Audio System Symptom Troubleshooting - Audio unit power will not turn on (No information display)

Audio unit power will not turn on (No information display)

NOTE:

	Check the vehicle 12 volt battery condition first.
	Check if the Display Mode () 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.
	Check the fuses and relays associated with the system, and check for a short in the related lines.

Problem verification:

Problem verification

?1.	Turn the vehicle to the ON mode.

?2.	Check if the display indicates any information.

Is any information displayed?


	YES

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


	NO: Display audio type

The failure is duplicated, go to step 2.


	NO: Color audio type

The failure is duplicated, go to step 8.

Determine possible failure area (LVDS1 circuit, others):

Determine possible failure area (LVDS1 circuit, others)

?1.	Shield the center display unit from the sun with your hand, and check that the display is back lit (only the back light is on).

Can you see the back light?


	YES

Go to step 11.


	NO

Go to step 3.

Open wire check (?B AUDIO line) 1:

Open wire check (?B AUDIO line) 1

?1.

Disconnect the following connector.

Center display unit connector A (5P)

?2.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Center display unit connector A (5P): disconnected
Test point 1	Center display unit connector A (5P) No. 1
Test point 2	Body ground

Is there battery voltage?


	YES

The ?B AUDIO wire is OK. Go to step 4.


	NO

Repair an open in the wire.?

Open wire check (GND line) 1:

Open wire check (GND line) 1

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Center display unit connector A (5P): disconnected
Test point 1	Center display unit connector A (5P) No. 5
Test point 2	Body ground

Is there continuity?


	YES

The GND wire is OK. Go to step 5.


	NO

Repair an open or high resistance in the ground wire or poor ground (G402).?

Determine possible failure area (DISP CONT line, others):

Determine possible failure area (DISP CONT line, others)

?1.	Reconnect center display unit connector A (5P).

?2.

Disconnect the following connector.

Audio unit connector E (16P)

?3.	Turn the vehicle to the ON mode.

?4.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle ON mode
	Audio unit connector E (16P): disconnected
Test point 1	Audio unit connector E (16P) No. 4
Test point 2	Body ground

Is there about 3.3 V?


	YES

The DISP CONT wire is OK. Go to step 7.


	NO

Go to step 6.

Open wire check (DISP CONT line):

Open wire check (DISP CONT line)

?1.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle ON mode
	Audio unit connector E (16P): disconnected
Test point 1	Center display unit connector A (5P) No. 4
Test point 2	Body ground

Is there about 3.3 V?


	YES

Repair an open in the wire.?


	NO

Replace the center display unit.?

Determine possible failure area (center display unit, others):

Determine possible failure area (center display unit, others)

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

?2.	Reconnect audio unit connector E (16P).

?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 unit connector E (16P) No. 4
Test point 2	Body ground

Is there less than 0.2 V?


	Yes

Replace the center display unit.?


	No

Go to step 8.

Open wire check (?B AUDIO line) 2:

Open wire check (?B AUDIO line) 2

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

?2.

Disconnect the following connector.

Audio unit connector A (24P)

?3.

Measure the voltage between test points 1 and 2.

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

Is there battery voltage?


	YES

The ?B AUDIO wire is OK. Go to step 9.


	NO

Repair an open in the wire.?

Open wire check (ACC/IG1 WITH DIODE FMVSS line):

Open wire check (ACC/IG1 WITH DIODE FMVSS 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 unit connector A (24P): disconnected
Test point 1	Audio unit connector A (24P) No. 23
Test point 2	Body ground

Is there battery voltage?


	YES

The ACC/IG1 WITH DIODE FMVSS wire is OK. Go to step 10.


	NO

Repair an open in the wire.?

10.

Open wire check (GND line) 2:

Open wire check (GND line) 2

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

?2.	Reconnect audio 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 unit connector A (24P) No. 1
Test point 2	Body ground

Is there less than 0.2 V?


	YES: Display audio type

Replace the audio unit.?


	YES: Color audio type

Substitute the known good audio panel then recheck. If the symptom does not go away, replace the audio unit.?


	NO

Repair an open or high resistance in the ground wire or poor ground (G402).?

11.

Shorted wire check (LVDS1? line to LVDS1? line):

Shorted wire check (LVDS1? line to LVDS1? line)

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

?2.

Disconnect the following connectors.

Audio unit connector H (3P)

Center display unit connector B (3P)

?3.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Audio unit connector H (3P): disconnected
	Center display unit connector B (3P): disconnected
Test point 1	Center display unit connector B (3P) No. 1
Test point 2	Center display unit connector B (3P) No. 2

Is there continuity?


	YES

There is a short in the wires. Replace the affected shielded harness.?


	NO

The LVDS1? wire and the LVDS1? wire are not shorted. Go to step 12.

12.

Shorted wire check (LVDS1 SH line to another lines):

Shorted wire check (LVDS1 SH line to another lines)

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Audio unit connector H (3P): disconnected
	Center display unit connector B (3P): disconnected
Test point 1	Center display unit connector B (3P) No. 1
Test point 2	Center display unit connector B (3P) No. 3

Test point 1	Center display unit connector B (3P) No. 2
Test point 2	Center display unit connector B (3P) No. 3

Is there continuity?


	YES

There is a short in the wires. Replace the affected shielded harness.?


	NO

The LVDS1 SH wire is not shorted. Go to step 13.

13.

Open wire check (LVDS1? line, LVDS1? line):

Open wire check (LVDS1? line, LVDS1? line)

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Audio unit connector H (3P): disconnected
	Center display unit connector B (3P): disconnected
Test point 1	Audio unit connector H (3P) No. 1
Test point 2	Center display unit connector B (3P) No. 1

Test point 1	Audio unit connector H (3P) No. 2
Test point 2	Center display unit connector B (3P) No. 2

Is there continuity?


	YES

The LVDS1? and the LVDS1? wires are OK. Go to step 14.


	NO

There is an open in the wire(s). Replace the affected shielded harness.?

14.

Center display unit check (substitution):

Center display unit check (substitution)

?1.	Substitute a known-good center display unit.

?2.	Reconnect all the connectors, and recheck.

Does the symptom go away?


	YES

Replace the original center display unit.?


	NO

Replace the audio unit.?