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Home >> Chevrolet >> 2020 >> Express 2500 LS, 6.0L Eng VIN G >> Repair and Diagnosis >> External Pages >> Different car >> Section 27 (Supplemental Inflatable Restraints) >> Diagnostic Information and Procedures >> DTC B0012 or B0013 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:

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

  • Driver steering wheel air bag
  • SDM
  • Driver steering wheel air bag wiring harness connector
  • SDM wiring harness connector

If the appropriate load tool adaptor can not be located, use two 3A fused jumper wires with appropriate test probe terminals to connect the harness connector to the load tool test tool.

    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.

  1. Verify that the steering wheel module connector and the CPA are engaged.
    • If the above condition is not found, make the appropriate repair.
  2. Ignition OFF, disconnect the harness connector at the driver steering wheel air bag.
  3. Install a 3A fused jumper between the J 38715-A  SIR driver/passenger load tool and the harness connector of the driver steering wheel air bag.
  4. Ignition ON, verify DTC is set as current.
    • If the DTC is not set or is set as history, cycle ignition OFF, disconnect the load tool and the jumper, reconnect the harness connector at the driver steering wheel air bag, and cycle the ignition ON. If the DTC resets after reconnecting the module, replace the driver steering wheel air bag.
  5. Ignition OFF, disconnect the load tool and the jumper.
  6. Disconnect the harness connector at the steering wheel module coil.
  7. Install a 3A fused jumper between the J 38715-A  SIR driver/passenger load tool and the harness connector of the steering wheel module coil.
  8. Ignition ON, verify the DTC is set as current.
    • If DTC is not set or is set as history, replace the steering wheel module coil.
  9. Ignition OFF, disconnect the load tool and jumper.
  10. Disconnect the harness connector at the SDM.
  11. Ignition ON, test for less than 1 volt between the appropriate high control circuit listed below and ground:
    • Steering wheel module coil harness connector - Stage 1 terminal A1 X276
    • Steering wheel module coil harness connector - Stage 2 terminal B1 X276
    • If greater than the specified range, test the control circuit for a short to voltage.
  12. Test for less than 1 volt between the appropriate low control circuit listed below and ground:
    • Steering wheel module coil harness connector - Stage 1 terminal A2 X276
    • Steering wheel module coil harness connector - Stage 2 terminal B2 X276
    • If greater than the specified range, test the control circuit for a short to voltage.
  13. Ignition OFF, test for infinite resistance between the appropriate high control circuit listed below and ground:
    • Steering wheel module coil harness connector - Stage 1 terminal A1 X276
    • Steering wheel module coil harness connector - Stage 2 terminal B1 X276
    • If less than the specified value, test the control circuit for a short to ground.
  14. Test for infinite resistance between the appropriate low control circuit listed below and ground:
    • Steering wheel module coil harness connector - Stage 1 terminal A2 X276
    • Steering wheel module coil harness connector - Stage 2 terminal B2 X276
    • If less than the specified value, test the control circuit for a short to ground.
  15. Test for less then 5 ohms between the appropriate high control circuit terminals listed below:
    • Steering wheel module coil harness connector - Stage 1 terminal A1 X276 and the SDM terminal 9
    • Steering wheel module coil harness connector - Stage 2 terminal B1 X276 and the SDM terminal 5
    • If greater than the specified range, test the control circuit for an open/high resistance.
  16. Test for less then 1 ohm between the appropriate low control circuit terminals listed below:
    • Steering wheel module coil harness connector - Stage 1 terminal A2 X276 and the SDM terminal 8
    • Steering wheel module coil harness connector - Stage 2 terminal B2 X276 and the SDM terminal 4
    • If greater that the specified range, test the control circuit for an open/high resistance.
  17. If all circuits test normal, replace the SDM.
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