Circuit Description
When the ignition switch is turned to ON, the sensing and diagnostic module (SDM) will perform a turn-on test to diagnose critical malfunctions within the SDM itself.
Upon passing this test, ignition and deployment loop voltages are measured to ensure that they are within their normal voltage ranges. The SDM monitors the voltages at the driver low and the passenger low to detect shorts to ground or voltage in the deploy loops.
The SDM checks the wiring connection to the passenger air bag module by letting the infinitesimal current flow through the internal circuit and verify the resistance. If the resistance is 2-10 kilo ohms, the defect may occur depending upon SDM. The normal resistance is over 10 kilo ohms.
Conditions for Setting the DTC
| • | The belt pretensioner wiring of the driver high is shorted to battery wiring. |
| • | The belt pretensioner wiring of the driver low is shorted to battery wiring. |
Step | Action | Values | Yes | No |
|---|---|---|---|---|
|
Caution: Refer to Sensing and Diagnostic Module Voltage after Ignition is Turned Off Caution in the Preface section. Caution: Refer to Sensing and Diagnostic Module Handling Caution in the Preface section. | ||||
1 | Perform the Diagnostic System Check - SIR. Did you perform the Diagnostic System Check - SIR? | -- | Go to Step 2 | |
2 |
The capacitor supplies reserve power to deploy the driver seat belt pretensioner even if the battery has been disconnected. Is there any visible damage to the SIR wiring harness? | -- | Go to Step 3 | Go to Step 4 |
3 |
Did you complete the repair? | -- | -- | |
4 |
The shorting bar at the disconnected SDM connector will create a complete circuit between the wires from the driver seat belt pretensioner module. Does the resistance measure greater than the specified value? | 0 V | Go to Step 3 | Go to Step 5 |
5 |
Is DTC 012 still shown as a current fault? | -- | Go to Step 6 | System OK |
6 |
Did you complete the repair? | -- | -- | |
