2 Added from the other answer ... just edit, don't double post, please.
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Check circuit F28 for open. (Pin 9 DLC to A16 PCM)

Power Management Diagram

EDIT:

Check pin 3 (Immobilizer) to 14 DLC for continuity.

If okay, may be inclined to replace immobilizer as first course of action.

After replacement, consider researching Honda 'automatic key registration'. Unfortunately, I don't have the time to look into it. Recently, I replaced an immobilizer on a Corolla and the automatic key registration procedure was key to 'on' to 'off' position - 5 times.

Power Management Diagram

Check circuit F28 for open. (Pin 9 DLC to A16 PCM)

Power Management Diagram

Check circuit F28 for open. (Pin 9 DLC to A16 PCM)

Power Management Diagram

EDIT:

Check pin 3 (Immobilizer) to 14 DLC for continuity.

If okay, may be inclined to replace immobilizer as first course of action.

After replacement, consider researching Honda 'automatic key registration'. Unfortunately, I don't have the time to look into it. Recently, I replaced an immobilizer on a Corolla and the automatic key registration procedure was key to 'on' to 'off' position - 5 times.

Power Management Diagram

1
source | link

Check circuit F28 for open. (Pin 9 DLC to A16 PCM)

Power Management Diagram