Hi wonderful people, I'm hoping you can help me with a new problem. My remote key has stopped working, the central locking still works fine manually, but then you have to get the key in the ignition and turn it on before the alarm goes off, very annoying!
The first thing I tried was to re-pair the key, I get the first chime after cycling the ignition 4 times, but the second chime doesn't happen when I press the key buttons.
So far I have tried:
Swapping the battery and even replacing the circuit board in the key.
Swapping the RF Module (3m5t-15k602-ac) - although it was second hand
Checked all wiring to and from the RF Module
Confirmed I am getting 12v to the GEM when key is inserted into the ignition and 0v when key is taken out
Checked fuse F9 for the RF Module
What else could I possibly be missing? Do I suspect the RF Module as it was used, or the GEM itself?

The car is a 2007 2.5L AWD estate

 

Are the remote keyfob transmitters WORKING?

I bought a tester.

But auto parts stores can usually test the transmitter for frequency output.

Failed transmitters will not work!!!

 

I had a similar problem and it is frustrating to debug because you can't see those pesky radio waves. Like motorcarman says test the key somehow to see if it is working at all. Car parts store or locksmith or repair shop might help, or buy a cheap tester. You say you have changed the circuit board. North American models use 315 GHz and European models use 434 GHz. Some (all?) FOB circuit boards have the ability to do both so it could be yours is set to the wrong frequency. Here is a post where someone explains how to switch frequencies:

Switch key FOB frequency

Edit to add: That link is for an S-Type forum but it also works on the X-Type keys.

 

Hi Steve
Check whether the flap inside the ignition slot is stuck in the open position. If it is, the system "thinks" the key is in the slot and it will not allow you to pair the key nor will it respond to the remote.