| 1. | Check the No. 7 (10A) fuse and No. 32 (7.5A) fuse in the under-dash fuse relay box, and reinstall the fuse if it is OK. Is the fuse OK? YES - Go to 2. NO - Replace the fuse and recheck.n |
| 2. | Turn the ignition switch to ACC (I). |
| 3. | Operate the radio and listen to the audio. Can audio be heard? YES - Go to 4. NO - Check the ACC circuit.n |
| 4. | Turn the ignition switch ON (II). |
| 5. | Measure the voltage between body ground and navigation unit connector B (12P) terminals No. 1 and No. 2 individually. Is there battery voltage? YES - Go to 6. NO - If the +B wire does not have voltage, repair open in the wire between the under-dash fuse relay box and the navigation unit. |
| 6. | Turn the ignition switch OFF. |
| 7. | Disconnect the navigation unit connector B (12P). |
| 8. | Check for continuity between navigation unit connector B (12P) terminal No. 4 and body ground. Is there continuity? YES - Go to 9. NO - Repair open in the wire between the navigation unit and body ground (G603).n |
| 9. | Reconnect the navigation unit connector B (12P). |
| 10. | Shield the display unit from the sun with your hand, and check that the display is back lit (only back light is ON.) Can you see the back light? YES - Replace the navigation unit with a known good unit.n
NO - Replace the display unit, refer to audio-HVAC display module removal.n |