Circuit Description
The inflatable restraint Sensing and Diagnostic and Seat Belt Pretensioner Module (SDM) performs tests to diagnose critical malfunctions within itself when the ignition switch is turned ON. The SDM monitors the six firing loops to detect leakage currents to ground in the frontal and side air bag inflator module and seat belt pretensioner circuits. The deployment loop resistances are measured to ensure they are within their respective normal resistance ranges. The SDM service wait time is 1 minute. Refer to On-Vehicle Service for enable/disable procedures
Conditions for Setting the DTC
The passenger deployment loop resistance is more than 5.0 ohms. The passenger deployment loop consists of the following components:
| • | The inflatable restraint IP module. |
| • | The harness wiring of CKT BA10. |
| • | The harness wiring of CKT BP10. |
| • | The connector terminal contact. |
The RESISTANCE MEASUREMENT test checks for this malfunction. This test only occurs continuously during each ignition cycle when the IGNITION 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 lamp. |
Conditions for Clearing the DTC
Current and History DTC codes must be cleared using a scan tool Clear DTC Information command. If the circuit fault has been successfully repaired and the conditions which caused the DTC to set are no longer existing, the DTC may be cleared using the scan tool. If the resistance in the inflatable restraint IP module circuit is less than 5.0 ohms, a Current DTC 33 will change to a History DTC 33, which may be cleared using the scan tool.
Diagnostic Aids
A poor connection can cause an intermittent condition. Check the following for a poor connection:
| • | The inflatable restraint IP module integral 2-way connector. |
| • | The SDM terminals 3 and 4. |
| • | The wire to terminal connections in CKT BA10. |
| • | The wire to terminal connections in CKT BP10. |
Inspect CKTs BA10 and BP10 carefully for cutting and/or chafing. The diagnostic table directs the technician to note the entry value of the PASSENGER AIR BAG RES. Comparing the value of the PASSENGER AIR BAG RES. over multiple ignition cycles 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 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 step numbers on the diagnostic table.
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This test determines the deployment loop resistance measured by the SDM.
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This test checks for proper contact or corrosion of the SDM.
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This test isolates the malfunction to one side of the inflatable restraint IP module yellow 2-way connector. This is done by substituting the known good resistance of the load tool and then, observing if the malfunction is still present.
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This test determines whether the malfunction is in CKT BA10.
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This test determines whether the malfunction is in CKT BP10.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the SIR Diagnostic System Check performed? | -- | ||
Has PASSENGER AIR BAG RES. been read and recorded on the repair order? | -- | -- | ||
3 |
Are the terminals damaged or corroded? | -- | ||
4 | Repair the inflatable restraint IP module yellow 2-way harness connector. Refer to SIR Connector (Plastic Body and Terminal Metal Pin) Repair in this section. Are the repairs complete? | -- | -- | |
5 | Check for proper connection at terminals 1 and 2 on the inflatable restraint IP module yellow 2-way connector. Are the terminals damaged and/or corroded? | -- | ||
6 | Replace the inflatable restraint IP module. Refer to Inflatable Restraint Instrument Panel Module Replacement . Is the replacement complete? | -- | -- | |
7 |
Are the terminals damaged and/or corroded? | -- | ||
8 | Use the J 42250 Catera Terminal Repair Kit to repair the SDM harness connector. Is the replacement complete? | -- | -- | |
9 | Check for proper connection at terminals 3 and 4 on the SDM. Are the terminals damaged or corroded? | -- | ||
10 | Check for proper connection at terminals 3 and 4 on the SDM. Are the terminals damaged or corroded? | -- | ||
11 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic and Seat Belt Pretensioner Module Replacement . Is the replacement complete? | -- | -- | |
Is PASSENGER AIR BAG RES. greater than the specified value? | 5.0 ohms | |||
13 |
Is the replacement complete? | -- | -- | |
Is the resistance reading within the specified values? | 0-0.5 ohms | |||
15 | Repair an open circuit or high resistance in CKT BA10. Is the repair complete? | -- | ||
Is the resistance reading within the specified values? | 0-0.5 ohms | Go to Integrity Check | ||
17 | Repair an open circuit or high resistance in CKT BP10. Is the repair complete? | -- | -- | |
18 | Reconnect all the SIR system components. Ensure all the SIR system components are properly mounted. Are all the SIR system components reconnected and are all the SIR system components properly mounted? | -- | -- | |
19 | Clear the SIR diagnostic trouble codes. Are all the SIR diagnostic trouble codes cleared? | -- | -- |
