B0019
DTC B0019 or B0020
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 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 ohm for 2 seconds.
B0019 0E, B0020 0E
The air bag deployment loop resistance is less than 1.4 ohm 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
Connector End View Reference
Component Connector End Views
Description and Operation
SIR System Description and Operation
Electrical Information Reference
^ Circuit Testing
^ Testing for Intermittent Conditions and Poor Connections
^ Wiring Repairs
^ Connector Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Note: Refer to SIR 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 ohm 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 ohm
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 ohm 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 ohm 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 ohm 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 ohm
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 ohm 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 ohm 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 ohm
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 ohm.
--> If 2 ohm or greater
11.1. Ignition OFF.
11.2. Disconnect the harness connector at the K36 SDM.
11.3. Test for less than 2 ohm in each control circuit end to end.
--> If 2 ohm or greater, repair the open/high resistance in the circuit.
--> If less than 2 ohm, replace the K36 SDM.
• If less than 2 ohm
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 ohm 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 ohm or less
Repair the short to ground on the circuit.
• If greater than 25 ohm
19. Ignition OFF.
20. Test for less than 5 ohm 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 ohm or less
Repair the short between the two circuits.
• If greater than 25 ohm
21. Replace the F105 passenger instrument panel air bag.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
^ Instrument Panel Inflatable Restraint Module Replacement
^ SIR/SRS Wiring Repairs
^ Control Module References for SDM replacement, programming and setup