B0078

CIRCUIT DESCRIPTION

SIR Schematics (Pickup): DLC, Inflatable Restraint Sensing And Diagnostic Module:

SIR Schematics (Utility): DLC, Fuse Block, Inflatable Restraint Sensing And Diagnostic Module:

SIR Schematics (Utility): Side Impact Sensors, Diagnostic Module:

SIR Schematics (30 Series Pickup): Fuse Block, Inflatable Restraint Sensing And Diagnostic Module:

The inflatable restraint side impact sensor (SIS) circuit consists of a side impact sensor (SIS), the SIS signal circuit, and the SIS voltage circuit. When the ignition is turned ON, the inflatable restraint sensing and diagnostic module (SDM) performs tests to diagnose critical malfunctions within itself. The SDM provides input power to the SIS. When input power is first detected, the SIS responds by performing internal diagnostics. The SIS then sends an ID message to the SDM. The SDM will consider this to be a valid ID if the response time is less than 5 seconds after the SIS is powered up. The SIS will continually communicate a status message to the SDM. The SDM is capable of resetting the SIS by removing and applying power to it.

CONDITIONS FOR RUNNING THE DTC
Ignition 1 voltage is within the normal operating voltage range.

CONDITIONS FOR SETTING THE DTC
^ A valid ID message is not received within 5 seconds of the right SIS being powered up.
^ Status message is not received.
^ The SDM has failed twice to reset the right SIS.

ACTION TAKEN WHEN THE DTC SETS
^ The SDM commands ON the AIR BAG indicator via Class 2 serial data.
^ The SDM attempts to reset the right SIS.

CONDITIONS FOR CLEARING THE DTC
^ The condition responsible for setting the DTC no longer exists.
^ You issue a scan tool CLEAR DTCs command.
^ A history DTC will clear once 255 malfunction free ignition cycles have occurred.

DIAGNOSTIC AIDS
The following can cause an intermittent condition:
^ A short between the right SIS signal and voltage circuits
^ High or low resistance in the right 815 signal and voltage circuits
^ Inspect the right SIS signal and voltage circuits carefully for cutting and/or chafing

Refer to Testing for Intermittent and Poor Connections in Diagrams.

TEST DESCRIPTION

Steps 1-11:

The numbers below refer to the step numbers on the diagnostic table:
4. Tests for a short to ground, a high resistance, or an open in the right SIS signal circuit.
5. Tests for a short to ground, a high resistance, or an open in the right SIS voltage circuit.
6. Tests for a short to voltage in the right SIS signal circuit.
7. Tests for a short to voltage in the right SIS voltage circuit.