B0102

CIRCUIT DESCRIPTION

SIR Schematics: Standard Air Bags (Power, Grounds And Side Impact Sensors):

SIR Schematics: Standard Air Bags (Inflator Modules):

SIR Schematics: Dual Stage Air Bags (Power, Ground And Sensors):

SIR Schematics: Dual Stage Air Bags (Module Controls):

The inflatable restraint electronic frontal sensor (EFS) (also known as inflatable restraint front end discriminating sensor) loop is a 2 wire 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 EFS. When input power is first detected, the EFS responds by performing internal diagnostics. Next the EFS 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 EFS is powered up. The EFS will continually communicate a status message to the SDM. The SDM can reset the EFS by removing and applying power to it.

CONDITIONS FOR RUNNING THE DTC
The SDM monitors the EFS loop with power on.
^ EFS will send an ID message to the SDM.
^ EFS will continuously send OK or NOK message to SDM.

CONDITIONS FOR SETTING THE DTC
^ Ignition 1 Voltage is within normal operating voltage range
^ The SDM has received an ID message from the EFS which does not match the ID stored in the SDM memory.
^ When 2 EFS resets attempted without the correct identification detected.

ACTION TAKEN WHEN THE DTC SETS
The SDM commands ON the AIR BAG warning indicator via Class 2 serial data.

CONDITIONS FOR CLEARING THE DTC
^ The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.
^ A history DTC will clear once 255 malfunction free ignition cycles have occurred.

DIAGNOSTIC AIDS
Check to ensure that the proper EFS is installed into vehicle.

TEST DESCRIPTION

Steps 1-4:

The following numbers refer to the step numbers in the diagnostic table:
2. This test checks the communication status of the EFS.