B1116

Circuit Description
When you first turn the ignition switch to the RUN position, the Inflatable Restraint Sensing and Diagnostic Module (SDM) performs 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 less than 1.4 Ohms. The passenger frontal deployment loop consists of the following components:
- Inflatable Restraint Instrument Panel (IP) module.
- Harness wiring of circuit 1403.
- Harness wiring of circuit 1404.
- Connector terminal contact.

The RESISTANCE MEASUREMENT test checks for this malfunction. This test only occurs once each ignition cycle when 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 (IPC) 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 more than 1.4 Ohms and the ignition switch is cycled.

^ History DTC
- You issue a scan tool CLEAR CODES command.
- 250 malfunction tree 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
The following can cause an intermittent condition:
^ A short circuit between circuit 1403 and circuit 347.
^ A short circuit between circuit 1403 and circuit 348.
^ A short circuit between circuit 1403 and circuit 1404.
^ A malfunctioning shorting bar on the Inflatable Restraint IP module connector.

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 a short from circuit 347 to circuit 1403.
4. This test checks for proper contact or corrosion of the Inflatable Restraint IP module connector.
5. This test isolates the malfunction to one side of the Inflatable Restraint IP module yellow 2-way connector.
7. This test checks for a short from circuit 1403 to circuit 1404.
9. This test checks for a short from circuit 1403 to circuit 348.