Circuit Description
When you first turn the ignition switch to the ON position, the inflatable restraint sensing and diagnostic module (SDM) performs tests to diagnose critical malfunctions within itself. Then the SDM 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 Setting the DTC
| • | Ignition 1 voltage is within the normal operating voltage range. |
| • | Driver frontal deployment loop is not open. |
| • | Driver frontal deployment loop is not shorted to voltage. |
| • | Driver frontal deployment loop is not shorted to ground. |
| • | Driver frontal deployment loop resistance is less than 1.2 ohms for 500 milliseconds. |
The driver frontal deployment loop consists of the following components:
| • | Inflatable restraint steering wheel module. |
| • | Inflatable restraint steering wheel module coil. |
| • | Harness wiring of the driver frontal high circuit. |
| • | Harness wiring of the driver frontal low circuit. |
| • | Connector terminal contact. |
This malfunction is detected during the deployment loop resistance measurement test.
Action Taken When the DTC Sets
| • | The SDM sets a DTC B1022. |
| • | The SDM turns ON the AIR BAG warning indicator. |
Conditions for Clearing the DTC
| • | Current DTC |
| The resistance of the driver frontal deployment loop is at least 1.2 ohms or more for 500 milliseconds. |
| • | History DTC |
| - | Issue a scan tool CLEAR CODES command. |
| - | Once 250 malfunction free ignition cycles have occurred. |
Diagnostic Aids
The following can cause an intermittent condition:
| • | A short between the driver frontal high circuit and the driver frontal low circuit. |
| • | A malfunctioning shorting bar on the inflatable restraint steering wheel module yellow 2-way connector. |
| • | A malfunctioning shorting bar on the inflatable restraint steering wheel module coil side of the inflatable restraint steering wheel module yellow 2-way connector. |
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
-
This step checks the inflatable restraint steering wheel module yellow 2-way connector.
-
This step determines if the inflatable restraint steering wheel module coil or the inflatable restraint steering wheel module is malfunctioning.
-
This step determines if there is a short between the driver frontal high circuit and the driver frontal low circuit or if there is a malfunctioning SDM.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the SIR Diagnostic System Check performed? | -- | ||
Are the inflatable restraint steering wheel module yellow 2-way connector and terminals free from damage and corrosion? | -- | |||
3 | Repair or replace the wiring harness side of the inflatable restraint steering wheel module yellow 2-way connector. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | -- | |
4 |
Is DTC B1022 current? | -- | Go to Diagnostic Aids | |
5 |
Is DTC B1022 current? | -- | ||
Is DTC B1022 current? | -- | |||
7 |
Is the repair complete? | -- | -- | |
8 |
Is the repair complete? | -- | -- | |
Is the measured resistance less than the specified value? | OL | |||
10 | Locate and repair a short between the driver frontal high circuit and the driver frontal low circuit. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | -- | |
11 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Is the repair complete? | -- | -- | |
12 |
Have all current and history SIR DTCs been cleared? | -- | -- |
