Volume does not increase with speed (without navigation)

WARNING: This page is about a different car, the 2013 Acura MDX, 2012 Acura MDX, 2011 Acura MDX, and 2010 Acura MDX. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

Check the vehicle battery condition first (see BATTERY TEST ).
Check the connectors for poor connections or loose terminals.
Set the fader and balance positions to the center.

Check the (SVC) mode setting in the audio unit sound set-up.
Is the (SVC) set to off?

YES -Change the setting to at least the Mid setting, and retest.

NO -Go to step 2.
Do the self-diagnostic function for the vehicle speed pulse indication (see SELF-DIAGNOSTIC FUNCTION ).
Does the self-diagnostic function indicate a VSP signal when the vehicle is moving?

YES -Substitute a known-good audio unit (see AUDIO UNIT REMOVAL/INSTALLATION ), and recheck. If the symptom/indication goes away, replace the original audio unit (see AUDIO UNIT REMOVAL/INSTALLATION ).

NO -Go to step 3.
Test-drive the vehicle at highway speeds, and monitor if the volume increases.
Does the volume increase?

YES -Intermittent failure, the system is OK at this time.

NO -Check for B-CAN DTCs (communication BUS Line Error) with the HDS and go to the indicated DTC's troubleshooting. If no B-CAN DTCs or communication bus line errors are found, substitute a known-good audio unit (see AUDIO UNIT REMOVAL/INSTALLATION ), and recheck. If the symptom goes away, replace the original audio unit (see AUDIO UNIT REMOVAL/INSTALLATION ).