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Home >> Cadillac >> 2009 >> CTS Base, 3.6 7, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 94 (Cellular System, Entertainment System & Navigation System) >> Diagnostic Information and Procedures >> Speaker Malfunction >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page is about a different car, the 2009 Buick Lucerne. However, it is still accessible from the selected car via links, so may be relevant.

Speaker Circuit Malfunction - without Amplifier

  1. Ignition OFF, disconnect the harness connector at the appropriate speaker.
  2. Radio ON, test for 5.0-7.5 volts between the signal circuit terminal A 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.
    • 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.
  3. Test for 5.0-7.5 volts between the signal circuit terminal B 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.
    • 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.
  4. If all circuits test normal, replace the appropriate speaker.

Amplifier Circuit Malfunction

  1. Ignition OFF, disconnect the X1 harness connector at the amplifier.
  2. Test for less than 10 ohms of resistance between the ground circuit terminal 4 and ground.
    • If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Ignition ON, verify 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. If the circuit tests normal and the circuit fuse is open, replace the amplifier.
  4. Disconnect the X3 harness connector at the amplifier.
  5. Radio ON, test for 0.5-1.0 volts between the signal circuit terminal 6 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.
    • 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.
  6. Verify a test lamp illuminates between the signal circuit terminal 13 and ground.
    • If the test lamp does not illuminate, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio.
  7. If all circuits test normal, replace the amplifier.

Speaker Circuit Malfunction with Amplifier

  1. Ignition OFF, disconnect the X3 harness connector at the amplifier.
  2. Radio ON, test for 5.0-7.5 volts between the appropriate signal circuit terminal listed below and ground.
    • Left front low level audio signal (-) - terminal 1
    • Left front low level audio signal (+) - terminal 9
    • Right front low level audio signal (-) - terminal 2
    • Right front low level audio signal (+) - terminal 10
    • Left rear low level audio signal (-) - terminal 3
    • Left rear low level audio signal (+) - terminal 11
    • Right rear low level audio signal (-) - terminal 4
    • Right rear low level audio signal (+) - terminal 12
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio.
    • 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.
  3. Ignition OFF, disconnect the X1 and X2 harness connectors at the amplifier.
  4. Ignition ON, test for less than 1 volt between each of the signal circuit terminals listed below and ground.
    • Left rear shelf speaker output (-) - terminal 2 X1
    • Left rear shelf speaker output (+) - terminal 6 X1
    • Right rear shelf speaker output (-) - terminal 3 X1
    • Right rear shelf speaker output (+) - terminal 7 X1
    • Front center speaker output (-) - terminal 6 X2
    • Front center speaker output (+) - terminal 14 X2
    • Left front speaker output (-) - terminal 2 X2
    • Left front speaker output (+) - terminal 10 X2
    • Right front speaker output (-) - terminal 3 X2
    • Right front speaker output (+) - terminal 11 X2
    • Left rear door speaker output (-) - terminal 4 X2
    • Left rear door speaker output (+) - terminal 12 X2
    • Right rear door speaker output (-) - terminal 5 X2
    • Right rear door speaker output (+) - terminal 13 X2
    • If greater than the specified range, test both signal circuits of the affected speaker for a short to voltage.
  5. Ignition OFF, test for infinite resistance between each of the signal circuit terminals listed below and ground.
    • Left rear shelf speaker output (-) - terminal 2 X1
    • Left rear shelf speaker output (+) - terminal 6 X1
    • Right rear shelf speaker output (-) - terminal 3 X1
    • Right rear shelf speaker output (+) - terminal 7 X1
    • Front center speaker output (-) - terminal 6 X2
    • Front center speaker output (+) - terminal 14 X2
    • Left front speaker output (-) - terminal 2 X2
    • Left front speaker output (+) - terminal 10 X2
    • Right front speaker output (-) - terminal 3 X2
    • Right front speaker output (+) - terminal 11 X2
    • Left rear door speaker output (-) - terminal 4 X2
    • Left rear door speaker output (+) - terminal 12 X2
    • Right rear door speaker output (-) - terminal 5 X2
    • Right rear door speaker output (+) - terminal 13 X2
    • If less than the specified range, test both signal circuits of the affected speaker for a short to ground.
  6. Reconnect all harness connectors at the amplifier. Disconnect the harness connector at the appropriate speaker.
  7. Radio ON, test for 5.0-7.5 volts between each of the appropriate signal circuit terminals listed below and ground.
    • Center IP speaker - terminals A and B
    • Door speakers - terminals A and B
    • Front tweeter speakers - terminals A and B
    • Rear shelf speakers - terminals A and B
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the audio amplifier.
    • 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 audio amplifier.
  8. If all circuits test normal, replace the appropriate speaker.
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