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Inspection Procedure 2: No sound is heard. <Vehicles with 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, tweeters or subwoofer is short-circuited, the protection circuit inside the radio and CD player disables all the speakers, tweeters or subwoofer to sound. Therefore, if all the speakers do not output sound, the speaker, tweeter or subwoofer circuit may be shorted or the speaker, tweeter, subwoofer or audio amplifier may be defective.
 
 
 
TROUBLESHOOTING HINTS
  • The radio and CD player may be defective
  • The speaker, tweeter or subwoofer may be defective
  • The audio amplifier 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, tweeter or subwoofer 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 5.
 
STEP 2. Check the speaker, tweeter or subwoofer.
(1) Remove the speaker, tweeter or subwoofer.
(2) Check that the speaker, tweeter or subwoofer outputs the noise when the voltage of 5 V is applied to the speaker, tweeter or subwoofer connector terminal.
Do the speaker output the noise?
Go to Step 3.
Replace the speaker, tweeter or subwoofer.
 
STEP 3. Check the wiring harness between the speaker, tweeter or subwoofer connector terminal and the audio amplifier connector terminal.
  • Check of short circuit in DFR+, DFR- line between front door speaker (RH) connector and audio amplifier connector. <Front door speaker (RH)>
  • Check of short circuit in DFL+, DFL- line between front door speaker (LH) connector and audio amplifier connector. <Front door speaker (LH)>
  • Check of short circuit in TFR+, TFR- line between tweeter (RH) connector and audio amplifier connector. <Tweeter (RH)>
  • Check of short circuit in TFL+, TFL- line between tweeter (LH) connector and audio amplifier connector. <Tweeter (LH)>
  • Check of short circuit in RR+, RR- line between rear door speaker (RH) connector and audio amplifier connector. <Rear door speaker (RH)>
  • Check of short circuit in RL+, RL- line between rear door speaker (LH) connector and audio amplifier connector. <Rear door speaker (LH)>
  • Check of short circuit in RW+, RW1+, RW-, RW1- line between subwoofer connector and audio amplifier connector. <subwoofer>
Is the check result normal?
Go to Step 4.
Repair the connector(s) or wiring harness.
 
STEP 4. Check of short circuit in FL+, FL-, FR+, FR-, RR+, RR- line between audio amplifier connector and radio and CD player connector
Is the check result normal?
Go to Step 8.
Repair the connector(s) or wiring harness.
 
STEP 5. Check the speaker, tweeter or subwoofer.
Follow the speaker test to check which speaker, tweeter or subwoofer does not sound.
(1) Remove the speaker, tweeter or subwoofer.
(2) Check that the speaker, tweeter or subwoofer outputs the noise when the voltage of 5 V is applied to the speaker, tweeter or subwoofer connector terminal.
Do the speaker output the noise?
Go to Step 6.
Replace the speaker, tweeter or subwoofer.
 
STEP 6. Check the wiring harness between the speaker, tweeter or subwoofer connector terminal and the audio amplifier connector terminal.
Follow the speaker test to check which speaker, tweeter or subwoofer circuit is defective.
  • Check of open circuit in DFR+, DFR- line between front door speaker (RH) connector and audio amplifier connector. <Front door speaker (RH)>
  • Check of open circuit in DFL+, DFL- line between front door speaker (LH) connector and audio amplifier connector. <Front door speaker (LH)>
  • Check of open circuit in TFR+, TFR- line between tweeter (RH) connector and audio amplifier connector. <Tweeter (RH)>
  • Check of open circuit in TFL+, TFL- line between tweeter (LH) connector and audio amplifier connector. <Tweeter (LH)>
  • Check of open circuit in RR+, RR- line between rear door speaker (RH) connector and audio amplifier connector. <Rear door speaker (RH)>
  • Check of open circuit in RL+, RL- line between rear door speaker (LH) connector and audio amplifier connector. <Rear door speaker (LH)>
  • Check of open circuit in RW+, RW1+, RW-, RW1- line between subwoofer connector and audio amplifier connector. <subwoofer>
Is the check result normal?
Go to Step 7.
Repair the connector(s) or wiring harness.
 
STEP 7. Check of open circuit in FL+, FL-, FR+, FR-, RR+, RR- line between audio amplifier connector and radio and CD player connector
Is the check result normal?
Go to Step 8.
Repair the connector(s) or wiring harness.
 
STEP 8. Retest the system
Check if the sound is output from all the speaker, tweeter or subwoofer.
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.