R024

CIRCUIT DESCRIPTION
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 terminal "B8" or "B7" is below a specified percentage of its respective 36 VLR power supply voltage for 500 milliseconds DTC R024 is set.

DTC 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. This test is run during the "Continuous Monitoring" test.

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

DTC WILL CLEAR WHEN
The voltage measured at "Driver Side Low" terminal "B8" 1s 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 milliseconds.

DTC CHART 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.
3. This test checks for a partial short across the diagnostic resistor in the RH discriminating sensor.
4. This test checks for a partial short across the diagnostic resistor in the forward discriminating sensor.
5. This test checks for a short from the low side of the driver deployment loop to ground.
6. This test checks for a short from the low side of the passenger deployment loop to ground.
7. This test checks for a short from the high side of the driver deployment loop to ground.
8. This test determines whether the malfunction is a short from the high side of the passenger deployment loop to ground.
9. This test checks for an open in the driver deployment loop diagnostic resistor of the dual pole arming sensor.
10. This test checks for an open in the passenger deployment loop diagnostic resistor of the dual pole arming sensor.
11. This test checks for high resistance in the "Driver 36 VLR" circuit.
12. This test checks for high resistance in the "Passenger 36 VLR" circuit.
13. This test checks for an open in the high side of the driver deployment loop.
14. This test checks for an open in the high side of the passenger deployment loop.

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 "O", a malfunctioning dual pole arming sensor, a malfunctioning discriminating sensor, an open in CKT 1403B or CKT 348, a short to ground in CKT 347, CKT 348, CKT 1403 or CKT 1404. Refer to DTC R025 to diagnose a possible short to B+. R025
When the malfunction occurs during an ignition cycle DTC R024 will set. If the malfunction is present at the beginning of the next ignition cycle DTC R025 will set and DTC R024 will be moved to a history file.