B1024

Circuit Description
When you first turn the ignition switch to the RUN position, the Inflatable Restraint Sensing and Diagnostic Module (SDM) performs tests in order to diagnose critical malfunctions within the SDM. Upon passing these test the following circuits are measured in order to ensure they are within their respective normal voltage ranges:
^ IGNITION 1
^ 23 VLR
^ Deployment loop voltage
The SDM monitors the voltages at DRIVER SIDE LOW terminal 3 and PASSENGER SIDE LOW terminal 4 to detect shorts to ground in the inflator module circuits. The service wait time is 10 minutes.

Conditions for Setting the DTC
^ The driver and passenger deployment loops are not open.
^ The passenger deployment loop is not shorted to voltage.
^ The voltage at PASSENGER SIDE LOW terminal 4 is more than 3.3 volts.
^ The voltage at DRIVER SIDE LOW terminal 3 is less than 3.3 volts for 500 milliseconds.
The following tests inspect for this DTC. These tests occur when IGNITION 1 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 DTC B1024.
^ The SDM sets DTC B1071.
^ The SDM turns the AIR BAG warning lamp to the ON position.

Conditions for Clearing the DTC
DTC B1024 is a latched code. You cannot clear a latched code. Repair the malfunction that set this DTC before you replace the SDM.

Diagnostic Aids
A short to ground in the Inflatable Restraint Steering Wheel Module circuit can cause an intermittent condition. A DTC B1024 would be accompanied by DTC B1071. Inspect circuit 347 and circuit 348 carefully for cutting or chafing. A careful inspection of the circuits and components indicated on the DTC B1024 table is essential in order to prevent damage to the replacement Inflatable Restraint Sensing and Diagnostic Module (SDM). The diagnostic table directs the technician to note the entry value of DRIVER SENSELO. Comparing the value of DRIVER SENSELO can be helpful in determining if an intermittent condition exists.
When measurements are requested in this table, use the J 39200 DMM with the correct terminal adapter from the J 35616-A Connector Test Adapter Kit.

Test Description
The numbers below refer to the step numbers on the diagnostic table:
2. This test determines the driver side low voltage which is measured by the Inflatable Restraint Sensing and Diagnostic Module (SDM). A reading of 3.3 V or more indicates that an intermittent condition may exist.
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 circuit 347.
9. This test determines whether the malfunction is in circuit 348.