No power locks with button, switch or key

The power locks on my truck suddenly quit. The windows are fine but locks on all 4 doors only work manually. Usually locks engage when truck is put in drive & unlock when put in park&engine is shut off. This doesn't happen & only the driver door locks from the outside using the key when all 4 doors are supposed to lock. I'd appreciate any ideas you could throw my way as to what the problem could be! Thank you!