The inflatable restraint sensing and diagnostic module (SDM) contains a sensing device that converts changes in vehicle velocity to an electrical signal. The SDM compares this signal to a value stored in memory. When the generated signal exceeds the stored value, the SDM performs additional signal processing and compares the generated signals to values stored in memory. When 2 of the generated signals exceed the stored values, the SDM will cause current to flow through the inflator modules, deploying the air bags. DTC B0053 will set instead of DTC B0051 when a deployment occurs while an inflator circuit fault is present that may result in a non-deployment situation in one or more of the inflator modules.

Ignition voltage is between 9-16 volts.

Ignition voltage must be present and the SDM must have commanded an air bag deployment with faults present.

DTC B0053 is a latched code. A latched code cannot be cleared. Replace the SDM after following the instructions in the circuit/system testing.

Schematic Reference

SIR Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

SIR System Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Important: The seat belt pretensioners may deploy for impacts that are not severe enough to warrent frontal or side air bag deployment. The SDM is capable of sustaining 3 pretensioners deployment events or one frontal or side deployment event. After the maximum number of deployments has occurred, DTC B0053 sets and becomes a latched code, which cannot be cleared.

1. Ignition OFF, verify no signs of inflator module or pretensioner deployment exists.

⇒	If any signs of deployment exists, refer to Repairs and Inspections Required After a Collision.

2. Verify the DTC B0053 is not set.

⇒	If the DTC is set, clear the DTC. If the DTC resets, replace the SDM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.