You see these all the time on fleabay for about £30 for a fully self-contained one, or about £15 for one that connects to a PC and uses free software.
The question is, do they work? Are they likely to cause damage to the car? Why do the professionals use the much more expensive kit, other than general build quality/features concerns?
I just spent £40 on a reading on my car at the local electrical specialist. That's fine, I'm paying for the guy's expertise as much as anything else, I realise that. But it would be great in future to know what the fault code is so I can do my own research before possibly taking the car in.
In my case the fault was tracked to a faulty MAF sensor (no massively severe symptoms exhibited by the car, just a general flatness of throttle response). The thought had occurred to me that if I had one of these boxes of tricks I could potentially have cleaned the MAF for nowt, or replaced myself on ebay for £40, before taking it in if that didn't work and paid the man to do the job properly (lol), rather than the £130 all in I'm paying now.
As I say, I don't begrudge the man his crust at all, just thought this would be a useful piece of kit for the toolbox, *if* it works without having to pay £200 for a proper one.
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My understanding is that the really useful diagnostic codes are manufacturer specific, and that very little useful information can be gleaned relating to a typical complex modern fuel system from the standard OBDC codes that these readers pick up.
Of course I might be wrong.
Cheers
DP
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without having to pay £200 for a proper one.
£200 is not the right figure for "a proper one", not by a long chalk!
The extra you pay for is for the extra level of access into the vehicle's systems, until you can see the same detail of information that the car specific tool at the dealer's can see.
The other thing to note, is that the codes themselves don't indicate a faulty component. So, fitting parts based solely on codes from cheap scanners without live data is little better than blind "poke & hope" type repairs, and, by the time you've paid for the parts you didn't actually need, you would have been better off going to someone with the skills and experience.
Codes plus some intelligent measurements of the system's sensors while th fault is present, on the other hand, can lead to more efficient trouble shooting.
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£200 is not the right figure for "a proper one" not by a long chalk!
£200, £2000, £20,000, the figure was plucked out of the air, apologies. Regardless, I wouldn't pay any of those figures.
The extra you pay for is for the extra level of access into the vehicle's systems until you can see the same detail of information that the car specific tool at the dealer's can see.
I fully realise that, and the fact that the codes only indicate a symptom -- I was merely asking if the cheaper units actually did what is advertised.
It's a bit like computer motherboards -- you can get PCI cards that will read BIOS error codes for a couple of quid, but you need to know how to interpret them. Point being though -- they work, and can be useful.
However, in this particular case I suspected the MAF sensor in any case, but didn't want to touch anything as I wasn't sure.
DP -- the code that came out in this case was Bosch-specific, but from the list of error codes on the Nissan OC site, coupled with the manual for one of these things it should have correctly read the code in this case. I do accept your point though.
Edited by jase1 on 14/09/2008 at 14:32
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>>I was merely asking if the cheaper units actually did what is advertised.
They do work as advertised, and they are unlikely to cause damage of themselves, but, the point I was getting at, is while they will reliably tell you the basic codes, that information alone usually isn't enough to reliably diagnose faults, and could lead you to spend far more in error than the £200 you're baulking at.
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Understood, and I agree -- I wouldn't be dismissing the expert opinion even if I had one of these boxes, it was more so that I had an idea of the kind of fault the car had before deciding on a course of action.
It's the curiosity factor really.
But, I do take your comments on board. I know how annoying it can be when some know-it-all comes to me with a fault, and an (often wrong) solution in my field. There is no substitute for years of experience and training/education.
Edited by jase1 on 14/09/2008 at 15:53
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jase
It's very rare for a failing MAF to leave a code - live-data or a 'scope is the usual way to see. [Cleaning rarely works and the fleabay ones are rubbish - however "genuine" they claim to be.]
If the cheapies [and I've never tried one] can only access EOBD codes; they are going to be seriously misleading if, as is normal, there are six codes stored and only one is EOBD-accessible - and it's not the crucial one.
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I bought a USB connecting interface lead and some cheap 'shareware' EOBD software to use with a laptop. It has been mainly used on our very unreliable 2003 Polo.
The fault light has been on twice this year and the software correctly identified the fault both times. First time it was a fault with the lambda sensor heater, second time a coil.
Saved me a lot of money given that the VW dealer charge about £100 for a code read and even an independent wants £50 - wihch was more than double what the lead cost me.
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Screwloose,
The code was fuel mixture too lean (P0171 I believe) -- I mentioned that the car had been running flat/hesitating etc -- he came to the (rational) conclusion that the MAF sensor was u/s. Before I mentioned the poor performance he was unsure of the reason for the fault.
I'd been thinking the same way (MAF fault) -- when he mentioned the diagnosis the same light came on in my head as in his.
It's therefore reasonable to assume that, on this occasion, I'd have come to the same conclusion with a scanner (assuming it had come up with the same result). That's what got me thinking (probably unreasonably given the complexity of many faults!!).
I have read up on these cheap MAF sensors and it does appear that they are pretty poor -- maybe good enough if you are shifting a car but no more.
I just hope now, after your comments on needing more data, that our combined 'hunch' is not a wrong'un, else it might just have cost me a fair few beers.....
Edited by jase1 on 14/09/2008 at 18:35
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jase
Yes; P0171 can be a MAF fault - along with many other causes from an inlet/exhaust air leak, through O 2 sensor and fuelling issues, to perished breather diaphragms/pipes.
What car was it?
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Nissan Primera 1.8S, 2000/X, QG18DE engine, 220K miles.
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Aprilia did some looking for far east code readers. He was using one and looking to buy a better one but I don't know what he concluded. He does not seem to be around anymore. Why? Did someone say why and I missed it?
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Argos are now selling 2 different scanners. Not sure how good they are, and unfortunately aren't included in their 30-day money back guarantee.
tinyurl.com/64kwap (£49.99)
tinyurl.com/5oqtzr (£99.99)
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The more expensive RAC one (£99.99) appears to be virtually identical to an Autel one being sold on fleabay:
[ebay auction ID 330270883626].
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If you wanted to spend £100, the same company do live data scanners with graph readouts etc for less than £100 (e.g 220280064788).
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This is also £100 (+VAT?) if you look around.
www.auteltech.com/ms509.htm
It makes many claims as to what it does.
Does graphics display and stores codes for later download.
I am not an expert on these so I welcome expert opinion.
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Yeah that's the one in the second ebay auction listed above.
It seems quite sophisticated on the face of it. I'd be interested as well.
PDF of manual is available on their website.
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"PDF of manual . . ."
Just downloaded it; 72 pages of it!
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