When the ignition switch is turned to ON, the sensing and diagnostic module (SDM) will perform a turn-on test to diagnose critical malfunctions within the SDM itself.

In case of the driver side air bag inflation by side impact, the SDM maintains the warning lamp ON and then all the air bag systems should be inspected including pretensioners and also the side air bag sensor, wiring should be replaced. If the driver side air bag inflation by side impact counts over 5, the SDM should also be replaced.

The history of the air bag inflation or belt pretensioner explosion is in the SDM.