DTC 38

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

When the ignition switch is turned to ON," the SDM will perform tests to diagnose critical malfunctions within itself. Upon passing these tests "Ignition 1," 23 VLR and deployment loop voltages are measured to ensure they are within their respective normal voltage ranges. The SDM then proceeds to "Continuous Monitoring." The SDM contains a resistor network connected to "Ignition 1," ground, and to "Low Pressure Sensor" terminal "11." when the passenger inflator module is connected, the 1.0K ohms resistor and the normally closed switch provide a parallel path to ground causing a specific percentage of "Ignition 1" voltage to appear at "Low Pressure Sensor." This voltage is monitored to detect shorts to B+ or an open low pressure switch.

DTC WILL SET WHEN

The voltage measured at "Low Pressure Sensor" terminal "11" is greater than or equal to a specified percentage of "Ignition 1" voltage for 500 milliseconds during "Continuous Monitoring."

ACTION TAKEN

SDM turns "ON" the "AIR BAG" warning lamp and sets a diagnostic trouble code.

DTC CLEAR SET WHEN

The voltage measured at "Low Pressure Sensor" terminal "11" is less than a specified percentage of "Ignition 1" voltage for 500 milliseconds during "Continuous Monitoring."

DTC CHART TEST DESCRIPTION

Numbers below refer to circled numbers on the diagnostic chart.

1. This test checks for an open in the low pressure switch circuit inside the passenger inflator module.

2. This test checks for an open in the low pressure switch circuit.

3. This test checks for an open in the ground feed to the low pressure switch.

4. This test checks for a short from the low pressure switch circuit to B+.

DIAGNOSTIC AIDS

Intermittent shorts or opens can be located by moving wires while monitoring the "AIR BAG warning lamp. An intermittent condition is likely to be caused by a poor connection to the SDM at terminal "11," a poor connection at the passenger inflator module harness connector terminal "B3" or B4," an open in CKT B1 or CKT B, a short from CKT B1 to B+ or a malfunction in the low pressure switch circuit inside the passenger inflator module which would require replacement of the passenger inflator module.