B0024

DTC B0024 LF/Driver Frontal Deployment Loop (Single Stage or Stage 1) Short to Ground/Voltage Out of Range

Schematic:

CIRCUIT DESCRIPTION
When you first turn the ignition switch to the RUN position, the inflatable restraint Sensing and Diagnostic Module (SDM) performs tests to diagnose critical malfunctions within itself. The SDM then performs the following continuous diagnostic tests on the deployment loops:
^ Deployment loop voltage out of range test
^ Deployment loop resistance measurement test

If the voltage out of range test detects a short to voltage condition, the resistance measurement test for that deployment loop will not be performed.

CONDITIONS FOR RUNNING THE DTC
^ Ignition 1 voltage is within the normal operating voltage range.
^ Driver frontal deployment loop is not shorted to voltage.

CONDITIONS FOR SETTING THE DTC
^ The SDM detects the voltage at driver frontal high is greater than 6 Volts for 300 milliseconds.
^ The SDM detects the voltage at driver frontal high is less than 2.4 Volts and driver frontal deployment loop resistance is less than 6 Ohms for 300 milliseconds.

ACTION TAKEN WHEN THE DTC SETS
^ The SDM disables the driver frontal deployment loop resistance test.
^ The SDM commands ON the AIR BAG warning lamp via Class 2 serial data.
^ The SDM also sets this DTC as current after an accident. The SDM will write the status of this DTC to the "crash log" area of the EEPROM for retrieval.

CONDITIONS FOR CLEARING THE DTC
^ Driver frontal high is 6 Volts or less for 300 milliseconds.
^ Driver frontal high is 2.4 Volts or greater and driver frontal deployment loop resistance is less than 6 Ohms for 300 milliseconds.
^ You issue a scan tool CLEAR CODES command.
^ A history DTC will clear once 255 malfunctions free ignition cycles have occurred.

When the SDM detects that no DTCs are present, the SDM commands the AIR BAG warning lamp OFF.

DIAGNOSTIC AIDS
The following can cause an intermittent condition:
^ A short between the driver frontal high and the driver frontal low circuits.
^ A malfunctioning shorting bar on the inflatable restraint steering wheel module 2-way connector.
^ A malfunctioning shorting bar on the inflatable restraint steering wheel module coil 2-way connector.
^ Refer to Testing for Intermittent and Poor Connections in Diagrams.

TEST DESCRIPTION

Test Step 1 - Step 5:

Test Step 6 - Step 12:

Test Step 13 - Step 18:

The number(s) below refer to the step number(s) on the diagnostic table.
2. This step inspects the driver inflator module in-line connector below the inflatable restraint steering wheel module coil.
6. Tests for the proper operation of the inflatable restraint steering wheel module coil and/or inflatable restraint steering wheel module.
9. Tests for a short to ground in the driver frontal high deployment circuit.
11. Tests for a short to ground in the driver frontal low deployment circuit.
13. Tests for a short to voltage in the driver frontal high deployment circuit.
15. Tests for a short to voltage in the driver frontal low deployment circuit or if there is a malfunctioning SDM.