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Inspection Procedure 2: No sound is heard. <Vehicles without audio amplifier>
 
 
cautionBefore replacing the radio and CD player, 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 radio and CD player may have a problem. In addition, if any of the speakers or tweeters is short-circuited, the protection circuit inside the radio and CD player 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 or tweeter may be defective.
 
 
 
TROUBLESHOOTING HINTS
  • The radio and CD player may be defective
  • The speaker or tweeter may be defective
  • Option coding information inconsistency
  • 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. Refer to .
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 4
 
STEP 2. Check the speaker or tweeter.
(1) Remove the speaker or tweeter. 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.
Do the speaker output the noise?
Go to Step 3
Replace the speaker or tweeter.
 
STEP 3. Check the wiring harness between the speaker or tweeter connector terminal and the radio and CD player connector terminal.
  • Check of short circuit in FR+, FR- line front door speaker (RH) connector and radio and CD player connector. <Front door speaker (RH)>
  • Check of short circuit in FL+, FL- line front door speaker (LH) connector and radio and CD player connector. <Front door speaker (LH)>
  • Check of short circuit in FR+, FR- line tweeter (RH) connector and radio and CD player connector. <Tweeter (RH)>
  • Check of short circuit in FL+, FL- line tweeter (LH) connector and radio and CD player connector. <Tweeter (LH)>
  • Check of short circuit in RR+, RR- line rear door speaker (RH) connector and radio and CD player connector. <Rear door speaker (RH)>
  • Check of short circuit in RL+, RL- line rear door speaker (LH) connector and radio and CD player connector. <Rear door speaker (LH)>
Is the check result normal?
Go to Step 6
Repair the connector(s) or wiring harness.
 
STEP 4. Check the speaker or tweeter.
Follow the speaker test to check which speaker or tweeter does not sound.
(1) Remove the speaker or tweeter. Refer to .
(2) Check that the speaker or tweeter outputs the noise when the voltage of 5 V is applied to the speaker connector terminal.
Do the speaker output the noise?
Go to Step 5
Replace the speaker or tweeter.
 
STEP 5. Check the wiring harness between the speaker or tweeter connector terminal and the radio and CD player connector terminal.
Follow the speaker test to check which speaker or tweeter circuit is defective.
  • Check of open circuit in FR+, FR- line front door speaker (RH) connector and radio and CD player connector. <Front door speaker (RH)>
  • Check of open circuit in FL+, FL- line front door speaker (LH) connector and radio and CD player connector. <Front door speaker (LH)>
  • Check of open circuit in FR+, FR- line tweeter (RH) connector and radio and CD player connector. <Tweeter (RH)>
  • Check of open circuit in FL+, FL- line tweeter (LH) connector and radio and CD player connector. <Tweeter (LH)>
  • Check of open circuit in RR+, RR- line rear door speaker (RH) connector and radio and CD player connector. <Rear door speaker (RH)>
  • Check of open circuit in RL+, RL- line rear door speaker (LH) connector and radio and CD player connector. <Rear door speaker (LH)>
Is the check result normal?
Go to Step 6
Repair the connector(s) or wiring harness.
 
STEP 6. Retest the system
Check if the sound is output from all the speakers or tweeters.
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 radio and CD player.