Audio System Symptom Troubleshooting - Volume does not increase with speed
Volume does not increase with speed
NOTE:
Check the vehicle 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, then compare it to a known-good vehicle.

Does the volume increase, and is it comparable to a known-good vehicle?

     
YES
     
     
     
Intermittent failure, the system is OK at this time. If the customer's concern is that the level of volume change is not enough, refer to the Owner's Manual to change the SVC level setting.?
     
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 unit 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, and use the vehicle speed pulse indication..

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

Is the vehicle speed indicated?

     
YES
     
     
     
     
NO
     
     
     
Go to step 4.
4.
Open wire check (B-CAN_H, B-CAN_L lines):

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

?2.
Disconnect the following connectors.
Audio unit connector B (20P)
Gauge control module connector A (32P)

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Audio unit connector B (20P): disconnected
 
Gauge control module connector A (32P): disconnected
Test circuit 1
  
Test point 1
Audio unit connector B (20P) No. 3
Test point 2
Gauge control module connector A (32P) No. 31

Test circuit 2
  
Test point 1
Audio unit connector B (20P) No. 13
Test point 2
Gauge control module connector A (32P) No. 30


Is there continuity?

     
YES
     
     
     
     
NO
     
     
     
Repair an open in the wire(s) between the audio unit and the gauge control module.?