I have a 2001 european model blazer LT in the uk,bought it in 2004 from a vauxhall dealer who brought them in to the uk.Over night it now appears that both key fobs wont open the vechicle or turn the immobiliser off,so it cranks but can't start and run,where and how do I find the control unit to investigate this problem.The RAC have been and the fobs are working but then he got lost .Any help is appreatiated.