Audio unit button illumination does not work

WARNING: This page is about a different car, the 2009 Acura MDX, 2008 Acura MDX, and 2007 Acura MDX. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

Check the connectors for poor connections or loose terminals.
Check the vehicle battery condition first.

Turn the ignition switch to ON (II).
Turn the combination lighting switch to the parking light position.
Check the illumination of the audio unit buttons.
Are the buttons illuminated?

YES - All buttons illuminated: Intermittent problem: the audio unit is OK at this time. Check for loose or poor connections at the audio unit connector C (24P).

Some button(s) illuminated: Audio panel is faulty, replace the audio panel.

NO - Go to step 4.
Check the illumination of several other buttons not related to the audio system.
Are the buttons illuminated?

YES - Go to the B-CAN line troubleshooting (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ). If the B-CAN line is OK, substitute a known-good audio unit and recheck. If the symptom/indicated goes away, replace the original audio unit (see AUDIO UNIT REMOVAL/INSTALLATION ). If the symptom is still present, substitute a known-good audio panel and recheck. If the symptom/indicated goes away, replace the original audio panel (see AUDIO UNIT REMOVAL/INSTALLATION ).

NO - Troubleshoot the interior lights. Start by checking the No. 22 (7.5 A) fuse in the under-hood fuse/relay box. If the fuse is OK, check the interior light relay.