key problem

Hi,Ive got a 2003 2.5tdi, the problem I have is the key,the fob opens the doors, but when I put the key into the ignition the alarm goes off and I cant turn the key, so far this has lasted anything up to an hour then it rights its self,its now becoming more frequent . Any ideas?
thanks Deek

Try replacing the fob battery. It's cheap and may make a difference. If not your alarm ecu is likely showing signs if failure.

Jiggle around the steering column lock, see if no play or something there cos the passive remobilisation exciter coil is there too... and if u cant turn the key the immobiliser will be on... give some wd40 to the ignition barrel

Passive remobilisation exciter coil
The passive remobilisation exciter coil consists of a coil around the steering column lock. The coil energises to create a magnetic field when the ignition is switched to position II.
This coil activates the handset initiating the mobilisation of the vehicle