Buick Regal: DTC B0016, B0018, B0023, or B0025

Diagnostic Instructions

• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B0016 01

Left Roof Rail Air Bag Deployment Loop Short to Battery

DTC B0016 02

Left Roof Rail Air Bag Deployment Loop Short to Ground

DTC B0016 04

Left Roof Rail Air Bag Deployment Loop Open

DTC B0016 0D

Left Roof Rail Air Bag Deployment Loop High Resistance

DTC B0016 0E

Left Roof Rail Air Bag Deployment Loop Low Resistance

DTC B0023 01

Right Roof Rail Air Bag Deployment Loop Short to Battery

DTC B0023 02

Right Roof Rail Air Bag Deployment Loop Short to Ground

DTC B0023 04

Right Roof Rail Air Bag Deployment Loop Open

DTC B0023 0D

Right Roof Rail Air Bag Deployment Loop High Resistance

DTC B0023 0E

Right Roof Rail Air Bag Deployment Loop Low Resistance

Diagnostic Fault Information

Circuit/System Description

During a side or frontal crash of sufficient force the inflatable restraint sensing and diagnostic module (SDM) will allow current to flow through the deployment loop in order to deploy an air bag or pretensioner. There are 2 shorting bars which will short together control circuits, when the connector is disconnected. This will help to prevent unwanted deployment of the air bag or pretensioner during servicing.

Conditions for Running the DTC

Ignition voltage is between 9 - 16 V.

Conditions for Setting the DTC

B0016 01, B0023 01

The air bag control circuit is shorted to voltage for 2 seconds.

B0016 02, B0023 02

The air bag control circuit is shorted to ground for 2 seconds.

B0016 04, B0023 04

The air bag control circuit is open for 2 seconds.

B0016 0D, B0023 0D

The air bag deployment loop resistance is greater than 4.2 Ω for 2 seconds.

B0016 0E, B0023 0E

The air bag deployment loop resistance is less than 1.4 Ω for 2 seconds.

Action Taken When the DTC Sets

• The SDM requests the instrument cluster to illuminate the AIR BAG indicator.
• The SDM will store a DTC, however if an event occurs the system will still attempt deployments.

Conditions for Clearing the DTC

• The condition for setting the DTC no longer exists.
• A history DTC will clear once 100 malfunction-free ignition cycles have occurred.

Diagnostic Aid

NOTE: The following diagnostic aids apply for both current and history DTCs.

An incorrectly installed connector position assurance (CPA) or incorrectly seated connector can cause a shorting bar to short both control circuits together. Check the connectors and CPAs if a DTC with symptom byte 02 or 0E is set, to ensure the shorting bars are not causing the circuits to be shorted together. Shorting bars are used in the locations listed below:

• Passenger instrument panel air bag
• Driver and passenger seat side air bags
• Left and right roof rail air bags
• Driver and passenger retractor pretensioners
• Inline harness connectors
• Harness side of the SDM connector

Terminal fretting or incorrectly seated connectors can cause an open/high resistance condition. Check the circuit terminals for fretting or incorrectly seated connector if a DTC with symptom byte 04 or 0D is set. DTCs of deployment loops which are in the seat DTC can occur because of stress or damage to the harness due to seat movement. Move the seat to the full extent of travel while using the scan tool to observe deployment type loop parameters.

Reference Information

Schematic Reference

SIR Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

Supplemental Inflatable Restraint System Description and Operation

Electrical Information Reference

• Circuit Testing
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Connector Repairs

Scan Tool Reference

Refer to Control Module References for scan tool information.

Special Tools

EL-38125-580 Terminal Release Tool Kit

Circuit/System Verification

NOTE: Refer to SIR Service Precautions.

Damage or corrosion in the following requires repair or replacement of the affected component/connector.

• Seat belt retractor pretensioner
• Passenger instrument panel air bag
• Seat side air bag
• Roof rail air bag
• SDM
• Seat belt retractor pretensioner wiring harness connector
• Passenger instrument panel air bag wiring harness connector
• Seat side air bag wiring harness connector
• Roof rail air bag wiring harness connector
• SDM wiring harness connector

NOTE: The connector and connector position assurance (CPA) may seat independent of each other. Both the connector and CPA should seat with an audible and/or tactile click. The CPA isolates the shorting-bars within the connector allowing the deployment circuit to operate properly.

If the condition is intermittent or cannot be duplicated, disconnect the connectors and add dielectric grease / lubricant (Nyogel 760G or equivalent, meeting GM specification 9986087). This procedure will correct the high resistance condition due to terminal fretting corrosion.

1. Verify the appropriate scan tool Deployment Loop Resistance parameters stay consistently between 2.1 and 4.0 Ω without any spikes or dropouts while moving the harness near each connector listed below:

• F105L Roof rail air bag - left
• F105R Roof rail air bag - right
• Any inline harness connector
• K36 SDM
• If less than 2.1 or greater than 4.0 Ω

Refer to Circuit/System Testing.

• If there are spikes or dropouts, perform the following:
• Inspect each connector terminal and harness for damage or corrosion and repair as necessary
• Apply dielectric grease / lubricant (Nyogel 760G or equivalent, meeting GM specification 9986087) to each connector terminal
• Insure each connector and CPA is correctly seated.
• Go to next step: If within 2.1 and 4.0 Ω without any spikes or dropouts

2. All OK

Circuit/System Testing

1. Ignition OFF. Scan tool disconnected. It may take up to 2 minutes for all vehicle systems to power down.

Disconnect the appropriate harness connector at the roof rail air bag listed below:

• DTC B0016 - F105L Roof rail air bag - left
• DTC B0023 - F105R Roof rail air bag - right

2. Test for greater than 25 Ω between the control circuit terminals 1 and 2.

• If 25 Ω or less

1. Disconnect the X2 harness connector at the K36 SDM.

NOTE: Some connectors may be equipped with shorting bars as a safety component to prevent accidental inflator deployment. When testing on a connector with shorting bars, the shorting bars must be disabled to ensure accurate test results. Insert an appropriate pick from EL- 38125-580 and depress the shorting bars above the appropriate terminals. This will lift the shorting bar from the terminal and allow accurate test results. Take care not to damage the connector, shorting bar, or terminal when depressing the shorting bar.

2. Test for infinite resistance between the two control circuits.
   • If less than infinite resistance, repair the short between the two circuits.
   • If infinite resistance, replace the K36 SDM.

• Go to next step: If greater than 25 Ω

3. Ignition ON.

4. Test for less than 11 V between the control circuit terminals listed below and ground:

• Control circuit terminal 1
• Control circuit terminal 2
• If 11 V or greater

1. Ignition OFF. Disconnect the X2 harness connector at the K36 SDM. Ignition ON.
2. Test for less than 1 V between the control circuit and ground.
   • If 1 V or greater, repair the short to voltage on the circuit.
   • If less than 1 V, replace the K36 SDM.

• Go to next step: If less than 11 V

5. Ignition OFF.

6. Test for greater than 25 Ω between the control circuit terminals listed below and ground:

• Control circuit terminal 1
• Control circuit terminal 2
• If 25 Ω or less

1. Disconnect the X2 harness connector at the K36 SDM.
2. Test for infinite resistance between the control circuit and ground.
   • If less than infinite resistance, repair the short to ground on the circuit.
   • If infinite resistance, replace the K36 SDM.

• Go to next step: If greater than 25 Ω

7. Ignition OFF. Install a 3 A fused jumper wire between the appropriate control circuit terminals 1 and 2.

Ignition ON.

8. Verify the scan tool Deployment Loop Resistance parameter is less than 2 Ω.

• If 2 Ω or greater

1. Ignition OFF. Disconnect the X2 harness connector at the K36 SDM.
2. Test for less than 2 Ω in each control circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit.
   • If less than 2 Ω, replace the K36 SDM.

• Go to next step: If less than 2 Ω

9. Ignition OFF, connect the harness connector at the F105L roof rail air bag - left or F015R roof rail air bag - right, press in the CPA (if equipped) until an audible and/or tactile click is heard.

10. Ignition ON, clear DTCs. Operate the vehicle within the Conditions for Running the DTC.

11. Verify DTC B0016, B0018, B0023, or B0025 is not set.

• If DTC B0016, B0018, B0023, or B0025 is set

Replace the appropriate F105L roof rail air bag - left or F015R roof rail air bag - right.

• Go to next step: If DTC B0016, B0018, B0023, or B0025 is not set

12. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• Front and Rear Row Seat Roof Rail Airbag Replacement (Hatchback) or Front and Rear Row Seat Roof Rail Airbag Replacement (Wagon)
• Front and Rear Row Seat Roof Rail Airbag Replacement (Hatchback) or Front and Rear Row Seat Roof Rail Airbag Replacement (Wagon)
• SIR/SRS Wiring Repairs
• Control Module References for SDM replacement, programming and setup

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