My c180 stopped and wont start,the lights ,(red/green)flash in the mirror. I have fitted new batts to fob,tried the card key and the small key that plugs in by the door .The immob is behind the dash (which is out now).I have tried the usual tricks to reset, the fob rattles but the card key does not work either so that rules out keys. I hear prob can be diode in mirror,sounder back up batt etc,but in the meantime would just like to dissable immob,does not look like system spliced in as all conections are plugs. No unit under passenger floor. Advice? is it poss to dismantle sounder?.i can do pcb repairs,so happy to try stuff.