Audio System Symptom Troubleshooting - Volume does not increase with speed
Volume does not increase with speed
NOTE:
Check the vehicle 12 volt battery condition first.
If possible, have the customer demonstrate their concern and compare it against a known-good vehicle.
Check for B-CAN DTCs and resolve them before troubleshooting.
Check the connectors for poor connections or loose terminals.
1.
Problem verification:

Problem verification
?1.
Test-drive the vehicle at freeway speeds, and monitor if the volume increases.

Does the volume increase?

     
YES
     
     
     
Intermittent failure, the system is OK at this time.?
     
NO
     
     
     
The failure is duplicated, go to step 2.
2.
Determine possible failure area (audio setting, others):

Determine possible failure area (audio setting, others)
?1.
Verify the SVC mode setting in the audio system sound set-up.

Is the SVC set to off?

     
YES
     
     
     
Change the setting to SVC MID, and recheck.?
     
NO
     
     
     
Go to step 3.
3.
Determine possible failure area (audio unit, others):

Determine possible failure area (audio unit, others)
?1.
Go into the System Diagnostic Mode:

?2.
Test-drive the vehicle with the help of an assistant, and then watch the vehicle speed in the center display.

Is the vehicle speed indicated?

     
YES: With stereo amplifier
     
     
     
Go to step 4.
     
YES: Without stereo amplifier, with navigation
     
     
     
     
YES: Without navigation
     
     
     
     
NO
     
     
     
Go to step 5.
4.
Stereo amplifier check (substitution):

Stereo amplifier check (substitution)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Substitute a known-good stereo amplifier, and recheck.

Does the symptom go away?

     
YES
     
     
     
Replace the original stereo amplifier.?
     
NO
     
     
     
5.
Open wire check (B-CAN_H line, B-CAN_L line):

Open wire check (B-CAN_H line, B-CAN_L line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connectors.
Gauge control module connector A (32P)
Audio-navigation unit connector A (24P) (with navigation)
Audio unit connector A (24P) (without navigation)

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Gauge control module connector A (32P): disconnected
 
Audio-navigation unit connector A (24P): disconnected
 
Audio unit connector A (24P): disconnected
Test point 1
Gauge control module connector A (32P) No. 30
Test point 2
Audio-navigation unit connector A (24P) No. 14
Audio unit connector A (24P) No. 14


Is there continuity?

     
YES: With navigation
     
     
     
     
YES: Without navigation
     
     
     
     
NO
     
     
     
Repair an open in the wire(s) between the audio-navigation unit or the audio unit and the gauge control module.?