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Home >> Chevrolet >> 2012 >> Traverse LS, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 8 (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 Cadillac SRX. 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. Test for less than 30 Ω between the ground circuit terminal listed below and ground.
    • E4Y turn signal repeater lamp-left terminal 2
    • E4Z turn signal repeater lamp-right terminal 2
    • If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Disconnect the inline harness connector at the appropriate E4LF turn signal lamp-front listed below:
    • E4LF turn signal lamp-left front X115 (Without TT6/TT7/TT8)
    • E4LF turn signal lamp-left front X111 (With TT6/TT7/TT8)
    • E4RF turn signal lamp-right front X116 (Without TT6/TT7/TT8)
    • E4RF turn signal lamp-right front X112 (With TT6/TT7/TT8)
  4. Connect a test lamp between the control circuit terminal listed below and ground.
    • E4LF turn signal lamp-left front terminal J
    • E4RF turn signal lamp-right front terminal J
    • E4Y turn signal repeater lamp-left terminal 1
    • E4Z turn signal repeater lamp-right terminal 1
  5. Command the appropriate Turn Signal 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 K9 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 K9 BCM.
  6. If all circuits test normal, replace the turn signal lamp.