Circuit Description
The inflatable restraint electronic frontal sensor (EFS)-Left, 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-Left. When input power is first detected, the EFS-Left responds by performing internal diagnostics. Next the EFS-Left 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-Left is powered up. The EFS-Left will continually communicate a status message to the SDM. The SDM can reset the EFS-Left by removing and applying power to it.
Conditions for Running the DTC
The SDM monitors the EFS-Left loop with power on.
| • | EFS-Left will send an ID message to the SDM. |
| • | EFS-Left will continuously send OK or NOK message to SDM. |
Conditions for Setting the DTC
| • | Ignition 1 Voltage is within the normal operating voltage range. |
| • | The SDM has received an ID message from the EFS-Left which does not match the ID stored in the SDM memory. |
| • | When 2 EFS-Left 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
| • | Replace the EFS-Left. |
| • | 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-Left is installed into vehicle.
Test Description
The following numbers refers to the step numbers in the diagnostic table:
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: SIR Schematics Connector End View Reference: SIR Connector End Views | |||
1 | Did you perform the Diagnostic System Check - SIR? | Go to Step 2 | |
Does the scan tool indicate that this DTC B0102 is current? | Go to Step 3 | Go to Step 4 | |
3 | Replace the inflatable restraint electronic frontal sensor (EFS)-Left, also known as inflatable restraint front end discriminating sensor. Refer to Inflatable Restraint Front End Discriminating Sensor Replacement . Did you complete the replacement? | Go to Step 4 | -- |
4 |
Does the DTC reset? | Go to Step 2 | System OK |
