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For 1990-2009 cars only
Makes 🢒 Buick 🢒 2007 🢒 Allure 🢒 Diagnostic Navigation 🢒 Vehicle Diagnostic Information 🢒 Speakers Inoperative - One or More

Diagnostic Instructions
    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Low Level Audio Signal (+)

B1025

1

B1025

--

Low Level Audio Signal (-)

B1025

1

B1025

--

Speaker Output Signal (+)

1

1

1

--

Speaker Output Signal (-)

1

1

1

--

1. No or reduced sound from speaker

Circuit/System Description

Each of the audio output channel circuits (+) and (-), at the radio and at the amplifier (if equipped) have a DC bias voltage that is one half of the battery voltage. When using a DMM, each of the audio output channel circuits will measure approximately 6.5V DC. The audio being played on the system is produced by a varying AC voltage that is centered around the DC bias voltage on the same circuit. The AC voltage is what causes the speaker cone to move and produce sound. This voltage will vary depending on what type of audio is being listened to, talk or music, and type of music, as well as the volume setting of the system. Low volume and talk settings will measure around 1V AC and less, where constant music may measure 3V AC and slightly higher. In an amplified audio system, these similar AC voltage measurements may be slightly higher on the output of the amplifier.

Reference Information

Schematic Reference

Radio/Navigation System Schematics

Connector End View Reference

Entertainment/Communication Connector End Views

Description and Operation

Radio/Audio System Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Circuit/System Verification

Without Amplifier

Radio ON, verify clear audio is heard from each audio speaker.

⇒If audio is inoperative from all speakers, replace the radio.
⇒If audio is inoperative from one or more, but not all, speakers or the audio emitted from the speakers is not clear, refer to Speaker Circuit Malfunction - without Amplifier.

With Amplifier

Radio ON, verify clear audio is heard from each audio speaker.

⇒If audio is inoperative from all speakers, refer to Amplifier Circuit Malfunction.
⇒If audio is inoperative from one or more, but not all, speakers or the audio emitted from the speakers is not clear, refer to Speaker Circuit Malfunction - with Amplifier.

Circuit/System Testing

Speaker Circuit Malfunction - without Amplifier

  1. Ignition OFF, inspect the appropriate speaker and the surrounding interior trim for proper and secure mounting. Improper speaker mounting or loose trim may cause an audible buzz or distortion.
    2. ⇒If the speaker or surrounding interior trim is found to be loose or improperly secured, correctly secure the item.
  2. Disconnect the harness connector at the appropriate speaker.
  3. Radio ON, test for 5.0-7.5 volts between the signal circuit terminal A and ground.
    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.
  4. Test for 5.0-7.5 volts between the signal circuit terminal B and ground.
    5. ⇒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.
  5. If all circuits test normal, replace the speaker.

Amplifier Circuit Malfunction

  1. Ignition OFF, disconnect the C1 harness connector at the amplifier.
  2. Test for less than 10 ohms between the ground circuit terminal 2 and ground.
    3. ⇒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 1 and ground.
    4. ⇒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 C3 harness connector at the amplifier.
  5. Radio ON, verify a test lamp illuminates between the signal circuit terminal 6 and ground.
    6. ⇒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.
  6. If all circuits test normal, replace the amplifier.

Speaker Circuit Malfunction - with Amplifier

  1. Ignition OFF, inspect the appropriate speaker and the surrounding interior trim for proper and secure mounting. Improper speaker mounting or loose trim may cause an audible buzz or distortion.
    2. ⇒If the speaker or surrounding interior trim is found to be loose or improperly secured, correctly secure the item.
  2. Disconnect the C3 harness connector at the amplifier.
  3. Radio ON, test for 5.0-7.5 volts between the appropriate signal circuit terminals listed below and ground.
    4. • Left front - Terminal 1
    • Right front - Terminal 10
    • Left rear - Terminal 4
    • Right rear - Terminal 11
    ⇒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.
  4. Radio ON, test for 5.0-7.5 volts between the appropriate signal circuit terminal listed below and ground.
    5. • Left front - Terminal 2
    • Right front - Terminal 9
    • Left rear - Terminal 3
    • Right rear - Terminal 12
    ⇒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.
  5. Ignition OFF, connect the C3 harness connectors at the amplifier. Disconnect the harness connector at the appropriate speaker.
  6. Radio ON, test for 5.0-7.5 volts between the signal circuit terminal A and ground.
    7. ⇒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 amplifier.
    ⇒If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the amplifier.
  7. Test for 5.0-7.5 volts between the signal circuit terminal Band ground.
    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 amplifier.
    ⇒If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the amplifier.
  8. If all circuits test normal, replace the speaker.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Speaker Replacement Reference
    •  Control Module References for amplifier or radio replacement, setup, and programming