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Home >> Cadillac >> 2009 >> STS V >> Repair and Diagnosis >> External Pages >> Different car >> Section 757 (Cellular System, Entertainment System, And Navigation System) >> Diagnostic Information and Procedures >> Radio Information Display Malfunction (With Navigation) >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page is about a different car, the 2013 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, verify the video interface cable is properly connected at the display X3 and radio X5 connections and there is no damage to the cable or connections.
    • Perform the appropriate repair or replacement to correct any issues found with the video interface cable or it's connections.
  2. Ignition OFF, disconnect the X1 harness connector at the Radio/HVAC Display.
  3. Test for less than 10 Ω between the ground circuit terminal 2 and ground.
    • If greater than the specified range, test the ground for an open/high resistance.
  4. Test for less than 20 Ω between the data shield circuit terminal 6 and ground.
    • If greater than the specified range, test the data shield circuit for an open/high resistance. If the circuit tests normal, replace the radio.
  5. Verify that a test lamp illuminates between the B+ circuit terminal 1 and ground.
    • If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  6. Ignition ON, radio ON, verify that a test lamp illuminates between the entertainment remote enable circuit terminal 4 and ground.
    • If the test lamp does not illuminate, test the remote enable circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio.
  7. Test for 2-3 V between the data circuit terminal 7 and ground.
    • If less than the specified range, test the data circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio.
    • If greater than the specified range, test the data circuit for a short to voltage. If the circuit tests normal, replace the radio.
  8. Test for 2-3 V between the data circuit terminal 8 and ground.
    • If less than the specified range, test the data circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio.
    • If greater than the specified range, test the data circuit for a short to voltage. If the circuit tests normal, replace the radio.
  9. Ignition OFF, reconnect the harness connector at the Radio/HVAC Display.
  10. Disconnect the X4 harness connector at the radio.
  11. Ignition ON, test for 4.5-5.5 V between the display reset signal circuit terminal 10 and ground.
    • If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the Radio/HVAC Display.
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the Radio/HVAC Display.
  12. If all circuits test normal, replace the video interface cable. Reconnect all harness connectors.
  13. Ignition ON, radio ON, verify the Radio/HVAC Display turns on and information is shown on the display.
    • If the information display still malfunctions, replace the Radio/HVAC Display. Ignition ON, radio ON, verify the Radio/HVAC Display turns on and information is shown on the display. If the Radio/HVAC Display still malfunctions, replace the radio.
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