496 HO Electrical gremlins
 

I have a 496 HO Mercury engine in my 2005 Baja 25 Outlaw that has an error code that can not be cleared, and it remains in Guardian mode. My mechanic has gone through Mercury for help, including changing ECM, checking grounding and wiring harness. Anyone else have a similar problem? It all started when I hit a wake of another boat and had a moderate jolt.

I've missed one poker run already, and if it isn't fixed this week, I'll me missing another.

Thanks for any suggestions

What exactly are the symptoms/alarm, and the error code that's popping up?

sounds somewhat familiar to the problem member " Haulinvols " had with a Baja 245......I am almost sure they had to replace the harness......maybe you could pm him and get his thoughts....good luck

Reckless - The mechanic said the initial error code was low water pressure for the sea water pump, he replaced the impeller and has good pressure now. I do not know the code.

Showdown - I will try contacing Haulinvols

Sounds just like a problem I had, there was a connection behind the dash that wasn't fully snapped together. I hit a wave and it would shake it enough to cause it to miss. Just might be the same thing.:eek:

Without knowing the active Guardian code its not going to be possible to play "1000 guesses" here. Get the complete Guardian code as well as Guardian history, then you can be helped.

Ray @ Raylar

Yup, been there and done that.

It started like any other day, the sun shining and the birds chirping. The wife and I were going down the river and the alarm sounded, went into guardian mode. I checked everything. All was perfect. Started back up, and ran fine the rest of the day. The next week, same thing, only this time it happened twice. I took it into the shop, they hooked up the computer and it read low water PSI. I knew that was not the case as I had a brand new impellor, and while running the computer showed perfect pressure within limits. This was the last time we got an error code. From that point on, every time it happened, there was no error code saved.

My tech called Mercury for assistance with the issue. They said that we were loosing 12volt to the computer. We checked the wiring and that was not the case. They then said that we were loosing ground. Once again, a check showed ground was fine.

My tech and I drove out in the boat once again and we were finally able to get a trouble code with the computer hooked up as we ran, it showed a bad relay. We replaced the relay but it did not make any difference.

A month has gone by now and nobody can find out what is wrong. The Mercury people want to keep throwing parts at my engine and I am getting pissed. I made a call to a friend of mine that was a VP for Sea Ray and he got me in touch with some higher-ups with Baja customer service. By this time we had decided that there was a short in the main wiring harness somewhere as the problem kept getting worse and worse. Baja Customer service had Mercury overnight a new wiring harness to my tech. After they replaced the harness, everything ran flawlessly after that.

Good luck

Did you have your guy reseat & check the main harness connection @ the engine.. I had a new boat last year that the connection looked ok, but the terminals were not seated all of the way in from the factory.. Once it was reseated it was ok..

Just a thought, although your guy may have already checked this... You may want to check & make sure the bung that your psi sensor threads into is clean/clear.. If something is restricting or blocking the sensor it can/will give you an issue like this..

Hope it helps.. :) Jamie / Lakeside


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An active code should be an easy fix. But as Ray said, without more details it's just a guessing game.

Dave

The latest from the mechanic said Mercury was approving a new wiring harness since they have tried everything else possible they know of. Hopefully it will be done by this weekends poker run.

If that doesn't fix it, I'll have the codes so the rest of you can help the mechanic.

Soooo, did the harness fix it?

im dealing with the same issue as well, except with twins and they both go into guardian mode. Teague marine already tried clearing the codes once, test drove it and did it again. Good to know it might be a wiring harness ill throw that out at the tech just in case. The fastest ive gone in my boat is 35ish, and I bought it new exactly a month ago.

Well that's awful coincidental that both would happen at the same time. There must be some common denominator between the two, to kick in the faults & guardian?? What are the codes your mech is finding on both?

not sure what codes, spoke to him today... he said he got mercury involved and looks like its a low voltage problem and it has to do with the wiring harness.

Remember that voltage problems can be both on the hot side (positive) and the ground (negative) side. It takes both to get good clean voltage.
Have them check, clean and recconect the grounds both the battery ground and the engine harness and ECM grounds on both engines and at the batteries. A loose positive or poor ground can cause havoc on any marine engine and its electronic systems. Sometimes on new boats its sometimes just a mistake of not going back over connections and making sure they are clean and tight.

Best Regards,

Ray @ Raylar

took the boat out again today to test it after having the wires all sorted out basicaly everything raylar mentioned was done, and I have the same PHUKING PROBLEM!! now its really getting frustrating. The guys at Teague Marine are great guys fortunitly specially Bob (not the owner) what a nice guy he is. He is doing the best he can working with mercury on this problem. I just cant believe I had such bad luck with this boat. I think I got a lemon!!!!

I finally got my boat fixed, it took a long time for Mercury to agree to replacing the wiring harness under warranty, service guy said it was a $1400 part. No problems now. It sounds like part of the root cause is due to a grounding problem at the seawater pump. Service guy says there is a bulletin out for the paint to be sanded away to allow for metal to metal contact.

I'm just glad Mercury covered under warranty since mine had actually expired.

Glad it fixed the problem. Sounds like we had the same issue.

Well mercury didn't cover chit on an electrical problem we had with a 6.2. Boat would shut off at cruising speed when it hit a good wave or you speed up. After a couple of trips to the mechanic he finally found the culprit. An exposed wire was tapping up against a piece of metal and shorting out the fuel pump. It sounds like mercury has some wiring issues that they need to fix before somebody gets hurt.

[QUOTE=TexomaPowerboater;2186439 It sounds like mercury has some wiring issues that they need to fix before somebody gets hurt.[/QUOTE]

Not wanting to sound like a racist but that´s what you get when you see Merc Stuff have made in China printed on them...was looking at a 496HO in a staggered engine bay yesterday and wasn´t impressed !!!!

As a sidenote Same thing happened with Alfa Romeo when they started they southern plant in Arese....
Being mostly former fishermen working at the plant made Alfa´s rep go seriously downhill ever since.
No fishers working at the Milano plant...:angry-smiley-055:

OK guys...i just read through all this and kinda think some of these descriptions match my problem but i'll give you a brief run down anyways....
Last weekend was running wide open down the lake, hit NOTHING! no waves, no chop, it was perfect glass! All of a sudden my rpm needle dropped to 0, warning alarm sounded, and i had no clue what was goin on so i just yanked back on throttle. Alarm stopped after 2-3 seconds. Everything was still good, motor still running, rpm reading accurate, all guages where they should be. So, i get goin again and just as i get to plane it happens again. Again, 2-3 seconds of alarm sounding and everything back to normal. Engine never died. check everything again...all normal. i take off again for the dock, after about 4 miles of it running just fine it does it again as i come off of plane to no wake zone. again...check it all out, it's ok. As i'm ideling into dock it does it a 4th time, but corrects itself after about 1 second. So, i have no idea what's goin on. I took it into shop and they're working on it currently. They replaced fuel pump, rewired kill switch (i had it messed up), and a few other things. They ran it on hose and got nothing. Took it to the lake and it DIED leaving the breakwall. Couldn't re-start it. Got a tow in and it fired as they got to the dock. WTF is up with my boat? They said they'd get the computer on it this week sometime and see what that says. I guess i'll just have to wait and see, but in the meantime...does this sound like what some of you were expierencing??? let me know please! thanks guys, i'm new to all of this.
BILL
BTW- it's a 496 mag HO in a 2002 baja outlaw

You need the results from the scan tool when its hooked up to the ECM on the engine. Don't let a shop just start replacing things and making "WAGMAR's -Wild ass guesses made at random!" The active fault codes in the ECM as well as the stored history codes and event times will tell you what needs fix'in! Some questionable shops don't like these new fangled self diagnotics that Mercury provides with every 496, mostly because they might have to just fix a simple connection, sensor or such, no big profit there! good Luck let us know what they find.

Regards
Ray @ Raylar