Circuit Description
When you first turn the ignition switch to the RUN position, the inflatable restraint sensing and diagnostic module (SDM) performs tests to diagnose critical malfunctions within itself. The SDM provides input power to the inflatable restraint side impact sensor (SIS). When input power is first detected, the SIS responds by performing internal diagnostics. The SIS then sends an ID message to the SDM. The SDM will consider this to be a valid ID if the response time is less than 5 seconds after the SIS is powered up.The SIS will continually communicate a status message to the SDM. The SDM can reset the SIS by removing and applying power to it.
Conditions for Running the DTC
| • | Ignition 1 voltage is within the normal operating voltage range. |
| • | The LF SIS sends an ID message to the SDM. |
Conditions for Setting the DTC
| • | The SDM has received an ID message from the LF SIS which does not match the ID stored in the SDM memory. |
| • | When 2 LF SIS resets are attempted without the correct identification being detected by the SDM. |
Action Taken When the DTC Sets
| • | The SDM commands ON the AIR BAG warning lamp via Class 2 serial data. |
| • | The SDM attempts to reset the LF SIS. |
Conditions for Clearing the DTC
| • | The LF SIS ID matches the LF SIS ID stored in the SDM memory. |
| • | You can issue a scan tool CLEAR CODES command. |
| • | A history DTC will clear once 255 malfunction free ignition cycles have occurred. |
When the SDM detects that no DTCs are present, the SDM commands the AIR BAG warning lamp OFF.
Diagnostic Aids
Verify that the proper LF side impact sensor (SIS) is installed in the vehicle.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the SIR Diagnostic System Check? | -- | ||
Does the scan tool indicate that DTC B0079 is current? | -- | -- | ||
3 | Replace the LF inflatable restraint side impact sensor (SIS). Refer to Inflatable Restraint Side Impact Sensor Replacement . Did you complete the replacement? | -- | -- | |
4 |
Did you complete the repair? | -- | -- |
