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Home >> Cadillac >> 2007 >> CTS Base, 2.8 T, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 113 (Cellular System, Entertainment System, And Navigation System) >> Diagnostic Information and Procedures >> Reduced Volume - One or More Speakers >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page is about a different car, the 2007 Cadillac SRX. However, it is still accessible from the selected car via links, so may be relevant.

Without Amplifier

  1. Center the balance and fade adjustment on the radio.
    • If adjustment of the fade and balance eliminates the concern, review the operation of the radio with the customer.
  2. Connect a DMM between the suspect low level audio signal circuits.
  3. Turn ON the radio and use the CD Diagnostic kit or tune the radio to a channel with no reception (static). Record the AC voltage of the suspect speaker channel and compare and verify the AC voltage output of the suspect low level audio signal is the same as the opposite low level channel.
    • If the suspect speaker channel low level audio signal AC voltage is lower than other channels, replace the radio.
    • If the recorded AC voltage is the same level as other speaker low level audio signal AC outputs, replace the suspect speaker.

With Amplifier

  1. Center the balance and fade adjustment on the radio.
    • If adjustment of the fade and balance eliminates the concern, review the operation of the radio with the customer.
  2. Disconnect the harness connector containing the low level audio circuits at the amplifier. Connect a DMM between the suspect low level audio signal circuits. Turn ON the radio and record the AC voltage of the suspect speaker channel. Compare and verify the AC voltage output of the suspect low level audio signal is the same as opposite low level channel.
    • If the suspect speaker channel low level audio signal AC voltage is lower than other channels, replace the radio.
  3. Reconnect the harness connector containing the low level audio circuits and disconnect the harness connector at the individual speakers. Connect a DMM between the suspect speaker signal circuits. With Turn ON the radio and record the AC voltage of the suspect speaker channel. Compare and verify the AC voltage output of the suspect speaker signal is similar to other speakers.
    • If the suspect channel speaker signal AC voltage is lower than other channels, replace the amplifier.
    • If the recorded AC voltage is the same level as other speaker signal AC outputs, replace the suspect speaker.
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