B001A
DTC B001A or B001B
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provide an overview of each diagnostic category.
DTC Descriptors
DTC B001A 01
- Driver Seat Belt Anchor Pretensioner Deployment Loop Short to Battery
DTC B001A 02
- Driver Seat Belt Anchor Pretensioner Deployment Loop Short to Ground
DTC B001A 04
- Driver Seat Belt Anchor Pretensioner Deployment Loop Open
DTC B001A 0D
- Driver Seat Belt Anchor Pretensioner Deployment Loop High Resistance
DTC B001A 0E
- Driver Seat Belt Anchor Pretensioner Deployment Loop Low Resistance
DTC B001B 01
- Passenger Seat Belt Anchor Pretensioner Deployment Loop Short to Battery
DTC B001B 02
- Passenger Seat Belt Anchor Pretensioner Deployment Loop Short to Ground
DTC B001B 04
- Passenger Seat Belt Anchor Pretensioner Deployment Loop Open
DTC B001B 0D
- Passenger Seat Belt Anchor Pretensioner Deployment Loop High Resistance
DTC B001B 0E
- Passenger Seat Belt Anchor Pretensioner 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 the appropriate seat belt anchor pretensioner. The SDM performs continuous diagnostic tests on the deployment loops to check for proper circuit continuity and for shorts to ground or voltage.
A shorting bar used within the seat belt anchor pretensioner connector will short together both seat belt anchor pretensioner high and low control circuits when the connector is disconnected, this will help to prevent unwanted deployment of the pretensioner during servicing.
Conditions for Running the DTC
Ignition voltage is between 9-16 V.
Conditions for Setting the DTC
B001A 01, B001B 01
The seat belt anchor pretensioner control circuit is shorted to voltage for 120 milliseconds.
B001A 02, B001B 02
The seat belt anchor pretensioner control circuit is shorted to ground for 120 milliseconds.
B001A 04, B001B 04
The seat belt anchor pretensioner control circuit is open for 120 milliseconds.
B001A 0D, B001B 0D
The seat belt anchor pretensioner deployment loop resistance is more than 4.2 ohm for 120 milliseconds.
B001A 0E, B001B 0E
The seat belt anchor pretensioner deployment loop resistance is less than 1.7 ohm for 120 milliseconds.
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 that the shorting bars are not causing the circuits to be shorted together. Shorting bars locations are listed below:
* Inline connectors - on the seat belt anchor pretensioner side of the harness connector
* Harness side of the SDM connector
Terminal fretting, an incorrectly installed CPA, or incorrectly seated connector can cause an open/high resistance condition. Check the circuit terminals for fretting, incorrectly installed CPAs, or incorrectly seated connectors if a DTC with symptom byte 04 or 0D is set.
If the seat belt anchor pretensioner has deployed 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 ([1][2]Air Bag Systems)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Description and Operation
SIR System Description and Operation (SIR System)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
Refer to SIR Service Precautions (Technician Safety Information).
Note: 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 anchor pretensioner
* SDM
* Seat belt anchor pretensioner 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. Replace any CPA that is damaged or missing.
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. Observe the scan tool Deployment Loop Resistance parameters. The reading should be between 2.1 and 4.0 ohm.
• If not within the specified range, refer to Circuit/System Testing.
2. Observe the scan tool Deployment Loop Resistance parameters while moving the harness near each connector listed below. The reading should stay consistently between 2.1 and 4.0 ohm without any drop outs or spikes.
* F113 Seat belt anchor pretensioner
* Any harness inline
* K36 SDM
• If the reading is erratic while moving the harness, perform the following:
* Inspect each connector terminal for damage or corrosion and repair as necessary.
* Apply Nyogel lubricant 760G to each connector terminal.
* Insure each connector and CPA is correctly seated.
Circuit/System Testing
Refer to SIR Service Precautions (Technician Safety Information).
Note: 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 anchor pretensioner
* SDM
* Seat belt anchor pretensioner 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. Replace any CPA that is damaged or missing.
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. Ignition OFF, disconnect the harness connector at the appropriate F113 seat belt anchor pretensioner.
2. Disconnect the scan tool.
3. Wait for 120 seconds and then test for greater than 25 ohm between the seat belt anchor pretensioner control circuits terminal 1 and terminal 2.
• If less than the specified range, test for a short between the control circuits, check each connector and CPA to ensure that the shorting bars are lifted. If the circuits and shorting bars tests normal, replace the K36 SDM.
4. Ignition ON, test for less than 11 V between each of the seat belt anchor pretensioner control circuit terminals 1 and 2 and ground.
• If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the K36 SDM.
5. Ignition OFF, test for greater than 25 ohm between each of the seat belt anchor pretensioner control circuit terminals 1 and 2 and ground.
• If less than the specified range, test the control circuit for a short to ground. If the circuit tests normal, replace the K36 SDM.
6. Install a 3 A fused jumper wire between the seat belt anchor pretensioner control circuits terminal 1 and terminal 2.
7. Verify the scan tool Deployment Loop Resistance parameter is less than 2 ohm.
• If greater than the specified range, test the control circuit terminals 1 and 2 for an open/high resistance. If the circuits test normal, replace the K36 SDM.
8. If all circuits test normal, replace the F113 seat belt anchor pretensioner.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Driver or Passenger Seat Belt Tensioner Replacement (Driver or Passenger Seat Belt Tensioner Replacement)
* SIR/SRS Wiring Repairs (SIR/SRS Wiring Repairs)
* Control Module References (Programming and Relearning) for SDM replacement, setup, and programming