Key Fob programing?

[Sierra2]

Just tried my 2nd key fob and it doesn't work. Any idea how hard this is to program, will it need Tech2?.

[plasma]

Did it work before? If it did then it may need a new battery, does it still start the car?

[MrDerv]

If it was already prorammed to the car, try a fresh battery in the key.

To re-learn an existing key, insert into the ignition, turn ignition on, then press the lock and unlock buttons on the fob 3 times each. When you turn the ignition off, your fob should now work perfectly.

[Sierra2]

Thanks guy's. I bought it from a VX dealer over a year ago. Diddn't check it (stupidly...) No, once the dash has done its start up the Service/spanner light flashes and it won't turn over (although the key is turning the lock). I'll swap the battery from the one that does work and try that, or is there a risk I might screw the working one up and leave myself stranded?
Chaz

[plasma]

Was it every programmed by them? Is it a PADLOCK symbol that appears, if it wont TURN OVER then it looks like its not been programmed to the car. Whereabouts in London are you?

[Sierra2]

No, the Yellow triangle with spanner flashes. Brentford, Junction2, M4. Chaz

[plasma]

i'll be up in Slough monday/tuesday during working hours if u can get there

[Big Dave]

No, the Yellow triangle with spanner flashes.

Immobiliser fault then.

The padlock symbol was on earlier Vectras.

[Sierra2]

Still works on one key Big Dave?

[Big Dave]

Still works on one key Big Dave?

Fault with the other key then. The transponder chip isn't being recognised by the car or hasn't been programmed correctly.

The battery inside the fob is only for the central locking. Under normal circumstances you could remove the fob battery and it will still start the car.