B1159

Circuit Description
When the ignition switch is first turned to ON, the dash integration module (DIM) sends 2 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 Communications Circuit Description in Data Link Communications.

Conditions for Setting the DTC
If the SDM does not receive the serial data keying message from the DIM, DTC B1159 will set without DTC B1155. 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 Instrument Panel Cluster (IPC) to turn ON the AIR BAG warning lamp and sets one 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 class 2 serial data line.
^ History DTC
- You issue a scan tool Clear DTCs command.
- Once 250 malfunction free ignition cycles have occurred.

Diagnostic Aids
DTC B1159 and DTC B1160 will set without DTC B1151 when the DIM is inoperative. DTC B1151 sets only when the wrong message is sent by the DIM. 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.

When measurements are requested in this table, use J 39200 Digital Multimeter with the correct terminal adapter from J 35616-A Connector Test Adapter Kit. When a check for proper connection is requested, refer to Diagrams. When a wire, connector or terminal repair is requested, use J 38125-B 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
Failure to follow the correct procedure could cause air bag deployment, personal injury, or unnecessary SIR system repairs.