Inspection Procedure 2: No Sound is Heard. <Vehicles with Audio Amplifier>














COMMENTS ON TROUBLE SYMPTOM



PROBABLE CAUSES



  • Malfunctions of audio visual navigation unit
  • Malfunction of audio amplifier
  • Option coding information inconsistency
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

STEP 1. ETACS-ECU coding data check
(1)Operate the M.U.T.-III to read the ETACS-ECU option coding information (Refer to GROUP 00 - Coding Table ).
(2)Check that the "Speaker" is set to "Premium."

Q. Is the check result normal?
Go to Step 2.
Operate the M.U.T.-III to set the option coding "Speaker" to "Premium," and check the trouble symptom.

STEP 2. Connector check: D-125 audio amplifier connector

Q. Is the check result normal?
Go to Step 3.
Repair or replace the damaged component(s).

STEP 3. Resistance measurement at D-125 audio amplifier connector.
(1)Disconnect audio amplifier connector D-125, and measure the resistance available at the wiring harness side of the connector.
(2)Check the continuity between terminal No.24 and body earth.
OK: Continuity exists (2 ohms or less)
(3)Check the continuity between terminal No.31 and body earth.
OK: Continuity exists (2 ohms or less)
(4)Check the continuity between terminal No.32 and body earth.
OK: Continuity exists (2 ohms or less)

Q. Is the check result normal?
Go to Step 5.
Go to Step 4.

STEP 4. Check the wiring harness between D-125 audio amplifier connector terminal No.24, 31, 32 and body earth.

  • Check the body earth wires for open circuit.

Q. Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Repair the wiring harness.

STEP 5. Voltage measurement at D-125 audio amplifier connector.
(1)Disconnect D-125 audio amplifier connector, and measure the voltage available at the wiring harness-side connector.
(2)Measure the voltage between terminal No.25 and body earth.
OK: System voltage
(3)Measure the voltage between terminal No.35 and body earth.
OK: System voltage
(4)Measure the voltage between terminal No.36 and body earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 7.
Go to Step 6.

STEP 6. Check the wiring harness between D-125 audio amplifier connector terminal No.25, 35, 36 and fusible link (34).
note Prior to the wiring harness inspection, check intermediate connector C-131, and repair if necessary.

  • Check the power supply line for open circuit and short circuit.

Q. Is the check result normal?
Go to Step 7.
Repair the wiring harness.

STEP 7. Connector check: C-07 audio visual navigation unit connector and D-126 audio amplifier connector

Q. Is the check result normal?
Go to Step 8.
Repair the defective connector.

STEP 8. Check the wiring harness between C-07 audio visual navigation unit connector terminal No.102 and D-126 audio amplifier connector terminal No.3.
note Prior to the wiring harness inspection, check intermediate connectors C-17 and C-22, and repair if necessary.

  • Check the communication lines for open circuit.

Q. Is the check result normal?

    Go to Step 9.
Repair the wiring harness.

STEP 9. Retest the system
Replace the audio amplifier, then check that the audio sound is output.

Q. Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Replace the audio visual navigation unit.