Navigation System Symptom Troubleshooting - Audio-navigation unit will not turn on (No information display and no sound)

Audio-navigation unit will not turn on (No information display and no sound)

NOTE:

	Check the vehicle 12 volt battery condition first.
	Check if the Day/Night () button has been pressed, and turned off the display (see the Owner's Manual for more information).
	Check the connectors for poor connections or loose terminals.

Problem verification:

Problem verification

?1.	Turn the vehicle to the ON mode.

?2.	Check if the audio-navigation unit display indicates any information.

Is any information displayed?


	YES

Intermittent failure, the system is OK at this time.?


	NO

The failure is duplicated, go to step 2.

Fuse check:

Fuse check

?1.	Turn the vehicle to the OFF (LOCK) mode.

?2.

Check the following fuses.

Fuse	No. B21
Fuse	No. C37

Are the fuses OK?


	YES

Go to step 3.


	NO

Replace the fuse(s), and recheck. If the fuse(s) blows again, check for a short in the No. B21 fuse and/or the No. C37 fuse circuits.?

Open wire check (+B BACKUP MAIN line):

Open wire check (+B BACKUP MAIN line)

?1.

Disconnect the following connector.

Audio-navigation unit connector A (24P)

?2.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Audio-navigation unit connector A (24P): disconnected
Test point 1	Audio-navigation unit connector A (24P) No. 3
Test point 2	Body ground

Is there battery voltage?


	YES

The +B BACKUP MAIN wire is OK. Go to step 4.


	NO

Repair an open in the wire.?

Open wire check (ACC RR CAMERA/ACC line):

Open wire check (ACC RR CAMERA/ACC line)

?1.	Turn the vehicle to the ON mode.

?2.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle ON mode
	Audio-navigation unit connector A (24P): disconnected
Test point 1	Audio-navigation unit connector A (24P) No. 23
Test point 2	Body ground

Is there battery voltage?


	YES

The ACC RR CAMERA/ACC wire is OK. Go to step 5.


	NO

Repair an open in the wire.?

Open wire check (GND line):

Open wire check (GND line)

?1.	Turn the vehicle to the OFF (LOCK) mode.

?2.	Reconnect audio-navigation unit connector A (24P).

?3.	Turn the vehicle to the ON mode.

?4.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle ON mode
Test point 1	Audio-navigation unit connector A (24P) No. 1
Test point 2	Body ground

Is there less than 0.2 V?


	YES

The GND wire is OK. Go to step 6.


	NO

Repair an open or high resistance in the wire or poor ground (G404).?

Audio panel check:

Audio panel check

?1.	Turn the vehicle to the OFF (LOCK) mode.

?2.	Substitute a known-good audio panel. and recheck.

Does the symptom go away?


	YES

Replace the original audio panel.?


	NO

Replace the audio-navigation unit.?