The question is really about MOT. I just bought an immaculate diesel 607 and asked my local MOT place to recheck it even though it has one already. They said that the ABS is not working even though it the dash light does just what it says in the book. It has to stay on for so many seconds and then go off.
Thing is they are right it does not work because you can skid the car on a wet road.
The MOT man reckons that someone has fiddled with the car computer to make it look like the ABS is OK.
The local Peugeot garage say that is not possible.
So two questions. Who is right and should it pass the MOT?
Edited by Dynamic Dave on 05/08/2008 at 11:11
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Probably been done to get through the MOT so it will more than likely pass again.The local Peugeot Garage is talking rubbish if you can hack into the pentagons computer abs software must be a doddle.
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The only MOT testable component of the ABS is the warning lamp which should come on with the ignition, and go out after a predetermined time. If it fails to come on, or fails to go out, it fails the test.
You might find the "bodge" is nothing more sophisticated than cutting one of the solder tracks to the ABS bulb, and then running a wire from this to another on the panel that follows a similar self test pattern (on for a few secs, then off). I suspect if you look at what it does when you turn the ignition on, it will comes on and go out at the *exact* same time as something else.
Of course, it could have been a software mod, but in my experience, bodgers are unsophisticated creatures.
Cheers
DP
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I should warn you that if you are aware that the ABS is not functioning then your insurance may be called into question. ABS is compulsory, to knowingly drive without it is a modification to the vehicle and some companies may even decline your insurance. Take the car back and get the seller to fix it or get a refund, or take the hit to get it fixed. Regards Peter
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Thanks Peter D. Makes sense what you say about insurance.
I already searched the forum for this type of question, and I think that there is some nonsense about the MOT situation. My tester just said he would fail it because the brakes are not working like they should and therefore the car is not roadworthy, and he would expect all others to do the same.
The interesting question remains about why Peugeot told me it can't be done.
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My tester just said he would fail it because the brakes are not working like they should
Tell him you'll report him to VOSA and to play to the rules and not his own.
My car has a mechanical ABS system which hasn't worked properly since the early 90s. It's passed every MoT since 1992!
Just to clarify - for MoT purposes the ABS light can follow any sequence laid down by the manufacturer, it doesn't have to be time based and can flash in time to jingle bells if they want it to.
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ABS was not a legal requirement if 1990. The MOT tester is correct. A non functioning ABS system takes a lot more pedal pressure to stop then a functioning one. The tester will have observed the low graking efficiency during the test. Regards Peter
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"The MOT tester is correct. A non functioning ABS system takes a lot more pedal pressure to stop then a functioning one. The tester will have observed the low graking efficiency during the test."
Er, no. There's no difference to pedal effort on with or without ABS - all it does is stop the wheels locking up. Usually it doesn't come into play until above 5mph, and the MOT brake test rollers run at less than this, so there is no test for the operation or otherwise of the ABS on the current MOT. Provided the light does what it is supposed to, and the brakes meet the efficiency and balance limits it will pass. I believe that there is a line in the manual that says to effect of even if parts of the ABS are obviously missing this is not reason for rejection, but should be reported to the vehicle presenter.
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What does Peter D mean about Legal Requirement? I had a 1992 car that did not have ABS.
Do you mean MOT test requirement? If so I think that any faults in the braking system always meant a fail and still do.
You dont have to be a rocket scientist to know that tampering with any safety kit like ABS must make the vehicle unsafe and so must make it a fail.
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Info on what is required for the ABS part of an MOT test.
www.motuk.co.uk/manual_340.htm
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If I were going to bodge an ABS fault light I'd drive the dash indicator from a timer circuit powered from the ignition, good old 555 timer should do the job, any delay time you want based on capacitor / resistor selection.
Fixing the ABS would be a much safer option of course....
I don't believe, to this day, fitting of ABS is mandatory under construction and use regs?
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ABS became a legal requirement on ALL cars in 2002 or 3 the year escapes me right now. The comment regarding brake pressure is fact. To Stop an ABS dis-connected car in the same distance as an ABS enabled car requires greater pressure to achieve the same performance. The system design often ends up with a different brake pad material as it uses differently when you really need it. Cars any year of design vary although the later years the fact is the opposite as the disabled ABS will just lock up thus increasing the stopping distance. It is totally irresponsible to disable the ABS system on a car and only right for the MOT guy to address this with the owner. Regards Peter
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I found this:
"ABS brakes will have to be fitted as standard to all new cars sold in Europe from July 1st, 2004."
I agree that disabling the system is irresponsible, but still disagree it will brake any differently under normal operation - the ABS only intervenes at lock up, and even then it only pumps fluid back OUT of the brake pistons to reduce the braking effort. Until that point it's entirely passive - and it would be a very astute MOT tester that noticed any difference - I doubt car makers would be allowed to sell a car whereby failure of the ABS would render the car unable to pass an MOT on brake efficiency - the bar is ludicrously low.
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I cannot condone disabling the ABS, nor do I agree with the above.
One of the benefits of ABS is that it removes the possibility of rear lock-up when this axle is lightly laden and in the event of a sudden stop. Consequently, pressure limiting valves of all types have now disappeared from cars currently in production.
Rear lock-up on a poor surface will make the vehicle uncontrollable.
659.
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You'll be telling me next that a non ABS system can stop in the same distance as a good modern ABS car. with the same experience of driver. Dream on !! Although some people will suggest a shorter distance for ABS is a myth the stopping distance of 4 wheel ABS is way shorter. Thus the old bumper label. 'I Can Stop Can You' Once a wheel is locked up and you have lit the rubber up the surface contact friction falls off significantly. I have demonstrated this at many race experience days in various cars. In some cases you have to remove the ABS fuse and here you will notice that to lock the wheels takes more effort never mind cadence braking which of course only the very, very experienced would use in a real emergency. Regards Peter
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Gents, I'm not condoning nor encouraging the disablement of ABS. My reference to the performance of the braking is under 'normal' operation ie not emergency braking: I still can't see non working of ABS changing the pedal feel*, so we'll have to agree to disagree :-)
In some ways I feel ABS is a bit of liability for most drivers - they adopt the "I've got ABS and can stop HERE" mentality; most fail to realise how it operates and lift off when it comes in; or fail to realise that it will allow them to steer and drive into what ever it was thay could have steered round.
I've had an ABS car for the last 3.5 years / 100k miles. ABS activated in anger once - and that was in a 30mph limit.
* not the most modern system but our recently departed 94 ZX had ABS. It went intermittent a while back and there was no noticeable difference in the pedal whether the light was on or not.
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Abs does not improve braking distance., regardless of the car and the type of brake material fitted!
It actually may worsen total stopping distance. BUT it will make that distance more controllable, allowing the car to be steered (subject to the laws of physics) at the same time as heavy braking.
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ABS became a legal requirement on ALL cars in 2002 or 3 the year escapes me right now.
1st July 2004
www.autofinder.ie/asp1/afmain.asp?lnk=101&id=277
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So I am a year out and your point is ????? Regard Peter
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None, other than providing the correct date when mainstream cars had ABS fitted as standard, and a link giving all the info.
Edited by Dynamic Dave on 07/08/2008 at 21:52
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Seems to be a lot of misinformation on this thread.
All the mot test is on abs brakes is to identify if the warning system (light on dashboard) operates correctly.
Abs system and operation is not tested (nor indeed is it detectable at test level).
Obviously needs correcting if its not working, regardless of the test result.
It will only fail the test if the light works correctly if the tester KNOWS (not suspects) of any reason why the light warning is incorrect. He may however issue an advise if he suspects there is a problem that he does not have PROOF of.
It is quite possible for a testing station to get a warning, for failing a car on abs even if the system doesnt work, but the warning system is correct !
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>>Seems to be a lot of misinformation on this thread.
>>It will only fail the test if the light works correctly if the tester KNOWS (not suspects) of any reason why the light warning is incorrect. He may however issue an advise if he suspects there is a problem that he does not have PROOF of.
What would be the reason for rejection?
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659's point above is the key issue, the brake system hardware on the car is not designed to work properly without the ABS working.
The car should NOT be on the road until the ABS is fixed.
The seller should be reported, perhaps trading standards.
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There are 2 completely unrelated points being discussed;
1) Is a car with ABS disabled actually safe.
The answer to this is probably not, especially if the ABS fulfills the function of pressure reduction/control for the rear axle in place of passive valves, as per 659's point.
2) Should a car with disabled ABS, but, somehow with a warning lamp which works correctly get an MOT pass.
The answer is yes, it should. A tester can only fail a car on an ABS related fault if the warning light doesn't work correctly. Obviously, if there were to be a fluid leak from the ABS unit, that would attract a fail, because no leaks are allowed anywhee in the brake system.
A car can justly and correctly obtain an MOT pass while having a fault that makes it unsafe. An MOT is just a limited, inspection of well defined aspects of a vehicle - while the MOT is a sensible, practical and value for money inspection, it is not rigorous or comprehensive.
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Equally, how many cars out there with the pressure regulating valve actually have it working? It used to stick constantly on both an Astra and my old Xsara, and when I discussed it during the MOTs the mechanic was of the opinion that "they all stick".
I was lucky enough to go on a skid control course a few years ago. I noticed that stopping distances with ABS turned on were virtually equivalent to when it was disabled. The other thing I was told is that in an emergency, unless I desperately needed to steer round something, to get on the brakes as hard as I possibly could. The instructor wanted all 4 wheels locked and sliding.
Depending on the car I think it's possible to get the ABS computer to spit out any fault codes via the dashboard light. If nothing happens, I guess that could be an indication that it's been fiddled with. If you pull the ABS fuse, does the light come on and stay on?
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Edited for spelling
Edited by David Horn on 09/08/2008 at 07:45
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Talking about skids, someone at work suggested that if the ABS was not working properly the car would have other lamps on, because the ESR system would also be showing a fault.
There is no fault on the ESR and the ESR can be turned on and off OK.
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