Audio unit button illumination does not work

NOTE:

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

Turn the ignition switch to ON (II).
Turn the headlight 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 the audio unit 20P connector.

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.
Turn the ignition switch to LOCK (0).
Disconnect the audio unit 20P connector.
NOTE: Eject the disc before removing the audio unit to prevent damaging the CD player's load mechanism.
'00-03 models: Disconnect gauge assembly connector B(12P).
'04-09 models: Disconnect gauge assembly connector A (22P).
'00-03 models: Check for continuity between audio unit 20P connector terminal No. 19 and gauge assembly connector B (12P) terminal No. 10. '04-09 models: Check for continuity between audio unit connector A (20P) terminal No. 19 and gauge assembly connector A (22P) terminal No. 19.
'00-03 models

Fig 1: Checking Continuity Between Audio Unit 20P Connector Terminal No. 19 And Gauge Assembly Connector B (12P) Terminal No. 10
Courtesy of AMERICAN HONDA MOTOR CO., INC.

'04-09 models

Fig 2: Checking Continuity Between Audio Unit Connector A (20P) Terminal No. 19 And Gauge Assembly Connector A (22P) Terminal No. 19
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 9.

NO -Repair open in the wire between the gauge assembly and the audio unit.
Turn the ignition switch to ON (II).
With the headlight switch still on, measure the voltage between audio unit 20P connector terminal No. 9 and body ground.

Fig 3: Measuring Voltage Between Audio Unit 20P Connector Terminal No. 9 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Check the connections at the audio unit 20P connector. If all connections are OK, replace the audio unit (see AUDIO UNIT REMOVAL/INSTALLATION ).

NO -Repair open in the wire between the under-dash fuse/relay box and the audio unit.