i had a guy come today to have a new key cut and programmed, forscan asked me to put the original key in but it failed to program, pats is showing 2 keys and the guys original key is not giving out a signal as he dropped it in water, now, i have 1 new key and one used key with a new cut blade, should i erase all keys and try to program new keys, i  have loads of used ford remotes which are the same type, would it be best to take out the transponder from original key and put it into a used key i am just worried that if i erase all keys then i might not be able to start the car, the car is a ford focus MK2 2007, any suggestions please

 

 

I am not clear on what you are saying. are you saying there are currently no keys that will start the car, or he still has one working key that will start the car. I can't see how moving a transponder chip from one key to another would help the transponder work. The transponder chip is a standalone thing that dose not connect to the circuit board in the key. If a transponder chip has a problem , then I would think it has the same problem whatever key casing it is in and even if not in one at all and just held next to the ignition lock.     Or have I misunderstood it all. 

If you try starting the car with a key where the transponder chip does not disarm the immobiliser it shows a different DTC for       failure to read the chip      and   reads the chip but it is not a code matched to the ECU.        Does that help? (might be b1600 and b1601 codes but I can't remember for sure)

3 hours ago, isetta said:

If a transponder chip has a problem , then I would think it has the same problem whatever key casing it is in and even if not in one at all and just held next to the ignition lock.     Or have I misunderstood it all?

No, spot on!

Do the keys start the car? Is it just the remote central locking bit that doesn't work?

You can program the remotes separately, but you need to program ALL of them at once. The procedure is on this forum somewhere 😁