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496 beep and rpm fluctuation
I have a 2006 496mag that has a single beep and rpm fluctuation all within a fraction of a second, but the motor never shuts down. This was happening once every time I would start the motor. It would usually do it while warming up, and it wouldn't happen again until I shut down and restarted. but it would only do it once. Now it has become a problem and doing this whenever it feels like it. sometimes it will stop for a few minutes, then comes back again. It seems to stop if I put the boat in neutral and bring the rpms up above 1200. Only one motor has the symptom.
I scanned the motor and no codes. Put in a crank sensor just because I had a spare, no fix. Cleaned battery connections, no fix. unplugged/replugged computer connections, no fix. pulled main harness plug, and its clean. Does anyone have any ideas ? I'm going to find the ground connection on the block and clean that next. The battery is at least five yrs old on that side, I thought I would try replacing that. Maybe take a look at the key switch ? swap computers from side to side ?? Here is video..... <iframe width="560" height="315" src="https://www.youtube.com/embed/ci-FFGQ5MOI?rel=0" frameborder="0" allowfullscreen></iframe> |
When was the last time you replaced the IAC?
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Originally Posted by Sydwayz
(Post 4581693)
When was the last time you replaced the IAC?
The only reason I didn't think that would be it cause it's happening above idle. |
Drive lube bottle warning horn
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Ive had drive lube warnings before. They never killed power to the motot before. You and actually feel The motor shutting down briefly
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If you have DTS you DO NOT have IAC or IAC muffler - Close to 35 percent of 496 do not have IAC nor the muffler in sport boats. With that said do you have Mechanical throttle & shift or DTS. That the question that needs to be answer first and foremost.
Also Cruiser and or Sport cruiser boat apps with 496 engines about 50 percent did not have IAC s because a lot those apps are DTS. All Mercruiser DTS do not have IAC nor IAC mufflers If you do not have DTS you will have an IAC and IAC muffler - there is such a thing as IAC complete maintenance whether you have a problem or not. IAC maintenance is part of a tune up persay. DTS = digital throttle & shift |
intermittent continuous beep OEM Merc warning horn systems is drive lube bottle
other Possible issues -- voltage problem -- and or low voltage also I would check ALL YOUR SPARK PLUG WIRES --- all connected very tight and then make sure one or more is not arching off something. An engine scan should be performed without question. |
No DTS here. This is happening on my formula PC.
It does have an IAC cause I've replaced the other side a couple years ago. Keep a spare now just in case. Ill try that next. |
I've scanned the motor and there were no codes. Voltage read 14 on the scanner.
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Have you checked the wires and connectors at the alternator?
There was a similar issue recently in the post below: http://www.offshoreonly.com/forums/b...it-second.html Hope you get it figured out. |
Originally Posted by bohmi
(Post 4581822)
Have you checked the wires and connectors at the alternator?
There was a similar issue recently in the post below: http://www.offshoreonly.com/forums/b...it-second.html Hope you get it figured out. |
Steve has almost the same thing. It turns the off and back on. But more random. It has been in and out of the shop for the last 2 years. No one can nail it down. Been down almost every street with the internet and shops. Bad grounds, bad batteries, bad computer, bad IAC, bad 50 amp circuit protector, bad fuel pump ,bad ignition switch, bad safety switch, bad coil, bad wires, and the list goes on and on. Funny the local shop has pretty much given up. So Ill do some more digging this off season into his boat. Yes I have and the shop have scanned the engine several times with nothing.
Originally Posted by bohmi
(Post 4581822)
Have you checked the wires and connectors at the alternator?
There was a similar issue recently in the post below: http://www.offshoreonly.com/forums/b...it-second.html Hope you get it figured out. |
Originally Posted by 92nsx
(Post 4581904)
Steve has almost the same thing. It turns the off and back on. But more random. It has been in and out of the shop for the last 2 years. No one can nail it down. Been down almost every street with the internet and shops. Bad grounds, bad batteries, bad computer, bad IAC, bad 50 amp circuit protector, bad fuel pump ,bad ignition switch, bad safety switch, bad coil, bad wires, and the list goes on and on. Funny the local shop has pretty much given up. So Ill do some more digging this off season into his boat. Yes I have and the shop have scanned the engine several times with nothing.
https://www.youtube.com/watch?v=YjpOWyRCmk0 ^^^^^^ This will now be on my list this winter to check. This is a new one I haven't seen. Thank you! |
Originally Posted by 92nsx
(Post 4581904)
Steve has almost the same thing. It turns the off and back on. But more random. It has been in and out of the shop for the last 2 years. No one can nail it down. Been down almost every street with the internet and shops. Bad grounds, bad batteries, bad computer, bad IAC, bad 50 amp circuit protector, bad fuel pump ,bad ignition switch, bad safety switch, bad coil, bad wires, and the list goes on and on. Funny the local shop has pretty much given up. So Ill do some more digging this off season into his boat. Yes I have and the shop have scanned the engine several times with nothing.
https://www.youtube.com/watch?v=YjpOWyRCmk0 ^^^^^^ This will now be on my list this winter to check. This is a new one I haven't seen. Thank you! I know I replied to this guys post. Maybe its interference from the empty beer bottle and beer koozy ? haha Where is this guys post ? |
I ended up swapping computers over the weekend and the problem followed. So now I guess I need a new PCM.
Where can I find one for a stock 2006 496mag non HO motor ? |
Will need your serial number to look it up
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Originally Posted by AllDodge
(Post 4582973)
Will need your serial number to look it up
number on the PCM is 866090-003, but I can't seem to find that exact number anywhere. I'm not sure if the 003 on the end is a revision # or it means something else. I find variations of 866090Txx numbers out there, but nothing that is the same as my #. |
The original part number was 866090T01
Genuine Mercury & Mercruiser parts. 866090T01 PCM Genuine OEM Mercury Marine-Mercruiser part BAM shows it has been superseded by 866090T05 Genuine Mercury & Mercruiser parts. 866090T05 PCM Genuine OEM Mercury Marine-Mercruiser part Looks like cheapest is at ebay but not that much cheaper. BRAND NEW Mercury Mercruiser Quicksilver OEM PCM PN 866090T05 | eBay |
ALLDodge, Thanks for the clarification on the part #'s.
The ebay auction has a different part # on the label of the PCM that is in the picture. I emailed him to clarify. Chit these things are expensive !! |
for the 555 controller most likely an alternator wire issue would should in the scan as a Voltage fault. Wanted to mention this from the post that were brought up about that issue. Also voltmeter testing would have found that problem as well. always start at the battery and work way thru all the other power systems, ie starter cables, power relays and or breakers, alternator and so on.
If you want to send me your PCM I can see if I can fix it . If I can not for a fix - a very min charge like 50 bucks with shipping back to you would be included. If I can fix it of course the changes will apply depending on what is the issue(s). Not all PCM 's are repairable. I will not be available until next Monday. So far I have fixed about 60 percent of the 555 PCM's / ECM's With that said I have not done that many but gaining more ground for that part of the business. |
to be clear you posted -- a 496 MAG Not the HO MAG ?
you have to get the correct PCM - there is different PCM's - you have to watch out what you buy and these sellers on the net are clueless with no idea how the operations of one apps truly works. . They have no idea that an inboard ECM / PCM is different that an I/O ECM / PCM and that HO is different than a MAG no HO --- just a few examples of the many. |
Originally Posted by BUP
(Post 4582547)
Have you replace the TACH and or checked all of its harness adaptions here ? Connections at cannon plug ? transom harness connections ?
I know I replied to this guys post. Maybe its interference from the empty beer bottle and beer koozy ? haha Where is this guys post ? New TACH, no. The engine physically turns off and back on. You can feel it the boat, it lists to port side when it happens. I like the Alt wiring theory. I know the shop has no put that down on any of it's inspections, nor have I checked it. All tho I just had to replace the IAC on that engine......... Since replacing it he has not reported the engine off/on problem. The engine harness, connections, and 12 or 15 pin connector were "supposedly " Unplugged and inspected for damage by the shop. |
depending on serial number 10 pin or 14 pin
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Originally Posted by BUP
(Post 4583002)
for the 555 controller most likely an alternator wire issue would should in the scan as a Voltage fault. Wanted to mention this from the post that were brought up about that issue. Also voltmeter testing would have found that problem as well. always start at the battery and work way thru all the other power systems, ie starter cables, power relays and or breakers, alternator and so on.
If you want to send me your PCM I can see if I can fix it . If I can not for a fix - a very min charge like 50 bucks with shipping back to you would be included. If I can fix it of course the changes will apply depending on what is the issue(s). Not all PCM 's are repairable. I will not be available until next Monday. So far I have fixed about 60 percent of the 555 PCM's / ECM's With that said I have not done that many but gaining more ground for that part of the business. |
Originally Posted by BUP
(Post 4583005)
to be clear you posted -- a 496 MAG Not the HO MAG ?
you have to get the correct PCM - there is different PCM's - you have to watch out what you buy and these sellers on the net are clueless with no idea how the operations of one apps truly works. . They have no idea that an inboard ECM / PCM is different that an I/O ECM / PCM and that HO is different than a MAG no HO --- just a few examples of the many. The ebay ad listed above shows Part number 866090T05 is in the description, but shows 8M2002205 on the unit itself. Seller told me "dont worry about the number difference as that number is used by mercury only". I don't trust it. |
[QUOTE=BUP;4583002]
If you want to send me your PCM I can see if I can fix it . If I can not for a fix - a very min charge like 50 bucks with shipping back to you would be included. If I can fix it of course the changes will apply depending on what is the issue(s). Not all PCM 's are repairable. QUOTE] The new PCM solved my issue. I'd like to send you the old one to see if it can be fixed, so I can have a spare. Let me know if you want to look at it. I tried to PM you, but you are full. PM me with how to contact you. |
Sorry about the full OSO Pms. I sent a visitor message and a PM to you. You can send me your PCM 555 as I PM all the info. THANKS.
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I am having the same problem!!! Were you able to get your pcm repaired? Would love some HELP |
this PCM in the thread had multiple issues, Clock chip, IAC circuit and capacitors. Let me know if I can help and testing of the PCM 555
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Hi, newbie here. I am having a very similar issue on my 2006 Mercruiser 496 mag 0W632320 I get a single short beep, drop in revs and then immediately returns and carries on ok. Usually happens shortly after starting (about first 5 minutes) and usually only once per trip although have had a couple more occasionally. last time I went out I did a bunch of runs to try and figure out what is happening. I noticed that when the beep occurred the revs dropped to about 600 - you can feel the boat slow momentarily- but it doesn’t sound like it is running rough or misfiring- the alarm is a single beep for about a second. Boat then carries on running as normal. This was happening shortly after starting up - within a few minutes. I did about 7 or 8 starts and it happened every time. The revs showing on the Smartcraft tachometer drop and the digital voltage display on the Smartcraft gauge goes down to 0 volts for a few seconds but the display stays live. The analog voltage gauge doesn’t move. I have VesselView mobile and it doesn’t give me any fault codes. I started checking all of the connections to see if it could be a ground short but haven’t found any loose or damaged connections. Have checked all fluids and all ok. I checked the harness connection at the engine and that seems ok. Strangely enough - I disconnected all of the Smartcraft gauges and just left the VesselView Mobile hooked up and the problem became a lot less frequent. I did about 5 starts and it didn’t happen but then on the last run out it happened after about 25 minutes. I’m guessing that is just coincidence that it improved when the gauges were disconnected. I’m not sure if a fault in the Smartcraft gauges or CAN cable could cause a problem. So I think it is fair to assume that I am losing voltage somewhere in the system....the fact that the gauges stay live and show 0volts....does that mean that my ignition switch and harness are ok or is that too much of an assumption? Is the interruption so quick that the gauges don’t respond? Noting that the previous issue on this thread was resolved by a new PCM (and the similarity in serial #) - is there an easy way to test if my issue is ‘upstream’ or downstream of the PCM? I am based in Australia and don’t have a scanner but do have multimeter. Thanks for any guidance, tips or ideas! |
Buy a VeselView Moblie its worth every penny and way cheaper then a scanner. https://publications.brunswick.com/P...ductCode=VV-MM
Also BUP is a great guy to work with and has a ton of knowledge. He actually called me a couple days after I bought plugs and wires to make sure everything wasn't damaged during shipping and fit properly. |
Originally Posted by iaoutlaw
(Post 4711948)
Buy a VeselView Moblie its worth every penny and way cheaper then a scanner. https://publications.brunswick.com/P...ductCode=VV-MM
Also BUP is a great guy to work with and has a ton of knowledge. He actually called me a couple days after I bought plugs and wires to make sure everything wasn't damaged during shipping and fit properly. |
For OP here Hi perf 2000 and many others - His issues was NOT rare but there was more than one issue going on here. During thru out on my end I keep trying to find out why the 555 s fail more than any other ecm / pcm in the marine world. Yes they fail more than any other ecm / pcm by far. Anyways I called HP2000 back months later to see how all was going plus I had some news what else I wanted for him to change out on his engine side to help against a failure again. He reported to me that his NEW and mine repaired PCM both were doing the same thing as before.
Anyways I told him to send it back to me and I will warranty my end. Also I needed him to change a couple parts out to new on the engine side as well cause the failures will keep happening no matter if the PCM was new or a repaired PCM. Once I fixed his pcm again - He wanted me to overnite it and he would pay for that end. . I also saved him overnite shipping costs from a discount I get at Fed Ex. . End of the story, he is all fixed up and running well FINALLY. The morel of the story here is ALL PCM failures have more than one internal issue and 80 percent of the time --- the cause was from on the engine side and or -- battery side and or - cabling side and or - VOLTAGE or a person self inflicted the damage -- all those ends need to be checked and or fixed as well. ECM / PCM s 80 percent failures are cause by something on the engine / boat / battery / person side. -- if that side goes unfixed then the ECM / PCM failures will happen again and again and again always. |
Originally Posted by Freobhoy
(Post 4711907)
Hi, newbie here. I am having a very similar issue on my 2006 Mercruiser 496 mag 0W632320 I get a single short beep, drop in revs and then immediately returns and carries on ok. Usually happens shortly after starting (about first 5 minutes) and usually only once per trip although have had a couple more occasionally. last time I went out I did a bunch of runs to try and figure out what is happening. I noticed that when the beep occurred the revs dropped to about 600 - you can feel the boat slow momentarily- but it doesn’t sound like it is running rough or misfiring- the alarm is a single beep for about a second. Boat then carries on running as normal. This was happening shortly after starting up - within a few minutes. I did about 7 or 8 starts and it happened every time. The revs showing on the Smartcraft tachometer drop and the digital voltage display on the Smartcraft gauge goes down to 0 volts for a few seconds but the display stays live. The analog voltage gauge doesn’t move. I have VesselView mobile and it doesn’t give me any fault codes. I started checking all of the connections to see if it could be a ground short but haven’t found any loose or damaged connections. Have checked all fluids and all ok. I checked the harness connection at the engine and that seems ok. Strangely enough - I disconnected all of the Smartcraft gauges and just left the VesselView Mobile hooked up and the problem became a lot less frequent. I did about 5 starts and it didn’t happen but then on the last run out it happened after about 25 minutes. I’m guessing that is just coincidence that it improved when the gauges were disconnected. I’m not sure if a fault in the Smartcraft gauges or CAN cable could cause a problem. So I think it is fair to assume that I am losing voltage somewhere in the system....the fact that the gauges stay live and show 0volts....does that mean that my ignition switch and harness are ok or is that too much of an assumption? Is the interruption so quick that the gauges don’t respond? Noting that the previous issue on this thread was resolved by a new PCM (and the similarity in serial #) - is there an easy way to test if my issue is ‘upstream’ or downstream of the PCM? I am based in Australia and don’t have a scanner but do have multimeter. Thanks for any guidance, tips or ideas! |
Thanks for all the info. Is there any way to confirm if my issue is similar to the previous ones and hence needs the same PCM repair? I’ll try and post a video. I dont get the multiple beeps - just one beep per trip, so far. |
One beep per trip ? How long is the trip ? and what kind of beep is it and what does your voltage on the gauge showing during that beep. A full engine scan would help to possible see whats going on
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Originally Posted by BUP
(Post 4712114)
One beep per trip ? How long is the trip ? and what kind of beep is it and what does your voltage on the gauge showing during that beep. A full engine scan would help to possible see whats going on
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I too am experiencing a single beep with loss of RPM on my 2006 496 Mag (Not HO). Mechanic tightened a loose battery cable, replaced ignition switch, and located and tightened a loose ground ground for the starboard Buss Bar at the stud on the engine. These have not corrected the issue. I get a single beep / RPM loss one time per engine start up - sometimes right away at engine warm up, others as we are under way.
BUP, you mentioned that one of the other boaters you helped above, that you directed him to replace some parts on the engine with new. What parts should I be looking to replace? Also are your still available to repair PCMs? I would like to get mine repaired and take care of the possible items that may cause the PCM to have future failures. -What is the process for sending the PCM to you and what is the turnaround time I need to plan for? - I tried to PM you, but your inbox is full. If can PM me, I would appreciate it. Josh |
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