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 the SDM. Next the SDM measures IGNITION 1 voltage to ensure that the IGNITION 1 voltage is within the IGNITION 1's 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 SIDE HIGH and PASSENGER SIDE LOW.
Conditions for Setting the DTC
| • | The voltage difference between PASSENGER SIDE HIGH terminal 1 and PASSENGER SIDE LOW terminal 4 is more than or equal to 400 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 turns ON the AIR BAG warning lamp. |
Conditions for Clearing the DTC
| • | Current DTC |
| The voltage difference between PASSENGER SIDE HIGH terminal 1 and PASSENGER SIDE LOW terminal 4 is less than 400 millivolts for 500 milliseconds. |
| • | History DTC |
| - | You issue a scan tool CLEAR CODES command |
| - | After 250 malfunction free ignition cycles have occurred |
Diagnostic Aids
The following 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 1 and 4 |
| • | An open in CKT 1403 |
| • | An open in CKT 1404 |
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 harness 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 Repair . Is the repair complete? | -- | Go to Step 5 | -- |
5 | Inspect for proper connection at terminals A and 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 terminals A and 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? | 400 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? | 400 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 proper connection at terminals 1 and 4 of the SDM. Are the terminals damaged or corroded? | -- | Go to Step 16 | Go to Step 21 |
15 | Inspect for proper connection at terminals 1 and 4 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 reading within the specified values? | 0-0.5 ohms | Go to Step 19 | Go to Step 18 | |
18 | Repair the high resistance condition in CKT 1403. Is the repair complete? | -- | Go to Step 21 | -- |
Measure the resistance from the SDM harness connector terminal 4 to the inflatable restraint IP module yellow 2-way harness connector terminal B. Is the resistance reading within the specified values? | 0-0.5 ohms | Go to Step 20 | ||
20 | Repair the high resistance condition in CKT 1404. Is the repair complete? | -- | Go to Step 21 | -- |
21 |
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? | -- | -- |
