LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2004 >> Impala SS >> Repair and Diagnosis >> External Pages >> Different car >> Section 919 (Lighting System) >> Diagnostic Information and Procedures >> DTC B3948 or B3949 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2010 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the harness connector at the appropriate turn signal lamp.
  2. Ignition OFF, exterior lamps OFF, test for less than 5 ohms between the appropriate ground circuit terminal listed below and ground.
    • Left front turn signal ground terminal B
    • Left front park/turn signal ground terminal G
    • Right front turn signal ground terminal B
    • Right front park/turn signal ground terminal G
    • If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Connect a test lamp between the control circuit terminal A and ground.
  4. Command the appropriate front Turn Lamp ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
    • If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
    • If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
  5. If all circuits test normal, test or replace the appropriate turn signal lamp assembly.
scientia non olet · About LEMON Manuals