Part 1 of 3

Test N: DTC 24 Initiator Circuit Voltage Low (Part 1 Of 3):

Supplemental Inflatable Restraint (SIR):

OPERATION:
During normal, non-deployment operation of the SIR system, a small amount of current flows through both the Driver and Passenger Deployment Loops. The Diagnostic Resistors within the Dual Pole Arming Sensor and the Discriminating Sensors along with the resistance of the Inflator Modules cause voltage drops within the Deployment Loops. The DERM monitors the voltages at "Driver Side Low" terminal "B8" and "Passenger Side Low" terminal "B7" to detect shorts or opens within the deployment loops. When the measured voltage at terminals "B8" and "B7" is below a specified percentage of its respective "36 VLR" power supply voltage for 500 milliseconds DTC 24 is set.

Test Conditions: Tested every 100 milliseconds during the "Continuous Monitoring" test.

Failure Conditions: DTC 24 will set when the voltage measured at "Driver Side Low" terminal "B8" is below a specified percentage of "Driver 36 VLR" or when the voltage measured at "Passenger Side Low" terminal "B7" is below a specified percentage of "Passenger 36 VLR" for 500 milliseconds.

Action Taken: DERM turns "ON" the "INFLATABLE RESTRAINT" warning lamp and sets a Diagnostic Trouble Code.

Conditions to Clear: DTC 24 will clear when the voltage measured at "Driver Side Low" terminal "B8" is within a specified percentage of "Driver 36 VLR" and the voltage measured at "Passenger Side Low" terminal "B7" is within a specified percentage of "Passenger 36 VLR" for 500 milliseconds.

POSSIBLE CAUSES:
Test Description: Number(S) below refer to circled number(S) on the diagnostic chart.
1. This test determines whether the malfunction is occurring in the Steering Column circuitry.
2. This test determines whether the malfunction is occurring in the Passenger Inflator Module circuitry.

DIAGNOSTIC AIDS:
An intermittent condition is likely to be caused by a poor connection at DERM terminals "A3" and "A4," dual pole arming sensor terminals "B," "C," "E" or "G," water intrusion in any discriminating sensor, an open in CKT 1403B or 347B, or a short to ground in CKTs 347, 348, 1403 or 1404. Refer to DTC 25 to diagnose a possible short to B+. When the malfunction occurs during an ignition cycle, DTC 24 will set. If the malfunction is present at the beginning of the next ignition cycle, DTC 25 will set and DTC 24 will be moved to a history file.