Polo MK3 1998 SKC VAG TACHO

Hi

I thought a spare key would be a good idea, so bought a photo-cut key, ID42 chip and Vag Tacho 3.01.

I managed to get the pin code through ECU "Motometer MM0/BOO" straight away, and through ECUs "Immo2 box VW LT bus (Temic)" and "Immo1 VW/SEAT (Siemmens)" after around 50 tries each. Code was same for all = "0000" (dodgy code?).

Thing is when I try and program a new key I get a "wrong code" message.

First time I got the code I tried programming the key straight away, without previously disconnecting the cable. Then I found out this had probably activated the "timer", so left it switched on for two hours, tried again, and again got a "wrong code" message, and again, and again...

The car still starts and runs perfectly on the old key.

My question is, does Vag Tacho support this model at all? I have never found it on any list!

Do I need to leave it switched on for longer before it unblocks?

I would really appreciate your thoughts.

Many thanks in advance!