HI guys recently bought a 2011 insignia 2.0cdti 

Car was running when i bought it. Started it the next morning and put it in my shed.

Serviced the car and done gearbox oil. 

When i went to start battery obviously wasn't great and car failed to start message poped up on dash 

Service Theft Deterrent System 

Have had the car at the dealer they say no response from bcm.

 

Put a used ecu kit in from a local breakers and same issue even got security code for replacement ecu and opcom but no joy

 

Hi....welcome to the Forum

First thoughts are it is related to the battery voltage (or lack of it) 

It sounds like the BCM needs resetting as the battery voltage will still be storing memory of the low voltage until it is reprogrammed to accept the new voltage from the replacement battery....but I'm sure the Vauxhall dealership would know that

Keep us updated on what you find out