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. Upon passing these tests the ignition positive voltage, the 23 VLR and the deployment loop voltages are measured in order to ensure that the voltages are within the respective normal voltage ranges. The SDM monitors the voltages at the DRIVER LOW terminal 3 and the PASSENGER LOW terminal 4 in order to detect shorts to B+ in the inflator module circuits.
Conditions for Setting the DTC
| • | The voltage at the PASSENGER LOW terminal 4 is less than 4.8 volts. |
| • | The voltage at the DRIVER LOW terminal 3 is more than 4.8 volts for 500 milliseconds. |
The continuous monitoring test inspects for this DTC. This test occurs when the ignition positive voltage 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 Indicator. |
Conditions for Clearing the MIL/DTC
| • | Current DTC |
| The voltage at DRIVER LOW terminal 3 is less than 4.8 volts for 500 milliseconds. |
| • | History DTC |
| - | You issue a scan tool CLEAR CODES command. |
| - | 250 malfunction free ignition cycles have occurred. |
Diagnostic Aids
A short to B+ in the inflatable restraint steering wheel module circuit may cause an intermittent condition. Carefully inspect CKT 347 and CKT 348 for cut or chafed wires. The diagnostic table directs the technician in order to note the entry value of the DRIVER SENSELO. Comparing the value of the DRIVER SENSELO may 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 the step numbers on the diagnostic table:
-
This test determines the driver low voltage measured by the inflatable restraint Sensing and Diagnostic Module (SDM).
-
This test isolates the malfunction to one side of the inflatable restraint steering wheel module coil yellow 2-way connector.
-
This test determines whether the malfunction is due to the inflatable restraint steering wheel module or the module coil.
-
This test determines whether the malfunction is in CKT 347.
-
This test determines whether the malfunction is in CKT 348.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the SIR Diagnostic System Check performed? | -- | ||
Has the DRIVER SENSELO been read and recorded on the repair order? | -- | -- | ||
Is DRIVER SENSELO more than the specified value? | 4.8 V | |||
Is DRIVER SENSELO more than the specified value? | 4.8 V | |||
5 |
Is the repair complete? | -- | -- | |
6 |
Is the repair complete? | -- | -- | |
Is the measured voltage less than the specified value? | 1.0 V | |||
8 |
Is the repair complete? | -- | -- | |
Using J 39200 DMM, measure the voltage on the SDM harness connector between terminal 3 and 6 (ground). Is the measured voltage less than the specified value? | 1.0 V | |||
10 |
Is the repair complete? | -- | -- | |
11 | Reconnect all the SIR components, make sure all the components are properly mounted. Have all the SIR components been reconnected and properly mounted? | -- | -- | |
12 | Clear all the SIR DTCs. Have all the SIR DTCs been cleared? | -- | -- |
