ECUs, fly-by-wire, multiplex wiring - who would choose it?

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Do you prefer your car without or without electronics?

Poll ended at 05 Nov 2012, 01:15

I would choose my car not to rely on electronic control to make it run - this allows for an ABS control unit and airbags.
10
63%
I appreciate the benefits and complexities and prefer a car with multiple electronic devices without which it will not run.
5
31%
I drive whatever is cheapest.
1
6%
 
Total votes: 16

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Spaces
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ECUs, fly-by-wire, multiplex wiring - who would choose it?

Post by Spaces »

Who would plump for a non-electronic car? I would, and still do with several ancient Citroens and an old W124 Mercedes diesel, all of which are/can be in daily service. With its duplex cam chain and rugged inline injector pump the MB will run for many hundreds of thousands of miles without a problem in the same way as a 2cv can - there is very little to stop it from running and the engine is understressed through 'over-engineering'. Of course if a car doesn't meet an end with electronic problems, it may suffer mechanical and corrosion problems, but those are easily minimised with proper maintenance and corrosion protection. The 3 litre Mercedes estate can easily achieve 40mpg on a run, the 2.1 Xantia can make a gallon stretch 45 miles, my Traction Avant went to the South Coast flat out at an average of 29mpg and 69mph, a 2cv has been to London at 59mpg (210 miles in 4 hours) and a diesel CX from the further reaches of Cornwall in the same time, with almost 20 gallons of plant oil combusted.

Whilst there are tough and dependable direct injection diesels which run on computers such as my A6(C4) 2.5TDi, many more modern ones seem to go wrong with frightening ease and regularity, whether it is injectors, pumps or other complexities. VWs, Peugoets, BMWs, Audis, Renaults, Mercedes, whatever - they all seem to share a relative complexity and fragility in their modern diesels when compared with what went before. A C5 2 litre HDi will easily do 50 miles on a gallon, whereas an old idi Xantia XUD is probably being nursed if it achieves anything near that - but if I had to cross a desert, deliver a very poorly person to hospital or drive in a war zone, my choice would be blindingly obvious.

Sometimes our choices are made for us - a computer-reliant C5 may cost so little you cannot afford not to buy it, or perhaps neighbours or wives partly dictate what we stand outside our houses. But as a daily tool, I would choose a good car without electronics rather than one with. I love the monotonous indestructability of the simpler vehicle. I would hate paying for electronic interrogation at a main dealer all for the sake of a smarter car or 7 miles further on every gallon - but I would be even less keen knowing that without warning, an electronically controlled car can stop at any moment without warning, and not go again until the right part has been singled out and replaced - or even worse, an intermittent electrical or electronic fault which causes dangerous situations through cutting out or other malfunction - such as with electronic stability control.

Someone recently told me that your speeds, locations and anything else of interest may easily be downloaded from your black boxes - as New Labour said "if you've nothing to hide you've nothing to fear". What are your thoughts?

Northern_Mike

Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by Northern_Mike »

Spaces wrote:Who would plump for a non-electronic car? I would, and still do with several ancient Citroëns and an old W124 Mercedes diesel, all of which are/can be in daily service. With its duplex cam chain and rugged inline injector pump the MB will run for many hundreds of thousands of miles without a problem in the same way as a 2cv can - there is very little to stop it from running and the engine is understressed through 'over-engineering'. Of course if a car doesn't meet an end with electronic problems, it may suffer mechanical and corrosion problems,
I used to help out in a garage when I was a kid in the 80s in school holidays, and then trained at Citroen in Bury. The number of repairs that were carried out on older cars was amazing compared to what I see today.

My thoughts on your question - while, there may be a few rarites like the W123/124 series diesel Mercs that could be used in Africa as taxis, old cars, in the main, were not great at all. Compared to modern cars, they are unreliable, need almost constant maintenance/cleaning/rustproofing and rot quickly. People simply don't have the time, money, or urge to keep old cars on the road. 99% of people want a car that starts, goes, stops, keeps them warm and dry, in whatever style they wish to be seen in. That's it. They want it to be safe and reasonably economical.

It's a complete fallacy that old cars are more reliable than newer ones. Newer cars are better, more economical and have better build quality. I just sold a Xantia with 210,000 miles on the clock. Everything electronic still works, the car drives fine. It's 12 years old and full of electronics. It's way more reliable than my mum's new 2CV ever was. My mum likes to buy Jap-o-hatches, and has ever since she traded the tin snail for one back in 1992. She ran that one for 9 years. It never broke down. She traded it for another. She ran that for 10 years. It never broke down in 90,000 miles. She bought a Kia Picanto last year. So far, it hasn't broke down at all. It has ESP,TC, ABS, AC and is full of electronics.

Car electronics, like most other technological advances improve all the time. When they first came along, they were a little unreliable and overly complex. However, they are now greatly improved and in the main, wholly reliable. A friend of mine has just retired his 03 plate Mondeo TDCi saloon, which he bought with 5,000 miles on the clock. It clicked over onto 270,000 recently. The only failure in that time has been the diesel pump - at 230,000 miles. It's not even had an oil change since 150,000...

lurchy666
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Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by lurchy666 »

for me it goes further than that, ecus, fly by wire, multiplex, abs, tc esp, and basically that sort of electronic interferance just ruin the experiance of driving, now i brought my xantia cause it was cheap but if i could (and if my back would cope with it) i'd go back to my first car a old mini with nothing the only electrics on that was a heater a rear demist and some lights and a few wires in the engine bay which only had the human controling them

ahh carbs points condesors perfect in my opinion

Peter.N.
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Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by Peter.N. »

I have maintained all my cars since I started driving in the mid ,50s and they were relatively easy to repair in those days, the only advantage I can see of electronics is improved fuel consumption, having said that, the 2.1TD engine in the XMs which was fully mechanical until 1996 is nearly as good on fuel as the modern electronically controlled engines but as there are very few left now I have had to join the Hdi brigade. I must say that these engines are more reliable and economical than I thought they would be, except the 2.2 which is not as good as the XM, but they are not as smooth at low revs, I would accept the electronics necessary to comply with emmision regs as we have no choice but anything beyond that is a step backwards in my opinion.

Peter

addo
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Post by addo »

I treat "failure to proceed" as an unplanned challenge. Nothing in my life is so important that automotive travel is a dealbreaker. Nothing. People who know me, will understand the principle that fidelity of purpose overrules a Bundy clock. Many of the scenarios people knock up to justify their paranoia are self-indulgent and highly unlikely.

The complexity level of later '90s cars is, to me, the perfect balance between function and repairability. After that multiplexing is really at the mercy of undersized connections, whose durability can falter - and solid state components ill-matched to the real world vagaries of an ageing motor (eg; one where a battery cell is beginning to bridge internally).

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CitroJim
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Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by CitroJim »

I used to be wary of electronics in cars but not any more; generally they're the most reliable bits!

All three of mine are bristling with the stuff, even the XM... One even has an electronic gearbox.

It just means you need diagnostic kit, which really is just another tool, and a bit of learning to understand what's going on.

No worries at all :-D

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Spaces
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Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by Spaces »

Rattiva_Mike, this isn't a debate as to whether older cars are inherently more or less reliable than more modern ones. Just whether or not you prefer a car with complex electronics running the engine, and without which it won't run.

Very soon there will be few second hand cars (which is what most of us buy and use day-to-day) available without - at the moment there is still the choice between an HDi and old-fashioned idi turbo-diesel Xantia. If I was looking to buy to keep for many years, I'm not sure which I'd buy - the electronics are inherently reliable and give improved running and fuel consumption, but can cause mayhem when they do fail - and add a layer of complexity and expense to an older car which is going to need other work as well. In ten or twenty years, what will be the supply of various electronic parts be like?

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spider
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Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by spider »

My only real thoughts on this matter are Multiplexing. Really I do think this is designed to reduce diagnostic times, but in the longer run (ie as cars age) it will cause more problems than an alternative wiring arrangement that was not plexed, simply as though there's (in theory) less wiring in a plexed car, there is more to actually go wrong.

I was there when the first plexed cars appeared.

Two good funny, amusing faults that I can remember:

1. One sidelight would come on when the brakes were applied

2. ABS light permanently on (led instrument panel) shame the car did not have ABS :D

COM2K springs to mind here, although the newer ones are better I know, the very first batch of plexed cars with these, well they were not too brilliant to be blunt, certainly compared to say a relay, fuse and conventional switch which would last for years and years and I would doubt the cost of two switches and a relay would be more than a C2K as well.

Older cars, well you have age problems there, putting aside body corrosion you will get electrical gremlins such as oxidising wires if you're unlucky, however the point being this would have highly unpredictable effects on a plexed car whereas a not plexed one, at least you would have a better chance to put it right.

I think most of it boils down to the CPM for fleet buyers as this is what they ultimately look at...

I do know now I've dearmoured the 106, it will run without the ECU, not very well as the timing is miles out but the fact is even with the ECU unplugged it will start and run (assuming tis warm as the heater plugs are controlled via the ECU that is) point being an electrical failure would not result in a breakdown, assuming I can get the solenoid out to remove its plunger etc.

Not sure what else to add. :)

Peter.N.
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Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by Peter.N. »

If the electronics were 100% reliable or faults could be diagnosed easily by the average mechanic I would have no argument, the fact is though that most mechanics know little about electronics and faults are frequently misdiagnosed leading to either unnecesseraly high repair bills and very often the writing off of an otherwise perfectly good vehicle.

My first C5 is a prime example, the previous owner had spent a lot of money trying unsuccesfuly to cure an electronic problem with the result that I bought the car for £300.00 with 6 months tax and MOT and a new battery, I found the fault quite quickly but only with the much appreciated help of this forum, without that and being able to have a go myself the car would have gone for scrap - that's why I don't like electronics on cars :(

Peter

Northern_Mike

Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by Northern_Mike »

Spaces wrote:Rattiva_Mike, this isn't a debate as to whether older cars are inherently more or less reliable than more modern ones
Well, yes, it is really isn't it?

They are.

I'd have a car full of electronics over an old, unsafe, hard to get parts for clunker one over an old clunker any day.

If you want one as a hobby car, fine. I do - Some may call my Xantia V6 an old clunker. It has plenty of electronics though.

As a daily driver I had to rely on? Not a chance. Modern(ish) for me any day.

Northern_Mike

Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by Northern_Mike »

Peter.N. wrote:If the electronics were 100% reliable or faults could be diagnosed easily by the average mechanic

Peter
That's not the fault of the car, it's the fault of the under-trained, under equipped mechanic. Any reasonable "backstreet" garage should have diagnostic equipment to read most cars and codes now. It's not as though it's a sudden new invention is it? Take the car elsewhere, to a mechanic that has the kit.

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Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by spider »

I don't think its electronics per-se as such its more their complexity. Taking a look at say a mid 90's car with electronics it seems (reasonably) easy to diagnose and rectify faults found.

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Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by Peter.N. »

Rattiva_Mike wrote:
Peter.N. wrote:If the electronics were 100% reliable or faults could be diagnosed easily by the average mechanic

Peter
That's not the fault of the car, it's the fault of the under-trained, under equipped mechanic. Any reasonable "backstreet" garage should have diagnostic equipment to read most cars and codes now. It's not as though it's a sudden new invention is it? Take the car elsewhere, to a mechanic that has the kit.
True, but its a fact of life, back street mechanics may be able to sort out the problems but the average dealer doesn't seem to be able to, just look at the problems experienced by many motorists in Honest John's forum. Most garages seem to work on a 'try it and see' basis, if it doesn't work the customer still pays, in some cases thousands of pounds and sometimes the car still gets written off.

Peter

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Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by RobinMasters »

You can't take an ecu apart, look at it, waggle a few bits, and work out what's wrong. I'm more than capable of learning how to diagnostic equipment, but I don't particularly enjoy it-if I did like that sort of thing I'd currently be on a computer forum, discussing computery stuff.

I don't think modern cars necessarily are any more or less reliable, they just break down for different reasons-usually things you can't bodge your way round at the roadside!

Northern_Mike

Re: ECUs, fly-by-wire, multiplex wiring - who would choose i

Post by Northern_Mike »

RobinMasters wrote:You can't take an ecu apart, look at it, waggle a few bits, and work out what's wrong. I'm more than capable of learning how to diagnostic equipment, but I don't particularly enjoy it-if I did like that sort of thing I'd currently be on a computer forum, discussing computery stuff.

I don't think modern cars necessarily are any more or less reliable, they just break down for different reasons-usually things you can't bodge your way round at the roadside!
I replaced the points and coil on two my 2cvs with 123 Electronic ignition units. It gave them slightly more response and made them far more reliable, removing the points and the heat-susceptible original coil and leads out of the HT equation. That's a very basic example I know, but it shows that electronics can, and usually are a better option.

It is true that you cannot waggle and ECU to find out what is wrong with it. However, you can spend £90 on a cheapy Lexia tool, and it will tell you instantly what is wrong with the car, rather than having to go through the old fault-finding route (is there fuel, spark, air, timing etc etc).I prefer the easier approach to fault finding. Many other cars can be hooked up to a £20 ebay OBD-II code reader - cheaper than many quality spanners, so as Jim says, it really is just another tool.