Circuit Description
When the ignition is turned on, the SDM performs a self-test to diagnose malfunctions
inside the module. The SDM provides input power to the SIS. When input power is first
detected, the SIS responds by performing internal diagnostics. Next the SIS 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 Setting the DTC
DTC B0081 can be set when an incorrect right SIS is installed. The following
conditions must be met to set this DTC:
| • | Ignition voltage is present at the SDM and continuous. |
| • | The SDM has received an ID message from the right SIS that does not match
the ID stored in the SDM memory. |
| • | The SDM resets the right SIS twice without detecting correct operation. |
Action Taken When the DTC Sets
| • | The air bag telltale will be on. |
Diagnostic Aids
| • | Always start diagnosis of the SIR DTCs with an inspection of the vehicle,
including its wiring and the SIR components for visible damage. |
B0081
