Supplemental Inflatable Restraint (SIR)

CIRCUIT DESCRIPTION
DTC 23 is set when the voltage at the "Sense Low" input, terminal "A6," is greater than a specific percentage of "36 VLR" output voltage for 500 milliseconds during the "Continuous Monitoring" tests performed by the DERM. The "Continuous Monitoring" tests are performed by the DERM after the initial "Turn-ON" tests are completed and are performed every 100 milliseconds while "Ignition 1" voltage is present at the DERM. The "Continuous Monitoring" tests check the continuity of the deployment loop from the "36 VLR" output of the DERM through the arming sensor, inflator module and the discriminating sensors to ground. DTC 23 indicates a shorted arming sensor, short to the "36 VLR," or an open in the low side of the deployment loop.

TEST CONDITIONS
Tested every 100 milliseconds during "Continuous Monitoring."

FAILURE CONDITIONS
DTC 23 will set if the voltage at the "Sense Low" input, terminal "A6," is greater than a specific percentage of "36 VLR" output voltage for 500 milliseconds.

ACTION TAKEN
DERM turns "ON" the "INFL REST" warning lamp.

CONDITIONS TO CLEAR
Current DTC 23 will clear if the voltage at the "Sense Low" input, terminal "A6," is within a specific range of "36 VLR" output voltage for 500 milliseconds (5 consecutive "Continuous Monitoring" cycles) after DTC 23 has been set.

TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This test checks the integrity of the low side of the deployment loop between the steering column and the LH forward discriminating sensor.
2. This test checks for an open in the LH forward discriminating sensor between terminal "A" and the splice.
3. This test checks for a short from the "36 VLR" circuit to the "Force High" circuit.
4. This test checks for a short from the "36 VLR" circuit to the "Sense Low" circuit.
5. This test checks for a short from the "36 VLR" circuit to the "Force Low" circuit.
6. This test checks for a short from the "36 VLR" circuit to CKT 347.
7. This test checks for a short from the "36 VLR" circuit to CKT 348 or CKT 349.
8. This diagnostic trouble code is being set by an arming sensor which is latched closed, a partial short across the arming sensor diagnostic resistor, or a malfunctioning DERM.