Go Back  Offshoreonly.com > Technical > General Q & A
496HO Freeze Frame... who can read this? >

496HO Freeze Frame... who can read this?

Notices

496HO Freeze Frame... who can read this?

Old 03-14-2012, 03:33 PM
  #1  
Registered
Thread Starter
 
Join Date: Feb 2012
Location: Fort Lauderdale, FL
Posts: 12
Likes: 0
Received 0 Likes on 0 Posts
Default 496HO Freeze Frame... who can read this?

Hey guys... so I had a problem with my 496ho. I had posted in another thread and thought the problem was fixed (so I thought).

Boat starts fine, runs great, would idle at dock all day. Run under a load about 15 minutes or so and Guardian alarm beeps once, then stays on solid a bit then repeats... engine starts to cough and sputter and eventually dies. If I let her cool down 15-20 minutes I can start it again and limp home.

I researched on here and thought it was a fuel issue. Drained all old fuel, put new fuel in, new water sep. filter. Still had same problem. Researched more... .replaced the Crank Position Sensor. Seemed okay on test run... but next time i took it out Guardian alarm and sputter, it runs rich and stalls again. Let it cool and it can make it home fine. I had a mechanic come out to look at it (no scanner). He checks fuel pressure at rail and it's 40psi. He is sure it's the IAC (idle air control) ... so I replaced that and test run was fine.

Take boat out with wife again and we make it a couple miles and same problem occurs again. Now I'm fed up with it. Call new mechanic and he comes today with a $6,000 (that's what he said it cost) scanner laptop tool.

It throws only nothing fault codes for sensors I deduce I don't have looking online (PITOT CKT LOH, FUEL LVL CKT HI and FUEL LVL2 H... I don't even have a 2nd fuel tank.)

We go for a test run for 2 hours and of course it won't do the problem again while mechanic is on boat and it's hooked up to scanner tool.

It only showed the 4 faults above currently... but he did print give me this report on the history (the 10 stored in freeze frame) and it shows a number of sensors popping up. Do these freeze frame codes mean they are bad??? Should I replace the MAP and TPS sensors? Any others?? The overspeed is because I ran it to the rev limiter with him to test it... Guardian kicked in and slowed it down.

Who's the resident scanner guru on here?

~~~~~~~~~~~~~~~~~~~~


496 MAG/8.1L HO SD ECM# 859610

Wed Mar 14 14:19:53 2012

Freeze Frame 0 Caused By Fault: FUEL LVL2 CKT H

Baro Press . . . 14.91 PSI Battery Volts. . 12.76 Volts
Block Press. . . 0.33 PSI Boat Speed . . . 1.5
Air Temp . . . . 98.6 °F Cool Temp. . . . 129.2 °F
Demand . . . . . 0.1 % Engine RPM . . . 0 RPM
Engine State . . 1 (STALL) FPC Total. . . . 0.0
Freq Counter . . 347 Fuel Level . . . 0.0 %
Shift Status . . 5 (IN GEAR) Lake/Sea Temp. . -29.2 °F
Load . . . . . . 0.0 % MPRLY Req. . . . 32772
MAP Press. . . . 14.92 PSI Oil Level. . . . 0.0 %
Port TAB Pos . . 0.0 Available Power. 100.0 %
Run Time . . . . 979.5 Star TAB Pos . . 0.0
TPI. . . . . . . 0.1 % Trim Position. . 19.2

Freeze Frame 1 Caused By Fault: STEER CKT HI

Baro Press . . . 14.91 PSI Battery Volts. . 12.76 Volts
Block Press. . . 0.34 PSI Boat Speed . . . 1.5
Air Temp . . . . 98.6 °F Cool Temp. . . . 129.2 °F
Demand . . . . . 0.1 % Engine RPM . . . 0 RPM
Engine State . . 1 (STALL) FPC Total. . . . 0.0
Freq Counter . . 337 Fuel Level . . . 0.0 %
Shift Status . . 5 (IN GEAR) Lake/Sea Temp. . -29.2 °F
Load . . . . . . 0.0 % MPRLY Req. . . . 32772
MAP Press. . . . 14.92 PSI Oil Level. . . . 0.0 %
Port TAB Pos . . 0.0 Available Power. 100.0 %
Run Time . . . . 979.5 Star TAB Pos . . 0.0
TPI. . . . . . . 0.1 % Trim Position. . 19.2

Freeze Frame 2 Caused By Fault: FUEL LVL CKT HI

Baro Press . . . 14.91 PSI Battery Volts. . 12.71 Volts
Block Press. . . 0.48 PSI Boat Speed . . . 1.5
Air Temp . . . . 98.6 °F Cool Temp. . . . 129.2 °F
Demand . . . . . 0.1 % Engine RPM . . . 0 RPM
Engine State . . 1 (STALL) FPC Total. . . . 0.0
Freq Counter . . 281 Fuel Level . . . 0.0 %
Shift Status . . 5 (IN GEAR) Lake/Sea Temp. . -29.2 °F
Load . . . . . . 0.0 % MPRLY Req. . . . 32772
MAP Press. . . . 14.91 PSI Oil Level. . . . 0.0 %
Port TAB Pos . . 0.0 Available Power. 100.0 %
Run Time . . . . 979.5 Star TAB Pos . . 0.0
TPI. . . . . . . 0.1 % Trim Position. . 19.2

Freeze Frame 3 Caused By Fault: PITOT CKT LO

Baro Press . . . 14.91 PSI Battery Volts. . 12.71 Volts
Block Press. . . 0.49 PSI Boat Speed . . . 1.5
Air Temp . . . . 98.6 °F Cool Temp. . . . 129.2 °F
Demand . . . . . 0.1 % Engine RPM . . . 0 RPM
Engine State . . 1 (STALL) FPC Total. . . . 0.0
Freq Counter . . 297 Fuel Level . . . 0.0 %
Shift Status . . 5 (IN GEAR) Lake/Sea Temp. . -29.2 °F
Load . . . . . . 0.0 % MPRLY Req. . . . 32772
MAP Press. . . . 14.91 PSI Oil Level. . . . 0.0 %
Port TAB Pos . . 0.0 Available Power. 100.0 %
Run Time . . . . 979.5 Star TAB Pos . . 0.0
TPI. . . . . . . 0.1 % Trim Position. . 19.2

Freeze Frame 4 Caused By Fault: TPS1 NO ADAPT

Throttle Position Indicator 1 No Adaptation Error: Most likely there is a connection or mechanical fault.

Baro Press . . . 14.79 PSI Battery Volts. . 12.79 Volts
Block Press. . . 0.34 PSI Boat Speed . . . 481.5
Air Temp . . . . 109.4 °F Cool Temp. . . . 170.6 °F
Demand . . . . . 13.2 % Engine RPM . . . 442 RPM
Engine State . . 3 (RUN) FPC Total. . . . 37.5
Freq Counter . . 12 Fuel Level . . . 0.0 %
Shift Status . . 5 (IN GEAR) Lake/Sea Temp. . -29.2 °F
Load . . . . . . 37.9 % MPRLY Req. . . . 33812
MAP Press. . . . 13.20 PSI Oil Level. . . . 0.0 %
Port TAB Pos . . 0.0 Available Power. 100.0 %
Run Time . . . . 973.1 Star TAB Pos . . 0.0
TPI. . . . . . . 13.2 % Trim Position. . 0.0

Freeze Frame 5 Caused By Fault: OVERSPEED

Manifold Absolute Pressure Sensor Fault (Input Too High)

Baro Press . . . 14.39 PSI Battery Volts. . 13.81 Volts
Block Press. . . 30.62 PSI Boat Speed . . . 337.7
Air Temp . . . . 122.0 °F Cool Temp. . . . 167.0 °F
Demand . . . . . 86.5 % Engine RPM . . . 5157 RPM
Engine State . . 3 (RUN) FPC Total. . . . 76.6
Freq Counter . . 238 Fuel Level . . . 0.0 %
Shift Status . . 5 (IN GEAR) Lake/Sea Temp. . -29.2 °F
Load . . . . . . 85.9 % MPRLY Req. . . . 33812
MAP Press. . . . 13.80 PSI Oil Level. . . . 0.0 %
Port TAB Pos . . 0.0 Available Power. 100.0 %
Run Time . . . . 978.7 Star TAB Pos . . 0.0
TPI. . . . . . . 86.5 % Trim Position. . 0.0

Freeze Frame 6 Caused By Fault: MAP INPUT HI

Baro Press . . . 14.90 PSI Battery Volts. . 12.46 Volts
Block Press. . . 0.23 PSI Boat Speed . . . 1.5
Air Temp . . . . 113.0 °F Cool Temp. . . . 167.0 °F
Demand . . . . . 0.0 % Engine RPM . . . 256 RPM
Engine State . . 3 (RUN) FPC Total. . . . 48.0
Freq Counter . . 7 Fuel Level . . . 0.0 %
Shift Status . . 5 (IN GEAR) Lake/Sea Temp. . -29.2 °F
Load . . . . . . 50.1 % MPRLY Req. . . . 33812
MAP Press. . . . 14.61 PSI Oil Level. . . . 0.0 %
Port TAB Pos . . 0.0 Available Power. 100.0 %
Run Time . . . . 979.3 Star TAB Pos . . 0.0
TPI. . . . . . . 0.0 % Trim Position. . 11.3

Freeze Frame 7 Caused By Fault: CAM SNSR

Baro Press . . . 14.90 PSI Battery Volts. . 12.46 Volts
Block Press. . . 0.25 PSI Boat Speed . . . 1.5
Air Temp . . . . 118.4 °F Cool Temp. . . . 167.0 °F
Demand . . . . . 0.0 % Engine RPM . . . 256 RPM
Engine State . . 3 (RUN) FPC Total. . . . 25.0
Freq Counter . . 3 Fuel Level . . . 0.0 %
Shift Status . . 5 (IN GEAR) Lake/Sea Temp. . -29.2 °F
Load . . . . . . 48.4 % MPRLY Req. . . . 33812
MAP Press. . . . 14.50 PSI Oil Level. . . . 0.0 %
Port TAB Pos . . 0.0 Available Power. 89.8 %
Run Time . . . . 979.3 Star TAB Pos . . 0.0
TPI. . . . . . . 0.0 % Trim Position. . 11.3

Freeze Frame 8 Caused By Fault: CRANK SNSR

Baro Press . . . 14.90 PSI Battery Volts. . 12.46 Volts
Block Press. . . 0.23 PSI Boat Speed . . . 1.5
Air Temp . . . . 116.6 °F Cool Temp. . . . 167.0 °F
Demand . . . . . 0.0 % Engine RPM . . . 256 RPM
Engine State . . 3 (RUN) FPC Total. . . . 25.0
Freq Counter . . 2 Fuel Level . . . 0.0 %
Shift Status . . 5 (IN GEAR) Lake/Sea Temp. . -29.2 °F
Load . . . . . . 50.1 % MPRLY Req. . . . 33812
MAP Press. . . . 14.50 PSI Oil Level. . . . 0.0 %
Port TAB Pos . . 0.0 Available Power. 89.8 %
Run Time . . . . 979.3 Star TAB Pos . . 0.0
TPI. . . . . . . 0.0 % Trim Position. . 11.3

Freeze Frame 9 Is Not Active

Last edited by Markmysite; 03-14-2012 at 03:39 PM.
Markmysite is offline  
Old 03-14-2012, 03:43 PM
  #2  
Registered
 
Join Date: May 2006
Location: Huntsville, AL
Posts: 1,628
Likes: 0
Received 0 Likes on 0 Posts
Default

had simaler problem with my dad 330 SS formula 496 mags. idel control valve on both motors went out.

had one do like your talking about... wwas limping home nad the other one did it. was liek WTF. what are the chances? he now has spares on board.
mittens is offline  
Old 03-14-2012, 05:50 PM
  #3  
Registered
Thread Starter
 
Join Date: Feb 2012
Location: Fort Lauderdale, FL
Posts: 12
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by mittens
had simaler problem with my dad 330 SS formula 496 mags. idel control valve on both motors went out.

had one do like your talking about... wwas limping home nad the other one did it. was liek WTF. what are the chances? he now has spares on board.
Yep, quite a few people had very similar symptoms so I threw an IAC at it. Actually I showed the 1st mechanic the posts and he agreed and suggested I change that. I typically only use mechanics as last resort and to diagnose... then I do the labor.
Markmysite is offline  
Old 03-14-2012, 06:34 PM
  #4  
Registered
 
Join Date: Jan 2004
Location: San Diego, California
Posts: 2,777
Likes: 0
Received 6 Likes on 6 Posts
Smile Need some more information

If I read your post correctly, the Guardian alarm definitly goes off with a single beep then a prolonged beep and then the engine starts to sputter, cough and then die. Is this correct/
If it is does the beep come just before the issue or does the beep come as the engine is coughing and stalling as the alram will go off on a stall. Your snapshots posted here are all faults at the point of the engine stalling and some of those codes will show when a 496 stalls in gear.. Can you get the fault history out of the ECM as this shows all seconds of faults even before this last event and will probably indicate possibly the real issue here. The other thing to remember is that when guardian alarms it will cut back power but not always stall the engine so it may not be a guardian event that is stalling the engine but a fueling issue or electrical issue. Has the engine ever overheated or lost an impellor or such? Have you cleaned all sensor plugs and grounds and made sure all grounds are tight and making good contacts. Are any of the plugs, sensors or connections corroded or marked with salt buildup or (blue stains). We need just a little more info here. Your post also sort of indicates the problem appears to be intermittant as it did not show up on the last use with the mechanic aboard? Was he scanning while the engine was running and the boat underway? What rpms were you at when the boat stalled and alramed each time it did? Did the mechanic measure fuel pressure underway with a good load on the engine? The problem is there and it can be found.

Best Regards,
Ray @ Raylar

Last edited by Raylar; 03-14-2012 at 09:28 PM.
Raylar is offline  
Old 03-14-2012, 08:20 PM
  #5  
Registered
Thread Starter
 
Join Date: Feb 2012
Location: Fort Lauderdale, FL
Posts: 12
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Raylar
If I read your post correctly, the Guardian alarm definitly goes off with a single beep then a prolonged beep and then the engine starts to sputter, cough and then die. Is this correct/
If it is does the beep come just before the issue or does the beep come as the engine is coughing and stalling as the alram will go off on a stall. Your snapshots posted here are all faults at the point of the engine stalling and some of those codes will show when a 496 stalls in gear.. Can you get the fault history out of the ECM as this shows all seconds of faults even before this last event and will probably indicate possibly the real issue here. The other thing to remember is that when guardian alarms it will cut back power but not always stall the engine so it may not be a guardian event that is stalling the engine but a fueling issue or electrical issue. Has the engine ever overheated or lost an impellor or such? Have you cleaned all sensor plugs and grounds and made sure all grounds are tight and making good contacts. are any oof the plugs, sensors or connections corroded or marked with salt buildup or (blue stains). We need just a little more info here. Your post also sort of indicates the problem appears to be intermittant as it did not show up on the last use with the mechanic aboard? Was he scanning while the engine was running and the boat underway? What rpms were you at when the boat stalled and alramed each time it did? Did the mechanic measure fuel pressure underway with a good load on the engine? The problem is there and it can be found.

Best Regards,
Ray @ Raylar
Correct on when it beeps... The guardian alarm sounds and it then starts to run bad and sputters yes. Not sure if it's ever overheated... Not with me. I just bought it 2 months ago. I know the previous owner had the out drive rebuilt, new manifolds and risers, and a new starter put on last fall... And it then sat 5 months. The mechanic here today said it didn't show any history of an overheat on the scan.

Yes, he had it hooked up during sea trial today.. No faults trigger except those 4 I mentioned above (that I have no sensors for ). It didn't do it today for the very first time... But has always done it the past 4 times I tried to run her. Of course it runs fine while mechanic is inboard and I'm paying him $75 an hour to go for a boat ride lol.

Fuel pressure was at 40 at rail under load at dock.. Tied off. It always went to Gaurdian alarm and sputtered and stalled before at idle wake speed.. So like 1000-1200 RPM.

I haven't checked every sensor contact.... But I checked the ones I could see and all looked good.

Did you read the codes above? It looks like the cam sensor, throttle sensor and map sensor all threw an error. Did you mean that it stalling could cause to show in the freeze frame memory.... And they might be fine? They aren't throwing the codes underway, or with just running a full diagnostic with the key on.
Markmysite is offline  
Old 03-14-2012, 08:34 PM
  #6  
Registered
 
Join Date: Oct 2005
Location: Waldorf, Md
Posts: 926
Received 166 Likes on 105 Posts
Default

Originally Posted by Markmysite
Lake/Sea Temp. . -29.2 °F
Mark,

I dont know the Mercruiser system at all but that temp reading sticks out like a sore thumb. If that temperature is really what it was showing then it sure does not look right to me . . . Minus 29.2 degrees ???????? Not sure how it would affect the Merc system.

What I tell my automotive customers is that the code is just giving a symptom, sort of like if you have a pain (the code) in your elbow. The pain might be because you played way too much tennis, or it could be because you are having a heart attack.

The only way to tell is to do further tests like you are but you also need someone that knows what the test results mean.

Bill Koustenis
Advanced Automotive Machine
Waldorf Md
BillK is offline  
Old 03-14-2012, 08:53 PM
  #7  
Registered
Thread Starter
 
Join Date: Feb 2012
Location: Fort Lauderdale, FL
Posts: 12
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by BillK
Mark,

I dont know the Mercruiser system at all but that temp reading sticks out like a sore thumb. If that temperature is really what it was showing then it sure does not look right to me . . . Minus 29.2 degrees ???????? Not sure how it would affect the Merc system.

What I tell my automotive customers is that the code is just giving a symptom, sort of like if you have a pain (the code) in your elbow. The pain might be because you played way too much tennis, or it could be because you are having a heart attack.

The only way to tell is to do further tests like you are but you also need someone that knows what the test results mean.

Bill Koustenis
Advanced Automotive Machine
Waldorf Md
I was wondering on that one too.... Maybe that sensor is messed up too. For the $300 I paid the mechanic today.... I could have bought all of those sensors from RockAuto and replaced them.... Doh
Markmysite is offline  
Old 03-14-2012, 09:10 PM
  #8  
Registered
Thread Starter
 
Join Date: Feb 2012
Location: Fort Lauderdale, FL
Posts: 12
Likes: 0
Received 0 Likes on 0 Posts
Default

The other thing I've been wondering about is the impeller like Raylar said .... Who knows when it was changed last. Or if it was and a piece of it is stuck sideways that could cause a problem I guess.

It doesn't show my sea pump pressure on his report though... Does it?
Markmysite is offline  
Old 03-14-2012, 09:40 PM
  #9  
Charter Member #1055/Moderator
Charter Member
iTrader: (1)
 
GO4BROKE's Avatar
 
Join Date: Feb 2001
Location: CNY
Posts: 4,585
Received 0 Likes on 0 Posts
Default

All the faults except the map fault show no block pressure. Most of them probably set at the stall as Raylar stated. I had a difficult guardian issue that tripped no codes, would only happen at WOT, in our bay. I could run WOT on Lake Ontario all day with no alarm. Only difference was the bay water was 10 degrees warmer, which softened the water intake hose for the sea pump, allowing it to collapse restricting the water intake. The reinforcing wire for the hose was rusted. Replace the hose and ran perfect.
__________________
[img][/img]
GO4BROKE is offline  
Old 03-14-2012, 10:17 PM
  #10  
Registered
 
Join Date: Jan 2004
Location: San Diego, California
Posts: 2,777
Likes: 0
Received 6 Likes on 6 Posts
Wink

Markmysite:

Slow down there partner!
Lets not start spending your money and time here replacing parts that may not be bad and confusing the real issue of whats wrong!

Lets go thru what we know and what is being recorded in the ECM.

First, Pitot, Fuel Level1 & Fuel level2 and Sea temp will always show up in this PCM555 for the 496 engines unless the Mercury devices anre installed in the boat and connected via a smartcraft connection. they don't mean anything in this case and they will not institute a guardian event.

Second, when a Merc 496 stalls in gear it will usually always throw some codes like crankshaft, camshaft, sometimes the MAP and the TPS. These will sometimes occur even though there maybe nothing wrong with these sensors. If these sensors are bad they will always usually throw a fault code with continued operation of the engine and its not common for the failure of these sensors to be intermittant, especially three at once. The negative sea temp of -29 degrees or so is a default reading becuse the Merc sea temp sensor is not installed or being used.

The TPS sensor fault showed up once when you hit the Rev-limiter at 5150rpms as recorded and that does not surprise me that a sensor code showed up at that point.

You or your mechanic can check the TPS voltage very easily with the key on engine not running. The scan tool will show it or you can read it across the blue wire to the black wire at the TPS harness just after the TPS connector. The scan tool also outputs the throttle open percentage which is derived from this voltage range. (0-3% to 97-99% ) Voltage should be about .56-.58 volts at idle and as you advance the throttle to full open it should go up to about 4.25-4.5 volts max. with a fairly smooth rise on a smooth throttle operation. If the voltage does not jump around, drop suddenly during throttle advance and is close to these ranges, chances are the TPS sensor is just fine.

You are saying that the boat operated just fine today even with diagnostics hooked up and no codes were present and active. I know frustrating, but it does happen.

You have to remember that with boats there is the Performance boaters law and there is Murphy's law. Performance boaters law reads: Murphy was a phuck'in Optomist!" You need a good laugh at this point!

Your mechanic measured fuel pressure under load and that showed approximatly 40 psi w/vacuum signal to the fuel pressure regulator and that would indicate that fuel pressure is not an issue. Also since this was measured under a good load and the engine is stalling at 1000-1200rpms it does not seem to be a fuel issue since at that rpm , the engine does not need a lot of fuel flow.

You could be seeing some intermittant connection that is basically dropping the engine out or off causing the stall and since the guardian will only usually stop the engine with severe overheat, super low or no oil pressure, then when you are loosing the engine at low rpms I doubt the guardian is shutting the engine down.

I believe you mentioned you may have already replaced the IAC so that should not be an issue since you are getting no fault codes for that. Normally when an IAC is going bad or failing it can cuase a 496 to stumble and stall when transitioning from higher rpms to lower rpms near idle as that is what it does. It is designed to open quickly and close to keep the transition rpms stable and smooth back to idle with the extra shots of air it feeds the engine bypassing the throttle blade and keeping a smooth decelleration.

The water pump and water pressure does not seem to be a problem from the events logged as it shows about 30 psi when the engine was at 5100 rpms and the engine coolant temperatures at that high rpm only show 167 degrees which is a very good cool operating temperature for this engine.

What does this leave: well we really need to have the history read outs from the ECM, because in those we may see a recurring problem that can be seen happening previously and at several times that you experienced the problem. If there was a guardina fault event that stalled the engine it should be recorded in the history file in the ECM. If its not showing up in those history files then I would say its probably something like a loose electrical connection, could be at the helm in a key switch, lanyard, etc., low battery voltage when operating, bad or loose ground connections, bad or fouled spark plugs, or possible loose or corroded connections at coil harness plugs, fuel injector harness plug or lets hope not a faulty wire in the engine harness somewhere.

The only real good news at this point is for now it seems to have stopped and there is a possibility it will never happen again, I've seen that happen before and we use the old reply there" If it ain't broke, don't fix it " approach.

Hope some of this info help you look for your problem and understand some of the systems the 496 engine and Ecm use.

Best Regards,
Ray @ Raylar
Raylar is offline  

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.