Circuit Description
When the ignition switch is first turned to RUN, the body control module (SBM) 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 the message to the information stored in memory. For more detailed information about the data lines, refer to Data Link Connector-Cell 50. DTC B1159 is diagnosed in the DTC B1155 Table.
Conditions for Setting the DTC
If the SDM does not receive the serial data keying message from the SBM, DTC B1159 will set without DTC B1155. If the message from the SBM does not match the information stored in the SDM, DTC B1155 will set along with DTC B1159. The POWER-ON test inspects for these DTCs. The SBM only sends this message at POWER-ON.
Action Taken When the DTC Sets
The SDM commands the instrument cluster to turn ON the AIR BAG warning lamp and sets 1 or more diagnostic trouble codes.
Conditions for Clearing the MIL/DTC
The DTC will clear when one of the following conditions is met:
| • | Current DTC |
| The SDM receives the correct message over the serial data line class 2. |
| • | History DTC |
| - | You issue a scan tool CLEAR CODES command. |
| - | 250 malfunction free ignition cycles have occurred. |
Diagnostic Aids
DTC B1159 will set without DTC B1155 when the SBM is inoperative. DTC B1155 sets only when the wrong message is sent by the SBM . The 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 | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the SIR Diagnostic System Check performed? | -- | Go to Step 2 | |
2 | This DTC is diagnosed in the DTC B1155 table. Was the DTC B1155 table followed? | -- |
