Hi

If a 2 circuit immob is fitted to a diesel car what circuits should be cut. Is it different to a petrol version? Cheers.

This all depends on the age of the diesel vehicle and what technology can be utilised.

If it's an older generation diesel engine with a mechanical fuel pump and no engine management system, then to satisfy the Thatcham criteria, a mechanical fuel valve must be fitted in the fuel line to cut the fuel supply to the engine - in addition to the usual starter motor cut. This fuel valve should be switched by a digital/coded signal and/or shielded to prevent by-passing.

If you're lucky, and it's a later generation diesel engine with an engine management system, (HDI, common rail etc) then the fuel cut can be made using the existing electrics to engine management system or fuel pump - as you would on a fuel injected petrol engined vehicle.

SS