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Circuit/System Testing

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2011 GMC Yukon XL, 2011 GMC Yukon, 2011 Chevrolet Tahoe, 2011 Chevrolet Suburban, and 2011 Chevrolet Avalanche. 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 speaker.

Amplifier Circuit Malfunction

  1. Ignition OFF, disconnect the X1 harness connector at the audio amplifier.
  2. Ignition OFF, test for less than 10 ohms between the ground circuit terminal 8 and ground.
    • If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Ignition ON, test for B+ between the B+ circuit terminal 4 and ground.
    • If less then specified value, test the circuit for a short to ground, or an open/high resistance.
  4. Ignition OFF, disconnect the X3 harness connector at the audio amplifier.
  5. For vehicles without RPO code Y91 only: Radio ON, test for B+ between the remote enable signal circuit terminal 8 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.
  6. If all circuits test normal, replace the audio amplifier.

Speaker Malfunction Radio Output Testing UQA

  1. Ignition OFF, disconnect the X3 harness connector at the audio 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 15
    • Left front low level audio signal (-) - terminal 7
    • Right front low level audio signal (+) - terminal 14
    • Right front low level audio signal (-) - terminal 6
    • Left rear low level audio signal (+) - terminal 13
    • Left rear low level audio signal (-) - terminal 5
    • Right rear low level audio signal (+) - terminal 12
    • Right rear low level audio signal (-) - terminal 4
    • 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.
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio.
  3. If all circuits test normal, replace the audio amplifier.

Speaker Malfunction Radio Output Testing UQS or UQA with Y91

  1. Ignition OFF, disconnect the X3 and X4 harness connectors at the audio 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 11 X3
    • Left front low level audio signal (-) - terminal 12 X3
    • Right front low level audio signal (+) - terminal 3 X3
    • Right front low level audio signal (-) - terminal 4 X3
    • Left rear low level audio signal (+) - terminal 11 X4
    • Left rear low level audio signal (-) - terminal 12 X4
    • Right rear low level audio signal (+) - terminal 3 X4
    • Right rear low level audio signal (-) - terminal 4 X4
    • Subwoofer low level audio signal (+) - terminal 5 X4
    • Subwoofer low level audio signal (-) - terminal 6 X4
    • Center Channel low level audio signal (+) - terminal 13 X4
    • Center Channel low level audio signal (-) - terminal 14 X4
    • 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.
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio.
  3. If all circuits test normal, replace the audio amplifier.

Speaker Malfunction Radio Output Testing UQA with U42

  1. Ignition OFF, disconnect the X3 harness connector at the audio 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 15
    • Left front low level audio signal (-) - terminal 7
    • Right front low level audio signal (+) - terminal 14
    • Right front low level audio signal (-) - terminal 6
    • 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.
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio.
  3. Ignition OFF, reconnect the X3 harness connector at the audio amplifier.
  4. Disconnect the X2 harness connector at the rear seat audio (RSA) module.
  5. Radio ON, test for 5.0-7.5 volts between the appropriate signal circuit terminal listed below and ground.
    • Left rear low level audio signal (+) - terminal 1
    • Left rear low level audio signal (-) - terminal 2
    • Right rear low level audio signal (+) - terminal 3
    • Right rear low level audio signal (-) - terminal 4
    • 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 rear seat audio (RSA) module.
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the rear seat audio (RSA) module.
  6. Ignition OFF, reconnect the X2 harness connector at the rear seat audio (RSA) module.
  7. Disconnect the X3 harness connector at the audio amplifier.
  8. Radio ON, test for 5.0-7.5 volts between the appropriate signal circuit terminal listed below and ground.
    • Left rear low level audio signal (+) - terminal 13
    • Left rear low level audio signal (-) - terminal 5
    • Right rear low level audio signal (+) - terminal 12
    • Right rear low level audio signal (-) - terminal 4
    • 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 rear seat audio (RSA) module.
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the rear seat audio (RSA) module.
  9. If all circuits test normal, replace the audio amplifier.

Speaker Malfunction Radio Output Testing UQA with Y91 or UQS

  1. Ignition OFF, disconnect the X3 and X4 harness connectors at the audio 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 11 X3
    • Left front low level audio signal (-) - terminal 12 X3
    • Right front low level audio signal (+) - terminal 3 X3
    • Right front low level audio signal (-) - terminal 4 X3
    • Left rear low level audio signal (+) - terminal 11 X4
    • Left rear low level audio signal (-) - terminal 12 X4
    • Right rear low level audio signal (+) - terminal 3 X4
    • Right rear low level audio signal (-) - terminal 4 X4
    • Subwoofer low level audio signal (+) - terminal 5 X4
    • Subwoofer low level audio signal (-) - terminal 6 X4
    • Center Channel low level audio signal (+) - terminal 13 X4
    • Center Channel low level audio signal (-) - terminal 14 X4
    • 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.
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio.
  3. If all circuits test normal, replace the audio amplifier.

Speaker Malfunction Radio Output Testing UQA with Y91 and with U42 or UQS with U42

  1. Ignition OFF, disconnect the X3 and X4 harness connector at the audio 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 11 X3
    • Left front low level audio signal (-) - terminal 12 X3
    • Right front low level audio signal (+) - terminal 3 X3
    • Right front low level audio signal (-) - terminal 4 X3
    • Subwoofer low level audio signal (+) - terminal 5 X4
    • Subwoofer low level audio signal (-) - terminal 6 X4
    • Center Channel low level audio signal (+) - terminal 13 X4
    • Center Channel low level audio signal (-) - terminal 14 X4
    • 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.
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio.
  3. Ignition OFF, reconnect the X3 harness connector at the audio amplifier.
  4. Disconnect the X2 harness connector at the rear seat audio (RSA) module.
  5. Radio ON, test for 5.0-7.5 volts between the appropriate signal circuit terminal listed below and ground.
    • Left rear low level audio signal (+) - terminal 1
    • Left rear low level audio signal (-) - terminal 2
    • Right rear low level audio signal (+) - terminal 3
    • Right rear low level audio signal (-) - terminal 4
    • 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 rear seat audio (RSA) module.
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the rear seat audio (RSA) module.
  6. Ignition OFF, reconnect the X2 harness connector at the rear seat audio (RSA) module.
  7. Disconnect the X2 harness connector at the audio amplifier.
  8. Radio ON, test for 5.0-7.5 volts between the appropriate signal circuit terminal listed below and ground.
    • Left rear low level audio signal (+) - terminal 15
    • Left rear low level audio signal (-) - terminal 14
    • Right rear low level audio signal (+) - terminal 16
    • Right rear low level audio signal (-) - terminal 8
    • 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 rear seat audio (RSA) module.
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the rear seat audio (RSA) module.
  9. If all circuits test normal, replace the audio amplifier.

Speaker Malfunction Amplifier Output Testing UQA

  1. Ignition OFF, disconnect the X1 and X2 connectors at the audio amplifier.
  2. Radio ON, test for less than 1 volt between the appropriate signal circuit terminal listed below and ground:
    • Left front speaker output (+) - terminal 4 X2
    • Left front speaker output (-) - terminal 3 X2
    • Right front speaker output (+) - terminal 2 X2
    • Right front low speaker output (-) - terminal 1 X2
    • Left rear speaker output (+) - terminal 8 X2
    • Left rear speaker output (-) - terminal 7 X2
    • Right rear speaker output (+) - terminal 6 X2
    • Right rear speaker output (-) - terminal 5 X2
    • Left or rear subwoofer speaker output (+) - terminal 7 X1
    • Left or rear subwoofer speaker output (-) - terminal 3 X1
    • Right subwoofer speaker output (+) - terminal 6 X1
    • Right subwoofer speaker output (-) - terminal 2 X1
    • If greater than the specified range, test both circuits of the affected speaker for a short to voltage.
  3. Radio OFF, test for infinite resistance between the appropriate signal circuit terminal listed below and ground:
    • Left front speaker output (+) - terminal 4 X2
    • Left front speaker output (-) - terminal 3 X2
    • Right front speaker output (+) - terminal 2 X2
    • Right front low speaker output (-) - terminal 1 X2
    • Left rear speaker output (+) - terminal 8 X2
    • Left rear speaker output (-) - terminal 7 X2
    • Right rear speaker output (+) - terminal 6 X2
    • Right rear speaker output (-) - terminal 5 X2
    • Left or rear subwoofer speaker output (+) - terminal 7 X1
    • Left or rear subwoofer speaker output (-) - terminal 3 X1
    • Right subwoofer speaker output (+) - terminal 6 X1
    • Right subwoofer speaker output (-) - terminal 2 X1
    • If less than the specified range, test both circuits of the affected speaker for a short to ground.
  4. If all circuits test normal, reconnect all harness connectors at the audio amplifier.
  5. Radio ON, disconnect the appropriate speaker.
  6. Test for 5.0-7.5 volts between the signal circuit terminals and ground.
    • If less then the specified range test the circuit for an open/high resistance. If the circuit tests normal, replace the amplifier.
    • If greater then the specified range test the circuit for a short to voltage. If the circuit tests normal, replace the audio amplifier.
  7. If the circuit tests normal, replace the appropriate speaker.

Speaker Malfunction Amplifier Output Testing UQA with Y91 or UQS

  1. Ignition OFF, disconnect the X1 and X2 connectors at the audio amplifier.
  2. Radio ON, test for less than 1 volt between the appropriate signal circuit terminal listed below and ground:
    • Left front speaker output (+) - terminal 4 X2
    • Left front speaker output (-) - terminal 5 X2
    • Right front speaker output (+) - terminal 7 X2
    • Right front speaker output (-) - terminal 6 X2
    • Left rear speaker output (+) - terminal 15 X2
    • Left rear speaker output (-) - terminal 14 X2
    • Right rear speaker output (+) - terminal 16 X2
    • Right rear speaker output (-) - terminal 8 X2
    • Front center speaker output (+) - terminal 13 X2
    • Front center speaker output (-) - terminal 12 X2
    • Right rear midrange speaker output (+) - terminal 3 X2
    • Right rear midrange speaker output (-) - terminal 2 X2
    • Left rear midrange speaker output (+) - terminal 11 X2
    • Left rear midrange speaker output (-) - terminal 10 X2
    • Left or rear subwoofer speaker output (+) - terminal 1 X1
    • Left or rear subwoofer speaker output (-) - terminal 2 X1
    • Right subwoofer speaker output (+) - terminal 7 X1
    • Right subwoofer speaker output (-) - terminal 3 X1
    • If greater than the specified range, test both circuits of the affected speaker for a short to voltage.
  3. Radio OFF, test for infinite resistance between the appropriate signal circuit terminal listed below and ground:
    • Left front speaker output (+) - terminal 4 X2
    • Left front speaker output (-) - terminal 5 X2
    • Right front speaker output (+) - terminal 7 X2
    • Right front speaker output (-) - terminal 6 X2
    • Left rear speaker output (+) - terminal 15 X2
    • Left rear speaker output (-) - terminal 14 X2
    • Right rear speaker output (+) - terminal 16 X2
    • Right rear speaker output (-) - terminal 8 X2
    • Front center speaker output (+) - terminal 13 X2
    • Front center speaker output (-) - terminal 12 X2
    • Right rear midrange speaker output (+) - terminal 3 X2
    • Right rear midrange speaker output (-) - terminal 2 X2
    • Left rear midrange speaker output (+) - terminal 11 X2
    • Left rear midrange speaker output (-) - terminal 10 X2
    • Left or rear subwoofer speaker output (+) - terminal 1 X1
    • Left or rear subwoofer speaker output (-) - terminal 2 X1
    • Right subwoofer speaker output (+) - terminal 7 X1
    • Right subwoofer speaker output (-) - terminal 3 X1
    • If less than the specified range, test both circuits of the affected speaker for a short to ground.
  4. If all circuits test normal, reconnect all harness connectors at the audio amplifier.
  5. Radio ON, disconnect the appropriate speaker.
  6. Test for 5.0-7.5 volts between the signal circuit terminals and ground.
    • If less then the specified range test the circuit for an open/high resistance. If the circuit tests normal, replace the audio amplifier.
    • If greater then the specified range test the circuit for a short to voltage. If the circuit tests normal, replace the audio amplifier.
  7. If the circuit tests normal, replace the appropriate speaker.
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