Display Does Not Dim Or Brighten With Dimmer (Without Navigation)

WARNING: This page is about a different car, the 2011 Honda Fit, 2010 Honda Fit, and 2009 Honda Fit. 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.
If the vehicle is equipped with navigation, refer to the display day/night mode does not work or does not work properly (see DISPLAY DAY/NIGHT MODE DOES NOT WORK OR DOES NOT WORK PROPERLY ).

Turn the ignition switch to ON (II).
Turn the combination light switch on and off to see if the symptom can be duplicated.
Can the symptom be duplicated?

YES - Go to step 3.

NO - Operation is normal at this time.
Turn the combination light switch off.
Operate the illumination control dial. Does it operate normally?
YES - Operation is normal at this time.

NO - Go to step 5.
Turn the ignition switch to LOCK (0).
Disconnect and check audio unit connector A (24P) for a loose or a poor connection.
NOTE: Eject all the audio disc before removing the audio unit and audio disc changer to prevent damaging the audio disc player's loading mechanism.
Reconnect audio unit connector A (24P), and recheck the symptom.
Does the display dim normally?

YES - Go to step 8.

NO - Operation is normal at this time.
Turn the ignition switch to ON (II).
Measure the voltage between audio unit connector A (24P) terminal No. 13 and body ground.

Fig 1: 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 - Go to step 10.

NO - Check the No. 29 (10 A) fuse in the under-dash fuse/relay box. If the fuse is OK, repair an open in the wire between the fuse and audio unit connector A (24P).
Measure the voltage between audio unit connector A (24P) terminals No. 13 and No. 1. Operate the dash brightness controller dial to see if the voltage changes.

Fig 2: Measuring Voltage Between Audio Unit Connector A (24P) Terminals No. 13 And No. 1
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Does the voltage change?

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 - There is an open in the wire between the under-dash fuse/relay box and the gauge control module.