Circuit Description
When you first turn the ignition switch to the ON position, the inflatable restraint sensing and diagnostic module (SDM) performs tests to diagnose critical malfunctions within itself. Next the SDM measures Ignition 1 voltage to make sure it is within its respective normal voltage range. Then the SDM proceeds with the Deployment Loop Continuity test. During the Deployment Loop Continuity test, the SDM measures the voltage difference between Passenger Frontal High and Passenger Frontal Low.
Conditions for Setting the DTC
| • | The voltage difference between Passenger Frontal High terminal 7 and Passenger Frontal Low terminal 8 is more than or equal to 426 millivolts. |
| • | The malfunction must be present for at least 500 milliseconds during one of the following tests: |
| - | Deployment Loop Continuity |
| - | If 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 (DTC). |
| • | The SDM commands the instrument cluster (IPC) to turn ON the AIR BAG warning lamp. |
Conditions for Clearing the MIL/DTC
| • | Current DTC |
| The voltage difference between Passenger Frontal High terminal 7 and Passenger Frontal Low terminal 8 is less than 426 millivolts for 500 milliseconds. |
| • | History DTC |
| - | You issue a scan tool Clear DTCs command. |
| - | Once 250 malfunction free ignition cycles have occurred. |
Diagnostic Aids
The following can cause an intermittent condition:
| • | A poor connection at the inflatable restraint IP module harness connector terminals A and B. |
| • | A poor connection at the SDM terminals 7 and 8. |
| • | An open in CKT 1403. |
| • | An open in CKT 1404. |
The diagnostic table directs the technician to note the scan tool value of Passenger Frontal VDIF Comparing the value of Passenger Frontal VDIF 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 General Electrical Diagnosis Procedures in Wiring Systems. 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 deployment loop voltage difference measured by the inflatable restraint sensing and diagnostic module (SDM).
-
This test checks for proper contact or corrosion of the yellow 2-way connector.
-
This test isolates the malfunction to one side of the inflatable restraint I/P module yellow 2-way connector.
-
This test checks for proper contact or corrosion of the SDM 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 Frontal VDIF been read and recorded on the repair order? | -- | -- | ||
Are the terminals damaged or corroded? | -- | |||
4 | Replace the inflatable restraint IP module yellow 2-way IP harness connector. Refer to Wiring Repair . Have the repairs been completed? | -- | -- | |
5 | Check for proper connection at terminals A and B on the inflatable restraint IP module yellow 2-way connector. Are the terminals damaged or corroded? | -- | ||
6 | Check for proper connection at terminals A and B on the inflatable restraint IP module yellow 2-way connector. Are the terminals damaged or corroded? | -- | ||
7 | Replace the inflatable restraint IP module. Refer to Inflatable Restraint Instrument Panel Module Replacement . Have the repairs been completed? | -- | -- | |
8 |
Is the Passenger Frontal VDIF greater than the specified value? | 426 mV | ||
9 |
Have the repairs been completed? | -- | -- | |
Is the Passenger Frontal VDIF greater than the specified value? | 426 mV | |||
11 |
Have the repairs been completed? | -- | -- | |
Is the connector damaged or corroded? | -- | |||
13 | Replace the SDM harness connector. Refer to Wiring Repair . Have the repairs been completed? | -- | -- | |
14 | Check for proper connection at terminals 8 and 7 of the SDM. Are the terminals damaged or corroded? | -- | ||
15 | Check for proper connection at terminals 8 and 7 of the SDM. Are the terminals damaged or corroded? | -- | ||
16 | Replace the inflatable restraint sensing and diagnostic module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Have the repairs been completed? | -- | -- | |
Using J 39200 DMM, measure the resistance from the SDM harness connector terminal 7 to the inflatable restraint IP module yellow 2-way harness connector terminal A. Is the resistance reading within the specified values? | 0.0-0.5 ohms | |||
18 | Repair the high resistance condition in CKT 1403. Refer to Wiring Repair . Have the repairs been completed? | -- | -- | |
Using J 39200 DMM, measure the resistance from the SDM harness connector terminal 8 to the inflatable restraint IP module yellow 2-way harness connector terminal B. Is the resistance reading within the specified values? | 0.0-0.5 ohms | |||
20 | Repair the high resistance condition in CKT 1404. Refer to Wiring Repair . Have the repairs been completed? | -- | -- | |
21 | Reconnect all the SIR system components, make sure all the components are properly mounted. Have all the SIR components been reconnected and properly mounted? | -- | -- | |
22 | Clear all the SIR DTCs. Refer to Diagnostic Trouble Code (DTC) Clearing in Wiring Systems. Have all the SIR DTCs been cleared? | -- | -- |
