The inflatable restraint sensing and diagnostic module (SDM) contains a sensing device that converts the vehicle longitudinal velocity changes to an electrical signal. When the SDM senses a frontal crash of sufficient force, the SDM may cause current to flow through the inflator modules. This deploys the air bags and causes DTC B1151 and DTC B1152 to set. The SDM records the information regarding the SIR system status and the vehicle system status in EEPROM. DTC  B1152 is set when the SDM finds the EEPROM memory data area full. The EEPROM data area will be full after one deployment event.

The SDM can be re-used after one frontal crash event, however the SDM will not store crash information in the event of another deployment. DTC B1152 will remain a history DTC. For these reasons the SDM should be replaced after a frontal deployment event.

DTC B1152 is set when the SDM attempts to store frontal crash information and finds the EEPROM memory data area full. This test is run each time the SDM stores or attempts to store information regarding a frontal crash event and also during the power-on tests.

DTC B1152 will clear when the SDM receives a scan tool Clear DTCs command. At the next ignition ON after receiving a Clear DTCs command, the SDM will detect that the data area is full and set a history DTC B1152. This allows the AIR BAG warning lamp to illuminate should any additional malfunctions be detected.