Electronic derating in a Cat engine: WTF?

[MapisM]

Today I had my first experience ever, while looking at a Cat engine display, of a message popping up saying "Low oil pressure derate" (C12 of 2003 vintage, fwiw).
Not only that, but the engine (which was running at idle when this happened) had an incertainty for a second, before returning to run smoothly again. Which suggests that the ECU indeed did something unusual, like reset itself or whatever.
Have anyone ever seen/heard something like that?

Aside from being curious about what "derate" exactly means, I recall something interesting that Latestarter explained us (IIRC, at least - but LS, feel free to correct me as appropriate): back in the earlier days of electronically controlled engines, derating was considered by all major engine builders, because in theory they could program the ECUs to derate the engines based on several conditions.
But this option was ruled out, because protecting the engine was apparently less important than avoiding potential legal troubles.

Otoh, what I witnessed today seem to suggest that Cat actually did something along these lines...

 

[Portofino]

With Man Monitoring Diagnostic System MMDS
They look at 16 parameters .
Three levels of interaction

CAT may be similiar - I would not worry about it -low oil pressure at tick over .

1- alarms audible and visual screen resorts only to it ( and keeps a record ,date etc for tech with lap top later )
For if it's strayed out side normal parameter ,but not that bad ,too far out allows you to continue at same rpm .
You can clear it .
2- same audible -visual alarms "derate " parameters exceeded so it cuts the rpm /from memory to arround 1200
3- "". "". ". ". -this time stops engine for you .
It's this 3rd level of nanny interfering -stopping - that raises a legal Q of safety ? Ie you are about to cary out a critical manoeuvre - and can,t .

Mine does a 1- sometimes @ start up with low oil pressure on the port engine .590 rpm , so just blip it in N to 800 to get the oil P up -then it seems to cancel itself .
This is normally when it's been stud a few days -and 2 mins after normal E room checks ,ie just dipped it and no oil in thr bilge -so know its not really low oil pressure ,just a sensor hiccup on start up .
The sensor looks new too , shiney brass bolt .where the Stb one seems original painted white .

I think VP do a limp home mode too ? -not sure they make it obvious why ? -like the MMDS

 

[bvickers]

MapisM

Do you have remote oil filters?

I have C12's and haven't had the same issue, but in chatting with the engineer when he was servicing my boat one time, I remember him mentioning that if remote oil filters are fitted, the threshold level for the oil pressure sensors needs to be set to a lower level, otherwise it will show low pressure, when in reality, the oil pressure is fine - or, could just be case that the sensor is kaput....

Hope this helps - good luck with sorting

 

[rafiki_]

Today I had my first experience ever, while looking at a Cat engine display, of a message popping up saying "Low oil pressure derate" (C12 of 2003 vintage, fwiw).
Not only that, but the engine (which was running at idle when this happened) had an incertainty for a second, before returning to run smoothly again. Which suggests that the ECU indeed did something unusual, like reset itself or whatever.
Have anyone ever seen/heard something like that?

Aside from being curious about what "derate" exactly means, I recall something interesting that Latestarter explained us (IIRC, at least - but LS, feel free to correct me as appropriate): back in the earlier days of electronically controlled engines, derating was considered by all major engine builders, because in theory they could program the ECUs to derate the engines based on several conditions.
But this option was ruled out, because protecting the engine was apparently less important than avoiding potential legal troubles.

Otoh, what I witnessed today seem to suggest that Cat actually did something along these lines...

P, LS1 is our expert is, and will be along in due course. I understand that he has been on the water of late, so not always on line. However, it is normal for electronically managed diesels (and gasoline) to debate if any of the parameters are out of their norm. Clearly this is designed to protect the engine as much as possible. Low oil pressure will be very much one of the parameters that will cause a the controller to derate.

 

[MapisM]

Thanks folks.
Yep, I'd be curious to hear from LS1 about this, because I'm aware of how "limp mode" works, but it's the terminology of the message, specifically mentioning "derate", that puzzled me.

@ bvickers: I wasn't on my boat, but the oil filters were in their normal position, directly attached to the engines.
When remote filters are fitted, are they in addition to the usual ones? If so, I might not have seen them.

 

[rafiki_]

Thanks folks.
Yep, I'd be curious to hear from LS1 about this, because I'm aware of how "limp mode" works, but it's the terminology of the message, specifically mentioning "derate", that puzzled me.

A word of caution P, the Cat language will not be English, but American, and they regularly have their own terminology over in the Colonies

 

[Portofino]

Something else -if you unplug something likes sensor - it flashes up sensor error as a level1 alarm ( which you can cancel )
Not low oil pressure !
Ie it knows the diff between a loss in continuity and an reading of say low pressure.
Once blipped up and immediately settles back to tick over, youcan cancel it and never hear from it fordays
Just. It seems to be a bit over sensitive to Oil pressure @ start up very intermittently -.
Manual is a German translation -so odd phase seems peculiar .

Ido not know if level 3 shutdown works-- or is active , or written out, -manual infers it's live 2003 motors.
Never had a level 2 -reduced rpm - " derate " -limp mode -assume they are the same thing ,just different terminology ?
happy to find out .

 

[MapisM]

Fwiw, there wasn't anything wrong with the sensor: indeed the pressure was low and for good reasons, as we afterwards discovered. Therefore, the electronics gizmos did their job nicely.
It was just the error message which made me curious, hence this thread.
Though it might well be just a matter of semantic, as rafiki says...

 

[Pinnacle]

All this oil pressure stuff (or rather the lack thereof) is all well and good.............................but what we really want to know, is have you put in an offer on the boat?

 

[MapisM]

Haha, not yet P, but I'm considering it.
Have you got some spare holiday left to join us for a 900Nm or so delivery trip?

 

[vas]

Haha, not yet P, but I'm considering it.
Have you got some spare holiday left to join us for a 900Nm or so delivery trip?

if P. cannot make and if the timing is right, if the route is worth it and of course if you make an open call, I may be interested

V.

PS. you have to fix the low oil pressure though

 

[Latestarter1]

Today I had my first experience ever, while looking at a Cat engine display, of a message popping up saying "Low oil pressure derate" (C12 of 2003 vintage, fwiw).
Not only that, but the engine (which was running at idle when this happened) had an incertainty for a second, before returning to run smoothly again. Which suggests that the ECU indeed did something unusual, like reset itself or whatever.
Have anyone ever seen/heard something like that?

Aside from being curious about what "derate" exactly means, I recall something interesting that Latestarter explained us (IIRC, at least - but LS, feel free to correct me as appropriate): back in the earlier days of electronically controlled engines, derating was considered by all major engine builders, because in theory they could program the ECUs to derate the engines based on several conditions.
But this option was ruled out, because protecting the engine was apparently less important than avoiding potential legal troubles.

Otoh, what I witnessed today seem to suggest that Cat actually did something along these lines...

I may be the architect of this confusion, engine protection de-rate and protection shut down are different, all engine calibrations have de-rate for a number of conditions in base calibration perimeters, setting up engine shutdown is an option in base calibration for certain engine applications, not marine.

'Derate' conditions can be most complex as certain conditions can activate different forms of de-rate, speed only, power only, power and torque, the diagnostic tool when identifying the fault with tell you the impact on engine performance.

Hope this clarifies...

PS 'Limp mode' grurr! No manufacturer uses such a term, no clue where it came from, probably the gasoline girls and motorcars.

 

[MapisM]

'Derate' conditions can be most complex as certain conditions can activate different forms of de-rate, speed only, power only, power and torque, the diagnostic tool when identifying the fault with tell you the impact on engine performance.

Hope this clarifies...

Indeed it does, many thanks P. :encouragement:

 

[MapisM]

if P. cannot make and if the timing is right, if the route is worth it and of course if you make an open call, I may be interested

It would be my pleasure, but don't hold your breath yet.
Regardless, as you already know, anyone who did what you did with Mythos is always more than welcome also on my old tub - just say when! :encouragement:

 

[jrudge]

Haha, not yet P, but I'm considering it.
Have you got some spare holiday left to join us for a 900Nm or so delivery trip?

I have missed what you have bought ....

 

[MapisM]

Nothing yet - in fact, staying with the old tub till she'll float is still an option...
But I drifted a bit in my search lately.
I'm not going to bore the asylum to death with the dozens of boats we've seen so far and their pros and cons, but I owe you a bit more details - will follow up via email! :encouragement:

 

[Pinnacle]

Haha, not yet P, but I'm considering it.
Have you got some spare holiday left to join us for a 900Nm or so delivery trip?

900Nm sounds great! That's one and a half Fastnet races. :encouragement:

 

[MapisM]

900Nm sounds great! That's one and a half Fastnet races. :encouragement:

Yeah, as long as you don't expect me to make it in less than 2 days - which IIRC is what some Fastnet monster sailboats are capable of...!

 

[Pinnacle]

Ha ha!

Has the look and feel of two weeks!

 

[vas]

It would be my pleasure, but don't hold your breath yet.
Regardless, as you already know, anyone who did what you did with Mythos is always more than welcome also on my old tub - just say when! :encouragement:

very kind of you P.,

serious if you decide to make the big move to planning hulls again and it's off season on the wrong side of Italy to CF I can steal a week and come and help.
Just coming to CF with wife in the season is a bit too difficult atm with 15yo kids and full time work.
Looks like we'll only manage 20days on board this season due to work commitments (mainly wife's) so that has to wait for a few more years.

cheers

V.