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 itself. When the driver side impact sensor (SIS) receives the Power-ON signal from the SDM, the driver SIS performs its own internal diagnostics. After performing the internal diagnostics, the driver SIS will send an ID message to the SDM. Upon receiving this message, the SDM compares it to an ID stored in memory. Once the SDM receives a valid ID from the driver SIS, the SDM proceeds to look for a OK/NOK (not OK) message from the driver SIS. If no valid ID is received by the SDM within three seconds of Power-On, the SDM will attempt to reset the driver SIS. After two unsuccessful reset attempts within 10-20 seconds, the SDM will set DTC B1045. Also, if the SDM suspends communication with the driver SIS four times within one ignition cycle because of a noise problem, the SDM will set a DTC B1045.
Conditions for Setting the DTC
DTC B1045 will set once the following conditions are met. This test is run during the SDM Turn-ON tests.
| • | IGNITION 1 is within normal operating voltage range. |
| • | An internal fault in the driver side impact sensor (SIS). |
| • | An open or a high resistance in the driver side impact sensor (SIS) loop. |
| • | Excessive noise in the driver side impact sensor (SIS) loop. |
| • | A short to ground in the driver side impact sensor (SIS) loop. |
| • | A short to voltage in the driver side impact sensor (SIS) loop. |
The driver side impact sensor (SIS) loop consists of the following components:
| • | The inflatable restraint side impact sensor (LH) . |
| • | The harness wiring of CKT 2131. |
| • | The harness wiring of CKT 2132. |
| • | The connector terminal contact. |
Action Taken When the DTC Sets
| • | The SDM sets a DTC B1045. |
| • | 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 repairedmand the conditions which caused the Current DTC B1045 to set no longer exist, History DTC B1045 will set. History DTC B1045 may be cleared using the scan tool.
Diagnostic Aids
An inflatable restraint driver side impact sensor (SIS) circuit short to ground can cause an intermittent condition. Inspect CKT 2131 and CKT 2132 carefully for cutting and/or chafing. A careful inspection of the circuits and components indicated on the DTC B1045 table is essential to make sure that the replacement SDM will not be damaged.
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 the step numbers on the diagnostic table:
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This step checks the inflatable restraint side impact sensor (LH) wiring harness connector for corrosion or damaged terminals.
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This step checks the inflatable restraint side impact sensor (LH) for corrosion or damaged terminals.
-
This step checks the SDM wiring harness connector for corrosion or damaged terminals.
-
This step checks to see if there is an open or a high resistance in CKT 2132.
-
This step checks to see if there is an open or a high resistance in CKT 2131.
-
This step checks to see if there is a short between CKT 2312 and CKT 2131.
-
This step checks to see if there is a short to ground in CKT 2131.
-
This step checks to see if there is a short to ground in CKT 2132.
-
This step checks to see if there is a short to voltage in CKT 2132.
-
This step checks to see if there is a short to voltage in CKT 2131.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the SIR Diagnostic System Check performed? | -- | ||
Are the terminals damaged or corroded? | -- | |||
3 | Replace the inflatable restraint side impact sensor (LH) wiring harness connector. Refer to Wiring Repair . Is the repair complete? | -- | -- | |
Check for a proper connection at terminal A and terminal B of the inflatable restraint side impact sensor (LH). Are the terminals damaged or corroded? | -- | |||
5 | Check for a proper connection at terminal A and terminal B of the inflatable restraint side impact sensor (LH). Are the terminals damaged or corroded? | -- | ||
6 | Replace the inflatable restraint side impact sensor (LH). Refer to Inflatable Restraint Side Impact Sensor Replacement . Is the repair complete? | -- | -- | |
Is the SDM wiring harness connector damaged or corroded? | -- | |||
8 | Replace the SDM wiring harness connector. Refer to Wiring Repair . Is the repair complete? | -- | -- | |
9 | Check for a proper connection at terminal 41 and terminal 42 of the SDM. Are the terminals damaged or corroded? | -- | ||
10 | Check for a proper connection at terminal 41 and terminal 42 of the SDM. Are the terminals damaged or corroded? | -- | ||
11 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Is the repair complete? | -- | -- | |
Is the measured resistance within the specified value? | 0-0.5 ohms | |||
13 |
Is the repair complete? | -- | -- | |
Use the J 39200 to measure the resistance between terminal 41 of the SDM wiring harness connector and terminal B of the inflatable restraint side impact sensor (LH) yellow 2-way wiring harness connector. Is the measured resistance within the specified values? | 0-0.5 ohms | |||
15 |
Is the repair complete? | -- | -- | |
Use the J 39200 to measure the resistance between terminal A and terminal B of the inflatable restraint side impact sensor (LH) yellow 2-way wiring harness connector. Is the measured resistance less than the specified value? | OL | |||
17 |
Is the repair complete? | -- | -- | |
Use the J 39200 to measure the resistance between terminal 41 of the SDM wiring harness connector and a known good ground. Is the measured resistance less than the specified value? | OL | |||
19 |
Is the repair complete? | -- | -- | |
Use the J 39200 to measure the resistance between terminal 42 of the SDM wiring harness connector and a known good ground. Is the measured resistance less than the specified value? | OL | |||
21 |
Is the repair complete? | -- | -- | |
Is the measured voltage less than the specified value? | 1 V | |||
23 |
Is the repair complete? | -- | -- | |
Use the J 39200 to measure the voltage between terminal 41 of the SDM wiring harness connector and a known good ground. Is the measured voltage less than the specified value? | 1 V | |||
25 |
Is the repair complete? | -- | -- | |
26 |
Is the repair complete? | -- | -- | |
27 |
Have all current and history SIR DTCs been cleared? | -- | ||
28 | Reconnect all the SIR components, making sure all the components are properly mounted. Have all the SIR components been reconnected and properly mounted? | -- | -- | |
29 | Use the scan tool to clear all current and history SIR DTCs. Have all current and history SIR DTCs been cleared? | -- | -- |
