Not so much an answer, but wanted to say that I recently bought a used 2004 Ody, and it does the exact same thing, and there are no problems with the vehicle. Could just be part of the start-up behavior. If this is a NEW behavior, then I'd be more concerned.
Good luck!
jah
Glenview, IL
The 1997 Dakota was the last year that you could pull codes by switching the ignition key on and off. Here's How: Within 5 seconds, turn the ignition key ON - OFF - ON - OFF - ON The trouble light will come on for two seconds then flash a number of times then pauses then flashes a number of times then pauses. when it flashes 55 it mean there are no more codes stored in memory. Multiple codes are separated by a 4 second pause.
The duration of Adventures in Odyssey is -1800.0 seconds.
Resetting the maintenance light on a 1998 Odyssey is very easy to do. All you need to do is hold the reset button down and then turn the ignition on at the same time. The button will need to be held for 10 seconds.
The duration of IPW Ignition is 3600.0 seconds.
The Amber Light Flashes For Four Seconds.
If the Odyssey uses the same routine as a Toyota, reset is accomplished by setting the mileage meter to total [as opposed to Trip A, Trip B] and then turning the ignition key to off. Then, holding the mileage reset button down, turning the ignition switch back on...continuing to hold the reset button .... in 5-10 seconds the maintenance 'reminder' light should go out.
It has a Lighthouse on it which flashes every 15 seconds.
600, 60(seconds)x60(minutes)=3600(seconds)/6=600
Turn the ignition key to RUN, with the engine off. Fully press and release the gas pedal 3 times within 5 seconds. If the light flashes 5 times then it has been reset.
Ignition key to run position, "engine off" pump throttle 3 times within 5 seconds CHG OIL SOON light flashes 2 times system is reset
360 times
It flashes 6 times per minute, , so 360 times per hour.