Circuit Description
When the ignition switch is first turned to ON, the dash integration module (DIM) sends two messages over the class 2 serial data line containing identification information. The first message contains serial data keying information. The second message contains 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 Replacement in Wiring Systems.
Conditions for Setting the DTC
If either or both of the messages from the DIM 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. The Power-On test checks for these DTCs. The DIM sends these messages only at DIM 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 (DTC).
Conditions for Clearing the MIL/DTC
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 DTCs command. |
| - | Once 250 malfunction free ignition cycles have occurred. |
Diagnostic Aids
DTC B1155 sets only when the wrong message is sent by the DIM. State Of Health (SOH) DTCs may set in addition to DTC B1155. SOH DTCs will likely clear when the malfunction causing DTC B1155 to set is repaired.
When measurements are requested in this table, use J 39200 Digital Multimeter with the correct terminal adapter from J 35616 Connector Test Adapter Kit. When a check for proper connection is requested, refer to General Electrical Diagnosis Procedures in Wiring Systems. When a wire, connector or terminal repair is requested, use J-38125 Terminal Repair Kit and refer to Wiring Repair .
CAUTION: Be careful when you handle a sensing and diagnostic module (SDM). Do
not strike or jolt the SDM. Before applying power to the SDM:
• Remove any dirt, grease, etc. from the mounting surface • Position the SDM horizontally on the mounting surface • Point the arrow on the SDM toward the front of the vehicle • Tighten all of the SDM fasteners and SDM bracket fasteners to
the specified torque value
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the SIR Diagnostic System Check performed? | -- | ||
2 | Was the inflatable restraint sensing and diagnostic module (SDM) replaced recently? | -- | ||
3 |
Have the repairs been completed? | -- | -- | |
4 | Was the dash integration module (DIM) replaced recently? | -- | ||
5 |
Have the repairs been completed? | -- | -- | |
6 | Reconnect all the SIR system components, make sure all the components are properly mounted. Have all the SIR components been reconnected and properly mounted? | -- | -- |
