No Sound Is Heard From One of the Speakers. [Vehicles With Audio Amplifier]

Inspection Procedure 3: No sound is heard from one of the speakers. [Vehicles with audio amplified

CAUTION: Before replacing the radio and CD player or audio amplifier, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.

Speaker System Circuit (Part 1):

Speaker System Circuit (Part 2):

Speaker System Circuit (Part 3):

TECHNICAL DESCRIPTION (COMMENT)

If the sound is not heard from one of the speakers, the speaker, radio and CD player, audio amplifier, communication line from the radio and CD player to the audio amplifier, or communication line from the audio amplifier to the speaker may have a problem. Also, the option coding information may be inconsistent.

TROUBLESHOOTING HINTS

- Speaker may be defective
- Radio and CD player may be defective
- Audio amplifier may be defective
- Option coding information inconsistency
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A

STEP 1. ETACS-ECU coding data check.

1. Operate scan tool MB991958 to read the ETACS-ECU option coding information (Refer to Coding Table). How to Perform Vehicle Identification Number (VIN) Writing
2. Check that the "Number of speaker" is set to "Premium."

Q: Is the check result normal?

YES : Go to Step 2.

NO : Operate scan tool MB991958 to set the option coding "Number of speaker" to "Premium," and check the trouble symptom.

STEP 2. Checking with speaker test

Perform the speaker test, and check which speaker does not output the sound. Testing and Inspection

NOTE: In the following procedure, check the speaker or tweeter that is abnormal.

Q: Is the check result normal?

YES : The trouble can be an intermittent malfunction. (Refer to How to use Troubleshooting/inspection sevice points - How to cope with Intermittent Malfunction).

NO : Go to Step 3.

STEP 3. Check door speaker connector E-13 [front-LH], E-11 [front-RH], E-24 [rear-LH] or E-23 [rear-RH], or tweeter connector E-02 [LH] or E-04 [RH], or sub woofer connector F-22 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is door speaker connector E-13 [front-LH], E-11 [front-RH], E-24 [rear-LH] or E-23 [rear-RH], or tweeter connector E-02 [LH] or E-04 [RH], or sub woofer connector F-22 in good condition?

YES : Go to Step 4.

NO : Repair or replace the damaged component(s).

STEP 4. Check the speaker, tweeter or subwoofer.

1. Remove the speaker, tweeter or subwoofer.
2. Check that the speaker or tweeter outputs the noise when the voltage of 5 V is applied to the speaker or tweeter connector terminal. [speaker or tweeter]
3. Check that the subwoofer outputs the noise when the voltage of 5 V is applied to the subwoofer connector terminal. [subwoofer]

Q: Is the check result normal?

YES : Go to Step 5.

NO : Replace the speaker, tweeter or subwoofer.

STEP 5. Check audio amplifier connector D-25 [front door speaker or sub woofer] or D-26 [rear door speaker or tweeter] for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is audio amplifier connector D-25 [front door speaker or sub woofer] or D-26 [rear door speaker or tweeter] in good condition?

YES : Go to Step 6.

NO : Repair or replace the damaged component.

STEP 6. Check the wiring harness between the speaker, tweeter or sub woofer connector terminal and the audio amplifier connector terminal.

Check the communication lines for open circuit and short circuit.

- [Front door speaker (LH)] Check the wiring harness between front door speaker (LH) connector E-13 (terminal 1, 2) and audio amplifier connector D-25 (terminal 28, 38).

NOTE: Also check intermediate connectors C-22 and C-125 for loose, corroded, or damaged terminals, or terminals pushed back in the connector If intermediate connector C-22 or C-125 is damaged, repair or replace the connector.

- [Front door speaker (RH)] Check the wiring harness between front door speaker (RH) connector E-11 (terminal 1, 2) and audio amplifier connector D-25 (terminal 27, 37).

NOTE: Also check intermediate connectors C-22 and C-114 for loose, corroded, or damaged terminals, or terminals pushed back in the connector If intermediate connector C-22 or C-114 is damaged, repair or replace the connector.

- [Rear door speaker (LH)] Check the wiring harness between rear door speaker (LH) connector E-24 (terminal 1, 2) and audio amplifier connector D-26 (terminal 1, 7).

NOTE: Also check intermediate connector D-20 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector D-20 is damaged, repair or replace the connector.

- [Rear door speaker (RH)] Check the wiring harness between rear door speaker (RH) connector E-23 (terminal 1, 2) and audio amplifier connector D-26 (terminal 2, 8).

NOTE: Also check intermediate connector D-01 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector D-01 is damaged, repair or replace the connector.

- [Tweeter (LH)] Check the wiring harness between tweeter (LH) connector E-02 (terminal 1, 2) and audio amplifier connector D-26 (terminal 14, 6).

NOTE: Also check intermediate connectors C-22 and C-126 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-22 or C-126 is damaged, repair or replace the connector.

- [Tweeter (RH)] Check the wiring harness between tweeter (RH) connector E-04 (terminal 1, 2) and audio amplifier connector D-26 (terminal 13, 5).

NOTE: Also check intermediate connectors C-22 and C-115 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-22 or C-115 is damaged, repair or replace the connector.

- [Subwoofer] Check the wiring harness between subwoofer connector F-22 (terminal 1, 2, 3, 4) and audio amplifier connector D-25 (terminal No.30, 22, 29, 21).

NOTE: Also check intermediate connector D-15 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector D-15 is damaged, repair or replace the connector.

Q: Is the wiring harness between the speaker, tweeter or sub woofer connector terminal and the audio amplifier connector terminal in good condition?

YES : Go to Step 7.

NO (harness wire is abnormal): Repair or replace the damaged component.

STEP 7. Check radio and CD player connector C-104 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is radio and CD player connector C-104 in good condition?

YES : Go to Step 8.

NO : Repair or replace the damaged component.

STEP 8. Check the harness wire between radio and CD player connector C-104 (terminal 26, 28, 36, 38) and audio amplifier connector D-26 (terminal 10, 4,11, 12).

- Check the communication lines for open circuit and short circuit.

NOTE: Also check intermediate connector C-22 for loose, corroded, or damaged terminals, or terminals pushed back in the connector If intermediate connector C-22 is damaged, repair or replace the connector.

Q: Is the wiring harness between radio and CD player connector C-104 (terminal 26, 28, 36, 38) and audio amplifier connector D-26 (terminal 10, 4,11,12) in good condition?

YES : Check the trouble symptom, go to Step 9.

NO : Repair or replace the damaged component.

STEP 9. Replace the audio amplifier temporarily, and check the trouble symptom.

Replace the audio amplifier temporarily, and check that the sound is output from the speaker.

Q: Is the check result normal?

YES : Replace the audio amplifier.

NO : Replace the radio and CD player.