DTC 56 is an indication of a potential internal inflatable restraint Sensing and Diagnostic Module (SDM) malfunction and requires SDM replacement.
| • | There has been a frontal air bag and pretensioners deployment commanded. | 
| • | There have been three pretensioner-only deployments commanded by this SDM. | 
| • | There have been three driver side air bag deployments commanded by this SDM. | 
| • | There have been three passenger side air bag deployments commanded by this SDM. | 
| • | The SDM sets a diagnostic trouble code. | 
| • | The SDM turns ON the AIR BAG warning lamp. | 
The SDM is replaced.
The numbers below refer to the step numbers on the diagnostic table:
Step  | Action  | Value(s)  | Yes  | No  | 
|---|---|---|---|---|
1  | Was the SIR Diagnostic System Check performed?  | --  | ||
 Is the replacement complete?  | --  | --  |