Hi Stephen, The amber light is a warning that something needs attention. You really need an OBD2 Scanner to find out what is the problem. My s type handbook says it might go into limp mode, but if it hasn't done that you just drive with caution, as the handbook says. A main dealer will plug it in to the diagnostic system, but will charge you about £70 for the time on their diagnostic kit. What part of Staffordshire are you in, as there is a Mobile mechanic in the South of the County-- Look him up on his website ----- James Price ---- and he might be able to help. Regards, Peter.