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Home >> GMC >> 2017 >> Acadia SL >> Repair and Diagnosis >> External Pages >> Different car >> Section 189 (Cellular System, Entertainment System, And Navigation System - Diagnostic Information And Procedures) >> Diagnostic Information and Procedures >> DTC B1025-B1135: Audio Output Circuits (UQA with LF4) >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2017 Cadillac ATS. However, it is still accessible from the selected car via links, so may be relevant.
    NOTE:

    In the following tests, audio signal frequencies (Hz) will be tested. To prevent misdiagnosis, the door chime must be OFF during testing. Ensure the driver door latch is closed during testing.

  1. Ignition OFF, disconnect the harness connector at the appropriate P19 speaker. Ignition ON, infotainment system ON, mute OFF.
  2. Test for 5-7 V between the appropriate signal circuit terminals listed below and ground.
    • Door, Tweeter, and Center I/P speakers audio (-) circuit terminal 1
    • Door, Tweeter, and Center I/P speakers audio (+) circuit terminal 2
    • Subwoofer and Rear Trim Panel speakers audio (-) circuit terminal A
    • Subwoofer and Rear Trim Panel speakers audio (+) circuit terminal B
    • If less than 5 V 
    1. Ignition OFF, disconnect the X1 and X2 harness connectors at the T3 audio amplifier.
    2. Test for infinite resistance between the signal circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. Test for less than 2 Ω in the signal circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the T3 audio amplifier.
    • If greater than 7 V 
    1. Ignition OFF, disconnect the X1 and X2 harness connectors at the T3 audio amplifier. Ignition ON.
    2. Test for less than 1 V between the signal circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the T3 audio amplifier.
    • If between 5-7 V 
  3. Mute OFF, play track number three (50 Hz bass test tone) from the test CD.
  4. Test for 49-51 Hz AC between the appropriate signal circuit terminals listed below and ground.
    • Door, Tweeter, and Center I/P speakers audio (-) circuit terminal 1
    • Door, Tweeter, and Center I/P speakers audio (+) circuit terminal 2
    • Subwoofer and Rear Quarter speakers audio (-) circuit terminal A
    • Subwoofer and Rear Quarter speakers audio (+) circuit terminal B
    • If not between 49-51 Hz AC 

      Replace the T3 audio amplifier.

    • If between 49-51 Hz AC 
  5. Test or replace the P19 speaker.
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