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B0019





DTC B0019 or B0020

Diagnostic Instructions

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

DTC Descriptors

DTC B0019 01: Passenger Instrument Panel Air Bag Deployment Loop Stage 1 Short to Battery

DTC B0019 02: Passenger Instrument Panel Air Bag Deployment Loop Stage 1 Short to Ground

DTC B0019 04: Passenger Instrument Panel Air Bag Deployment Loop Stage 1 Open

DTC B0019 0D: Passenger Instrument Panel Air Bag Deployment Loop Stage 1 High Resistance

DTC B0019 0E: Passenger Instrument Panel Air Bag Deployment Loop Stage 1 Low Resistance

DTC B0020 01: Passenger Instrument Panel Air Bag Deployment Loop Stage 2 Short to Battery

DTC B0020 02: Passenger Instrument Panel Air Bag Deployment Loop Stage 2 Short to Ground

DTC B0020 04: Passenger Instrument Panel Air Bag Deployment Loop Stage 2 Open

DTC B0020 0D: Passenger Instrument Panel Air Bag Deployment Loop Stage 2 High Resistance

DTC B0020 0E: Passenger Instrument Panel Air Bag Deployment Loop Stage 2 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

B0019 01, B0020 01

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

B0019 02, B0020 02

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

B0019 04, B0020 04

The air bag control circuit is open for 2 seconds.

B0019 0D, B0020 0D

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

B0019 0E, B0020 0E

The air bag deployment loop resistance is less than 1.4 ohms 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 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
- Inline connectors - on the side of the harness connector
- 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 can occur because of stress or damage to the harness due to seat movement. Move the seat to the full extend of travel while using the scan tool to observe deployment type loop parameters.

If the pretensioner, passenger instrument panel air bags or seat side air bag has inflated under unexpected conditions and/or DTC with symptom byte 01 is set, check both control circuits for a short to voltage.

Reference Information

Schematic Reference

SIR Schematics Electrical Diagrams

Connector End View Reference

Component Connector End Views Connector Views

Description and Operation

SIR System Description and Operation Description and Operation

Electrical Information Reference

- Circuit Testing Component Tests and General Diagnostics
- Testing for Intermittent Conditions and Poor Connections Component Tests and General Diagnostics
- Wiring Repairs Component Tests and General Diagnostics
- Connector Repairs Component Tests and General Diagnostics

Scan Tool Reference

Control Module References for scan tool information Programming and Relearning

Circuit/System Verification

Note: Refer to SIR Service Precautions. Service Precautions

Inspect all terminals for damage or corrosion when disconnecting connectors. 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 Nyogel lubricant 760G. This procedure will correct the high resistance condition due to terminal fretting corrosion.

1. Verify the scan tool Deployment Loop Resistance 1 and 2 parameters stay consistently between 2.1 and 4.0 ohms without any spikes or dropouts while moving the harness near each connector listed below:
- F105 Passenger instrument panel air bag
- Any inline harness
- K36 SDM
- If less than 2.1 or greater than 4.0 ohms
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 Nyogel lubricant 760G to each connector terminal
- Insure each connector and CPA is correctly seated.
- If within 2.1 and 4.0 ohms without any spikes or dropouts
2. All OK

Circuit/System Testing

1. Ignition OFF.
2. Disconnect the scan tool.
3. Disconnect the harness connector X203.
4. Test for greater than 25 ohms between the appropriate control circuit terminals listed below on the SDM side of the connector:
- F105 Passenger instrument panel airbag stage 1 X203 terminal A1 and A2
- F105 Passenger instrument panel airbag stage 2 X203 terminal B1 and B2
- If 25 ohms or less
4.1. Disconnect the harness connector at the K36 SDM.
4.2. 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.
- If greater than 25 ohms
5. Ignition ON.
6. Test for less than 11 V between the control circuit terminals listed below and ground:
- X203 control circuit terminal A1
- X203 control circuit terminal A2
- X203 control circuit terminal B1
- X203 control circuit terminal B2
- If 11 V or greater
6.1. Ignition OFF.
6.2. Disconnect the harness connector at the K36 SDM.
6.3. Ignition ON.
6.4. 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.
- If less than 11 V
7. Test for greater than 25 ohms between the control circuit terminals listed below and ground:
- X203 control circuit terminal A1
- X203 control circuit terminal A2
- X203 control circuit terminal B1
- X203 control circuit terminal B2
- If 25 ohms or less
7.1. Disconnect the harness connector at the K36 SDM.
7.2. 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.
- If greater than 25 ohms
8. Ignition OFF.
9. Install a 3 A fused jumper wire between the control circuit terminals listed below:
- F105 Passenger instrument panel airbag stage 1 X203 terminal A1 and A2
- F105 Passenger instrument panel airbag stage 2 X203 terminal B1 and B2
10. Ignition ON.
11. Verify the scan tool Deployment Loop Resistance parameter is less than 2 ohms.
- If 2 ohms or greater
11.1. Ignition OFF.
11.2. Disconnect the harness connector at the K36 SDM.
11.3. Test for less than 2 ohms in each control circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms, replace the K36 SDM.
- If less than 2 ohms
12. Ignition OFF.
13. Reconnect harness connector X203.
14. Disconnect the F105 air bag harness connector X1 or X2.
15. Ignition ON.
16. Test for less than 11 V between the control circuit terminals listed below and ground:
- Passenger instrument panel air bag control circuit terminal 1 X1
- Passenger instrument panel air bag control circuit terminal 2 X1
- Passenger instrument panel air bag control circuit terminal 1 X2
- Passenger instrument panel air bag control circuit terminal 2 X2
- If 11 V or greater
Repair the short to voltage on the circuit.
- If less than 11 V
17. Ignition OFF.
18. Test for greater than 25 ohms between the control circuit terminals listed below and ground:
- Passenger instrument panel air bag control circuit terminal 1 X1
- Passenger instrument panel air bag control circuit terminal 2 X1
- Passenger instrument panel air bag control circuit terminal 1 X2
- Passenger instrument panel air bag control circuit terminal 2 X2
- If 25 ohms or less
Repair the short to ground on the circuit.
- If greater than 25 ohms
19. Ignition OFF.
20. Test for less than 5 ohms between the control circuit terminals listed below:
- X203 control circuit terminal A1 and F105 air bag harness connector control circuit terminal 1 X1
- X203 control circuit terminal A2 and F105 air bag harness connector control circuit terminal 2 X1
- X203 control circuit terminal B1 and F105 air bag harness connector control circuit terminal 1 X2
- X203 control circuit terminal B2 and F105 air bag harness connector control circuit terminal 2 X2
- If 5 ohms or less
Repair the short between the two circuits.
- If greater than 25 ohms
21. Replace the F105 passenger instrument panel air bag.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure Testing and Inspection.

- Instrument Panel Inflatable Restraint Module Replacement Removal and Replacement
- SIR/SRS Wiring Repairs Component Tests and General Diagnostics
- Control Module References for SDM replacement, programming and setup Programming and Relearning