B1115

Circuit Description
When you first turn the ignition switch to the RUN position, the Inflatable Restraint Sensing and Diagnostic Module (SDM) perform tests to diagnose critical malfunctions within the module. Next the SDM measures Ignition Positive Voltage and the deployment loop voltages to make sure they are within their respective normal voltage ranges. Then the SDM proceeds with the RESISTANCE MEASUREMENT test. During one portion of the RESISTANCE MEASUREMENT test, the SDM does the following:
^ Grounds the PASSENGER FRONTAL LOW terminal 8 through an internal current sink.
^ Connects the PASSENGER FRONTAL HIGH terminal 7 to an internal constant current source. This current produces proportional voltage drops in the deployment loop.
^ Measures the voltage difference between PASSENGER FRONTAL HIGH and PASSENGER FRONTAL LOW.
^ Calculates the resistance of the passenger frontal deployment loop using the measured voltage.

Conditions for Setting the DTC
^ The driver and passenger frontal deployment loops are not open.
^ The driver and passenger frontal deployment loops are not shorted to voltage.
^ The driver and passenger frontal deployment loops are not shorted to ground.
^ The passenger frontal deployment loop resistance is more than 3.0 Ohms.
^ The passenger frontal deployment loop consists of the following items:
- An Inflatable Restraint Instrument Panel (IP) module.
- A harness wiring of circuit 1403.
- A harness wiring of circuit 1404.
- A connector terminal contact.

The RESISTANCE MEASUREMENT test checks for this malfunction. This test only occurs once each ignition cycle when the ignition positive voltage is within the normal operating voltage range.

Action Taken When the DTC Sets
^ The SDM sets a diagnostic trouble code.
^ The SDM commands the instrument panel cluster to turn ON the AIR BAG warning lamp.

Conditions for Clearing the MIL/DTC
^ Current DTC
The resistance of the passenger frontal deployment loop is less than 3.0 Ohms and the ignition switch is cycled.
^ History DTC
- You issue a scan tool CLEAR CODES command.
- 250 malfunction free ignition cycles occur.

When you issue a scan tool CLEAR CODES command and the malfunction is still present, the DTC will not reappear until the next ignition cycle.

Diagnostic Aids
A poor connection may cause an intermittent condition. Inspect the following items for a poor connection:
^ The Inflatable Restraint Instrument Panel module harness connector terminals A and B.
^ The SDM terminals 7 and 8.
^ The wire to terminal connections in circuit 1403.
^ The wire to terminal connections in circuit 1404.

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 Intermittents and Poor Connections. When a wire, connector or terminal repair is requested, use J 38125-B Terminal Repair Kit and refer to Wiring Repair. Intermittents and Poor Connections

Test Description
The numbers below refer to the step numbers on the diagnostic table:
2. This test checks for proper contact or corrosion of the Inflatable Restraint IP module yellow 2-way connector.
9. This test isolates the malfunction to one side of the Inflatable Restraint IP module yellow 2-way connector.
11. This test checks for proper contact or corrosion of the SDM connector.
16. This test determines whether the malfunction is in circuit 1403.
18. This test determines whether the malfunction is in circuit 1404.