2002 mondeo speedo?

i have a 2002 mondeo , and the speedo does not work petrol light on all the time airbag light flashes once a few seconds pause then 3 flashes repeats this so many times then stays on , looked all over the net and all they keep saying is this vss on the gearbox , well farfoo i have replaced the vss and still no difference , i am now at my wits end , any help at all what else it could be , many thanks .