Check for continuity between navigation unit connector B (12P) terminal No. 4 and body ground. Is there continuity?
YES | - | Go to Step 9 .
NO | - | Repair open in the wire between the navigation unit and body ground (G603).■
Reconnect the navigation unit connector B (12P). 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. ■ If the symptom is gone, replace the original unit. If the display does not show any back light, substitute a known-good display unit, and recheck. If the symptom is gone, replace the original display unit.
NO | - | Replace the display unit, refer to audio-HVAC display module removal. ■