How to tell if computer has been replaced?
 

I have been looking at a lot of boats lately. The one yesterday was a 2008 with 24 hours. The guy said the speedometer did not work and I was thinking the boat had more than 24 hours on it. Is there a way by looking to see if the computer has been replaced, or is there something to reference? Any tell-tell way to verify the hours? I was thinking the speedometer and the low hours might give it away. Today I went and looked at a 2009 with 200 hours and the interior gave me the idea that it had more hours as well.

An '08 would have been done under warranty. Run the engine serial numbers through a dealer. The engine warranty follows the engine, not the boat or owner. The cost of an ECM isn't worth the silly buggers of falsifying engine hours.
200 seems right for an '09, maybe they have kids that trashed the interior, don't be too paranoid, you should see my wife's car.

The Speedo and hour meter don't have anything to do with one another. The hours can be cleared without buying a new computer if you have the scan tool.

Is there a way to tell if it has been done? Can I buy a scan tool and see this? I would be willing to make a long term investment in such a tool if it would help me steer clear of a potential problem - like tampering might. I am surprised this is possible. I would think that would be something that would be/should be illegal.

That is a good idea. Are dealerships good about running this through their system? I know car dealerships usually won't do it, or at least not for free.

I doubt that it's legal but I know it can be done. I've seen it happen by accident. I really doubt that there are very many boat out there that have been tampered with. I'm not a expert but I doubt you could tell that it's been done. You can buy a scan tool though and see if there have been any other codes thrown.

I'd put more thought into having a compression test done.

While it true you can erase the rpm history on some ecm's with the correct software, it is very rare to be able to completely erase the total engine hours in the ECM. I know it can't be erased on mercury, marine power, and any Japanese outboard. Not completely positive on PCM or indmar, but since they use the same mefi program as other chevy based efi systems, i'd bet the total hours are tamper proof.

200 hours of engine time could easily be 400+ hours of boat usage time. Out here in CO once the water gets trashed we throw the anchor and hang out for hours. Figure a lot of days we do 7-7 so that's 12 hours of interior usage vs probably 4-5 hours of engine usage. Also if the engine was replaced due to lemon of an engine, neglect, or whatever the ECU will also be replaced so the display will show the new engine hours. I'd do like what was suggested above and run the hull ID and engine serial numbers through your local dealer.

Maybe just the fact that you feel something is not right. There are tons of good boats out there for sale, if it doesn't seem right, just walk away

I own a Mercruiser Scan tool and it does not have provisions to erase ECM hour memory. RPM history yes, but not hours. The hour log is a protected area just like an odometer on a vehicle otherwise imagine all the people that would be altering this feature for personal gain. Only seen it happen once and it certainly wasn't intentional, but just one of those freak things that nobody could answer as to why it happened. Only way I know to erase ECM hours is to replace the module.

Meathead,

I just spoke with a local Mechanic and he said that generally speaking you are right. I know this guy knows his S&*t and what he said is you can't erase it on newer boats and some engines like PCM. He also said that you can't do it with a cheapo scan tool. He said that it can be done on older Mercruisers if your not careful.

Like I said before I'm not a expert on the topic but I know that it can be done because it happened on my boat ( 2000 Mercruiser) and one of the best marine mechanics in the area said that it can be done on some ECU's like mine.

A little off topic but I was surprised at how off the hour meter was to the ECU.

Unfortunetly there is no such thing as a "cheapo" scan tool for Mercruiser or any of the companies as far as I know. Try pricing them and you'll see.

I've seen it happen too....

Not by accident, but out of pure necessity. The digital gauges on early-2000's model year Nautiques were faulty. Sooooo many in that range had their tach+hour meter go. Cruddy, kinda unproven early marine digital gauges thrown into hundreds of these boats. But they go, not a year into ownership... like 6. So a significant amount of hours get wiped. I hate these things. Hate hate hate them.

Ugh. Sorry to hear you're wasting a second of your time with this horse s**t. This is why I'm straight analog. Good luck.

Don't confuse the dash hour meter with the hours stored in the engines ECM...they aren't always the same thing. Many tachs with digital hour meters are self contained and do not represent what the ECM hours are on the motor.

Walt....I'm 20 years into this marine service game, so I know a little.

I never said you didn't :)

Sorry, feeling a little sensitive these days.

No worries buddy !

So is there a scan tool I can buy to take with me when looking at boats? The moral of the thread is that it is in the realm of possibilities to mess with the hour numbers but not very easy.

Sure you can have your own. Starting @ $400 and going up from there. http://www.rinda.com/acro/prodlist.pdf