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Inspection Procedure 3: When the speech switch is pressed, the voice guide is output, but the voice recognition is not performed.
 
 
cautionBefore replacing the hands free module, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
 
 
TECHNICAL DESCRIPTION (COMMENT)
When the speech switch is pushed, if the voice guide is sent but voice recognition is not executed, the microphone unit, hands free module or the communication between the microphone unit and hands free module may have a problem. It may also be possible that the voice recognition is interfered by external noise.
 
 
 
TROUBLESHOOTING HINTS
  • The hands free module may be defective.
  • The microphone unit 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. Retest the system
Close all the windows to suppress external noise as much as possible. Then check whether the voice recognition operates normally when you utter a word as close to the microphone unit as possible
Is the check result normal?
Diagnosis complete.
Go to Step 2
 
STEP 2. Check the diagnosis mode
Check if the microphone check result "HFM MIC Check" is displayed on the diagnosis mode of hands free module. (Refer to <Vehicles with 1CD audio> or <Vehicles with display audio>.)
Is the check result normal?
Go to Step 4
Go to Step 3
 
STEP 3. Check of short to power supply, short to ground, and open circuit in MIC+, MIC- line between hands free module connector and microphone unit connector.
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 connector(s) or wiring harness.
 
STEP 4. Replace the microphone unit temporarily, and check the trouble symptom.
Is the check result normal?
Replace the microphone unit.
Go to Step 5
 
STEP 5. Replace the hands free module temporarily, and check the trouble symptom.
Is the check result normal?
Replace the hands free module.
The trouble can be an intermittent malfunction (Refer to GROUP 00, How to use Troubleshooting/inspection Service Points, How to Cope with Intermittent Malfunction ).