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Home >> Cadillac >> 2009 >> SRX 3.6 7, AWD >> Repair and Diagnosis >> Accessories & Equipment >> Entertainment Systems >> Cellular System, Entertainment System & Navigation System >> Diagnostic Information and Procedures >> Radio Poor Reception >> Circuit/System Testing

Circuit/System Testing

  1. Inspect the radio antennas and antenna leads for damage.
    • If damage is found, repair or replace as necessary.
  2. Inspect each radio antenna module grounding surface and the mounting hardware for any corrosion that may cause a poor ground.
    • If corrosion is noted, clean the grounding surfaces and hardware.
  3. Ignition OFF, disconnect the X1 harness connector at the left radio antenna module.
  4. Radio ON, test for B+ between the signal circuit terminal 1 and ground.
    • If less than the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio.
  5. Ignition OFF, connect the harness connector at the left antenna module.
  6. Disconnect the X1 harness connector at the right antenna module.
  7. Radio tuned to FM, test for 4.5 - 8.5 volts on the FM composite signal terminal 1.
    • If less than specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the radio.
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio.
  8. Radio tuned to AM, test for less than 1 volt on the FM composite signal terminal 1
    • 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, connect the harness connector at the right antenna module.
  10. Disconnect the coax cable from the left antenna module.
  11. Ignition ON, radio tuned to FM, test for 4.5 - 8.5 volts between the center terminal and the outer shield.
    • If greater than the specified range, test the coax for a short to voltage. If the circuit tests normal, replace the right antenna module.
    • If less than specified range, test the coax for a short to ground or an open/high resistance. If the circuit tests normal, replace the right antenna module.
  12. Ignition ON, radio tuned to AM, test for less than 1 volt between the center terminal and the outer shield.
    • If greater than the specified range, test the coax for a short to voltage. If the circuit tests normal, replace the right antenna module.
    13. NOTE: For steps 13-17, perform the tests on the disconnected coax cable between the radio and the right antenna module.
  13. Ignition OFF, disconnect the coax cable at the radio and right antenna module.
  14. Test for infinite resistance between the antenna coax center terminal and ground.
    • If less than the specified value, replace the antenna coax.
  15. Test for less than 5 ohms on the antenna coax center terminal from end to end.
    • If greater than the specified range, replace the antenna coax.
  16. Test for less than 5 ohms on the antenna coax outer shield from end to end.
    • If greater than the specified range, replace the antenna coax.
  17. Test for infinite resistance between the coax center terminal and the outer shield.
    • If less than the specified value, replace the antenna coax.
  18. Ignition ON, radio ON, verify the radio reception has improved.
    • If there is still poor reception, replace the left antenna module.
  19. If all circuits test normal, replace the radio.
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