1. Check for continuity between the appropriate terminals of navigation unit connector A (20P) and display unit connector B (20P) based on the missing color(s).

   Missing color | Navigation unit connector A (12P) | Display unit connector B (20P)
   --- | --- | ---
   Blue | A11 | B10, B20
   Green | A2 | B10, B20
   Red | A1 | B10, B20

Is there continuity?

YES | - | There is a short to body ground in the circuit between the display unit and the navigation unit. Replace the affected shielded harness.■
NO | - | Replace the navigation unit. If the problem is still unresolved, replace the display unit.■