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Inspection Procedure 3: No sound is heard from one of the speakers. <Vehicles with audio amplifier>


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.






















COMMENTS ON TROUBLE SYMPTOM


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.

PROBABLE CAUSES



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 GROUP 00, Coding Table ).
(2)Check that the "Number of speaker" is set to "Premium."

Q. Is the check result normal?
Go to Step 2.
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 (Refer to ).
note In the following procedure, check the speaker or tweeter that is abnormal.

Q. Is the check result normal?
YES (normal for all) : The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
NO (abnormal for all) : Check the radio and CD player power supply and ground circuit, and repair if necessary. If the radio and CD player power supply and ground circuit is normal, replace the radio and CD player.
NO (Either a speaker is abnormal) : 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?
Go to Step 4.
Repair or replace the damaged component(s) (Refer to GROUP 00E, Harness Connector Inspection ).

STEP 4. Check the speaker, tweeter or subwoofer.
(1)Remove the speaker, tweeter or subwoofer (Refer to ).
(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?
Go to Step 5.
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?
Go to Step 6.
Repair or replace the damaged component (Refer to GROUP 00E, Harness Connector Inspection ).

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 as described in GROUP 00E, Harness Connector Inspection .
  • <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 as described in GROUP 00E, Harness Connector Inspection .
  • <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 as described in GROUP 00E, Harness Connector Inspection .
  • <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 as described in GROUP 00E, Harness Connector Inspection .
  • <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 as described in GROUP 00E, Harness Connector Inspection .
  • <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 as described in GROUP 00E, Harness Connector Inspection .
  • <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 as described in GROUP 00E, Harness Connector Inspection .

Q. Is the wiring harness between the speaker, tweeter or sub woofer connector terminal and the audio amplifier connector terminal in good condition?
YES <front door speaker> : Go to Step 7.
YES <except front door speaker> : Go to Step 9.
NO (harness wire is abnormal) : Repair or replace the damaged component (Refer to GROUP 00E, Harness Connector Inspection ).

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?
Go to Step 8.
Repair or replace the damaged component (Refer to GROUP 00E, Harness Connector Inspection ).

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 as described in GROUP 00E, Harness Connector Inspection .

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?
Check the trouble symptom, go to Step 9.
Repair or replace the damaged component (Refer to GROUP 00E, Harness Connector Inspection ).

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?
Replace the audio amplifier.
Replace the radio and CD player.