Supplemental Inflatable Restraint (SIR)

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION
Closure of the arming sensor is detected when the voltage measured at "Driver Side High" terminal "B9" is within a specified amount of its deployment loop supply voltage. Closure of either discriminating sensor is detected when the voltage measured at "Driver Side Low" terminal "B8" is within a specified amount of ground potential. When both conditions are met simultaneously for not less than 250 microseconds "Crash Data" is recorded and DTC 51 is set.

DTC WILL SET WHEN
Closure of the arming sensor and at least one of the discriminating sensors is detected simultaneously for not less than 250 microseconds.

ACTION TAKEN
DERM turns "ON" the "AIR BAG" warning lamp, records "Crash Data," and sets a diagnostic trouble code.

DTC WILL CLEAR WHEN
A scan tool "Clear Codes" command is received by the DERM.

DTC TABLE TEST DESCRIPTION
Number(s) below refer to step number(s) on the diagnostic table.
1. The "SIR DIAGNOSTIC SYSTEM CHECK" should be the start of all diagnosis. SIR Diagnostic System Check
2. When DTC 42 and DTC 51 are set simultaneously, perform DTC 42 diagnosis first.
3. If inflator module has not deployed, DTC 51 may have set falsely.
4. If DTC 51 has set with no signs of frontal impact, the diagnostic trouble code has set falsely.
5. When a frontal crash has occurred, it is necessary to perform the indicated procedures to ensure the SIR system is fully functional.
6. This test checks for a DERM malfunction setting the diagnostic trouble code.
7. This test checks for a DERM malfunction setting the diagnostic trouble code.
8. This test determines whether the diagnostic trouble code was set inadvertently during diagnosis or by a DERM malfunction.