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Home >> Saturn >> 2007 >> Vue Red Line, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 991 (Supplemental Inflatable Restraint System) >> Diagnostic Information and Procedures >> DTC B0021 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2008 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.
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.
    • If the above condition is not found, make the appropriate repair.
  2. Ignition OFF, disconnect the harness connector at the RF inflatable restraint side impact module.
  3. With the appropriate load tool adapter, connect J 38715-A  or SA9409Z-A  in place of the RF inflatable restraint side impact module.
  4. Ignition ON, with a scan tool, verify that DTC B0021 is set as current.
    • 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 RF inflatable restraint side impact module, and cycle the ignition ON. If the DTC resets after reconnecting the module, replace the RF inflatable restraint side impact module.
  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 20 and ground.
    • If not within 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 21 and ground.
    • If not within 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 20 and ground.
    • If not within the specified range, test the control circuit for a short to ground.
  10. Ignition OFF, test for infinite resistance between the high control circuit terminal 21 and ground.
    • If not within the specified range, test the control circuit for a short to ground.
  11. Test for less than 1 ohm between the low control circuit terminal A and the SDM terminal 20.
    • If not within the specified range, test the control circuit for an open/high resistance.
  12. Test for less than 1 ohm between the high control circuit terminal B and the SDM terminal 21.
    • If not within the specified range, test the control circuit for an open/high resistance.
  13. If all circuits test normal, replace the SDM.
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