Been to look at a polo that i have inherited from another garage, they have replaced the heater matrix, since then the car will not start.
the engine will crank over and sometimes will start and run for 2 seconds but after that will just crank over and not fire, the car was running before the heater was done so i can only assume some wiring has been disturbed somewhere, the immobiliser light was flashing when i got to the job so i read its memory, key not authorised, so re-programmed the keys, light is now out but car still cranks but will not start, fault code for ecu locked in diesel ecu but that will clear and does not always come back, interested to hear your thoughts before i send the ecu to have the immobiliser removed from the software.