GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2006 🢒 XLR 🢒 DTC 🢒 DTC B0064, B0065, or B0066

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

Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Circuit

Short to Ground

High Resistance

Open

Short to Voltage

Signal Performance

Seat Belt Pretensioner - LF High Circuit

B0066

B0066

B0065

B0066

B0064

Seat Belt Pretensioner - LF Low Circuit

B0066

B0066

B0065

B0066

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 short to ground or short 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 commands the AIR BAG indicator ON via serial data communication.
    • 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

SIR Connector End Views

Electrical Information Reference

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

Special Tools Required

    • J 38715-A SIR Driver/Passenger Load tool
    • J 38715-60 SIR Load Tool Adapter

Circuit/System Testing

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

       • The seat belt pretensioner - LF
       • The SDM module
       • The seat belt pretensioner - LF wiring harness connector
       • The SDM wiring harness connector

  1. Ignition OFF, disconnect the seat belt pretensioner - LF wiring harness connector located under the driver front seat.
  2. Use J 38715-60 to connect the J 38715-A to the harness side of the seat belt pretensioner - LF wiring harness connector. Use the PASSENGER INFLATOR connector located on the load tool.
  3. Ignition ON, use a scan tool to observe the SIR DTC display. Verify DTC B0064, B0065, or B0066 is set current.
    4. ⇒If DTC B0064, B0065, or B0066 is history replace the seat belt retractor pretensioner - LF.
  4. Ignition OFF, disconnect and remove both the J 38715-A and J38715-60. Then remove the SDM connector. Refer to SDM replacement in Repair Instructions for connector location.
  5. Test the high and low circuits between the SDM and seat belt pretensioner - LF for a short to voltage, short to ground, or open/low resistance. Verify that a short to voltage, short to ground, or open/low resistance does not exist.
    6. ⇒If any of the above conditions are found make the appropriate repair.
  6. If all circuits test normal then replace the SDM.

Repair Instructions

Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Seat Belt Buckle Pretensioner Replacement
    •  Control Module References for SDM replacement, setup, and programming