GM Service Manual Online
For 1990-2009 cars only

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 B0069: Right Front/Passenger Roof Rail/Head Curtain Bag Deployment Loop Resistance Low

DTC B0070: Right Front/Passenger Roof Rail/Head Curtain Bag Deployment Loop Open

DTC B0071: Right Front/Passenger Roof Rail/Head Curtain Bag Deployment Loop Voltage Out of Range

Diagnostic Fault Information

Circuit

Short to Ground

High Resistance

Open

Short to Voltage

Signal Performance

Roof Rail Module - Right High Control

B0071

B0071

B0070

B0071

B0069

Roof Rail Module - Right Low Control

B0071

B0071

B0070

B0071

B0069

Circuit/System Description

The driver roof rail deployment loop consists of an inflatable restraint roof rail module - right and the roof rail module high and low circuits. A shorting bar used within the roof rail module connector shorts together both the roof rail module high and low circuits when the connector is disconnected. This will help to prevent unwanted deployment of the inflator module during servicing. 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 roof rail module. The SDM performs continuous diagnostic tests on the deployment loops to check for proper circuit continuity and for shorts to ground or voltage. If a malfunction is detected, a diagnostic trouble code (DTC) will be stored in memory.

Conditions for Running the DTC

Ignition voltage is between 9-16 volts.

Conditions for Setting the DTC

B0069

DTC B0069 will set when the roof rail module-right deployment loop resistance is less than 1.3 ohms for 500 milliseconds.

B0070

DTC B0070 will set when one of the following conditions occurs:

    • Roof rail module - right high circuit is less than 2.4 volts and the roof rail module-right deployment loop is greater than 6 ohms for 500 milliseconds.
    • Roof rail module - right deployment loop resistance is greater than 4.8 ohms for 500 milliseconds.

B0071

DTC B0071 will set when one of the following conditions occur:

    • Roof rail module - right high or low circuits are shorted to voltage or shorted to ground for 500 milliseconds.
    • Roof rail module - right high circuit is less than 2.4 volts and roof rail module - right 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 DTC function is used.
    • A history DTC will clear once 255 malfunction-free ignition cycles have occurred.

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 SIR Driver/Passenger 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 module
   • 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 RF inflatable restraint side impact module connector and CPA are engaged.
  2. If the above condition is not found, make the appropriate repair.
  3. Ignition OFF, disconnect the harness connector at the right roof rail inflatable restraint module.
  4. With the appropriate load tool adapter, connect J 38715-A in place of the right roof rail inflatable restraint module.
  5. Ignition ON, with a scan tool, verify that the appropriate DTC is set as current.
  6. 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 right roof rail inflatable restraint module, and cycle the ignition ON. If the DTC resets after reconnecting the module, replace the right roof rail inflatable restraint module.
  7. Ignition OFF, disconnect the load tool and the adapter.
  8. Disconnect the harness connector at the SDM.
  9. Ignition ON, test for less than 1.0 volt between the low control circuit terminal 15 and ground.
  10. If not within the specified range, test the control circuit for a short to voltage.
  11. Ignition ON, test for less than 1.0 volt between the high control circuit terminal 14 and ground.
  12. If not within the specified range, test the control circuit for a short to voltage.
  13. Ignition OFF, test for infinite resistance between the low control circuit terminal 15 and ground.
  14. If not within the specified range, test the control circuit for a short to ground.
  15. Ignition OFF, test for infinite resistance between the high control circuit terminal 14 and ground.
  16. If not within the specified range, test the control circuit for a short to ground.
  17. Test for less than 1.0 ohm between the low control circuit terminal 4 and the SDM terminal 15.
  18. If not within the specified range, test the control circuit for an open/high resistance.
  19. Test for less than 1.0 ohm between the high control circuit terminal 3 and the SDM terminal 14.
  20. If not within the specified range, test the control circuit for an open/high resistance.
  21. If all circuits test normal, replace the SDM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Inflatable Restraint Roof Side Rail Module Replacement - Front
    •  SIR/SRS Wiring Repairs
    •  Control Module References for SDM replacement, setup, and programming