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

   -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)

   -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):

   Go into the System Diagnostic Mode:

   • Display Audio Type: Do the Vehicle Status diagnosis to check the Speed indication;
   • • With navigation
     • Without navigation 
   • Color Audio Type: Do the VSPNE in the Vehicle Information to check the C_VSP indication .

   -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

   Replace the audio-navigation unit .

   YES: Without stereo amplifier, without navigation

   Replace the audio unit .

   NO 

   Go to step 5.

4. 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: With navigation

   Replace the audio-navigation unit .

   NO: Without navigation

   Replace the audio unit .

5. 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. Measure the resistance 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) (with navigation): disconnected
   	Audio unit connector A (24P) (without navigation): disconnected
   Test point 1	Gauge control module connector A (32P) No. 30
   Test point 2	Audio-navigation unit connector A (24P) (with navigation) No. 14
   	Audio unit connector A (24P) (without navigation) No. 14

   Test point 1	Gauge control module connector A (32P) No. 31
   Test point 2	Audio-navigation unit connector A (24P) (with navigation) No. 24
   	Audio unit connector A (24P) (without navigation) No. 24

   Is there 1.0 Ω or less?

   YES: With navigation

   Replace the audio-navigation unit .

   YES: Without navigation

   Replace the audio unit .

   NO 

   Repair an open in the wire(s).