Programming key

[Old Git]

Can any members help, one of my keys will not unlock/lock my car I put a new Battery in the key but not sure how to programme to car.

[PCM]

I thought it worked automatically.

When I have changed a Battery it just works...

[ColinBarber]

9 minutes ago, PCM said:

I thought it worked automatically.

When I have changed a battery it just works...

Correct. In fact the key isn't programmed, the vehicle ECU is programmed to the key.

Try holding down the unlock button for 20 seconds.

[Old Git]

Sorry forgot to say the Battery in the key must have been completely flat for some time I put a new Battery in it but will not lock/unlock the doors but will start the car ok

 

[Stupot]

I take it you are talking about a remote key with the three buttons on it?

If it is starting the car OK, then the car ECU and the immobiliser chip in the key are talking to each other.... as Colin says, might just need some kind of re-set for the central locking? Sorry if this is teaching granny to suck eggs etc... but is the Battery you have put in located the right way up, making contact, right size? (mine is a 1616 size Battery, probably same as yours)

My spare key Battery was flat when I got the car and it worked fine with a new Battery, no messing.

[Old Git]

Yes new Battery right way up, when I press the unlock button key light flashes yes its the 3 button key, I read a few blogs and there was a routine opening shutting drivers door key in/out of ignition none of these seem to work it think they are for USA spec cars will get there eventually.

[Delphius1]

I've done the key programming thing from scratch, so I have a bit of experience. ;-)

I posted back in 2018 my experience of getting key electronics programmed to my RX300. I'm not sure if the 350 is the same. It's worth a shot anyway. 

I assume the key starts the car fine, it's just the central locking part of the key that has become unsynchronised with the central locking module? If the key fails to start the car, then something else is wrong.

To get the central locking module to re-learn the key's code, here's the procedure I posted back in 2018:

The programming goes something like this. (I did it at the speed you can read this text)

Sit in car with drivers door closed

Open drivers door.

Key in ignition, key out of ignition, key in ignition, key out of ignition (Don't turn the key, just insert it into the barrel and remove)

Close drivers door, open drivers door, close drivers door, open drivers door,

Key in ignition, key out of ignition, (don't turn the key as above)

Close drivers door, open drivers door, close drivers door, open drivers door,

Key in ignition, close drivers door, turn ignition to on (lights on dash), turn ignition off and remove key

Central locking locks doors... wait for doors to unlock, (you have to wait for the doors to unlock before the next step. It may take a couple of seconds)

Press lock & unlock buttons on key fob at the same time for a second, release, then press lock button within 3 seconds

Central locking should lock/unlock.

Key is now programmed: open drivers door to cancel programming mode.

 

[royoftherovers]

How on EARTH did you work that sequence out Mark ?