I am trying to get my brother's stereo working while he is on holiday as a surprise. I have pressed and held the AS button and it comes up with '6 safe'. I know I need to wait about 40 mins with the ignition on but I don't have the unlock code. Information of the stereo: NO: 90 533 422 TYPE: CAR (F) GM0300Y6224750 7 649 852 320 I would be grateful for any help. Thanks