ID numbers. And, presumably, its own
RF format. Are there FCC regs on that?

So, in theory, there should be no two cars anywhere that respond to the same
code.

Well, no. There\'s no intern\'l body allocating the codes, so in theory, there
could be duplication.

Whereas, in the phone network, you dial a number, it\'s guaranteed to ring exactly
one target device.

--
Rich

Ralph Mowery · Nov 21, 2021