B1024

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

Schematics:

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 the following circuits are measured to verify they are within their respective normal voltage ranges:
^ IGNITION 1 voltage
^ 23 VLR
^ Deployment loop voltages

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. Refer to SIR Service Precautions.

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 check for this DTC. These tests occur when IGNITION 1 voltage 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 ON the AIR BAG warning lamp.

CONDITIONS FOR CLEARING THE DTC
DTC B1024 is a latched code. You may not 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 may cause an intermittent condition. A DTC B1024 would be accompanied by DTC B1071. Inspect CKT 347 and CKT 348 carefully for cut or chafed wires. 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 may be helpful in determining if an intermittent condition exists.

When measurements are requested in this table, use the J 39200 Digital Multimeter with the correct terminal adapter from the J 35616-A Connector Test Adapter Kit. When an inspection for proper connection is requested, refer to Testing for Intermittent and Poor Connections in Diagrams. When a wire, connector or terminal repair is requested, use the J 38125-B Terminal Repair Kit. Refer to Wiring Repairs in Diagrams.

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 CKT 347.
9. This test determines whether the malfunction is in CKT 348.