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. 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) (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 continuity?

   YES 

   Repair a short to body ground in the wire.

   NO: With navigation

   Replace the audio-navigation unit .

   NO: Without navigation

   Replace the audio unit .

5. 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)

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

   Is there continuity?

   YES 

   Repair an open in the wire.

   NO: With navigation

   Replace the audio-navigation unit .

   NO: Without navigation

   Replace the audio unit .

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. 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) (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 continuity?

   YES 

   Repair a short to body ground in the wire.

   NO: With navigation

   Replace the audio-navigation unit .

   NO: Without navigation

   Replace the audio unit .

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. 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) (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 continuity?

    YES 

    There is a short to body ground in the wire(s). 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)

    -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) (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 continuity?

    YES 

    There is a short in the wires. 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)

    -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) (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 continuity?

    YES 

    There is a short in the wires. 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)

    -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) (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 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). 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 .