B1041

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 itself. Next the SDM measures IGNITION 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 Diver Belt Low terminal 9 through an internal current sink.
^ Connects the Driver Belt High terminal 8 to an internal constant current source. This current produces proportional voltage drops in the deployment loop.
^ Measures the voltage difference between Driver Belt High and Driver Belt Low.
^ Calculates the resistance of the driver seat belt pretensioner deployment loop using the measured voltage.

Conditions for Setting the DTC
^ The driver seat belt pretensioner deployment loop is not open.
^ The driver seat belt pretensioner deployment loop is not shorted to voltage.
^ The driver seat belt pretensioner deployment loop is not shorted to ground.
^ The driver seat belt pretensioner deployment loop resistance is less than 1.35 ohms. The driver seat belt pretensioner deployment loop consists of the following components:
- Driver seat belt pretensioner.
- Harness wiring of circuit 2118.
- Harness wiring of circuit 2119.
- Connector terminal contact.

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

Action Taken When the DTC Sets
^ The SDM sets a DTC B1041.
^ The SDM turns ON the AIR BAG warning lamp.

Conditions for Clearing the DTC
^ Current DTC
The resistance of the driver seat belt pretensioner deployment loop is more than 1.85 ohms and the ignition switch is cycled.
^ History DTC
- You issue a scan tool CLEAR CODES command.
- Once 250 malfunction free ignition cycles have occurred.

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 between circuit 2118 and circuit 2119.
^ A malfunctioning shorting bar on the driver seat belt pretensioner yellow 2-way yellow connector.

The diagnostic table directs the technician to note the entry value of LH PRETENS. RESIST. Comparing the value of LH PRETENS. RESIST. over multiple ignition cycles can be helpful in determining if an intermittent condition exists.

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:
3. This step checks the driver seat belt pretensioner yellow 2-way wiring harness connector for corrosion or damaged terminals.
10. This step isolates the malfunction to one side of the driver seat belt pretensioner yellow 2-way connector.
12. This step checks the SDM wiring harness connector for corrosion or damaged terminals.
17. This step determines if there is a short between circuit 2118 and circuit 2119 or if there is a malfunctioning SDM.