can anyone tell me what alarm is on the sti 03 as standard, i have all the books for it but it doesnt say what make or model it is?

thanks in advance for any help

Sigma I believe fitted as standard on My03

The system fitted is basically a Sigma M30, however, the wiring configuration (using the factory harness) and general immobilisation system is slightly different to an standard Sigma M30 aftermarket installation.
For the standard UK fitted system, Thatcham asses both the Sigma alarm/immobiliser and the vehicle's standard immobiliser and security as a whole vehicle, to obtain a lower insurance grouping for the vehicle, therefore the vehicle has it’s own unique “Thatcham Evaluation Number” that should be used for the combined systems on a UK supplied vehicle, rather than the generic Sigma M30 evaluation number.
If you need this information for your insurance company's reference, then you should quote the “Subaru SUB/AT100 Alarm/Immobiliser” Category 1 system - as the combined assesed systems are known. The Thatcham evaluation number of the vehicle as a whole is TC2-1265/1002. This applies to all UK supplied Impreza models with the standard fitment alarm system from 2002 to 2007MY.