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 serial data keying information.When the ignition switch is first 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. For more detailed information about the data lines, refer to Data Link Connector - Cell 50.
Conditions for Setting the DTC
If either or both of the messages do 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 PCM send these messages only at POWER-ON.
Action Taken When the DTC Sets
The SDM commands the IPC to turn ON the AIR BAG warning lamp and sets one or more diagnostic trouble codes.
Conditions for Clearing DTC B1155
The DTC will clear when one of the following conditions is met:
| • | Current DTC |
| The ignition switch is turned OFF. |
| • | History DTC |
| - | You issue a scan tool CLEAR CODES command. |
| - | Once 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 SBM/PCM send this message only at POWER-ON. |
| • | History DTC |
| - | You issue a scan tool CLEAR CODES command. |
| - | Once 250 malfunction free ignition cycles have occurred. |
Diagnostic Aids
DTC B1155 sets only when the wrong message is sent by the SBM or PCM. State Of Health (SOH) DTCs may set in addition to DTC B1155/B1159/B1160. SOH DTCs will likely clear when the malfunction causing DTC B1155/B1159/B1160 to set is repaired. Refer to Diagnostic Aids for that specific SOH DTC.
Test Description
The numbers below refer to the step numbers on the diagnostic table:
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If DTC B1155, DTC B1159, and DTC B1160 are all set, the SDM is receiving the mesages from the SBM and the PCM, however both messages are incorrect according to the SDM in the vehicle.
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If DTC B1155 and B1159 are set, then the SDM is receiving the wrong message from the SBM.
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If DTC B1155 and B1160 are set, then the SDM is receiving the wrong message from the PCM.
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If DTC B1159 is set alone, then the SDM did not receive the message from the SBM.
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If DTC B1160 is set alone, then the SDM did not receive the message from the PCM.
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If DTC B1160 and B1159 are set without DTC B1155, then the SDM did not receive either message from the SBM or the PCM.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the SIR Diagnostic System Check performed? | -- | ||
Are DTC B1155, B1159 and B1160 all set? | -- | |||
3 |
Install the correct SDM in the vehicle. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Is the replacement complete? | -- | -- | |
Are DTC B1155 and B1159 set? | -- | |||
5 |
Has the malfunction been repaired? | -- | -- | |
Are DTC B1155 and B1160 set? | -- | |||
7 |
Has the malfunction been repaired? | -- | -- | |
Is DTC B1159 set alone? | -- | |||
9 |
Has the malfunction been repaired? | -- | -- | |
Is DTC B1160 set alone? | -- | |||
11 |
Has the malfunction been repaired? | -- | -- | |
Are DTC B1160 and DTC B1159 set? | -- | |||
13 |
Has the malfunction been repaired? | -- | -- |
