B1024

Diagnostic Chart:

Wiring Diagram:

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. Upon passing these tests IGNITION, 23VLR and the deployment loop voltages are measured to make sure they are within their respective normal voltage ranges. The SDM monitors the voltages at Driver Frontal Low terminal 2 and Passenger Frontal Low terminal 3 to detect shorts to ground in the inflator module circuits. The service wait time is 10 minutes. Refer to SERVICE AND REPAIR.

Conditions for Setting the DTC
- The driver and passenger frontal air bag deployment loops are not open.
- The passenger frontal air bag deployment loop is not shorted to voltage.
- The voltage at Passenger Frontal Low terminal 3 is more than 2.2 volts.
- The voltage at Driver Frontal Low terminal 2 is less than 2.2 volts for 500 milliseconds.

The following tests check for this DTC. These tests occur when IGNITION is within the normal operating voltage range.
- POWER-ON-When the malfunction is detected in this test, the RESISTANCE MEASUREMENT test will not be performed.
- CONTINUOUS MONITORING

Action Taken When the DTC Sets
- The SDM sets a Diagnostic Trouble Code.
- The SDM turns ON the AIR BAG warning lamp.

Conditions for Clearing the DTC
- Current DTC-The voltage at Driver Frontal Low terminal 2 is greater than 2.5 volts for 500 milliseconds.
- 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
A short-to-B+ in the inflatable restraint steering wheel module circuit can cause an intermittent condition. Inspect CKT 347 and CKT 348 carefully for cutting or chafing. The diagnostic table directs the technician to note the entry value of DRIVER FRONTAL SENSELO. Comparing the value of DRIVER FRONTAL SENSELO 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-A Terminal Repair Kit and refer to Wiring Repair. Intermittent Problems Service and Repair

Test Description
The numbers below refer to the step numbers on the diagnostic table:
2. This test determines the driver frontal air bag low voltage measured by the inflatable restraint sensing and diagnostic module (SDM).
3. This test isolates the malfunction to one side of the inflatable restraint steering wheel module coil yellow 2-way connector.
4. This test determines whether the malfunction is due to the inflatable restraint steering wheel module or the module coil.
7. This test determines whether the malfunction is in CKT 347.
9. This test determines whether the malfunction is in CKT 348.