I've got one remote that has been gradually going flat for a while, and another the stopped working recently, not sure if it just 'broke' or if it also went gradually flat as its the key my wife uses, but she often borrows mine so didn't take note.
I replaced the battery in the one that has been going flat last week, and that works fine. Now I replaced the battery in the second key, it does not remote unlock the car, the red light does not come on, but it starts the car fine.
1) Does the lack of red light definitely mean the fob is broken? Is there anything can attack with a soldering iron? I tested the new battery and it was approx 3.3v but I tried a 2nd brand new one just in case. I wasn't sure so tried to resync the fobs anyway;
2) Using the good remote, I just cannot get the car into key programming mode. Its a 2009 2.2CDTi. On the ignition I have tried both position 0 to position II and position I to position II, switching the ignition on, pressing the lock button (w/ red light) and ignition off again for 4 cycles and do not get any lock clunking.
Any help appreciated