Circuit Description
When you turn ON the ignition, the Body control Module (BCM) sends a message over the serial data line Class 2 containing identification information. The message contains serial data keying information. The inflatable restraint sensing and diagnostic module (SDM) receives this message and compares it to information stored in memory. DTC B1159 is diagnosed in the DTC B1155 Table.
Conditions for Setting the DTC
The SDM does not receive the serial data keying message from the BCM, DTC B1159 will set without DTC B1155. If the message from the Instrument Panel Cluster (IPC) do not match information stored in the SDM, DTC B1155 will set, along with DTC B1159. The IPC sends this message only at power-on.
Action Taken When the DTC Sets
The SDM commands the AIR BAG warning lamp ON via Class 2 serial data.
Conditions for Clearing
The DTC will clear when one of the following conditions is met:
| • | The SDM receives the correct message over the Class 2 serial data line. |
| • | You can issue a CLEAR CODES command |
| • | A history DTC will clear once 250 malfunction free ignition cycles have occurred |
Diagnostic Aids
DTC B1159 will set without DTC B1155 when the IPC is inoperative. DTC B1155 sets only when the wrong message is sent by the IPC. State Of Health (SOH) DTCs may set in addition to DTC B1159. SOH DTCs will likely clear when the malfunction causing DTC B1159 to set is repaired. DTC B1159 is diagnosed in the DTC B1155 table.
Step | Action | Yes | No |
|---|---|---|---|
1 | Did you perform A Diagnostic System Check - SIR? | Go to Step 2 | |
2 | This DTC is diagnosed in the DTC B1155 table. Refer to DTC B1155 . Did you complete the repairs? | -- |
