A squib driver module comprises a squib circuit for deploying a squib, e.g., in an airbag assembly, the squib circuit including a high side driver and a low side driver in combination for driving a firing signal to the squib: a circuit for activating the firing signal in response to a firing condition; squib diagnostic circuits for conducting diagnostic tests without activating the firing signal and without delivering a diagnostic signal equivalent of the firing signal to the squib, and for generating digital fault information based on the tests; registers for storing the fault information; logic for recognizing a fault condition based on the fault information; and a communication module for communicating the fault condition to a microprocessor unit. The squib diagnostic circuit may include node voltage diagnostic circuits, USD and/or LSD open/short circuits, USD and/or LSD driver fault diagnostic circuits, squib-squib short diagnostic circuits, and/or squib resistance diagnostic circuits.