DTC B0026 LF/Driver Frontal Deployment Loop (Single Stage or Stage 1) Open. Buick LeSabre 2000

For 1990-2009 cars only

Makes 🢒 Buick 🢒 2000 🢒 LeSabre 🢒 Restraints 🢒 SIR 🢒 DTC B0026 LF/Driver Frontal Deployment Loop (Single Stage or Stage 1) Open

SIR Components
SIR Schematics
SIR Handling Caution
Handling ESD Sensitive Parts Notice
SIR Schematic Icons

Circuit Description

When you first turn ON the ignition, 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 Running the DTC

Deployment loop voltage out of range test:

•	Ignition 1 voltage is within the normal operating voltage range.

•	The driver frontal deployment loop is not shorted to voltage.

•	The driver frontal high terminal is less than 2.4 volts.

Deployment loop resistance measurement test:

•	Ignition 1 voltage is within the normal operating voltage range.

•	The driver frontal deployment loop is not shorted to voltage.

•	The driver frontal deployment loop is not shorted to ground.

Conditions for Setting the DTC

Deployment loop voltage out of range test - Driver frontal high is less than 2.4 volts, driver frontal loop resistance is greater or equal to 6 ohms for 500 milliseconds.

Deployment loop resistance measurement test - Driver frontal deployment loop resistance is more than 4.8 ohms for 500 milliseconds.

Action Taken When the DTC Sets

The SDM commands ON the AIR BAG warning lamp via Class 2 serial data.

Conditions for Clearing the DTC

•	The driver frontal deployment loop resistance is 4.8 ohms or less for 500 milliseconds.

•	The driver frontal high is more than 2.4 volts, driver frontal loop resistance is less than 6 ohms for 500 milliseconds.

•	You can issue a CLEAR CODES command.

•	A history DTC will clear once 255 malfunction free ignition cycles have occurred.

Diagnostic Aids

The following may cause an intermittent condition:

•	The inflatable restraint steering wheel module coil harness connector.

•	The SDM wiring harness connector.

•	The wire to terminal connections in the driver frontal high circuit.

•	The wire to terminal connections in the driver frontal low circuit.

Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

This step checks the driver inflator module in-line connector below the steering wheel restraint module coil.

This step test for the proper operation of inflatable restraint steering wheel module coil and/or inflatable restraint steering wheel inflator module.

This step checks to see if the inflatable restraint sensing and diagnostic module (SDM) wiring harness connector is OK.

This step checks to see if there is an open or a high resistance in the driver frontal high circuit.

This step determines if there is an open or a high resistance in the driver frontal low circuit, or if there is a malfunctioning SDM.

Step

Action

Value(s)

Yes

Did you perform the Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - SIR

Turn OFF the ignition.
Disconnect the in-line connector that connects steering wheel restraint module coil to vehicle wiring harness.
Inspect both wiring harness connectors for the following conditions:

•

Corrosion

•	Terminal damaged

•	Poor connections/terminal tension

•	Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Does connector exhibits any signs of corrosion, terminal damaged, or poor connections?

Go to Step 3

Go to Step 4

Replace the wiring harness side of in-line connector. Refer to Connector Repairs in Wiring Systems.
If steering wheel restraint module coil exhibits any of the above conditions, the module must be replaced. Refer to Inflatable Restraint Steering Wheel Module Coil Replacement .

Did you complete the replacement?

Go to Step 16

Reconnect the in-line connector.
Verify that the connector position assurance (CPA) is properly installed.
Turn ON the ignition, with the engine OFF.
Use the scan tool to request SIR DTCs displayed.

Does the scan tool indicate that this DTC is current?

Go to Step 5

Go to Diagnostic Aids

Turn OFF the ignition.
Disconnect the in-line connector below the steering wheel restraint module coil.
Install the J 38715-A SIR Load Tool to the vehicle wiring harness side of the in-line connector. Use the appropriate wiring harness connector adaptors where necessary.
Turn ON the ignition, with the engine OFF.
Use the scan tool to request SIR DTCs displayed.

Does the scan tool indicate that this DTC is current?

Go to Step 9

Go to Step 6

Turn OFF the ignition.
Remove the inflatable restraint steering wheel inflator module. Refer to Inflatable Restraint Steering Wheel Module Replacement .
Disconnect the J 38715-A from the in-line connector.
Reconnect the in-line connector back together.
Connect the J 38715-A to the upper inflatable restraint steering wheel module coil connector on the steering column.
Turn ON the ignition, with the engine OFF.
Use the scan tool to request SIR DTCs displayed.

Does the scan tool indicate that this DTC is current?

Go to Step 8

Go to Step 7

Turn OFF the ignition.
Replace the inflatable restraint steering wheel inflator module. Refer to Inflatable Restraint Steering Wheel Module Replacement .

Did you complete the replacement?

Go to Step 16

Turn OFF the ignition.
Replace the inflatable restraint steering wheel module coil. Refer to Inflatable Restraint Steering Wheel Module Coil Replacement .

Did you complete the replacement?

Go to Step 16

Turn OFF the ignition.
Disconnect the inflatable restraint sensing and diagnostic module (SDM) wiring harness connector. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
Disconnect the J 38715-A .
Inspect for proper connections at the driver frontal high terminal and the driver frontal low terminal of the SDM wiring harness connector.

Is the SDM wiring harness connector OK?

Go to Step 11

Go to Step 10

Replace the SDM wiring harness connector. Refer to Connector Repairs in Wiring Systems.

Did you complete the replacement?

Go to Step 16

Use the J 39200 DMM and measure the resistance between driver frontal high deployment circuit of in-line connector and the SDM wiring harness connector.

Does the resistance measure greater than the specified value?

0-0.5 ohms

Go to Step 12

Go to Step 13

Locate and repair an open or a high resistance in the driver frontal high circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 16

Use the J 39200 and measure the resistance between driver frontal low deployment circuit of in-line connector and the SDM wiring harness connector.

Does the resistance measure greater than the specified value?

0-0.5 ohms

Go to Step 14

Go to Step 15

Locate and repair an open or a high resistance in the driver frontal low circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 16

Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .

Did you complete the replacement?

Go to Step 16

Reconnect all SIR components.
Verify that all components and connectors are properly mounted.
Turn ON the ignition, with the engine OFF.
Use the scan tool in order to clear the DTCs.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Did you complete the action?

Go to Diagnostic System Check - SIR