Chevrolet Trax: Speaker malfunction

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/System Description

Each of the audio output channel circuits (+) and (-), at the radio and audio amplifier have a DC bias voltage that is approximately one half of battery voltage. When using a DMM, each of the audio output channel circuits will measure approximately 6.5 V 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. The frequency (Hz) of the AC voltage signal is directly related to the frequency of the input (audio source playing) to the audio system. Both the DC bias voltage and the AC voltage signals are needed for the audio system to properly produce sound.

Diagnostic Aids

• Improper speaker mounting or loose trim may cause an audible buzz or distortion. Inspect the appropriate speaker and the surrounding interior trim for proper and secure mounting.

  The EL-50334-6 Audio System Diagnostic CD contains audio tracks that can be used to duplicate and isolate such concerns. Tracks 11 and 12 contain audio sweep tones for testing for speaker and grill rattles.

  If the speaker or surrounding interior trim is found to be loose or improperly secured, correctly secure the item.

• The test tones on the CD may be copied to a USB drive or other device to use during testing.
• When equipped with an amplifier, it is possible for some individual circuit faults to affect more than one speakers operation. Perform diagnostic tests in the sequence listed to avoid misdiagnosis.
• The amplifier control circuit will measure less than 1 V when the mute function is OFF, and approximately 8 V DC when at full mute. When mute is active, the radio stops sending the varying AC voltage to the amplifier/speakers.

Reference Information

Schematic Reference

Radio/Navigation System Schematics (Encore), Radio/Navigation System Schematics (Trax)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX

Description and Operation

Radio/Audio System Description and Operation (with Monochrome Display), Radio/Audio System Description and Operation (with Color Display)

Electrical Information Reference

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

Scan Tool Reference

Control Module References for scan tool information

Special Tools

EL-50334-50 USB Cable and Adapter Kit

For equivalent regional tools, refer to Special Tools, Special Tools (MIT tool instructions).

Circuit/System Verification

Without Amplifier

1. Ignition ON, A11 radio ON, mute OFF.
2. Verify clear audio is heard from each speaker, adjusting fade and balance controls to test each speaker individually.

• If audio is inoperative from one or more speakers, or the audio emitted is not clear

Refer to Circuit/System Testing - Speaker Malfunction - without Amplifier

• If clear audio is heard from all speakers

3. All OK.

With Amplifier

1. Ignition ON, A11 radio ON, mute OFF.
2. Verify clear audio is heard from each speaker, adjusting fade and balance controls to test each speaker individually.

If audio is inoperative from one or more speakers, or the audio emitted is not clear

Refer to Circuit/System Testing - Speaker Malfunction - with Amplifier

If clear audio is heard from all speakers

3. All OK.

Circuit/System Testing

Speaker Malfunction - without Amplifier

1. Ignition OFF, disconnect the harness connector at the appropriate P19 Speaker. Ignition ON, radio ON, mute OFF.
2. Test for 5-7 V between each audio signal circuit terminal 1 and terminal 2 and ground.

If less than 5 V

1. Ignition OFF, disconnect the X1 harness connector at the A11 Radio.
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 ohms in the signal circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the A11 Radio.

If greater than 7 V

1. Ignition OFF, disconnect the X1 harness connector at the A11 Radio. 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 A11 Radio.

If between 5-7 V

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.

3. .Play track number three (50 Hz bass test tone) from the EL-50334-6 Audio Test CD.
4. Test for 49-51 Hz AC between each signal circuit terminal 1 and terminal 2 and ground.

If not between 49-51 Hz AC

Replace the A11 Radio.

If between 49-51 Hz AC

5. Test or replace the P19 Speaker.

Speaker Malfunction - with Amplifier

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 X1 harness connector at the T3 Audio Amplifier.
2. Test for less than 10 ohms between the ground circuit terminal 8 and ground.

If 10 ohms or greater

1. Ignition OFF.
2. Test for less than 2 ohms in the ground circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.

If less than 10 ohms

3. Verify that a test lamp illuminates between the B+ circuit terminal 4 and ground.

If the test lamp does not illuminate and the circuit fuse is good

1. Ignition OFF.
2. Test for less than 2 ohms in the B+ circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, refer to Power Mode Mismatch

If the test lamp does not illuminate and the circuit fuse is open

1. Ignition OFF.
2. Test for infinite resistance between the B+ circuit and ground.

• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the T3 Audio Amplifier.

If the test lamp illuminates

4. Disconnect the X3 harness connector at the T3 Audio Amplifier.
5. Verify a test lamp does not illuminate between the control circuit terminal 8 and ground.

If the test lamp illuminates

1. Disconnect the X1 harness at the A11 Radio.
2. Verify a test lamp does not illuminate between the control circuit and ground.

• If the test lamp illuminates, repair the short to voltage on the circuit.
• If the test lamp does not illuminate, replace the A11 Radio.
• If the test lamp does not illuminate

6. Ignition ON, A11 Radio ON.
7. Verify a test lamp illuminates between the control circuit terminal 8 and ground.

If the test lamp does not illuminate

1. Ignition OFF. Disconnect the X1 harness at the A11 Radio.
2. Test for less than 2 ohms in the control circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the A11 Radio.
• If the test lamp illuminates

8. Radio ON, mute ON.
9. Test for 7.5-8.5 V between the control circuit terminal 11 and ground.

• If greater than 8.5 V

1. Ignition OFF, disconnect the X1 harness connector at the A11 Radio. Ignition ON.
2. Test for less than 1 V between the control circuit and ground.

• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the A11 Radio.
• If less than 7.5 V

1. Ignition OFF, disconnect the X1 harness connector at the A11 Radio.
2. Test for infinite resistance between the control 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 ohms in the signal circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the A11 Radio.
• If between 7.5-8.5 V

10. Radio ON, mute OFF.
11. Test for less than 1 V between the control circuit terminal 11 and ground.

• If greater than 1 V

Replace the A11 Radio.

• If less than 1 V

12. Test for 5-7 V between the signal circuit terminals 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 5 V

1. Ignition OFF, disconnect the X1 harness connector at the A11 Radio.
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 ohms in the signal circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the A11 Radio.

If greater than 7 V

1. Ignition OFF, disconnect the X1 harness connector at the A11 Radio. 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 A11 Radio.
• If between 5-7 V

13. Insert the EL-50334-6 Audio Test CD from the EL-50334-50 USB cable and adapter kit. Play track number three (50 Hz bass test tone) from the test CD.
14. Test for 49-51 Hz AC between the audio signal circuit terminals 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 not between 49-51 Hz AC

Replace the A11 radio.

• If between 49-51 Hz AC

15. Ignition OFF, connect all harness connectors.
16. Disconnect the harness connector at the appropriate P19 Speaker. Ignition ON, A11 Radio ON.
17. Test for 5-7 V between the appropriate speaker signal terminals listed below and ground:

• Speaker signal (-) circuit terminal 1
• Speaker signal (+) circuit terminal 2
• If less than 5 V

1. Ignition OFF, disconnect the 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 ohms in the signal circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the T3 Audio Amplifier

If greater than 7 V

1. Ignition OFF, disconnect the 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

18. Mute OFF, play track number three (50 Hz bass test tone) from the test CD.
19. Test for 49-51 Hz AC between each signal circuit terminal and ground.

• If not between 49-51 Hz AC

Replace the T3 Audio Amplifier.

• If between 49-51 Hz AC

20. Test or replace the P19 Speaker.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

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

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