DTC 64

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 1 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.

DTC 64 Will Set When
The resistance of the left side belt pretensioner loop is out of a specified value. The test is run once each ignition cycle during the resistance measurement test when
- No higher priority faults are detected when the ignition is turned ON.
- Ignition 1 voltage is above a specified value.

Action Taken
The SDM will turn ON the AIRBAG indicator and set a diagnostic trouble code (DTC) 64.

DTC 64 Will Clear When
The ignition switch is turned OFF or the scan tool CLEAR CODES command is received.

Test Description
The number(s) below refer to step(s) on the diagnostic table.

3. See the first caution below.
5. See the first caution below.

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 C301 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.

Steps 1 - 7:

DTC 64 - Left Side Belt Pretensioner Loop Shorted

CAUTION: The SDM can maintain sufficient voltage to deploy the airbags for 10 minutes after the Ignition is OFF and the fuse has been removed. If the airbags are not disconnected, service cannot begin until 10 minutes have passed after disconnecting power to the SDM.

CAUTION: During service procedures, be very careful when handling the SDM. Never strike or jar the SDM.