Navigation frequently asks for code and needs GPS initialization

WARNING: This page is about a different car, the 2006 Honda Odyssey and 2005 Honda Odyssey. However, it is still accessible from the selected car via links, so may be relevant.

Check for battery voltage on navigation unit connector C (8P) terminals No. 1 and No. 2.
Is there battery voltage?
1. YES - Go to step 2.
2. NO - Repair the circuits.
Check for continuity between navigation unit connector C (8P) terminal No. 4 and body ground.

Fig 1: Checking Continuity Between Navigation Unit Connector C (8P) Terminal No. 4 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Replace the navigation unit.
2. NO - Repair the open in the circuit.