Supplemental Inflatable Restraint (SIR)

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION
When "Ignition 1" voltage is first applied to the DERM it will perform "Turn-ON" tests followed by "Continuous Monitoring for one second. The DERM also monitors "Driver Side Low" terminal "B8" to ensure that voltage is being applied to the inflator module and monitors "Driver Source Sense" terminal "A5" to ensure that "Driver 36 VLR" is supplying voltage to the deployment loop. Ground is applied at terminal "B7" (passenger side low for a Driver/Passenger DERM) and the voltage is measured at "Driver Side Low" and at terminal "A6" (passenger source sense for a Driver/Passenger DERM). When grounding terminal "B7" grounds "Driver Side Low" or volfag9 is measured at terminal "A6," DTC 55 is set.

DTC WILL SET WHEN
The conditions described above indicate a Driver/Passenger DERM has been installed in the vehicle. This test is run once each ignition cycle during the "Initiator Assembly Resistance Test" when: 1) No "higher priority faults" are detected during "Turn-ON," 2) No "higher priority faults" are detected during "Continuous Monitoring" for one second, 3) No "Crank" signal present, 4) "Ignition 1" voltage is above a specified value.

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

DTC WILL CLEAR WHEN
The ignition switch is turned "OFF."