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 SIDE HIGH and PASSENGER SIDE LOW.
Conditions for Setting the DTC
| • | The voltage difference between the PASSENGER SIDE HIGH terminal 4 and the PASSENGER SIDE LOW terminal 3 is more than or equal to 400 millivolts. |
| • | The malfunction must be present for at least 500 milliseconds during one of the following tests: |
| - | The DEPLOYMENT LOOP CONTINUITY Test--If the malfunction is detected in this test, the RESISTANCE MEASUREMENT test will not be performed. |
| - | The CONTINUOUS MONITORING Test. |
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
| • | Clear the Current DTC when the voltage difference between the PASSENGER SIDE HIGH terminal 4 and PASSENGER SIDE LOW terminal 3 is less than 400 millivolts for 500 milliseconds. |
| • | Clear the History DTC under the following conditions: |
| - | You issue a scan tool CLEAR CODES command. |
| - | 250 malfunction free ignition cycles have occurred. |
Diagnostic Aids
The following can cause and intermittent condition:
| • | A poor connection at the inflatable restraint IP module harness connector terminal 1 and terminal 2. |
| • | A poor connection at the SDM terminal 4 and terminal 3. |
| • | An open in the YEL /RED wire. |
| • | An open in the YEL wire. |
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 in this section.
Test Description
The numbers below refer to step numbers on the diagnostic table.
-
This determines the passenger deployment loop voltage difference measured by the inflatable restraint Sensing and Diagnostic Module (SDM).
-
The test checks for proper contact and/or corrosion of the yellow connector.
-
This test isolates the malfunction to one side of the inflatable restraint IP module yellow connector. This is done by substituting the known good resistance of the load tool and then observing if the malfunction is still present.
-
This test checks for proper contact and/or corrosion of the SDM connector.
-
This test determines whether the malfunction is in the YEL/RED wire.
-
This test determines whether the malfunction is in the YEL wire.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the SIR Diagnostic System Check performed? | -- | ||
Did you read the PASSENGER VDIF. Did you record the PASSENGER VDIF on the repair order? | -- | -- | ||
Are the terminals damaged or corroded? | -- | |||
4 | Replace the inflatable restraint IP module harness connector. Refer to SIR Connector (Plastic Body and Terminal Metal Pin) Repair portion of Wiring Repair in this section. Did you replace the inflatable restraint IP module harness connector? | -- | -- | |
5 | Check proper connection at terminal B1 and terminal B2 on the inflatable restraint IP module connector. Are the terminals damaged or corroded? | -- | ||
6 | Check for proper connection at terminal B1 and terminal B2 on the inflatable restraint IP module connector. Are the terminals damaged or corroded? | -- | ||
7 | Replace the inflatable restraint IP module. Refer to Inflatable Restraint Instrument Panel Module Replacement . Did you replace the inflatable restraint IP module? | -- | -- | |
8 |
Is PASSENGER VDIF more than the specified value? | 400 mV | ||
9 |
Did you replace the inflatable restraint IP module harness connector? | -- | -- | |
Is PASSENGER VDIF more than the specified value? | 400 mV | |||
11 |
Did you replace the inflatable restraint IP module? | -- | -- | |
Is the SDM harness connector damaged or corroded? | -- | |||
13 | Replace the SDM harness connector. Refer to SIR Connector (Plastic Body and Terminal Metal Pin) Repair portion of Wiring Repair . Did you replace the SDM harness connector? | -- | -- | |
14 | Check for the proper connection at terminal 4 and terminal 3 in the SDM. Are the SDM terminals damaged or corroded? | -- | ||
15 | Check for proper connection at terminal 4 and terminal 3 in the SDM. Are the SDM terminals damaged or corroded? | -- | ||
16 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Did you replace the SDM? | -- | -- | |
Zero the J 39200 . Measure the resistance from the SDM harness connector terminal 4 to the inflatable restraint IP module harness connector terminal B2. Is the resistance reading within specified values? | 0-0.5 ohms | |||
18 | Repair high resistance in the YEL/RED wire. Is the circuit repair complete? | -- | -- | |
Zero the J 39200 . Measure the resistance from the SDM harness connector terminal 3 to the inflatable restraint IP module harness terminal B1. Is the resistance reading within specified values? | 0-0.5ohms | Go to Integrity Check | ||
20 | Repair high resistance in the YEL wire. Is the circuit repair complete? | -- | -- | |
21 | Reconnect all the SIR system components. Verify that all the components are properly mounted. Did you reconnect all the SIR components? Did you properly mount all the SIR components? | -- | -- | |
22 | Clear the SIR diagnostic trouble codes. Did you clear the SIR diagnostic trouble codes? | -- | -- |
