Audio remote switch does not work properly (with 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.
Before troubleshooting, make sure you have anti-theft codes for the audio-navigation unit.
After troubleshooting, enter the anti-theft codes for the audio-navigation unit.

Turn the ignition switch to ON (II).
Turn on the audio-navigation unit and check the audio remote switch operation (volume up, volume down, CH (UP), CH (DOWN), MODE).
Is the audio-navigation unit operation OK?

YES -Operation is normal.

NO -Go to step 3.
Test the audio remote switch (see AUDIO REMOTE SWITCH TEST ).
Is the audio remote switch OK?

YES -Go to step 4.

NO -Replace the audio remote switch (see AUDIO REMOTE SWITCH TEST ).
Turn the ignition switch to LOCK (0).
Remove the audio-navigation unit (see AUDIO-NAVIGATION UNIT REMOVAL/INSTALLATION ), and disconnect audio-navigation unit connector A (24P).
NOTE: Eject all the discs before removing the audio-navigation unit to prevent damaging the CD/DVD player's load mechanism.

Reconnect the audio remote switch, and measure the resistance between audio-navigation unit connector A (24P) terminals No. 5 and No. 16 as specified in the table.

Fig 1: Measuring Resistance Between Connector A (24P) Terminals No. 5 And No. 16

Courtesy of AMERICAN HONDA MOTOR CO., INC.

AUDIO REMOTE SWITCH TABLE

Button held down	VOL DOWN	VOL UP	CH (-)	CH (+)	MODE	(No button pressed)
Resistance	about 100 Ω	about 357 Ω	about 775 Ω	about 1.7 kΩ	about 3.7 kΩ	about 10 kΩ

Is the resistance OK?

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

NO -Go to step 7.

Disconnect the cable reel subharness 20P connector from the cable reel.
Check for continuity between body ground and audio-navigation unit connector A (24P) terminals No. 5 and No. 16 individually.

Fig 2: Checking Continuity Between Body Ground And Connector A (24P) Terminals No. 5 And No. 16
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 9.

NO -Substitute a known-good audio-navigation unit (see AUDIO-NAVIGATION UNIT REMOVAL/INSTALLATION ), and recheck. If the symptom/indication goes away, replace the original audio-navigation unit (see AUDIO-NAVIGATION UNIT REMOVAL/INSTALLATION ).
Disconnect the dashboard wire harness 20P connector from the cable reel.
Check for continuity between body ground and audio-navigation unit connector A (24P) terminals No. 5 and No. 16 individually.

Fig 3: Checking Continuity Between Body Ground And Connector A (24P) Terminals No. 5 And No. 16
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair a short to body ground in the wire(s) between the audio-navigation unit and the cable reel.

NO -Replace the cable reel (see CABLE REEL REPLACEMENT ).