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 Side Low terminal 10 and Passenger Side Low terminal 14 to detect shorts to ground in the frontal inflator module circuits. The service wait time is 10 minutes. Refer to ENABLE/DISABLE procedures.
Conditions for Setting the DTC
| • | The driver and passenger side air bag deployment loops are not open. |
| • | The driver side air bag deployment loop is not shorted to voltage. |
| • | The voltage at Driver Side Low terminal 10 is less than 2.2 volts for 500 milliseconds. |
| • | The voltage at Passenger Side Low terminal 14 is more than 2.2 volts. |
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 Side Low terminal 10 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. |
Diagnostic Aids
A short to ground in the inflatable restraint driver seat module circuit can cause an intermittent condition. Inspect CKT 2137 and CKT 2138 carefully for cutting or chafing. Wiring pigtail damage requires replacement of the inflatable restraint driver seat module. The diagnostic table directs the technician to note the entry value of LH SIDE AIR BAG SENSELO. Comparing the value of LH SIDE AIR BAG 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 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 Terminal Repair Kit and refer to Wiring Repair .
Test Description
The numbers below refer to the step numbers on the diagnostic table:
-
This test determines the driver side air bag low voltage measured by the inflatable restraint sensing and diagnostic module (SDM).
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This test isolates the malfunction to one side of the inflatable restraint front side impact module (LH) yellow 2-way connector.
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This test determines whether the malfunction is in CKT 2138.
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This test determines whether the malfunction is in CKT 2137.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the SIR Diagnostic System Check performed? | -- | ||
Is the LH SIDE AIR BAG SENSELO less than the specified value? | 2.2 V | Refer to Diagnostic Aids | ||
Is LH SIDE AIR BAG SENSELO less than the specified value? | 2.2 V | |||
4 |
Is the replacement complete? | -- | -- | |
Is the resistance less than the specified value? | OL | |||
6 | Repair a short to ground condition in CKT 2138. Are the repairs complete? | -- | -- | |
Measure the resistance on the SDM harness connector from terminals 11 to 7 (ground). Is the resistance less than the specified value? | OL | Go to Integrity Check | ||
8 | Repair a short to ground condition in CKT 2137. Are the repairs complete? | -- | -- | |
9 | Reconnect all the SIR system components, make sure all the components are properly mounted. Have all the SIR components been reconnected and properly mounted? | -- | -- | |
10 | Clear all the SIR DTCs. Have all the DTCs been cleared? | -- | -- |
