DTC 37

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION
When the ignition switch is turned "ON," the SDM will perform tests to diagnose critical malfunctions within itself. Upon passing these tests "Ignition 1," 36 VLR and deployment loop voltages are measured to ensure they are within their respective normal voltage ranges. The SDM then proceeds with the "Current Source Diagnostics" followed by "Continuous Monitoring." The SDM contains a resistor network connected to "Ignition 1," ground, and to "Low Pressure Sensor" terminal "B8." When the passenger inflator module is connected, the 1.0K ohm 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." During normal operation the voltage measured at "Low Pressure Sensor" will be slightly more than one half of "Ignition 1" voltage.

DTC WILL SET WHEN
The voltage measured at "Low Pressure Sensor" terminal "B8" is less 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 "B8" is greater than a specified percentage of "Ignition 1" voltage for 500 milliseconds during "Continuous Monitoring.

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This test checks for a short across the "Low Pressure Sensor" circuit inside the passenger inflator module.
2. This test checks for a short from the "Low Pressure Sensor" circuit to ground.

DIAGNOSTIC AIDS
An intermittent condition is likely to be caused by a short from CKT B1 to ground or a malfunction in the "Low Pressure Sensor circuit inside the passenger inflator module which would require replacement of the passenger inflator module.