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 itself. Upon passing these tests IGNITION 1, 23VLR and the deployment loop voltages are measured in order to make sure they are within their respective normal voltage ranges. The SDM monitors the voltages at driver sense low terminal 3 and passenger sense low terminal 4 in order to detect shorts to B+ in the inflator module circuits.
Conditions for Setting the DTC
| • | The voltage at driver sense low terminal 3 is less than 4.8 volts. |
| • | The voltage at passenger sense low terminal 4 is more than 4.8 volts for 500 milliseconds. |
The continuous monitoring test checks for this DTC. This test occurs when IGNITION 1 is within the normal operating voltage range.
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 passenger sense low terminal 4 is less than 4.8 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 B+ in the inflatable restraint I/P module (passenger inflator module) circuit can cause an intermittent condition. Inspect CKT 1403 and CKT 1404 carefully for cutting or chafing. Wiring pigtail damage requires replacement of the inflatable restraint I/P module (passenger inflator module). The diagnostic table directs the technician to note the entry value of PASSENGER SENSELO. Comparing the value of PASSENGER SENSELO can 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 Connector Test Adapter Kit. When an inspection for proper connection is requested, refer to Intermittents and Poor Connections . When a wire, connector or terminal repair is requested, use the J-38125 Terminal Repair Kit. Refer to Wiring Repair .
Test Description
The numbers below refer to the step numbers on the diagnostic table:
-
This determines the passenger side low voltage measured by the inflatable restraint Sensing and Diagnostic Module (SDM).
-
This isolates the malfunction to one side of the inflatable restraint I/P module yellow 2-way connector.
-
This determines whether the malfunction is in CKT 1403.
-
This determines whether the malfunction is in CKT 1404.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the SIR Diagnostic System Check performed? | -- | ||
Have you read and recorded the voltage on the repair order? | -- | -- | ||
Is the voltage more than the specified value? | 4.8 V | |||
4 |
Are the repairs complete? | -- | -- | |
Is the measured voltage less than the specified value? | 1.0 V | |||
6 |
Are the repairs complete? | -- | -- | |
Measure the voltage on the SDM harness connector from terminal 4 to terminal 6 (ground). Is the measured voltage less than the specified value? | 1.0 V | Go to Integrity Check | ||
8 |
Are the repairs complete? | -- | -- | |
9 | Reconnect all the SIR system components, make sure all the components are properly mounted. Have you reconnected and properly mounted all of the SIR components? | -- | -- | |
10 | Clear all the SIR DTCs. Have all the SIR DTCs been cleared? | -- | -- |
