Engine Complexity vs Reliability/Mission-Worthiness – Control Systems
Personal notes and rules of engagement
© 2024 MV Clock Work
Call from a friend today that quickly worked its way around to two standard questions in life these days... why exactly do I loathe complexity in design, and of all the things I list as Clock Work features, why do I place a mechanical Cummins 6CT as its absolute most important. A quick peek at YW and I know why he brought these up. These two conversations are actually the same one. It’s common to attract the questions when discussing CW’s competitive advantages vs inventory, or especially, new units and I’m used to it, but I know this guy and he heard my thinking on where complexity belongs in design long before I owned the boat.
There’s a fair bit of commentary in my blog on this matter because toxic, pointless, just-because-I-can complexity degrades mission-worthiness along the reliability pathway. Mission-worthiness is the ultimate success predictor in “designed things” and while I value and seek dialectic, w.r.t. this one thing... I am not that tolerant of amateur disagreement. I linger on this pinnacle (to-me) of systems design because in my experience, I NEVER get to talk with individuals with design chops (combined hours experience/training but I wanted to sound hip)... with technical decision chops... and have found the subject/intuition is utterly bottom/out-of-mind in so many boaters I know.. and is/are immediately forgotten by most 20 seconds after the conversation ends. Or maybe not, but simply was never sufficiently internalized as to be fluently applicable. Whatever.. it’s not part of most people’s background, and it shows, and it’s a perspective that merits significant consideration... it’s stochastically predictive of one or more consequential experiences for some that in the end NEVER had to have happened.
Intended use of this note - This note is my engineering/systems take wrt fully mechanical vs electronic diesel engine control considerations, which comes up with literally everyone I speak with about Clock Work. Important.. the note is intended for the person in the process of deciding, when a choice actually exists, between those approaches.. not for the person who already made the decision.
Finally, I’m not writing a paper here, and just want to put in the least time to get what is my opinion and POV on this subject out for that possibility someone I’ll be speaking with later will see it, and maybe (please God) shorten a few future conversations. Remember those tests in math or physics or chemistry or something where you could bring in a 4x6 card with whatever you wanted to write on it? Resulting in a dense disorganized mess? That’s my standard here. So with that, directly to the heart of the matter...
Regarding mechanical vs electronic controlled engines
I’m going to start this out talking about non-marine diesels. The purpose will hopefully become clear later.
There are three vehicles over which I will drool uncontrollability and pretend to know something. Two are diesel.. the Mercedes W123 platform and the Dodge pre-1988.5 2500/3500 pickup. The former is the most perfect/reliable diesel car ever made (conveniently excluding the vacuum-actuated peripherals) and was good for a million miles. Its birth attributable to moonshot-grade devotion to design and engineering-thinking that prized perfection/reliability [see end-note 1] and excellent basic education of the results of that dedication to the addressable market for that car, so not really a lot of failure data that I’m aware of. You know... exactly like the 6CT.
The engine in the Dodge that hooked me was the fully mechanical 5.9L diesel by Cummins in the 90’s... Uncountable rave comments very much out of scale with most trucks. Later “modernized” to electronic fuel injection in the 5.9L offering and on to the follow-on 6.7L Cummins. I hope to have a barn, with a lift, in a free state, someday and will instantly perform the killer-dowel pin fix on a new to me mechanical 5.9L prior to first starting it myself.
One side effect of my stalker-grade devotion to reliable things and specifically, for the Dodge/Cummins diesel offerings, is this laptop happens to be crammed full of accounts/descriptions of failure-relevant factors for both the 5.9L and 6.7L versions collected over the years. An AI search reports 2.7M Dodge trucks manufactured with either the 5.9L or 6.9L diesel engine.. which is obviously a very large data set of Cummins-made diesel systems, both with and without electronically controlled engines. And further, they were made during an approximately overlapping time frame as the 6CT marine engine and its successors. In my opinion, this is a significantly more predictively valid data set than any scraps of data I’ll find limiting my decision set to post-6CT Cummins marine engines... my memory of the NT fleet list is that it looked like maybe a few 100. And why Cummins? Because they made the 6CT.. the marine diesel equivalent of the W123 IMO.
Discussion
Two suggested references
From this site. 1. Because they already exist (20 second rule), and 2. because the focus of both is the most common (IMO) pathognomonic sign of degraded reliability, and therefore mission-worthiness.. complexity (parts count and/or number of system states). [See end note 2]
If it’s not there, it can’t fail.
Regarding “how mechanical/electronic” something is
The Dodge timeline included a shift from full mechanical to electronic control during the availability of the 5.9L
Fully mechanical
Electronic engine control (beyond injection). Inputs from/outputs to peripheral/environmental hardware. More hardware. More system states.
The first.. fully mechanical.. intrinsically more reliable. If it’s not there, it cant fail.
Electronic – Extra hardware and connectivity that can fail (and strand you). Relatively giant state space thanks to adding a microprocessor.
Not just the ECM but all the stuff that comprise it’s inputs/sensors and outputs/servos.
Added to implement electronic engine control..
More hardware and parts (c.f. next section)
More system states (vs zero)
More control methods for the amateur or weak/typical mechanic to try and wrap his head around... classical control, statistical, rule based, fuzzy, etc etc etc
Much bigger solution space for the designers, and they can fail to consider regions (comes from 5 years being roped into teaching the microprocessor-based hardware control course, and studying the 737max debacle for the book). If so, it can result in unforeseen failure (or fail-safe if that was built into the design culture/intent) due to touching an uncommon territory in solution space.
“The ECM in the 1990 Dodge Cummins engine acts as the central control unit, receiving and processing data from various sensors and actuators to optimize engine performance, emissions, and overall vehicle operation. It interacts with multiple onboard systems, including transmission, fuel, ignition, cooling, braking, and others, to ensure seamless operation and proper functioning of the vehicle.” (Ignition??)
Which flavor of engine failure is your favorite?
Every machine ultimately fails in some way. Let’s divide “failure space” up into just two territories, and for simplicity intentionally ignore the intermittent flavor of failure, which only favors the electronic case. My consulting life of ~131 rescue consults would have been only a handful of engagements without the psychotic symptom set... very low-frequency of recurrence, fault manifesting in successively different parts of the system (migratory), not repeatable in debug using conventional methods of fault-stimulation. These are real and wretched things (thank God!).. efficiently tracking these kinds of failures down is not widely understood in the general population of engineers.
So pick which you want...
Gradual loss of functionality with warning
Sudden loss of functionality with no warning
The gradual case is overwhelmingly a hallmark of mechanical systems in my experience. And for me when it happens, it’s often repaired by adjustment and/or gives you time to limp home.
The sudden case is the hallmark of silicon... electronics. Bad memory... walk into the prototype lab for the ECL mainframe CPU you're designing and it blows up when you come within 5-6 feet. For real, at least it was for me. Repair, in my experience, is almost never repair... just replacement. Trying to think back on one case in my life where this was a “fail gracefully” scenario. No joy. Of course, those with a lot repair time under their belt and 100’s of thousands of dollars of test equipment at their disposal might be able to handle it DIY. I think unlike when I bought, if I had to take a boat with an EPA engine today, I think my only decision, short of abandoning my mission-worthiness/intrinsically reliable requirement, would be a two engine boat with entirely independent sets of engine controls. One is none.. as they say. Not advice.. just how it would work for me.
One more thing on this point.. habits formed with a recalcitrant mechanical engine might not serve you well with a more complex silicon-based one. The quote below was for a marine engine but all I saved is the quote and can’t relocate it. Also, of my 8 or 9 motorcycles, only one (least favorite btw) is electronically controlled and I was warned to avoid damage to not keep working to start it once it has made it clear it is resisting starting. Was that guy right? I don’t know.. Is there a lot of upside to pretending I didn’t hear it? No.
Important Considerations: Before attempting to run the engine with a failed ECM or replacing it, consult the engine’s documentation and manufacturer’s guidelines to ensure compliance with safety regulations and to avoid potential damage to the engine.
Why, for the love of God, is all this crap on EVERYTHING now?
Answer #1 – I’m cutting corners, so... go google Tier 3-Non-road. The government drum circle has spoken. The engine companies had no choice, but also, literally nobody seemed to be asking for a different outcome (see next answer).
Answer #2 – The non-critical unquestioned embrace of all things eco-utopian by the citizenry.
Answer #3 – If the drum circle is forcing you to make something that no actual-thinking person would ever want (e.g. reduced reliability through exploding complexity/consequential vulnerability), the manufacturing/selling side has a choice...
Either sell it as something rammed up your exhaust pipe to be at best, tolerated by your customer, or
Since you were forced to add a microprocessor, you can distract the customer with a dancing bear extolling the gee-whiz unnecessary yuppie crap you “can do now” [c.f. end note 3]..
Almost every gee-whiz feature you ever see now in boats, cars and motorcycles is realized by mostly just some more lines of code. This quote came up on one of the AI searches on the diesel marine engines: “you will find electronically controlled engines are generally preferred by your customers and therefore machines with those engine types will be more saleable.” They believe whatever you put on page one of your brochures. And this snippet.. “If you’re seeking the latest designs...” Sadly, I’ve met many people who are actually wired like this.
Quick AI-search Answers
Diesel Engine Electronic Controls Diagram – (AI search – the diagram it produced was a jumble)
A block diagram of a diesel engine electronic control system typically consists of several interconnected components, including:
Engine Control Unit (ECU): The brain of the system, responsible for processing sensor data and sending control signals to actuators.
Sensors: Monitor various engine parameters, such as:
Air flow
Fuel flow
Engine speed
Intake manifold pressure
Exhaust gas temperature
Fuel temperature
Actuators: Implement control decisions, including:
Fuel injectors
Exhaust gas recirculation (EGR) valves
Turbocharger wastegate
Fuel pumps
Coolant pumps
The 3 bullets above are the extra hardware for electronic control. Inside that ECU is all the stuff they programmed it to execute. All those sensors and servos and their potential correct AND faulty operating values (because they screw up too and that should be handled too), and the set of the intended system/engine behaviors across the cross product of ALL that stuff is a HUGE dynamic state space. System failure is a non-zero probability and not huge, but if you’re the one, well... super sorry. While you’re being blown toward a lee rocky shore with a dead engine.. deploy that drogue chute I suggested you make to cut your wind-driven velocity by up to 90%.
The block diagram may also include additional components, such as:
Fuel injection mapping: Stores fuel injection timing and quantity data for various engine operating conditions.
Engine calibration: Adjusts fuel injection and ignition timing to optimize engine performance and emissions.
Fault detection and diagnosis: Monitors sensor and actuator signals to detect and diagnose faults.
Dodge Cummins 5.7 vs 6.7 (AI search)
The Dodge Cummins diesel engines, specifically the 5.9L and 6.7L inline-six cylinder engines, have distinct differences in design, performance, and features.
5.9L (1989-2007)
Displacement: 5.9 liters (359 cubic inches)
Power: 160-615 horsepower (depending on the model year and modifications)
Torque: 400-765 lb-ft (depending on the model year and modifications)
Emissions: Pre-emissions control era, with no EGR, DPF, or SCR
Fuel injection: Mechanical fuel injection (MFI) until 2003, then switched to electronic fuel injection (EFI)
Turbocharger: Fixed geometry turbocharger (FGT) until 2004, then switched to variable geometry turbocharger (VGT)
6.7L (2007-2018)
Displacement: 6.7 liters (410 cubic inches)
Power: 350-385 horsepower (depending on the model year and trim level)
Torque: 650-800 lb-ft (depending on the model year and trim level)
Emissions: Post-emissions control era, with EGR, DPF, and SCR (selective catalytic reduction)
Fuel injection: Electronic fuel injection (EFI) with high-pressure common rail (HPCR)
Turbocharger: Variable geometry turbocharger (VGT) with wastegate
Key differences:
Displacement: The 6.7L has a larger displacement than the 5.9L, resulting in more torque and power.
Emissions control: The 6.7L has more stringent emissions control systems, including EGR, DPF, and SCR, which require the use of diesel exhaust fluid (DEF).
Fuel injection: The 6.7L uses a more advanced electronic fuel injection system with high-pressure common rail (HPCR), while the 5.9L used mechanical fuel injection (MFI) until 2003 and then electronic fuel injection (EFI).
Turbocharger: The 6.7L has a variable geometry turbocharger (VGT) with wastegate, while the 5.9L had a fixed geometry turbocharger (FGT) until 2004 and then a VGT without wastegate.
Performance: The 6.7L generally has better low-end torque and responsiveness due to its VGT and HPCR fuel injection system, while the 5.9L has a reputation for being more durable and having a wider range of aftermarket support.
Dodge Cummins 5.7 vs 6.7 Reliability (AI search)
The Dodge Cummins diesel engines, specifically the 5.9L and 6.7L variants, have distinct reliability profiles. While both engines have their strengths and weaknesses, here’s a summary of the key differences:
5.9L Cummins (2003-2007)
Known for its legendary reliability and durability, with many owners reporting high mileage without major issues.
Fewer complex emissions systems and less prone to problems caused by modern emissions regulations.
Head gasket failures were relatively rare, and aftermarket support was extensive.
Overall, the 5.9L Cummins is considered a reliable choice, especially for those who plan to keep their truck for a long time.
6.7L Cummins (2007.5-2018)
Introduced with more complex emissions systems, including EGR and DPF, which have contributed to reliability issues.
While still a robust engine, the 6.7L has experienced problems with these emissions components, such as clogged DPF filters, EGR cooler failures, and turbocharger issues.
Some owners have reported higher maintenance costs due to these emissions-related problems.
[Curious lack of mention of ECM failure despite there being so many reports individual and multiple unit failures in remarkably short periods of time]
However, the 6.7L’s variable geometry turbocharger and exhaust brake function are notable improvements over the 5.9L.
Key Takeaways
The 5.9L Cummins is generally considered more reliable due to its simpler emissions design and fewer potential failure points.
The 6.7L Cummins has been affected by the added complexity of modern emissions regulations, leading to more frequent issues with emissions components.
If you prioritize reliability and are willing to accept slightly less power, the 5.9L Cummins might be the better choice. However, if you value the added power and features of the 6.7L, and are willing to accept the potential for more maintenance and repairs, it can still be a reliable option.
In conclusion, while both engines have their strengths and weaknesses, the 5.9L Cummins is generally considered more reliable due to its simpler design. However, the 6.7L Cummins can still be a reliable choice for those who are willing to accept the added complexity and potential maintenance costs associated with its modern emissions systems.
Comments harvested over the years paint a picture of single-point failures
It was supposed to be plug and play [Said so in the brochure]
it’s common to lose programming [Stochastically true I’m sure as implemented, but I doubt it has to be]
If all of that checks and tests good, where is the next step to look at. I’ve burned up 4 ecms and everyone including two dealers are scratching there heads
I will be on my third ecm and sill no solid answers. My last ecm died a few minutes after engaging the cruise control up idle, just revved up once for a few seconds, and then took a hike along with my gear indicator. Hasn't run since. [Was somebody just talking about failing gracefully.. i.e. mechanically?? Good thing there are no rock-strewn lee shores on surface streets]
There are known ECM issues with the CM2100. Don't buy them from any refurbished place. It is a defect in the processing unit that can't be refurbed. [Is EBay ok? The service world is so chock full of half-assed service providers that buying anything from anyone is loaded with risk. As I type this, I believe my numbers on just household goods is we’ve had to return 9 of our last 11 Amazon orders]
It frustrating not being able to fix it myself. [We live in a wildly different world now]
I know this is several years old but I have 07.5 Cummins same issue – 5 ECMs in and still no fix.
First 1 lasted 1 yr
2nd 2 months
3rd 2 weeks
4th 4 hrs
[Does this guy remind anyone else of that punishment-magnet who shows up at the opening of Gunsmoke each week to call Matt out.. just to get his ass blasted off? ]
2nd replacement just died. 1st on lasted for 40 miles. Second (original ecm rebuild) lasted for 600 miles. Dealer wants 6k for a new one.
sorry for another ecm post
15 miles later - ecm dies again [No way to see that coming]
looks like about $650 for another used one and the dealer wants over $3,000 for parts and labor if I buy through them.
Low voltage is not a friend to these ECM'S, good and or brand new batteries are a must along with clean terminals, grounds, with no corrosion. [See end-note 4]
so i removed it and took it to the local Cummins dealer for test they confirmed its bad and the replacement is available and they can have it in a day or so which sounds great then they tell me it will be $2500 and some change plus tax.
Two weeks later it is towed in. No comm, dead again. The rebuilder sent another unit and requested we replace the batteries and we did. Within 8 minutes it failed again. There were no voltage issues with existing batteries but the builder said it didn't take much to zap the ECM memory. [Maybe he watched the wrong YT video?]
From a repair shop - A customer brought us a well maintained Ram 3500 6.7 diesel. He also brought it with a reman ECM in the box. He said it was the third and wanted me to check it out before installing. I loaded circuits and checked for excessive amp draw as in the old days. I suggested replacing the fan clutch. I cannot find a load issue and I know the B+ is good. I don't like the info the builder that low voltage zaps the ECM enough that it loses it beans forever. I figure I should have a lot full of these if that's the case. To be clear the builder states that voltage is being pulled down therefore blanking the ECM programming but not damaging the hardware. I've rechecked the truck again looking at load circuits and cannot see anything drawing excessive current. Any ideas?
[I honestly do not see complexity as a “success space” for most mechanics]
are both of your batteries good? IE load test. is your alternator good? have you checked your grounds (all of them)? is your crossover cable still good? IE not corroded and ohming resistance within spec (<0.5ohm drop, IIRC). if the sensor has crapped the bed or the battery has crapped the bed, it may be overcharging and leading to random voltage spikes going thru the ECM. it's a known issue that the computers in these trucks are VERY finicky when it comes to input voltage and tend to do spooky stuff like randomly shut the truck off when there's the slightest fluctuation in power. if the sensor is ok and everything else is ok then i'd suggest looking into how the alternator
Oh.. found a credible 6CT quote on here... Seaboard on the 6CT: “super engines and are easy to keep alive for decades”
Conclusions
I’ve tried to make a point about the comparative system reliability of mechanically vs electronically controlled diesel engines because I am frequently in conversations with people considering purchasing my boat, Clock Work. My position is that mechanical control and the resulting effect on reliability and mission-worthiness was to me worth waiting for over a year to locate when I bought it, and given they aren’t (can’t) making any new ones, it’s much more worth it now.
I used an analog of Cummins diesel trucks, with both mechanical and electronic control because there’s so much more data to make the point. On the truck side (rich data set) and on the boat side (sparse data set), you have Cummins as the manufacturer and significantly overlapping time frames. I believe it is implied strongly you have similar design cultures if not the same groups making both classes of engines.
There are at least three perspectives when examining “designed” things.
One is by intent (see page one of the brochure, or the functional design spec, or the system architecture definition, or... words, words, words, etc.). Every rescue consult proved that intent is only intent.
One is to examine the behavior of an early implementation (prototype) and see what/how it’s messing up and or working. This might equivalently be labeled as a phenomenological perspective. THIS is what they actually built (vs the intent that design managers seemed more than a little bit married to at some clients). There is a perspective in cybernetics called POSIWID.. the Purpose Of a System Is What It Does. POSIWID is a useful tool in discriminating correct from anomalous behaviors in amateurs who may be too attached to intent. If you and I were discussing diesel engine control over a coffee, I might come around to say for some subset of owners, POSIWID appears to define an electronically controlled diesel engine as an expensive way to get pissed off or blown up on the rocks, because that is what it does for some.
And sometimes you can just use first principles to examine a designed thing.. like, if something isn’t there, it can’t break.
I watched friends and mechanics I knew bitch up a blue streak when every control system converted to OBD back in the late 80’s early 90’s. Still.. more than a little of that from my yuppie friends who think changing their own oil makes them “mechanical”. Mechanics are wrench turners now after their robot tells them what to fix. While I find OBD control easy and intuitive to understand.. easier in cases.. but find the “special secret/undocumented proprietary behaviors” an act of war. I don’t see how anyone I know with a boat is prepared to think through the complexity on an effective/diagnostic level with all the garbage mandated by the EPA. Merely finding the documentation or contacting a human at the manufacturer's customer support line might be more than some can stand (when I was chasing the generator oil leak, I couldn't find a phone number anyone answered). If you read about the pure wasted heartbeats I went through with 4 different mechanics trying to get just a (literally) designed-in generator oil pan leak repaired, I can’t see any of those guys being your go-to guy when your electronic system craps out. Those quotes above include mechanics. Thinking back to OBD days.. I personally would not/did not trust the four I had to fire last year, but would have LOVED life if they did what they said to me they'd do. . I can think of one owner from my marina I’d expect to get to the other side of this modern BS complexity, if he were the type to buy high-complexity boats. For the wrong failure presentation, how long will you be willing to squirm with a dead boat if the swirl of possibilities exceed your diagnostic experience, hired or DIY?
To finally depart this subject, a few simple facts that guided my choice when I purchased and would still use.. summarized:
If it’s not there, it can’t fail - WHY WOULD YOU DO OTHERWISE?!!
See previous bullet
Silicon usually fails instantly and without warning
Mechanical usually fails gradually with warning and can often be repaired by adjustment.
Embrace the Lindy Effect
Evaluate serious systems seriously
Never trust/read page one of the brochure for any lux product
Avoid advice on engineered things from low-hours amateurs
Consider an engine’s reputation if it has had sufficient sales to do that validly
Remember... risk evaluation has 3 parts. Probability. Consequence. Costs of mitigation
See first bullet
To repeat the intended use of this note - This note is my engineering/systems take wrt fully mechanical vs electronic diesel engine control considerations, which comes up with literally everyone I speak with about Clock Work. It is exactly the decision strategy I implemented when I bought the boat. The note is intended for the person currently in the process of deciding, when a choice actually exists, between those approaches.. not for the person who already made the decision. BTW, I think everyone should have a drogue and even though I have mechanical, I made one from a surplus parachute designed to drag cargo out the back end of military cargo planes. I think it was a 90% reduction of wind-blown velocity.. more time for rescue to get there.
Closing out with my designer’s hat on... We obviously have to make electronically controlled diesel engines to save all the cute lorax and not harsh the drum circle's mellow. But I just cannot believe how unreliable electronically controlled diesels seem based on the data I have. And by that, I don’t BELIEVE that is necessary. I just parked a truck I drove for 300k mi/20 yr. (frame rust) that never stranded me and the engine is still working perfectly as it sits the driveway waiting for a new frame. That’s gas but so what. The expert amateurs/amateur experts in the comments above continue to pass around the admonition that the ECM hates low voltage. Not new information and if it’s what they say.. that is a very wrong state of affairs. As I sit here... competing to sell the only mechanical Nordic Tug 42 I’ve seen on YW for months [See end note 5], I’m thrilled what seem like a handful of avoidable design issues.. I can think of three.. that have been solved for years.. are what's in the things I have to compete against.
END NOTES
[End-note 1]: In the early 90’s, I was working near Sindelfingen and my host set up two visits to the MB plant to spend a day with a designer. I was given the chance to spend significant time talking design and engineering with designers that worked on that platform 10-15 yr. earlier. One of the most rewarding side trips across all the flying I did.
[End note 2] - I know the arguments about throwing more parts and/or systems states at a base, but complex, machine to “urge” incipient failure toward a more gracefully degraded state. I actually chose that topic (fault-tolerant design) as one of 9? for my qualifying exam. I think it’s an interesting specialty-knowledge design idea that absolutely belongs in the “smart guy” bucket if I go by the designers I got to know over consults at two fault-tolerant computer companies. Together both companies amounted to microscopic slices of the computing landscape but served a customer base of “hardcore” need (i.e. too critical to fail), and I don’t see marine engine design ever experiencing that sort of pull from the hull manufacturers.
[End note 3] – A humble suggestion: Consider a campaign like.. Open on a pretentious white-linen dressed metrosexual as he presses the only button on his portable smart control panel to make his boat^H^H^H^H yacht self-drive (the next leading cause of rivers of blood in the streets, BTW) from the slip at one marina to a slip at another, just like his cars... while 2-3 near-supermodels in bikinis and/or Taylor Swift, Bono, and Clooney raise their wine glasses with approving smiles and glint of awe... because... if the brochure says it, the functionality AND the image bump must be real. Oh.. close with a quick shot en route.. interior... the party continues... Bono looks out.. concerned expression forms.. fade up “Do They Know It’s Christmas” as he looks... he has noticed a lone glass of wine sitting on a table in the spray-affected cockpit (or aft lounging space if testing finds cockpit too toxically masculine) as the bo... yacht.. crosses an angry sea with 3DDP or Three-Dimensional Dynamic Positioning watching over this important group, while an opulent white font bleeds on to the screen... “3DDP... when every drop counts” (or “no drop left behind”? test it), just as the metro guy casually assures all with comforting pat on Bono's shoulder “it’ll be fine”. But of course that would only work if there were unselective more-$$$-than-brains buyers out there for that stupidity. Turns out.. I actually do know that guy. Hi!!
[End note 4] Regarding low-voltage and silicon... valid., though it shouldn’t be IMO. This is why you load test a suspect truck/car battery. If you draw so hard on the battery that you drop below 9.6V (doing this from memory), you’re on the verge of falling below what ALL that yuppie silicon needs, including your ECM/TCM/PCM. How is this shit not stored in NVRAM??? If I’m missing some key fact given I’m not looking deeply into blasting out this note, I would still think a smart designer can be repair both the existing design as well as making a simple $250 add on/local source of electrons. Multiple device-level rescue consults turned out to be charge starvation on small test boards.
[End note 5] – I’ve been tracking NT42 inventory for about 12 years... populating my own data base and analysis. This analysis was/is for me... I had no idea at all I’d ever have a reason to share it with anyone and it kicked out metrics/scores of THE NT42 I wanted... 6CT engine... 2nd gen layout.. east coast.. bridge.. hours non-trivially below the moving accumulated typical... which all mattered only to me. If a 42 was not in that specific bucket, I was not interested and it didn’t land in the “consider seriously” section. Though I have held since before I owned CW that that was the pinnacle of 42 production, at least for a hyper-analytic like me. But non-6CT non-bridge and non-east did factor in for price comparison metrics via adjustment factors to see the real difference in value of the product, because while I was “competing for boats with the 6CT/bridge/east” I knew the average guy walking down a dock thought less precisely and was far less likely to prioritize mechanical.. “partial threat” was the term I believe. Actually not recording anything the last 2-3 years because... no matter what.. the number of NT 42’s with mechanical engines has been drying up while the hours continued to climb, and did not see that analysis method worth the heartbeats. Sort of like trying to cut down on salt while standing in front of a firing squad. So, I don’t/have never tracked non-mechanical 42’s (or 1st gen layout)... I didn’t need to for my own personal goals. Not a judgment of anyone else and I truly can’t wait to delete this entire site and focus on vastly more important things. Unless I lease this to someone else thinking of DIY-selling their 42.
Appendix – AI search results of ECM repair for two marine diesels.
The following was AI’s take on ECM repair of two Cummins marine engines. Caution... AI searches (at least the ones I use) do not always produce wonderful results and especially when dealing with relatively sparse underlying data, and have only partial repeatability between identical searches.
Extreme example.. An AI search on Cummins 6CT ECM repair ---> “The Cummins 6CT ECM is not repairable.” No shit. Technically, true I suppose, but swap out the robot anyway. In any case, I suspect the law of large numbers is the root cause of severe boundary errors.
QSC ECM Repair Refurbishment
Based on the search results, here is a summary of the feasibility and costs of repairing or refurbishing a failed ECM on a Cummins Marine QSC engine:
Repair Feasibility: According to the search results, the ECM internal failure is considered a non-repairable issue (e.g., “Repairs are not possible to the ECM” and “Cummins does not sell ECMs ready to use; they are in a ‘Seeded’ state”). This suggests that the ECM cannot be repaired or refurbished.
Refurbishment: While there is no explicit mention of ECM refurbishment, Cummins Marine Diesel Repower Specialists do offer a factory repair process for existing ECMB and ECMC units (as described in the “ECMB and ECMC factory repair solution” snippet). This process involves inspecting the ECM, determining feasibility for repair, and performing necessary maintenance and repairs. However, this service is only available for specific Cummins models and engines, and it’s unclear if it applies to the QSC engine.
Costs: The search results do not provide specific cost estimates for ECM repair or refurbishment. However, it’s likely that the costs would be substantial, as they would involve labor, parts, and potentially reprogramming or re-flashing the ECM.
Timelines: The timelines for ECM repair or refurbishment are also unclear. The factory repair process described in the snippet implies a potentially lengthy process, involving inspection, diagnosis, and repair. However, without specific information on the QSC engine, it’s difficult to estimate the exact timeframe.
Recommendation: Based on the search results, it appears that the ECM internal failure is likely non-repairable, and refurbishment options are unclear. If the engine is still under warranty, it may be worth contacting Cummins Marine Diesel Repower Specialists to inquire about their repair process and potential costs. For out-of-warranty engines, it may be more cost-effective to consider replacing the ECM or the entire engine, depending on the extent of the damage and the age of the engine. [Man, I hope that’s an AI screw up]
Cummins QSL ECM Repair Options
Based on the search results, here is a summary of the information:
Repair/Refurbishment Options:
Cummins Factory Repair Process: Cummins offers a factory repair process for failed ECMB and ECMC Electronic Control Modules (ECM). The process involves inspecting the ECM to determine feasibility of repair, replacing failed parts, and performing preventative maintenance. The repaired ECM is then sent back to the customer.
Re-manufactured ECM: Some companies specialize in re-manufacturing Cummins ECMs, including the QSL engine. These re-manufactured ECMs are built to meet original equipment specifications and can be a cost-effective alternative to purchasing a new ECM.
Associated Costs:
Factory Repair Process: The cost of the factory repair process is not explicitly stated, but it likely involves a fee for inspection, repair, and testing, as well as any necessary parts replacement.
Re-manufactured ECM: The cost of a re-manufactured ECM varies depending on the supplier and the specific model. As a rough estimate, a re-manufactured Cummins ECM can range from $1,000 to $5,000 or more, depending on the complexity of the repair and the age of the ECM.
Timelines:
Factory Repair Process: The timeline for the factory repair process is not explicitly stated, but it likely takes several weeks to a few months, depending on the complexity of the repair and the workload of the Cummins repair facility.
Re-manufactured ECM: The timeline for receiving a re-manufactured ECM depends on the supplier and their production schedule. As a rough estimate, it may take 2-6 weeks to receive a re-manufactured ECM after ordering.
In summary, a Cummins Marine QSL engine with a failed ECM can be repaired or refurbished through Cummins’ factory repair process or by purchasing a re-manufactured ECM from a specialized supplier. Associated costs and timelines vary depending on the chosen option and supplier. It’s essential to diagnose the ECM failure correctly and work with authorized dealers or reputable suppliers to ensure a quality solution.
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