Circuit Description
The inflatable restraint sensing and diagnostic module (SDM) contains a sensing device that converts vehicle longitudinal velocity changes to an electrical signal when the SDM senses a frontal crash of sufficient force, the SDM will cause current to flow through the frontal inflator modules and the pretensioners. This deploys the frontal air bags and the pretensioners and causes DTC B1151 to set. The SDM then records information regarding the SIR system status and vehicle system status in EEPROM. DTC B1152 is set when the SDM finds the EEPROM memory data area full. The EEPROM memory data area will be full after one deployment event. The SDM will deploy the airbags 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.
Conditions for Setting the DTC
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.
Action Taken When the DTC Sets
| • | The SDM sets a Diagnostic Trouble Code (DTC). |
| • | The SDM commands the instrument cluster (IPC) to turn ON the AIR BAG warning lamp. |
Conditions for Clearing the MIL/DTC
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.
CAUTION: Be careful when you handle a sensing and diagnostic module (SDM). Do
not strike or jolt the SDM. Before applying power to the SDM:
• Remove any dirt, grease, etc. from the mounting surface • Position the SDM horizontally on the mounting surface • Point the arrow on the SDM toward the front of the vehicle • Tighten all of the SDM fasteners and SDM bracket fasteners to
the specified torque value
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the SIR Diagnostic System Check performed? | -- | ||
2 | Replace the inflatable restraint sensing and diagnostic module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Have the repairs been completed? | -- | -- |
