Supplemental Inflatable Restraint (SIR)

CIRCUIT DESCRIPTION
The DERM determines that the arming sensor is closed when a specific percentage of deployment loop voltage or more is present at the "Sense High" input, terminal "A7," and it determines that a discriminating sensor is closed when a specific percentage of deployment loop voltage or less is present at the "Sense Low" input, terminal "A6." If both conditions are detected simultaneously, DTC 51 is set.

TEST CONDITIONS
DTC 51 conditions are monitored whenever the DERM is functioning properly.

FAILURE CONDITIONS
Current DTC 51 will set if the DER,M senses that both the Arming Sensor and at least one of the discriminating sensors are closed simultaneously -

ACTION TAKEN
DERM turns "ON" the "AIR BAG" warning lamp until current DTC 51 is cleared. History DTC 51 will not turn "ON" the warning lamp.

CONDITIONS TO CLEAR
Current DTC 51 can be cleared using a scan tool "Clear Codes" command. History DTC 51 will remain in the DERM thereafter.

TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. DTC 51, once detected, can be erased as a current DTC but will remain as an unerasable history DTC.
2. If the inflator module has not deployed, DTC 51 may have set falsely.
3. If DTC 51 is current with no signs of frontal impact, the DTC has set falsely.
4. This test checks for a DERM malfunction setting the code falsely.
5. This test determines whether the DTC was set inadvertently during diagnosis.
6. When an accident has occurred, it is necessary to perform the indicated procedures to ensure the SIR system is fully functional.