Hello, I hope the following is of assistance.
This model isn't equipped with a fuel cut off switch as there is no electric lift pump.
Depending on the extent of the front end impact it is possible for the wiring to the fuel pump to become damaged. If there is no communication to the engine management then make sure the fuses are OK, again if the wiring has been damaged it could create a short circuit that would blow a fuse. There is no reset procedure for the pump on a TDCi the pump is controlled by the engine management.
Start with checking the wiring and why the code reader won't communicate and go from there.
Let me know if I can assist further or if you have more questions regarding this and I'll reply as soon as I'm able to.