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.

1. 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.

2. 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.

3. Open wire check (+B_AUDIO line)

   -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.

4. Open wire check (GND line)

   -1. Measure the resistance 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 1.0 Ω or less?

   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).

5. 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.

6. 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 .

7. 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.

8. Open wire check (+B_AUDIO line)

   -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.

9. Open wire check (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 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 wire is OK. Go to step 10.

   NO 

   Repair an open in the wire.

10. Open wire check (GND line)

    -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)

    -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. Measure the resistance 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 1.0 MΩ or more?

    YES 

    The LVDS1+ wire and the LVDS1- 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 (LVDS1 SH line to another lines)

    -1. Measure the resistance 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 1.0 MΩ or more?

    YES 

    The LVDS1 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 (LVDS1+ line, LVDS1- line)

    -1. Measure the resistance 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 1.0 Ω or less?

    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)

    -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 .