B1026

Diagnostic Chart (Part 1 Of 3):

Diagnostic Chart (Part 2 Of 3):

DTC B1026 Driver Deployment Loop Open (Part 3 Of 3):

Wiring Diagram:

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
^ Deployment loop voltage out of range test.
- Ignition 1 voltage is within the normal operating voltage range.
- Driver frontal deployment loop is not shorted to voltage.
- Driver frontal high terminal A6 is less than 2 volts AND the driver frontal deployment loop resistance is at least 4.5 ohms for 500 milliseconds.
^ Deployment loop resistance measurement test.
- Ignition 1 voltage is within the normal operating voltage range.
- Driver frontal deployment loop is not shorted to voltage.
- Driver frontal deployment loop is not shorted to ground.
- Driver frontal deployment loop resistance is more than 4.5 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.

ACTION TAKEN WHEN THE DTC SETS
^ The SDM sets a DTC B1026.
^ The SDM turns ON the AIR BAG warning indicator.

CONDITIONS FOR CLEARING THE DTC
^ Current DTC
- Deployment loop voltage out of range test- driver frontal high terminal A6 is more than 2 volts AND driver frontal deployment loop resistance is less than 4.5 ohms for 500 milliseconds.
- Deployment loop resistance measurement test-driver frontal deployment loop resistance is4.5 ohms or less for 500 milliseconds.
^ History DTC
- Issue a scan tool CLEAR CODES command.
- Once 250 malfunction free ignition cycles have occurred.

DIAGNOSTIC AIDS
A poor connection can cause an intermittent condition. Check the following for a poor connection:
^ The inflatable restraint steering wheel module yellow 2-way connector terminal 1 and terminal 2.
^ The wiring harness side of the inflatable restraint steering wheel module yellow 2-way connector.
^ The SDM terminal A6 and terminal A7.
^ The wire to terminal connections in the driver frontal high circuit.
^ The wire to terminal connections in the driver frontal low circuit.


TEST DESCRIPTION
The number(s) below refer to the step number(s) on the diagnostic table.
2. This step checks the inflatable restraint steering wheel module yellow 2-way connector..
6. This step determines if the inflatable restraint steering wheel module coil or if the inflatable restraint steering wheel module is defective.
9. This step checks to see if the SDM wiring harness is connected properly at the SDM.
11. This step checks to see if there is an open or a high resistance condition in the driver frontal high circuit.
13. This step determines if there is an open or a high resistance condition in the driver frontal low circuit or if there is a malfunctioning SDM.