Do you think he meant the opposite?
Haha.
Correct David. I was all primed up and ready to go into full rant mode.
I'm over it now.
Does that mean we're allowed to talk to you about it now?
Of course. If you had mentioned ECU's on Monday my mencal elf would have taken a real nose-dive but today I'm all serene and rational.
So tell me Tom; what's your general thoughts on ECUs and DPFs?
Just don't talk to me about how electric vehicles are more like computers on wheels than cars.
A belated answer to Matt's question.
I like women. I also like machinery and, for me at least, they seem to share many of the same attributes. They are beautiful, complicated, exhilarating, frustrating, useful, practical and several dozen other adjectives.
It's a fact that virtually everyone who works on mechanical things on a regular basis refers to them as 'She'.
Like women, I've always credited mechanical things with a degree of personality and the ability to be accommodating and benevolent or malicious and spiteful depending on how the mood takes them.
With this in mind I always try to treat them well and keep on their good side. Usually it's a case of “Come on now sweetheart, you know I love you and I've tended to all your needs so now be a good girl and show me what you can do.”
Very occasionally it's “Jesus Christ! What the Hell is wrong with you now you cantankerous old bitch?” But I try to avoid outbursts of that nature, they almost never work and within no time I'm reduced to apologising and begging forgiveness.
So like women, machines have personalities and moods and feelings but also like women they have very little cerebral capacity. When it comes to common sense or logical thought they are much the same. That's great though, it makes them all the more wonderful and fascinating.
Enter the ECU. AKA the engine control unit or sometimes electronic control unit. Essentially, it's artificial intelligence, a man made brain for your car/fridge/shaver/lawnmower etc first invented by some Kraut at BMW. (May he, by the grace of God, spend the rest of eternity broken down on the Autobahn)
Modern ECU's are connected to every aspect of your car. They monitor air intake, exhaust gas composition, fuel delivery, electrical output, electrical consumption, oil/coolant/temperature, ABS, traction control, service intervals, crank position, throttle position, even bloody door and window position, the list is endless...
Car brains, like woman brains wouldn't be so bad if they were combined with just a smidgen of rational thought but no, they get the slightest hint that something might be less than absolutely perfect and they over-react big style.
Like women, an over-reaction from an ECU takes one of two forms.
Option one: Complete shut-down and refusal to do anything, (This includes refusing to tell you what's wrong)
Option two: The dreaded limp mode. This is where your car or woman does absolutely the minimum required to function and repeatedly tells you what's wrong even if it isn't true and makes absolutely no sense.
Which brings us to the DPF, or diesel particulate filter.
There is nothing wrong with the DPF in principle apart from the fact that it's a total balls up. (May the man who invented it be getting a lift home with the man who invented the ECU when God stranded him for all eternity on the Autobahn)
The DPF is a device that sits inside your exhaust pipe to filter out all the particles of pollution and soot etc, that's great so far, now concentrate, here comes the balls up part.
When the particulate filter is full, the ECU squirts some diesel into the exhaust system and over the course of 20 or so miles allows it to heat up to an enormous temperature which burns up all the filtered out particles. Are you with me so far? Good.
Now sometimes the ECU starts the particle-burning process and then the driver stops the vehicle before the process has finished so what does the ECU do? It dumps the unburned soot particles and excess diesel into the sump, I shit you not.
Fortunately, the dumping of soot and diesel into the engine oil isn't too problematic, not ideal by any means but I often make 20min+ journeys and anyway its a large sump, a lot of oil and a tiny amount of contaminate. It will all be OK as long as I service my vehicle at the recommended intervals. (Pity the poor bastards who only use their car to potter around town in 10/15 minute stints)
My ECU put my camper into limp mode. I had to take it to my mate who has a plug-in diagnostic computer to find out why.
We extracted a fault-code which translated into “DPF failed to regenerate” (Regenerate is ECU speak for burn off excess soot and diesel)
What the ECU didn't tell me was why the DPF wasn't regenerating. I hit the online forums and discovered endless tales of woe.
The main cause of DPF non regeneration is not driving far or fast enough, it only needs to be around 50mph for 20 mins once every few weeks so I was OK on that score.
Next candidate was a faulty sensor, I checked it out, it wasn't that.
Anyway, to cut a very long story a bit shorter I tried loads of things and made no progress, so eventually I went back to my mate and asked him to plug in his diagnostic computer again.
We made no progress until I forked out for some specialist Fiat orientated software that could interrogate my ECU in more depth. (I imagine that's the equivalent of a nice meal and a bunch of flowers)
Why do you think my DPF wasn't regenerating? Because my fucking ECU
told it not to.Why did it tell it not to? Because it thought that my oil had not been changed and if it tried to regenerate and failed it would have to dump the crud into what it supposed was my already contaminated oil.
But why did it think my oil hadn't been changed? Because when The Fiat main dealer changes your oil he re-sets a behind-the-scenes oil change mileage counter. I change my own oil so had no knowledge of the counter and even if I had I found out that the counter can only be re-set by the main dealer and they won't do it unless they have serviced it.
Why though, did the supposedly clever ECU stop my DPF from regenerating and put me into limp mode instead of simply telling me it thought I needed an oil change?
If that's not woman's logic I don't know what is.
PS- The good news is that the Fiat software I forked out for also allows me to re-set my own oil change counter. The bad news is that Mrs Red looked over my shoulder while I was writing this and now she has gone into limp-mode.
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