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 module. Upon passing these tests the ignition positive voltage, the 23 VLR and the deployment loop voltages are measured in order to ensure that the voltages are within the respective normal voltage ranges. The SDM monitors the voltages at DRIVER LOW terminal 3 and the PASSENGER LOW terminal 4 to detect shorts to B+ in the inflator module circuits.
Conditions for Setting the DTC
| • | The voltage at the DRIVER LOW terminal 3 is less than 4.8 volts. |
| • | The voltage at the PASSENGER LOW terminal 4 is more than 4.8 volts for 500 milliseconds. |
The continuous monitoring test checks for this DTC. This test occurs when the ignition positive voltage 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 Indicator. |
Conditions for Clearing the MIL/DTC
| • | Current DTC |
| The voltage at PASSENGER LOW terminal 4 is less than 4.8 volts for 500 milliseconds. |
| • | History DTC |
| - | You issue a scan tool CLEAR CODES command. |
| - | 250 malfunction free ignition cycles have occurred. |
Diagnostic Aids
A short to B+ in the inflatable restraint I/P module circuit may cause an intermittent condition. Inspect CKT 1403 and CKT 1404 carefully for cutting or chafing. Wiring pigtail damage requires the replacement of the inflatable restraint I/P module. The diagnostic table directs the technician in order to note the entry value of the PASSENGER SENSELO. Comparing the value of the PASSENGER SENSELO may 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 passenger side low voltage measured by the inflatable restraint Sensing and Diagnostic Module (SDM).
-
This test isolates the malfunction to one side of the inflatable restraint IP module yellow 2-way connector.
-
This test determines whether the malfunction is in CKT 1403.
-
This test determines whether the malfunction is in CKT 1404.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the SIR Diagnostic System Check performed? | -- | ||
Has the PASSENGER SENSELO been read and recorded on the repair order? | -- | -- | ||
Is PASSENGER SENSELO more than the specified value? | 4.8 V | |||
4 |
Is the repair complete? | -- | -- | |
Is the measured voltage less than the specified value? | 1.0 V | |||
6 |
Is the repair complete? | -- | -- | |
Using J 39200 DMM, measure the voltage on the SDM harness connector between terminals 4 and 6 (ground). Is the measured voltage less than the specified value? | 1.0 V | |||
8 |
Is the repair 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 SIR DTCs been cleared? | -- | -- |
