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Home >> Chevrolet >> 2009 >> Impala SS >> Repair and Diagnosis >> External Pages >> Different car >> Section 956 (Data Communication System) >> Diagnostic Information and Procedures >> Scan Tool Does Not Power Up >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page is about a different car, the 2008 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition ON, verify a test lamp illuminates between the battery positive voltage circuit terminal 16 of the DLC and ground.
    • If the test lamp does not illuminate, test the voltage supply circuit for a short to ground or an open/high resistance.
  2. Test for less than 2.0 ohms of resistance between the ground circuits terminal 4 of the DLC and ground, and terminal 5 of the DLC and ground.
    • If greater than specified, repair the ground circuit for an open/high resistance.
  3. If all circuits test normal, refer to the scan tool/CANdi module user guide.