AM/FM radio display is blank or no station information is displayed

NOTE: 

• Check the vehicle 12 volt battery condition first .
• Check the connectors for poor connections or loose terminals.

1. 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 blankΩ

   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)

   -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)

   -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) (with navigation) No. 1
   	Audio unit connector E (16P) (without navigation) No. 1
   Test point 2	Body ground

   Is there about 6.0 V?

   YES 

   Repair an open in the wire.

   NO 

   The TUNER_6V wire is not open. Go to step 4.

4. Shorted wire check (TUNER_6V line)

   -1. Disconnect the following connector.

   Audio-navigation unit connector E (16P) (with navigation) Audio unit connector E (16P) (without navigation)

   -2. Measure the resistance between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	Tuner unit connector A (10P): disconnected
   	Audio-navigation unit connector E (16P) (with navigation): disconnected Audio unit connector E (16P) (without navigation): disconnected
   Test point 1	Audio-navigation unit connector E (16P) (with navigation) No. 1
   	Audio unit connector E (16P) (without navigation) No. 1
   Test point 2	Body ground

   Is there 1.0 MΩ or more?

   YES: With navigation

   Replace the audio-navigation unit .

   YES: Without navigation

   Replace the audio unit .

   NO 

   Repair a short to body ground in the wire.

5. Determine possible failure area (TUNER_GND line, others)

   -1. Measure the resistance 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 1.0 Ω or less?

   YES 

   The TUNER_GND wire is OK. Go to step 7.

   NO 

   Go to step 6.

6. Open wire check (TUNER_GND line)

   -1. Measure the resistance 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) (with navigation) No. 9
   	Audio unit connector E (16P) (without navigation) No. 9
   Test point 2	Body ground

   Is there 1.0 MΩ or more?

   YES: With navigation

   Replace the audio-navigation unit .

   YES: Without navigation

   Replace the audio unit .

   NO 

   Repair an open in the wire.

7. 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)

   -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) (with navigation) No. 2
   	Audio unit connector E (16P) (without navigation) No. 2
   Test point 2	Body ground

   Is there about 9.0 V?

   YES 

   Repair an open in the wire.

   NO 

   The TUNER_9V wire is not open. Go to step 9.

9. 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) (with navigation) Audio unit connector E (16P) (without navigation)

   -3. Measure the resistance between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	Tuner unit connector A (10P): disconnected
   	Audio-navigation unit connector E (16P) (with navigation): disconnected Audio unit connector E (16P) (without navigation): disconnected
   Test point 1	Audio-navigation unit connector E (16P) (with navigation) No. 2
   	Audio unit connector E (16P) (without navigation) No. 2
   Test point 2	Body ground

   Is there 1.0 MΩ or more?

   YES: With navigation

   Replace the audio-navigation unit .

   YES: Without navigation

   Replace the audio unit .

   NO 

   Repair a short to body ground in the wire.

10. 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) (with navigation) Audio unit connector E (16P) (without navigation)

    -3. Measure the resistance between test points 1 and 2.

    Test condition	Vehicle OFF (LOCK) mode
    	Tuner unit connector A (10P): disconnected
    	Audio-navigation unit connector E (16P) (with navigation): disconnected Audio unit connector E (16P) (without navigation): 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 1.0 MΩ or more?

    YES 

    The TUNER_RS485+ and the TUNER_RS485- wires are not shorted to ground. Go to step 11.

    NO 

    There is a short to body ground in the wire(s). Replace the affected shielded harness.

11. Shorted wire check (TUNER_RS485+ line to TUNER_RS485- line)

    -1. Measure the resistance between test points 1 and 2.

    Test condition	Vehicle OFF (LOCK) mode
    	Tuner unit connector A (10P): disconnected
    	Audio-navigation unit connector E (16P) (with navigation): disconnected Audio unit connector E (16P) (without navigation): disconnected
    Test point 1	Tuner unit connector A (10P) No. 5
    Test point 2	Tuner unit connector A (10P) No. 7

    Is there 1.0 MΩ or more?

    YES 

    The TUNER_RS485+ wire and the TUNER_RS485- wire are not shorted. Go to step 12.

    NO 

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

12. Shorted wire check (TUNER_RS485_SH line to another lines)

    -1. Measure the resistance between test points 1 and 2.

    Test condition	Vehicle OFF (LOCK) mode
    	Tuner unit connector A (10P): disconnected
    	Audio-navigation unit connector E (16P) (with navigation): disconnected Audio unit connector E (16P) (without navigation): 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 1.0 MΩ or more?

    YES 

    The TUNER_RS485_SH wire is not shorted. Go to step 13.

    NO 

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

13. Open wire check (TUNER_RS485+ line, TUNER_RS485- line)

    -1. Measure the resistance between test points 1 and 2.

    Test condition	Vehicle OFF (LOCK) mode
    	Tuner unit connector A (10P): disconnected
    	Audio-navigation unit connector E (16P) (with navigation): disconnected Audio unit connector E (16P) (without navigation): disconnected
    Test point 1	Tuner unit connector A (10P) No. 5
    Test point 2	Audio-navigation unit connector E (16P) (with navigation) No. 15

    Audio unit connector E (16P) (without navigation) No. 15

    Test point 1	Tuner unit connector A (10P) No. 7
    Test point 2	Audio-navigation unit connector E (16P) (with navigation) No. 16
    	Audio unit connector E (16P) (without navigation) No. 16

    Is there 1.0 Ω or less?

    YES 

    The TUNER_RS485+ and the TUNER_RS485- wires are OK. Go to step 14.

    NO 

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

14. 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: With navigation

    Replace the audio-navigation unit .

    NO: Without navigation

    Replace the audio unit .