Go Back  Offshoreonly.com > Technical > General Q & A
496HO issues >

496HO issues

496HO issues

Old 06-09-2018, 10:51 PM
  #1  
Registered
Thread Starter
 
Join Date: Jul 2013
Location: Nelson, BC, Canada
Posts: 57
Likes: 0
Received 0 Likes on 0 Posts
Default 496HO issues

Put a used 08 496 HO in my 99 Searay 230 last summer and it seems to be in guardian mode. Bought the bluetooth unit for scanningto see what is wrong and it powers up fine, tablet pairs up but no PCM communication. Other issue was I had to jump a ground wire on neutral switch to get it to turn over in neutral to start. Runs fine but cant get any rpm over 3500 and seems like has less power than the old Alpha 350 setup no matter what I prop it with. I have a feeling PCM is issue as the start issue I believe is lack of ground through PCM to complete circuit. Havent found proper diagram for electrical to trace properly. Would a reflash correct this? Do I need a new PCM?
brianscathouse70 is offline  
Old 06-10-2018, 08:12 AM
  #2  
Registered
 
Join Date: Apr 2018
Posts: 133
Likes: 0
Received 0 Likes on 0 Posts
Default

Before you go blaming the PCM I would look at you scan tool, we had the genuine Mercruisers bluetooth attachment thing and it ended up in the lake...........it didn't work very well for us lol. Also the safety natural switch does not have a ground wire, it will be yellow with an orange trace, it's the starter trigger wire. The switch will be closed in natural and this switch is in your throttle/shift controller. If or when the 496 goes into guardian it will alarm and shut you down, read the DTC if none are shown read the freeze frame data, your find your answer in that. Personally I would look at your fuel system pull the fuel filter cartage from the cool fuel, under that filter there is a "pancake" style fuel filter that many people don't change and gets clogged.
Camalot is offline  
Old 06-10-2018, 11:05 AM
  #3  
BUP
Registered
iTrader: (9)
 
Join Date: Jul 2011
Location: Ft. Worth TX
Posts: 9,574
Likes: 0
Received 12 Likes on 11 Posts
Default

before you even get started and a bunch dart throwing for answers gets posted. He the deal. 496's are app specific - meaning what and which 496 did you buy ??? 2008 at least half of the 496 s were DTS apps if not more. so did you get a DTS app ? Next is at least half 496 were installed in inboards and or even jet boat apps and even wake boats. . The PCM 555 is app specific per Inboard and or a app with a transmission or I/O and wake boats.

An engine serial number of the 496 you bought needs to be posted for exactly what what it is and set up

Being app specific with the tune in PCM 555 will automatically cause guardian at 3 K to 3500 K --- ( the set up and wrong cal in the PCM 555 for the wrong app installed.)

How did u wire up your trim wires and so forth with a 99 transom assembly ? Who's wiring harness did you use for the bought 496 ? That should be a 14 pin not a 10 pin - How many spliced wires were done for the complete install ? There should be zero. Too many unknowns here to even come close why you have guardian and many unknown installs. Alot more info is needed for any help.

Most important did you buy an 496 that was installed in an inboard app and then installed in youir I/O app ? if so that is problem number ONE. to start with.

Do you have a shift in gear switch and set up correctly for the install ?

Last edited by BUP; 06-10-2018 at 01:59 PM.
BUP is offline  
Old 06-10-2018, 11:27 AM
  #4  
BUP
Registered
iTrader: (9)
 
Join Date: Jul 2011
Location: Ft. Worth TX
Posts: 9,574
Likes: 0
Received 12 Likes on 11 Posts
Default

marine apps are marine specific scan tools needed. no go for blue tooth or some internet software. or auto store scan tool will not work period.
BUP is offline  
Old 06-10-2018, 01:11 PM
  #5  
Registered
Thread Starter
 
Join Date: Jul 2013
Location: Nelson, BC, Canada
Posts: 57
Likes: 0
Received 0 Likes on 0 Posts
Default

Engine is an 08 non DTS out of stern drive. Using Mercury Vesselview with bluetooth. Had to ground the one wire to neutral to get key to start engine in neutral. Used the Mercury 10-14 pin adapter for harness. No splices. I purchased motor used and believe reason I am having issues is why it was removed. Was sold as an insurance claim due to broken starter mount which turned out to be nonissue other than removing rest of broken bolt. Rebuilt the seawater pump ( bad bearings and seals), tore fuel pump down and replaced both filters and pump. Runs and starts good at low power but no performance. Vesselview is supposed to communicate and display codes. Powers up and communicates with Android device but no pcm. Hard to find any marine guys in our area familiar with the 496.
brianscathouse70 is offline  
Old 06-10-2018, 01:18 PM
  #6  
BUP
Registered
iTrader: (9)
 
Join Date: Jul 2011
Location: Ft. Worth TX
Posts: 9,574
Likes: 0
Received 12 Likes on 11 Posts
Default

you need a scan tool connected to the DLC - and scanned while lake tested. 4 scans needed - key on only then running at idle - then fully warmed up and one running around all rpms on the lake.

Then know what all means from the scanning. Many think just because they have a scan tool that will find the fix. I wished it was that easy. Many times no fault codes will show but many out of spec parameters are the issue.

ALSO you could have a BAD PCM. If a storm engine very possible for a BAD PCM. Make sure all your 5 V sensor circuits are showing good and not out of spec
BUP is offline  
Old 06-10-2018, 01:57 PM
  #7  
BUP
Registered
iTrader: (9)
 
Join Date: Jul 2011
Location: Ft. Worth TX
Posts: 9,574
Likes: 0
Received 12 Likes on 11 Posts
Default

and lets forget the people you bought from could possible be hacks. And or they installed an inboard set up 496 for an I/O that did not work for them hence why they sold it. Not uncommon. The used market is full of hacked crap from owners and cobbed jobbed shops. Actually this statement is more true than not. Even a few OSO members selling junk crap. either clueless or think their crap is worth something. I bought some stuff here and it was dumpster chit when I received it. Not even that long ago.

for starters I would and check which PCM u have by the sticker on the back.

Last edited by BUP; 06-10-2018 at 02:00 PM.
BUP is offline  
Old 07-09-2018, 11:43 PM
  #8  
Registered
Thread Starter
 
Join Date: Jul 2013
Location: Nelson, BC, Canada
Posts: 57
Likes: 0
Received 0 Likes on 0 Posts
Default

Finally got boat out of storage. First new question, would non dts setup need anything plugged into transom harness? I plugged 1 wire in to get trim sender to work, all else seems ok. Vesselview powers up, connects to bluetooth but cant find Pcm. I still think I am missing a power wire somewhere and pcm isnt fully reading something. I have asked other places and searched the internet and cant find a proper diagramfor a non dts 2008 496 HO. Anybody able to help? Found info on an old 496 thread about shift in gear switch. I have mine grounded to get it to start in neutral but that ground may also make computer think it is always in neutral limiting power and rpm. The way I grounded it seems to make neutral switch work as it wont turn over in gear but it is a bandaid partially masking real problem, hence needing a diagram. Engine serial on cover is partially rubbed off, original transom and drive #s there(I dont have the units). Any other place to find #?

Last edited by brianscathouse70; 07-10-2018 at 12:08 AM. Reason: foundnewinfo
brianscathouse70 is offline  
Old 07-13-2018, 11:08 PM
  #9  
Registered
Thread Starter
 
Join Date: Jul 2013
Location: Nelson, BC, Canada
Posts: 57
Likes: 0
Received 0 Likes on 0 Posts
Default

Did some more testing today and all harness checks are good but to get engine to turn over with key the 5V signal through in gear sensor needs to be grounded and after engine starts it is limited in RPM. The sensor tests ok. I am thinking PCM is issue as there is also no communication on data lines to vesselview. Analog guages all work. Some numbers on PCM are rubbed off. What is left is XR002E6V on top under bar code, PCM0701 next, build date of 01-29-2008 and then 897906 which I believe only identifies main case as that number seems to apply to alot of these units in different engines. Of the rubbed off numbers Bravo is visible so I believe it is proper sterndrive application.
brianscathouse70 is offline  
Old 07-16-2018, 03:07 PM
  #10  
Registered
Thread Starter
 
Join Date: Jul 2013
Location: Nelson, BC, Canada
Posts: 57
Likes: 0
Received 0 Likes on 0 Posts
Default

Any suggestions at all? Do I need a transom harness plugged in? Is start in gear switch on engine a possible issue. I dont want to buy a computer if I don't have to. Serial number is rubbed off engine cover but numbers posted above for computer are all I have. Cant find anyone nearby with a Rinda scanner. No warning beeps unless I unplug a sensor with key on. 5V reference good at all sensors. Dont want to rely on fact vesselview not working to condemn computer either.

Last edited by brianscathouse70; 07-16-2018 at 03:09 PM. Reason: more thoughts
brianscathouse70 is offline  

OSO Sponsor
OSO Advertiser
OSO Advertiser

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.

OSO Advertiser