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Home >> Cadillac >> 2006 >> STS Base, 4.6 A, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 770 (Cellular System, Entertainment System, And Navigation System) >> Diagnostic Information and Procedures >> Radio Information Display Malfunction (Without 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, disconnect the harness connector at the radio/HVAC controls.
  2. Test for less than 10 Ω between the ground circuit terminal 16and ground.
    • If greater than the specified range, test the ground for an open/high resistance.
  3. Test for less than 20 Ω between the data shield circuit terminal 3 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 A11 radio.
  4. Verify that a test lamp illuminates between the B+ circuit terminal 8 and ground.
    • If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  5. Ignition ON, test for 2-3 V between the data circuit terminal 1 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.
  6. Ignition ON, test for 2-3 V between the data circuit terminal 2 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.
  7. Test for less than 1 V between the wake signal terminal 4 and ground.
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio.
  8. Test for less than 1 V between the reset signal terminal 11 and ground.
    • If greater than the specified range, test the signal 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 controls.
  10. Disconnect the X1 harness connector at the A11 radio.
  11. Test for 4.5-5.5 V between the signal circuit terminal 27 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 controls.
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio/HVAC controls.
  12. Test for 4.5-5.5 V between the signal circuit terminal 13 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 controls.
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio/HVAC controls.
  13. If all circuits test normal, replace the radio/HVAC controls. Reconnect all harness connectors.
  14. Ignition ON, radio ON, verify the display turns on and information is shown on the display.
    • If the display still malfunctions, replace the radio.
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