The SDM performs test to diagnose critical malfunctions within itself when the ignition switch is turned ON. Upon passing these tests the Ignition, the VLR, and the deployment loop voltages are measured to ensure they are within their respective normal voltage ranges. Next, the SDM proceeds with the Initialization tests including the Diagnostics Resistance Measurements. Then, the SDM goes into a Continuous Monitoring mode.

There is a mismatch between the serial data configuration programming request and the SDM determined vehicle system configuration. This malfunction is detected immediately when the ignition switch is turned to the ON position.

Current and History DTC codes must be cleared using a scan tool Clear DTC Information command. If the circuit fault has been successfully repaired and the conditions which caused the DTC to set are no longer existing, the DTC may be cleared using the scan tool. If the SDM determines that the vehicle system configuration matches serial data configuration programming attempt, a Current DTC 53 will change to a History DTC 53, which may be cleared using the scan tool.

An example test description follows:

2. This step checks to see if the SDM is properly configured.

3. This step programs the SDM.