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Inspection Procedure 2: No sound is heard. <Vehicles with audio amplifier>
 
 
cautionBefore replacing the multivision display, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
 
 
TECHNICAL DESCRIPTION (COMMENT)
If the audio sound is not output, the multivision display may have a problem. In addition, if any of the speakers or tweeters is short-circuited, the protection circuit inside the multivision display disables all the speakers or tweeters to sound. Therefore, if all the speakers do not output sound, the speaker or tweeter circuit may be shorted or the speaker, tweeter or audio amplifier may be defective.
 
 
TROUBLESHOOTING HINTS
  • The multivision display may be defective
  • The audio amplifier may be defective
  • The speaker or tweeter may be defective
  • 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
STEP 1. Checking with audio speaker test.
Perform the audio speaker test, and check which speaker or tweeter does not output the sound.
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 ).
: Go to Step 2.
: Go to Step 5.
 
STEP 2. Check the speaker or tweeter.
(1) Remove the speaker or tweeter.
(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.
Is the check result normal?
Go to Step 3.
Replace the speaker or tweeter.
 
STEP 3. Check the wire harness between the speaker or tweeter connector terminal and the audio amplifier connector terminal.
Front door speaker (LH)
  • Check of short circuit in DFL+, DFL- line between front door speaker (LH) connector and audio amplifier connector.
Front door speaker (RH)
  • Check of short circuit in DFR+, DFR- line between front door speaker (RH) connector and audio amplifier connector.
Front tweeter (LH)
  • Check of short circuit in TFL+, TFL- line between front door speaker (LH) connector and audio amplifier connector.
Front tweeter (RH)
  • Check of short circuit in TFR+, TFR- line between front door speaker (RH) connector and audio amplifier connector.
Rear door speaker (LH)
  • Check of short circuit in RL+, RL- line between front door speaker (LH) connector and audio amplifier connector.
Rear door speaker (RH)
  • Check of short circuit in RR+, RR- line between front door speaker (RH) connector and audio amplifier connector.
Is the check result normal?
Go to Step 4.
Repair the connector(s) or wiring harness.
 
STEP 4. Check of short to power supply, short to ground, and open circuit in DFL+, DFL-, DFR+, DFR-, RR+ and RR- line between audio amplifier connector and multivision display connector.
Is the check result normal?
Go to Step 8.
Repair the connector(s) or wiring harness.
 
STEP 5. Check the speaker or tweeter.
Follow the speaker test to check which speaker or tweeter does not sound.
(1) Remove the speaker or tweeter.
(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.
Do the speaker output the noise?
Go to Step 6.
Replace the speaker or tweeter.
 
STEP 6. Check the wire harness between the speaker or tweeter connector terminal and audio amplifier connector terminal.
Follow the speaker test to check which speaker or tweeter circuit is defective.
Front door speaker (LH)
  • Check of open circuit in DFL+, DFL- line between front door speaker (LH) connector and audio amplifier connector.
Front door speaker (RH)
  • Check of open circuit in DFR+, DFR- line between front door speaker (RH) connector and audio amplifier connector.
Front tweeter (LH)
  • Check of open circuit in TFL+, TFL- line between front door speaker (LH) connector and audio amplifier connector.
Front tweeter (RH)
  • Check of open circuit in TFR+, TFR- line between front door speaker (RH) connector and audio amplifier connector.
Rear door speaker (LH)
  • Check of open circuit in RL+, RL- line between front door speaker (LH) connector and audio amplifier connector.
Rear door speaker (RH)
  • Check of open circuit in RR+, RR- line between front door speaker (RH) connector and audio amplifier connector.
Is the check result normal?
Go to Step 7.
Repair the connector(s) or wiring harness.
 
STEP 7. Check of short to power supply, short to ground, and open circuit in DFL+, DFL-, DFR+, DFR-, RR+ and RR- line between audio amplifier connector and multivision display connector.
Is the check result normal?
Go to Step 8.
Repair the connector(s) or wiring harness.
 
STEP 8. Retest the system.
Replace the audio amplifier, then check that the audio sound is output.
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 multivision display (Refer to ).