Comments On Trouble Symptom: 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.
- Operate scan tool MB991958 to read the ETACS-ECU option coding information (Refer to CODING LIST ).
- Check that the "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 "Speaker" to "Premium," and check the trouble symptom.
- STEP 2. Checking with audio speaker check.
Perform the audio speaker check, and check which speaker does not output the sound. Refer to HARNESS CONNECTOR INSPECTION .
Q: Is the check result normal?
YES < normal for all > : The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).
NO < abnormal for all > : Refer to HARNESS CONNECTOR INSPECTION .
NO < only front door speaker (RH) is abnormal > : Go to Step 3.
NO < only front door speaker (LH) is abnormal > : Go to Step 9.
NO < only rear door speaker (RH) is abnormal > : Go to Step 15.
NO < only rear door speaker (LH) is abnormal > : Go to Step 19.
NO < only tweeter (RH) is abnormal > : Go to Step 23.
NO < only tweeter (LH) is abnormal > : Go to Step 27.
NO < only subwoofer is abnormal > : Go to Step 31.
- STEP 3. Check front door speaker (RH) connector E-04 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is front door speaker (RH) connector E-04 in good condition?
YES: Go to Step 4.
NO: Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION .
- STEP 4. Check the front door speaker (RH).
- Remove the front door speaker (RH). Refer to CONNECTOR ENGAGEMENT INSPECTION .
- Check that the front door speaker (RH) outputs the noise when the voltage of five volts is applied to the front door speaker (RH) connector terminal.
Q: Does the front door speaker (RH) output the noise?
YES: Go to Step 5.
NO: Replace the front door speaker (RH).
- STEP 5. Check audio amplifier connector D-126 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is audio amplifier connector D-126 in good condition?
YES: Go to Step 6.
NO: Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION .
- STEP 6. Check the wiring harness between audio amplifier connector D-126 (terminal 27, 37) and front door speaker (RH) connector E-04 (terminal 1, 2). NOTE: Also check intermediate connectors C-20 and C-112 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-20 or C-112 is damaged, repair or replace the connector as described in HARNESS CONNECTOR INSPECTION .
- Check the communication lines for open circuit and short circuit.
Q: Is the wiring harness between audio amplifier connector D-126 (terminal 27, 37) and front door speaker (RH) connector E-04 (terminal 1, 2) in good condition?
YES: Go to Step 7.
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 7. Check radio and CD changer connector C-104 and audio amplifier connector C-16 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are radio and CD changer connector C-104 and audio amplifier connector C-16 in good condition?
YES: Go to Step 8.
NO: Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION .
- STEP 8. Check the wiring harness between radio and CD changer connector C-16 (terminal 26, 36) and audio amplifier connector D-127 (terminal 10, 11). 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 HARNESS CONNECTOR INSPECTION .
- Check the communication lines for open circuit and short circuit.
Q: Is the wiring harness between radio and CD changer connector C-16 (terminal 26, 36) and audio amplifier connector D-127 (terminal 10, 11) in good condition?
YES: Check the trouble symptom, and go to Step 35.
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 9. Check front door speaker (LH) connector E-17 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is front door speaker (LH) connector E-17 in good condition?
YES: Go to Step 10.
NO: Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION .
- STEP 10. Check the front door speaker (LH).
- Remove the front door speaker (LH). Refer to FRONT OR REAR DOOR SPEAKER .
- Check that the front door speaker (LH) outputs the noise when the voltage of five volts is applied to the front door speaker (LH) connector terminal.
Q: Does the front door speaker (LH) output the noise?
YES: Go to Step 11.
NO: Replace the front door speaker (LH).
- STEP 11. Check audio amplifier connector D-126 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is audio amplifier connector D-126 in good condition?
YES: Go to Step 12.
NO: Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION .
- STEP 12. Check the wiring harness between audio amplifier connector D-126 (terminal 28, 38) and front door speaker (LH) connector E-17 (terminal 1, 2). NOTE: Also check intermediate connectors C-20 and C-126 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connectors C-20 and C-126 is damaged, repair or replace the connector as described in HARNESS CONNECTOR INSPECTION .
- Check the communication lines for open circuit and short circuit.
Q: Is the wiring harness between audio amplifier connector D-126 (terminal 28, 38) and front door speaker (LH) connector E-17 (terminal 1, 2) in good condition?
YES: Go to Step 13.
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 13. Check radio and CD changer connector C-16 and audio amplifier connector C-127 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is radio and CD changer connector C-16 and audio amplifier connector C-127 in good condition?
YES: Go to Step 14.
NO: Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION .
- STEP 14. Check the wiring harness between radio and CD changer connector C-16 (terminal 28, 38) and audio amplifier connector D-127 (terminal 4, 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 HARNESS CONNECTOR INSPECTION .Q: Is the wiring harness between radio and CD changer connector C-16 (terminal 28, 38) and audio amplifier connector D-127 (terminal 4, 12) in good condition?
YES: Check the trouble symptom, and go to Step 35.
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 15. Check rear door speaker (RH) connector E-10 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is rear door speaker (RH) connector E-10 in good condition?
YES: Go to Step 16.
NO: Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION .
- STEP 16. Check the rear door speaker (RH).
- Remove the rear door speaker (RH). Refer to FRONT OR REAR DOOR SPEAKER .
- Check that the rear door speaker (RH) outputs the noise when the voltage of five volts is applied to the rear door speaker (RH) connector terminal.
Q: Does the rear door speaker (RH) output the noise?
YES: Go to Step 17.
NO: Replace the rear door speaker (RH).
- STEP 17. Check audio amplifier connector D-127 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is audio amplifier connector D-127 in good condition?
YES: Go to Step 18.
NO: Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION .
- STEP 18. Check the wiring harness between audio amplifier connector D-127 (terminal 2, 8) and rear door speaker (RH) connector E-10 (terminal 1, 2). NOTE: Also check intermediate connector D-36 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector D-36 is damaged, repair or replace the connector as described in HARNESS CONNECTOR INSPECTION .
- Check the communication lines for open circuit and short circuit.
Q: Is the wiring harness between audio amplifier connector D-127 (terminal 2, 8) and rear door speaker (RH) connector E-10 (terminal 1, 2) in good condition?
YES: Check the trouble symptom, and go to Step 35.
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 19. Check rear door speaker (LH) connector E-24 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is rear door speaker (LH) connector E-24 in good condition?
YES: Go to Step 20.
NO: Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION .
- STEP 20. Check the rear door speaker (LH).
- Remove the rear door speaker (LH). Refer to FRONT OR REAR DOOR SPEAKER .
- Check that the rear door speaker (LH) outputs the noise when the voltage of five volts is applied to the rear door speaker (LH) connector terminal.
Q: Does the rear door speaker (LH) output the noise?
YES: Go to Step 21.
NO: Replace the rear door speaker (LH).
- STEP 21. Check audio amplifier connector D-127 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is audio amplifier connector D-127 in good condition?
YES: Go to Step 22.
NO: Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION .
- STEP 22. Check the wiring harness between audio amplifier connector D-127 (terminal 1, 7) and rear door speaker (LH) connector E-24 (terminal 1, 2). NOTE: Also check intermediate connector D-21 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector D-21 is damaged, repair or replace the connector as described in HARNESS CONNECTOR INSPECTION .
- Check the communication lines for open circuit and short circuit.
Q: Is the wiring harness between audio amplifier connector D-127 (terminal 1, 7) and rear door speaker (LH) connector E-24 (terminal 1, 2) in good condition?
YES: Check the trouble symptom, and go to Step 35.
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 23. Check tweeter (RH) connector E-02 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is tweeter (RH) connector E-02 in good condition?
YES: Go to Step 24.
NO: Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION .
- STEP 24. Check the tweeter (RH).
- Remove the tweeter (RH). Refer to FRONT OR REAR DOOR SPEAKER .
- Check that the tweeter (RH) outputs the noise when the voltage of five volts is applied to the tweeter (RH) connector terminal.
Q: Does the tweeter (RH) output the noise?
YES: Go to Step 25.
NO: Replace the tweeter (RH).
- STEP 25. Check audio amplifier connector D-127 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is audio amplifier connector D-127 in good condition?
YES: Go to Step 26.
NO: Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION .
- STEP 26. Check the wiring harness between audio amplifier connector D-127 (terminal 5, 13) and tweeter (RH) connector E-02 (terminal 2, 1). NOTE: Also check intermediate connectors C-22 and C-113 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-22 or C-113 is damaged, repair or replace the connector as described in HARNESS CONNECTOR INSPECTION .
- Check the communication lines for open circuit and short circuit.
Q: Is the wiring harness between audio amplifier connector D-127 (terminal 5, 13) and tweeter (RH) connector E-02 (terminal 2, 1) in good condition?
YES: Check the trouble symptom, and go to Step 35.
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 27. Check tweeter (LH) connector E-14 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is tweeter (LH) connector E-14 in good condition?
YES: Go to Step 28.
NO: Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION .
- STEP 28. Check the tweeter (LH).
- Remove the tweeter (LH). Refer to FRONT OR REAR DOOR SPEAKER .
- Check that the tweeter (LH) outputs the noise when five volts are applied to the tweeter (LH) connector terminal.
Q: Does the tweeter (LH) output the noise?
YES: Go to Step 29.
NO: Replace the tweeter (LH).
- STEP 29. Check audio amplifier connector D-127 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is audio amplifier connector D-127 in good condition?
YES: Go to Step 30.
NO: Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION .
- STEP 30. Check the wiring harness between audio amplifier connector D-127 (terminal 6, 14) and tweeter (LH) connector E-14 (terminal 2, 1). NOTE: Also check intermediate connectors C-22 and C-113 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-22 or C-113 is damaged, repair or replace the connector as described in HARNESS CONNECTOR INSPECTION .
- Check the communication lines for open circuit and short circuit.
Q: Is the wiring harness between audio amplifier connector D-127 (terminal 6, 14) and tweeter (LH) connector E-14 (terminal 2, 1) in good condition?
YES: Check the trouble symptom, and go to Step 35.
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 31. Check subwoofer connector D-15 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is subwoofer connector D-15 in good condition?
YES: Go to Step 32.
NO: Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION .
- STEP 32. Check the Subwoofer.
- Remove the subwoofer. Refer to FRONT OR REAR DOOR SPEAKER .
- Check that the subwoofer outputs the noise when five volts are applied to the subwoofer connector terminal.
Q: Does the subwoofer output the noise?
YES: Go to Step 33.
NO: Replace the subwoofer.
- STEP 33. Check audio amplifier connector D-126 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is audio amplifier connector D-126 in good condition?
YES: Go to Step 34.
NO: Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION .
- STEP 34. Check the wiring harness between audio amplifier connector D-126 (terminal 21, 22, 29, 30) and subwoofer connector D-15 (terminal 4, 2, 3, 1).
- Check the communication lines for open circuit and short circuit.
Q: Is the wiring harness between audio amplifier connector D-126 (terminal 21, 22, 29, 30) and subwoofer connector D-15 (terminal 4, 2, 3, 1) in good condition?
YES: Check the trouble symptom, and go to Step 35.
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 35. 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: The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).
NO: Replace the radio and CD player or CD changer.