B1147

CAUTION: Be careful when you handle an inflatable restraint Side Impact Sensing Module (SISM). Do not strike or jolt the SISM. Before applying power to the SISM:
^ Remove any dirt, grease, etc. from the mounting surface.
^ Position the SISM on the mounting surface.
^ Point the connector on the SISM toward the rear of the vehicle.
^ Tighten all of the SISM fasteners to the specified torque value.
Failure to follow the correct procedure could cause air bag deployment, personal injury, or unnecessary Air Bag system repairs.

When measurements are requested in this table, use J 39200 DVM with the correct terminal adapter from J 35616-A Connector Test Adapter Kit. When a check for proper connection is requested, refer to Intermittents and Poor Connections in Diagram Information in Diagrams. When a wire, connector, or terminal repair is requested, use J 38125-A Terminal Repair Kit and refer to Wiring Repair.

CIRCUIT DESCRIPTION
When you turn the ignition switch to the RUN position, the inflatable restraint Side Impact Sensing Module (SISM) performs tests to diagnose critical malfunctions within itself. The SISM then tests for the following conditions:
^ Deployment loop open
^ Deployment loop short to ground
^ Deployment loop short to ignition
^ Deployment loop resistance high
^ Deployment loop resistance low
^ Deployment reserve energy failure

The inflatable restraint Side Impact Sensing Module (SISM) transmits a pulse width modulated signal to the inflatable restraint Sensing and Diagnostic Module (SDM) over CKT 985. A 300 millisecond pulse width with a 50 percent duty cycle is the Normal mode and indicates that the SISM is operating normally and no faults exist. The SISM communicates that it is turning OFF (ignition OFF) by sending a 20 millisecond pulse width modulated signal with a 50 percent duty cycle.

CONDITIONS FOR SETTING THE DTC
The SDM receives a pulse width signal other than the Normal signal, or no signal at all.

The SISM performs tests during POWER-ON tests, CONTINUOUS MONITORING tests, and Asynchronously.

ACTION TAKEN WHEN THE DTC SETS
^ The SDM sets DTC B1147.
^ The SDM commands the Instrument Panel Cluster (IPC) to turn ON the AIR BAG warning lamp.

CONDITIONS FOR CLEARING THE DTC
^ Current DTC.
- The SDM receives a Normal signal from the SISM.
- The ignition switch is cycled.
If a side impact deployment occurs the SISM must be replaced. Follow the instructions in the diagnostic table.
^ History DTC.
- You issue a scan tool CLEAR CODES command.
- 250 malfunction-free ignition cycles occur.

DIAGNOSTIC AIDS
A poor connection can cause an intermittent condition. Check the following for a poor connection:
^ The SISM.
^ The inflatable restraint side impact inflator module.
^ The SDM terminal 13.
^ The wire to terminal connections of all circuits going to the SISM.

DTC TABLE TEST DESCRIPTION
Numbers below refer to step numbers on the diagnostic table.
2. If the driver inflatable restraint side impact inflator deployed, DTC B1147 will set.
3. Components require inspection and possibly replacement after a side impact accident, whether deployment occurred or not.
5. This test determines if the malfunction is in the inflatable restraint side impact inflator module.
11. This test checks for an open in CKT 1751.
13. This test checks for an open in CKT 1139.
15. This test checks for a short to ground in CKT 978.
17. This test checks for high resistance or open in CKT 978.
19. This test checks for a short to voltage in CKT 978.
21. This test checks for a short to voltage in CKT 979.
23. This test checks for a short to ground in CKT 979.
25. This test checks for high resistance or open in CKT 979.
27. This test checks for a short to ground in CKT 985.
29. This test checks for a short to voltage in CKT 985.
35. This test checks for high resistance or open in CKT 985.
37. If all wiring and connections are OK, then and only then should the inflatable restraint Side Impact Sensing Module (SISM) be replaced.