DTC 97

Diagnostic Chart:

Wiring Diagram:

Circuit Description
The inflatable restraint Sensing and Diagnostic and Seat Belt Pretensioner Module (SDM) performs tests to diagnose critical malfunctions within itself when the ignition switch is turned ON. The SDM is hard-wired to the Body Control Module (BCM) CKT XY999. After the ignition is turned ON, the SDM sends fixed frequency pulses to the BCM. In the event of a collision involving air bag deployment, the SDM sends higher frequency pulses to the BCM, which in turn sends a Class 2 message to the Vehicle Interface Unit (VIU). The VIU transmits a DCO signal to OnStar via the vehicle's cellular telephone. The SDM monitors CKT XY999 to detect leakage currents to voltage and open circuits in the Deployment Commanded (DCO) link to the BCM. The SDM service wait time is 1 minute. Refer to Air Bag(s) Arming and Disarming.

Conditions for Setting the DTC
The following conditions can cause DTC 97 to set:

^ A short circuit between CKT XY999 and system voltage.
^ A open circuit condition in CKT XY999 between the SDM and the BCM.

This test is run during the SDM Turn-ON and Continuous Monitoring tests.

Action Taken When the DTC Sets
^ The SDM sets a Diagnostic Trouble Code.
^ 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 repaired and the conditions which caused the DTC to set are no longer existing, the DTC may be cleared using the scan tool.

Diagnostic Aids
A short circuit to a voltage source in the DCO circuit CKT XY999 can set this DTC. Inspect CKT XY999 carefully for cutting and/or chafing. A careful inspection of the circuit and components indicated on the DTC 97 Table is essential to make sure that the SDM and/or BCM will not be unnecessarily replaced.

When measurements are requested in this table, use J 39200.

Test Description
The numbers below refer to the step numbers on the diagnostic table:

2. This test determines if the BCM harness connector C1 is damaged.
4. This test checks for proper contact or corrosion of the BCM terminals.
7. This test checks for proper contact or corrosion of the SDM harness connector.
12. This test checks for an open circuit or high resistance condition in CKT XY999.
14. This test checks for a short to voltage condition in CKT XY999.
16. This test determines if the fault is internal to the BCM or the SDM.