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

The belt tensioner cannot be deployed independently and should be deployed with other modules regardless of frontal or side impact. DTC B1657 will set with B1651 or B1652.

In case of the belt tensioner deployment, the SDM maintains the warning lamp ON. Deployed modules and the SDM should be replaced. After replacement the entire system should be checked.

Ignition voltage is between 9-16 volts.

The history of the belt pretensioner explosion is in the SDM.

The SDM commands ON the AIR BAG warning lamp.

The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.

Electrical Information Reference

Note: When removing connectors inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector.

•	The I/P module

•	The SDM module

•	The I/P wiring harness connector

•	The SDM wiring harness connector

1. Ignition ON, use the scan tool to request SIR DTCs. Verify that DTC B1657 is set as current.

⇒	If DTC B1657 was current replace the SDM.

2. Ignition ON, use the scan tool to clear the DTCs.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for SDM replacement, setup, and programming