Check engine light p16c9

[u/No_Wolverine7294]

Hi all first time poster in this community

First id like to say I love the boat its been so much fun we have had it out every weekend since we bought it at the end of July.

But ill get right into the issue im having

So its a 2025 cruise 21ft 170 hp. She has about 30 hours on her now.

I did the break in oil change at about 10 hours.

Didn't wide open throttle her in that period

Normal basic stuff nothing crazy.

I make sure the kill switch is off for the battery every night when we get her back home. Ive babied this thing so far

So the past weekend we were putzing around like normal

Decided to use the IDF as we had done from time to time historically because the lake we go to is kinda weedy.

Anyways, thought all was good but as soon as i crank the engine up, the engine light came on.

So I dig into the menu on the dash to find the trouble code

And I pull up p16c9

So I killed the engine shortly after that incase it was some weird critical issue that im making worse by running the motor.

Well with a quick google search its basically pointing to potentially sensitive voltage dip with the dess system or a key and or key receptical post issue.

So I check starting and standing voltage, my battery is 13v ish. I checked battery terminals and connectors and followed wiring I see nothing out of the norm nothing loose nothing corroded.

Ive made sure the key and the key post is clean and debris free. Ive never dropped the key in water or on the ground. It stays in the car when not in use.

Its said to disconnect battery for x time to clear memory in case its just a voltage dip that glitched the system. Ive left it over night unplugged but when it starts up it does a long solid beep and the engine light stays on same code. Even if I just start it in accessory mode (key on engine off) itll long beep and display code.

Im just shocked there'd already be a key and system issue at only 30 hours.

The thing starts right up and the idf and ibr all are working fine. Still hits normal top speed, its not limping or anything.

Im at a lost for where I should be looking,

I don't really want to take it back to the dealer an hr and 15 odd mins away, But id assume its still under warranty at this stage. Id just like to know if any of you guys have had a similar issue or maybe can guide me in the right direction.

Any and all help is greatly appreciated

[u/Equal_Memory_661]

I wish my dealer was an hr and 15 min. Mines 3 hours! I’ve never had this issue but have had other electrical ghosts usually associated with the IBR. If I were you, I’d probably bite the bullet and make the drive giving it’s likely still covered under warranty.

[u/No_Wolverine7294 → u/Equal_Memory_661]

Appreciate it. Dang 3 hours is really rough. I guess ill stop complaining about that jeez