B1155

CIRCUIT DESCRIPTION

When the ignition is turned to RUN, the Body Control Module (SBM) sends a message over the Serial Data Line Class 2 containing serial data keying information. When the ignition is turned to RUN, the Powertrain Control Module (PCM) sends a message over the Serial Data Line Class 2 containing a partial Vehicle Identification Number (VIN). The inflatable restraint Sensing and Diagnostic Module (SDM) receives these messages and compares them to information stored in memory. These messages are sent once per ignition cycle at Power-ON. For more detailed information about the data lines, refer to Data Link Connector.

CONDITIONS FOR SETTING THE DTC

If either or both of the messages does not match information stored in the SDM, DTC B1155 will set, along with DTC B1159 and/or DTC B1160 depending on the message that does not match. If the SDM does not receive the serial data keying message from the SBM, DTC B1159 will set without DTC B1155. If the SDM does not receive a partial VIN message from the PCM, DTC B1160 will set without DTC B1155. The POWER-ON test checks for these DTCs. The SBM and the PCM send these messages only at Power-ON.

ACTION TAKEN WHEN THE DTC SETS

The SDM commands the WC to turn ON the AIR BAG warning lamp and sets (a) diagnostic trouble code(s).

CONDITIONS FOR CLEARING DTC B1155

^ Current DTC.
- The ignition switch is turned OFF.
^ History DTC.
- You issue a scan tool CLEAR CODES command.
- 250 malfunction-free ignition cycles have occurred.

CONDITIONS FOR CLEARING DTC B1159 and B1160

^ Current DTC.
- The SDM receives the correct message over the Serial Data Line Class 2. The IPC sends this message only at IPC Power-ON.
^ History DTC.
- You issue a scan tool CLEAR CODES command.
- 250 malfunction-free ignition cycles have occurred.

DIAGNOSTIC AIDS

DTC B1155 sets only when the wrong message is sent by the SBM or the PCM. State Of Health (SOH) DTCs may set in addition to DTC B 1155/59/60. SOH DTCs will likely clear when the malfunction causing DTC B 1155/59/60 to set is repaired. Refer to Diagnostic Aids for that specific SOH DTC.

DTC TABLE TEST DESCRIPTION

Numbers below refer to step numbers on the diagnostic table.
2. If DTC B1155, DTC B1159, and DTC B1160 are all set, the SDM is receiving the messages from the SBM and the PCM, however both messages are incorrect according to the SDM in the vehicle.
4. If DTC B1155 and B1159 are set, then the SDM is receiving the wrong message from the SBM.
6. If DTC B1155 and B1160 are set, then the SDM is receiving the wrong message from the PCM.
8. If DTC B1159 is set alone, then the SDM did not receive the message from the SBM.
10. If DTC B1160 is set alone, then the SDM did not receive the message from the PCM.
12. If DTC B1160 and B1159 are set without DTC B1155, then the SDM did not receive either message from the SBM or the PCM.