I purchased a flood damaged volvo s90. I checked all the brains of the vehicle and there was no water replaced. The engine cranks but does not start. Is there such a thing as a shock sensor?

 

I’m not sure about your specific car model, but yes, some Volvos do come with a shock sensor for security, but it shouldn't stop your car from starting. I'd look for other causes for the no-start issue.
Firstly, make sure there’s no water in the engine and fuel system, as it can mess up combustion and fuel delivery.
Plus, I'd suggest checking the ignition components, like spark plugs, ignition coils, and wiring.
Also, maybe, check the fuel pump, injectors, and lines.

 

also check fuses/relays.