GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2009 🢒 LaCrosse 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC B0064, B0065, or B0066

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 B0064: Left Front Pretensioner Deployment Loop Resistance Low

DTC B0065: Left Front Pretensioner Deployment Loop Open

DTC B0066: Left Front Pretensioner Deployment Loop Voltage Out of Range

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Seat Belt Pretensioner - RF High Control

B0059

B0059

B0058

B0057

Seat Belt Pretensioner - RF Low Control

B0059

B0059

B0058

B0057

Seat Belt Pretensioner - LF High Control

B0066

B0066

B0065

B0064

Seat Belt Pretensioner - LF Low Control

B0066

B0066

B0065

B0064

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 seat belt pretensioner - LF. 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 pretensioner - LF connector which will short together both seat belt pretensioner - LF high and low circuits when the connector is disconnected, this will help to prevent unwanted deployment of the inflator module during servicing.

Conditions for Running the DTC

Ignition voltage is between 9-16 volts.

Conditions for Setting the DTC

B0064

The seat belt pretensioner - LF deployment loop resistance is less than 1.3 ohms for 500 milliseconds.

B0065

    • Seat belt pretensioner - LF high circuit is less than 2.4 volts and the seat belt pretensioner - LF deployment loop is more than 6 ohms for 500 milliseconds.
    • Seat belt pretensioner - LF deployment loop resistance is more than 4.8 ohms for 500 milliseconds.

B0066

    • Seat belt pretensioner - LF high and/or low circuits is shorted to ground or shorted to voltage for 500 milliseconds.
    • Seat belt pretensioner - LF high circuit is less than 2.4 volts and seat belt pretensioner - LF deployment loop resistance is less than 6 ohms for 500 milliseconds.

Action Taken When the DTC Sets
    • The SDM requests the instrument panel cluster (IPC) to illuminate the AIR BAG indicator.
    • The SIR system is disabled and no deployments are allowed.

Conditions for Clearing the DTC
    • The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.
    • A history DTC will clear once 255 malfunction-free ignition cycles have occurred.

Diagnostic Aids

If there is more than one DTC set diagnose the open DTC first.

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

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 38715-A Driver and Passenger Sir Load Tool

Circuit/System Testing

Important: Refer to SIR Service Precautions .

When removing the connectors, inspect for damage or corrosion. Damage or corrosion to the following requires repair or replacement of the affected component/connector:

   • Inflatable restraint seat belt pretensioner
   • SDM module
   • Front end sensor wiring harness connector
   • SDM wiring harness connector

Important: 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 shoring-bars within the connector allowing the deployment circuit to operate properly.

  1. Verify that the LF inflatable restraint seat belt pretensioner connector and CPA are engaged.
    2. ⇒If the above condition is not found, make the appropriate repair.
  2. Ignition OFF, disconnect the harness connector at the LF inflatable restraint seat belt pretensioner.
  3. With the appropriate load tool adapter, connect J 38715-A in place of the LF inflatable restraint seat belt pretensioner.
  4. Ignition ON, with a scan tool, verify that the appropriate DTC is set as current.
    5. ⇒If the DTC is not set or is set as history, cycle the ignition OFF, disconnect the load tool and adapter, reconnect the harness connector at the LF inflatable restraint seat belt pretensioner, and cycle the ignition ON. If the DTC resets after reconnecting the pretensioner, replace the LF inflatable restraint seat belt pretensioner.
  5. Ignition OFF, disconnect the load tool and the adapter.
  6. Disconnect the harness connector at the SDM.
  7. Ignition ON, test for less than 1.0 volt between the low control circuit terminal B and ground.
    8. ⇒If greater than the specified range, test the control circuit for a short to voltage.
  8. Ignition ON, test for less than 1.0 volt between the high control circuit terminal A and ground.
    9. ⇒If greater than the specified range, test the control circuit for a short to voltage.
  9. Ignition OFF, test for infinite resistance between the low control circuit terminal B and ground.
    10. ⇒If less than the specified value, test the control circuit for a short to ground.
  10. Ignition OFF, test for infinite resistance between the high control circuit terminal A and ground.
    11. ⇒If less than the specified value, test the control circuit for a short to ground.
  11. Test for less than 1.0 ohm between the low control circuit terminal B and the SDM terminal A6.
    12. ⇒If greater than the specified range, test the control circuit for an open/high resistance.
  12. Test for less than 1.0 ohm between the high control circuit terminal A and the SDM terminal A5.
    13. ⇒If greater than the specified range, test the control circuit for an open/high resistance.
  13. If all circuits test normal, replace the SDM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Seat Belt Buckle Pretensioner Replacement
    •  SIR/SRS Wiring Repairs
    •  Control Module References for SDM replacement, setup, and programming