Circuit Description
When the ignition switch is turned to ON, the sensing and diagnostic module (SDM) will perform tests to diagnose critical malfunctions within itself. Upon passing these tests, ignition and deployment loop voltages are measured to ensure that they are within their respective normal voltage ranges. The SDM then proceeds with the resistance measurement test. Left side belt pretension low terminal B2 is grounded through a current sink, and the left side belt pretensioner current source is connected to the left side belt pretensioner high terminal to allow a known amount of current to flow. By monitoring the voltage difference between the left side pretensioner high and left side belt pretensioner low terminals, the SDM calculates the combined resistance of the left side belt pretensioner harness wiring, and connector terminal contacts.
Conditions for Setting the DTC
| • | Resistance of the left side belt pretensioner loop is less than 1.2 ohms for 500 milliseconds. |
| • | Ignition voltage is within the normal operation range. |
Action Taken When the DTC Sets
The SDM will turn ON the AIRBAG indicator and set a diagnostic trouble code DTC 64.
Conditions for Clearing the DTC
| • | Resistance of the left side belt pretensioner loop is higher than or equal to 1.2 ohms for 500 milliseconds. |
| • | Turn OFF the ignition switch. |
| • | The scan tool CLEAR CODES command is received. |
Diagnostic Aids
An intermittent condition is likely to be caused by a short between the left side belt pretensioner high and low circuits, a short on C221 or a short between the left side belt pretensioner high circuit and the right side belt high circuit, or a short between the left side belt pretensioner high circuit and the right side belt low circuit. The problem could also be a malfunctioning shorting bar in the left side belt pretensioner connector, which would require replacement of the left side belt pretensioner. The test for this DTC is run only while the AIRBAG indicator is performing the turn-on test. When a scan tool CLEAR CODES command is issued while the malfunction is still present, the DTC will not reappear until the next ignition cycle.
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.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 | Perform the Diagnostic System Check - SIR. Is the Diagnostic System Check complete? | -- | Go to Step 2 | |
2 |
Is DTC 57 also displayed? | -- | Go to Step 3 | Go to Step 4 |
3 |
Did you complete the repair? | -- | -- | |
4 |
Refer to Diagnostic Illustration 17 in SIR Diagnostic Illustrations . Did you complete the repair? | ∞ | Go to Step 5 | Go to Step 7 |
5 |
Did you complete the repair? | -- | System OK | Go to Step 6 |
6 | Replace the left side belt pretensioner. Did you complete the repair? | -- | System OK | -- |
7 | Repair the short between the left side belt pretensioner high circuit and the left side belt pretensioner low circuit or replace the wiring harness. Did you complete the repair? | -- | -- |
