Audio System Symptom Troubleshooting - AM/FM radio display is blank or no station information is displayed (With Navigation)

1.

Problem verification:

Problem verification

?1.	Turn the vehicle to the ON mode.

?2.	Turn on the audio system, and select AM or FM.

Does the AM or FM radio station information display blank?


	YES

The failure is duplicated, go to step 2.


	NO

Intermittent failure, the system is OK at this time. If the AM or FM sound is not heard, go to Poor or no sound with AM/FM radio troubleshooting.?

2.

Determine possible failure area (TUNER 6V line, others):

Determine possible failure area (TUNER 6V line, others)

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

?2.

Disconnect the following connector.

Tuner unit connector A (10P)

?3.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Tuner unit connector A (10P): disconnected
Test point 1	Tuner unit connector A (10P) No. 10
Test point 2	Body ground

Is there about 6.0 V?


	YES

The TUNER 6V wire is OK. Go to step 5.


	NO

Go to step 3.

3.

Open wire check (TUNER 6V line):

Open wire check (TUNER 6V line)

?1.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Tuner unit connector A (10P): disconnected
Test point 1	Audio-navigation unit connector E (16P) No. 1
Test point 2	Body ground

Is there about 6.0 V?


	YES

Repair an open in the wire between the audio-navigation unit and the tuner unit.?


	NO

The TUNER 6V wire is not open. Go to step 4.

4.

Shorted wire check (TUNER 6V line):

Shorted wire check (TUNER 6V line)

?1.

Disconnect the following connector.

Audio-navigation unit connector E (16P)

?2.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Tuner unit connector A (10P): disconnected
	Audio-navigation unit connector E (16P): disconnected
Test point 1	Audio-navigation unit connector E (16P) No. 1
Test point 2	Body ground

Is there continuity?


	YES

Repair a short to body ground in the wire between the audio-navigation unit and the tuner unit.?


	NO

Replace the audio-navigation unit.?

5.

Determine possible failure area (TUNER GND line, others):

Determine possible failure area (TUNER GND line, others)

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Tuner unit connector A (10P): disconnected
Test point 1	Tuner unit connector A (10P) No. 2
Test point 2	Body ground

Is there continuity?


	YES

The TUNER GND wire is OK. Go to step 7.


	NO

Go to step 6.

6.

Open wire check (TUNER GND line):

Open wire check (TUNER GND line)

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Tuner unit connector A (10P): disconnected
Test point 1	Audio-navigation unit connector E (16P) No. 9
Test point 2	Body ground

Is there continuity?


	YES

Repair an open in the wire between the audio-navigation unit and the tuner unit.?


	NO

Replace the audio-navigation unit.?

7.

Determine possible failure area (TUNER 9V line, others):

Determine possible failure area (TUNER 9V line, others)

?1.	Turn the vehicle to the ON mode.

?2.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle ON mode
	Tuner unit connector A (10P): disconnected
Test point 1	Tuner unit connector A (10P) No. 1
Test point 2	Body ground

Is there about 9.0 V?


	YES

The TUNER 9V wire is OK. Go to step 10.


	NO

Go to step 8.

8.

Open wire check (TUNER 9V line):

Open wire check (TUNER 9V line)

?1.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle ON mode
	Tuner unit connector A (10P): disconnected
Test point 1	Audio-navigation unit connector E (16P) No. 2
Test point 2	Body ground

Is there about 9.0 V?


	YES

Repair an open in the wire between the audio-navigation unit and the tuner unit.?


	NO

The TUNER 9V wire is not open. Go to step 9.

9.

Shorted wire check (TUNER 9V line):

Shorted wire check (TUNER 9V line)

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

?2.

Disconnect the following connector.

Audio-navigation unit connector E (16P)

?3.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Tuner unit connector A (10P): disconnected
	Audio-navigation unit connector E (16P): disconnected
Test point 1	Audio-navigation unit connector E (16P) No. 2
Test point 2	Body ground

Is there continuity?


	YES

Repair a short to body ground in the wire between the audio-navigation unit and the tuner unit.?


	NO

Replace the audio-navigation unit.?

10.

Shorted wire check (TUNER RS485+ line, TUNER RS485? line):

Shorted wire check (TUNER RS485+ line, TUNER RS485? line)

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

?2.

Disconnect the following connector.

Audio-navigation unit connector E (16P)

?3.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Tuner unit connector A (10P): disconnected
	Audio-navigation unit connector E (16P): disconnected
Test point 1	Tuner unit connector A (10P) No. 5
Test point 2	Body ground

Test point 1	Tuner unit connector A (10P) No. 7
Test point 2	Body ground

Is there continuity?


	YES

There is a short to body ground in the wire(s) between the audio-navigation unit and the tuner unit. Replace the affected shielded harness.?


	NO

The TUNER RS485+ and the TUNER RS485? wires are not shorted to ground. Go to step 11.

11.

Shorted wire check (TUNER RS485+ line to TUNER RS485? line):

Shorted wire check (TUNER RS485+ line to TUNER RS485? line)

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Tuner unit connector A (10P): disconnected
	Audio-navigation unit connector E (16P): disconnected
Test point 1	Tuner unit connector A (10P) No. 5
Test point 2	Tuner unit connector A (10P) No. 7

Is there continuity?


	YES

There is a short in the wires between the audio-navigation unit and the tuner unit. Replace the affected shielded harness.?


	NO

The TUNER RS485+ wire and the TUNER RS485? wire are not shorted. Go to step 12.

12.

Shorted wire check (TUNER RS485 SH line to another lines):

Shorted wire check (TUNER RS485 SH line to another lines)

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Tuner unit connector A (10P): disconnected
	Audio-navigation unit connector E (16P): disconnected
Test point 1	Tuner unit connector A (10P) No. 5
Test point 2	Tuner unit connector A (10P) No. 6

Test point 1	Tuner unit connector A (10P) No. 6
Test point 2	Tuner unit connector A (10P) No. 7

Is there continuity?


	YES

There is a short in the wires between the audio-navigation unit and the tuner unit. Replace the affected shielded harness.?


	NO

The TUNER RS485 SH wire is not shorted. Go to step 13.

13.

Open wire check (TUNER RS485+ line, TUNER RS485? line):

Open wire check (TUNER RS485+ line, TUNER RS485? line)

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Tuner unit connector A (10P): disconnected
	Audio-navigation unit connector E (16P): disconnected
Test point 1	Tuner unit connector A (10P) No. 5
Test point 2	Audio-navigation unit connector E (16P) No. 15

Test point 1	Tuner unit connector A (10P) No. 7
Test point 2	Audio-navigation unit connector E (16P) No. 16

Is there continuity?


	YES

The TUNER RS485+ and the TUNER RS485? wires are OK. Go to step 14.


	NO

There is an open in the wire(s) between the audio-navigation unit and the tuner unit. Replace the affected shielded harness.?

14.

Tuner unit check (substitution):

Tuner unit check (substitution)

?1.	Substitute a known-good tuner unit.

?2.	Reconnect all the connectors, and recheck.

Does the symptom go away?


	YES

Replace the original tuner unit.?


	NO

Replace the audio-navigation unit.?