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, 23 VLR 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 Belt Low terminal 9 and Passenger Belt Low terminal 15 to detect shorts to ground in the seat belt pretensioner deployment loop circuits. The service wait time is 10 minutes. Refer to ENABLE/DISABLE procedures.
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 voltage at Driver Belt Low terminal 9 is less than 1.25 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 DTC B1043. |
| • | The SDM turns ON the AIR BAG warning lamp. |
Conditions for Clearing the DTC
| • | Current DTC |
| The voltage at Driver Belt Low terminal 9 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 passenger seat belt pretensioner deployment loop circuit can cause an intermittent condition. Inspect CKT 2118 and CKT 2119 carefully for cutting or chafing. Wiring pigtail damage requires replacement of the passenger seat belt pretensioner. The diagnostic table directs the technician to note the entry value of LH PRETENS. SENSELO. Comparing the value of LH PRETENS. 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 step isolates the malfunction to one side of the driver seat belt pretensioner yellow 2-way connector.
-
This step checks for a short to ground in CKT 2118.
-
This step determines if there is a short to ground in CKT 2119 or if there is a malfunctioning SDM.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the SIR Diagnostic System Check performed? | -- | ||
2 |
Is the LH PRETENS. SENSELO less than the specified value? | 1.25 V | Refer to Diagnostic Aids | |
Is LH PRETENS. SENSELO less than the specified value? | 1.25 V | |||
4 |
Is the repair complete? | -- | -- | |
Is the measured resistance less than the specified value? | OL | |||
6 |
Is the repair complete? | -- | -- | |
Use the J 39200 to measure the resistance between terminal B of the driver seat belt pretensioner yellow 2-way wiring harness connector and a known good ground. Is the measured resistance less than the specified value? | OL | |||
8 |
Is the repair complete? | -- | -- | |
9 | Reconnect all the SIR system components, making sure all the components are properly mounted. Have all the SIR components been reconnected and properly mounted? | -- | -- | |
10 | Use the scan tool to clear all current and history SIR DTCs. Have all current and history DTCs been cleared? | -- | -- |
