Inspection Procedure 3

INSPECTION PROCEDURE 3: No Sound Is Heard From One Of The Speakers. [Vehicles With Audio Amplifier]

CAUTION: Before replacing the multivision display and audio amplifier, ensure that the power supply circuit, the ground circuit, and the communication circuit are normal. (Check that the voltage is 10 V or more.)

Speaker System Circuit (Part 1):

Speaker System Circuit (Part 2):

Speaker System Circuit (Part 3):

COMMENTS ON TROUBLE SYMPTOM
If the sound is not heard from one of the speakers, the speaker, multivision display, audio amplifier, communication line from the multivision display 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
- The speaker may be defective
- The multivision display may be defective
- The audio amplifier may be defective
- Option coding information inconsistency
- Damaged harness wires and connectors

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. Check the ETACS-ECU coding data.

Use scan tool MB991958 to diagnose the CAN bus lines.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.







1. Connect scan tool MB991958. Refer to "How to connect the Scan Tool (M.U.T.-III)." How to Connect the Scan Tool (M.U.T.-III)
2. Turn the ignition switch to "ON" position.
3. Operate the scan tool MB991958 to read the ETACS-ECU option coding information.
4. 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. Check the MMCS service mode, CAN communication confirmation, and coding data.

1. Display the CAN Communication Confirmation and Coding Data of the MMCS service mode. Service Mode
2. Check if PREMIUM is displayed.

Q: Is the check result normal?

YES : Go to Step 3.

NO : Go to Step 4.

STEP 3. Check the service data log for the MMCS service mode.

With the service data log of MMCS service mode displayed, check if the service data log for SP (speaker) is displayed. Service Mode

Q: Is the service data log for SP (speaker) displayed?

YES : Go to Step 4.

NO : Go to Step 7.

STEP 4. Using scan tool MB991958, diagnose the CAN bus line.

Use scan tool MB991958 to diagnose the CAN bus lines
1. Turn the ignition switch to "ON" position.
2. Diagnose the CAN bus line.

Q: Is the check result normal?

YES : Go to Step 5.

NO : Repair the CAN bus line.

STEP 5. Using scan tool MB991958, read the CAN box unit diagnostic trouble code.

Check again if the DTC is set to the CAN box unit.

Q: Is the DTC set?

YES : Troubleshoot the MMCS. Diagnostic Trouble Code Descriptions

NO : Go to Step 6.

STEP 6. Using scan tool MB991958, read the ETACS-ECU diagnostic trouble code.

Check if the diagnostic trouble code is set to the ETACS-ECU.

Q: Is the DTC set?

YES : Diagnose the ETACS-ECU (Refer to - ETACS-ECU - Troubleshooting). Diagnostic Trouble Code Descriptions

NO : Go to Step 7.

STEP 7. Checking with audio speaker check

Perform the audio speaker check, and check which speaker does not output the sound. Service Mode

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

Q: Is the check result normal?

YES (normal for all) : The trouble can be an intermittent malfunction.

NO (Either a speaker, a tweeter or a subwoofer is abnormal) : Go to Step 8.

STEP 8. Check door speaker connector E-13 [front-LH], E-11 [front-RH], E-23 [rear-LH] or E-22 [rear-RH], or tweeter connector E-02 [LH] or E-04 [RH], or subwoofer connector F-26 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-23 [rear-LH] or E-22 [rear-RH], or tweeter connector E-02 [LH] or E-04 [RH], or subwoofer connector F-26 in good condition?

YES : Go to Step 9.

NO : Repair or replace the damaged component.

STEP 9. 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: Does the speaker, tweeter or subwoofer output the noise?

YES : Go to Step 10.

NO : Replace the speaker, tweeter or subwoofer.

STEP 10. Check audio amplifier connector D-29 [front door speaker or sub woofer] or D-30 [tweeter or rear door speaker] for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is audio amplifier connector D-29 [front door speaker or sub woofer] or D-30 [tweeter or rear door speaker] in good condition?

YES : Go to Step 11.

NO : Repair or replace the damaged component.

STEP 11. Check the wiring harness between the speaker or tweeter 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-29 (terminal 28, 38).

NOTE: Also check intermediate connectors C-23 and C-128 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-23 or C-128 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-29 (terminal 27, 37).

NOTE: Also check intermediate connectors C-23 and C-116 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-23 or C-116 is damaged, repair or replace the connector.

- [Rear door speaker (LH)] Check the wiring harness between rear door speaker (LH) connector E-23 (terminal 1, 2) and audio amplifier connector D-30 (terminal 1, 7).

NOTE: Also check intermediate connector D-24 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector D-24 is damaged, repair or replace the connector.

- [Rear door speaker (RH)] Check the wiring harness between rear door speaker (RH) connector E-22 (terminal 1, 2) and audio amplifier connector D-30 (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-30 (terminal 14, 6).

NOTE: Also check intermediate connectors C-24 and C-129 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-24 or C-129 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-30 (terminal 13, 5).

NOTE: Also check intermediate connectors C-24 and C-117 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-24 or C-117 is damaged, repair or replace the connector.

- [Subwoofer] Check the wiring harness between subwoofer connector F-26 (terminal 1, 2, 3, 4) and audio amplifier connector D-29 (terminal 30, 22, 29, 21).

NOTE: Also check intermediate connector D-16 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector D-16 is damaged, repair or replace the connector.

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

YES [front door speaker] : Go to Step 12.
YES [except front door speaker] : Go to Step 14.

NO (harness wire is abnormal) : The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.

STEP 12. Check multivision display connector C-13 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is multivision display connector C-13 in good condition?

YES : Go to Step 13.

NO : Repair or replace the damaged component.

STEP 13. Check the wiring harness between multivision display connector C-13 (terminal 3, 7, 12, 15) and audio amplifier connector D-30 (terminal 12, 11, 4, 10).

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

NOTE: Also check intermediate connectors C-24 and C-108 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-24 or C-108 is damaged, repair or replace the connector.

Q: Is the wiring harness between multivision display connector C-13 (terminal 3, 7, 12, 15) and audio amplifier connector D-30 (terminal 12, 11, 4, 10) in good condition?

YES : Check the trouble symptom, go to Step 14.

NO : The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.

STEP 14. Replace the multivision display temporarily, and check the trouble symptom.

Replace the multivision display temporarily, and check that the sound is output from the speaker.

Q: Is the check result normal?

YES : Replace the multivision display.

NO : Replace the audio amplifier.