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. Next the SDM measures the ignition positive voltage in order to ensure that the voltage is within the 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 the PASSENGER HIGH and the PASSENGER LOW.
Conditions for Setting the DTC
| • | The voltage difference between the PASSENGER HIGH terminal 7 and PASSENGER 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. |
| • | The SDM commands the instrument cluster in order to turn ON the AIR BAG warning lamp. |
Conditions for Clearing the MIL/DTC
The DTC will clear when one of the following conditions is met:
| • | Current DTC |
| The voltage difference between the PASSENGER HIGH terminal 7 and PASSENGER LOW terminal 8 is less than 426 millivolts for 500 milliseconds. |
| • | History DTC |
| - | You issue a scan tool CLEAR CODES command. |
| - | 250 malfunction free ignition cycles have occurred. |
Diagnostic Aids
The following conditions may 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 VDIF. Comparing the value of PASSENGER VDIF may be helpful in determining if an intermittent condition exists.
When measurements are requested in this table, use the J 39200 DMM with the correct terminal adapter from the J 35616 Connector Test Adapter Kit. When an inspection for proper connection is requested, refer to Testing for Electrical Intermittents in Wiring Systems. When a wire, connector or terminal repair is requested, use the J-38125 Terminal Repair Kit and refer to Wiring Repairs in Wiring Systems.
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 inspects for proper contact or corrosion of the yellow 2-way connector.
-
This test isolates the malfunction to one side of the inflatable restraint IP module yellow 2-way connector.
-
This test inspects 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? | -- | Go to Step 2 | |
Has the PASSENGER VDIF been read and recorded on the repair order? | -- | Go to Step 3 | -- | |
Are the terminals damaged or corroded? | -- | Go to Step 4 | Go to Step 6 | |
4 | Replace the inflatable restraint IP module yellow 2-way IP harness connector. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 5 | -- |
5 | Inspect for proper connection at terminal A and terminal B on the inflatable restraint IP module yellow 2-way connector. Are the terminals damaged or corroded? | -- | Go to Step 7 | Go to Step 21 |
6 | Inspect for proper connection at terminal A and terminal B on the inflatable restraint IP module yellow 2-way connector. Are the terminals damaged or corroded? | -- | Go to Step 7 | Go to Step 8 |
7 | Replace the inflatable restraint IP module. Refer to Inflatable Restraint Instrument Panel Module Replacement . Is the repair complete? | -- | Go to Step 21 | -- |
8 |
Is the PASSENGER VDIF less than the specified value? | 426 mV | Go to Step 9 | Go to Step 10 |
9 |
Is the repair complete? | -- | Go to Step 21 | -- |
Is the PASSENGER VDIF less than the specified value? | 426 mV | Go to Step 11 | Go to Step 12 | |
11 |
Is the repair complete? | -- | Go to Step 21 | -- |
Is the connector damaged or corroded? | -- | Go to Step 13 | Go to Step 15 | |
13 | Replace the SDM harness connector. Refer to Wiring Repair . Is the repair complete? | -- | Go to Step 14 | -- |
14 | Inspect for the proper connection at terminal 8 and terminal 7 of the SDM. Are the terminals damaged or corroded? | -- | Go to Step 16 | Go to Step 21 |
15 | Inspect for the proper connection at terminal 8 and at terminal 7 of the SDM. Are the terminals damaged or corroded? | -- | Go to Step 16 | Go to Step 17 |
16 | Replace the inflatable restraint sensing and diagnostic module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Is the repair complete? | -- | Go to Step 21 | -- |
Is the resistance less than the specified value? | 0.5 ohms | Go to Step 19 | Go to Step 18 | |
18 | Repair the high resistance condition in CKT 1403. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 21 | -- |
Is the resistance less than the specified value? | 0.5 ohms | Go to Step 20 | ||
20 | Repair the high resistance condition in CKT 1404. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 21 | -- |
21 | Reconnect all the SIR system components. Ensure that all the components are properly mounted. Have all the SIR components been reconnected and properly mounted? | -- | Go to Step 22 | -- |
22 | Clear all the SIR DTCs. Have all the SIR DTCs been cleared? | -- | -- |
