Audio unit button illumination does not work

NOTE:

Check the vehicle battery condition first (see BATTERY TEST ).
Check the connectors for poor connections or loose terminals.
If the audio unit does not turn on, go to Audio unit power switch will not turn on troubleshooting (see AUDIO REMOTE SWITCH DOES NOT WORK PROPERLY ).

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

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

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 step 5.

NO -Troubleshoot the interior lights. Start by checking the No. 4 (15 A) fuse in the under-hood fuse/relay box. If the fuse is OK, check for an open in the wire between the under-hood fuse/relay box and the audio unit. ■
Turn the ignition switch to LOCK (0).
Disconnect audio unit connector A (24P).
NOTE: Eject all the CDs before removing the audio unit and CD changer to prevent damaging the CD player's load mechanism.
Disconnect the gauge control module connector C (20P) (see GAUGE CONTROL MODULE REPLACEMENT ).
Check for continuity between audio unit connector A (24P) terminal No. 1 and gauge control module connector C (24P) terminal No. 20.

Fig 1: Checking Continuity Between Audio Unit Connector A (24P) Terminal 1 And Gauge Control Module Connector C (24P) Terminal 20
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 9.

NO -Repair open in the wire between the gauge control module and the audio unit. ■
Turn the ignition switch to ON (II).
With the headlight switch still on, measure the voltage between audio unit connector A (24P) terminal No. 13 and body ground.

Fig 2: Measuring Voltage Between Audio Unit Connector A (24P) Terminal No. 13 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Check the connections at the audio unit connector A (24P). If all connections are OK, 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 -Troubleshoot the interior lights circuit. Start by checking the No. 4 (15A) fuse in the under-hood fuse/relay box. If the fuse is OK, repair an open in the wire between the under-hood fuse/relay box and the audio unit.