Quicky ABS question

Neil Haughey · Jul 11, 2007

My ABS warning light came on this morning. Never seen it before but I haven't driven the car for 3 weeks and it has been sat out in the torrent that has been this summers weather. Am I right in guessing that this is likely no more then corrosion on the sensors?

BTW without ABS on an S2 with track pads you find that you don't need much peddle pressure to lock the brakes up. It is scary how easilly the front brakes lock up at pretty much any speed. Also interesting how fast the car slows down with just the weight of my leg on the peddle, not so sure now if it is defo quicker slowing down with functioning ABS. Very tempted to pull the fuse out for next weeks track outing, is this a mad idea?

xenon · Jul 11, 2007

I thought ABS was standard on the S2 ??

Neil Haughey · Jul 11, 2007

ABS is standard on S2 and afaik all turbos from istr 1988 onwards.

You can disable the ABS by pulling the ABS circuit fuse out.

My car fixed itself, I guess it must have been corrosion related and a good hard drive this morning did enough to clean it all up.

Diver944 · Jul 12, 2007

This could be the beginning of a long frustrating process [8|]

Our S2 started intermittently lighting the ABS warning lamp a few years ago. I did all the usual checks on the sensors and the wiring, then gave up and have now had three seperate independants look at it and none could find the definitive cause. One took the risk to fit another ECU which seemd to cure it, but a few weeks later it started doing it again [

]

The ABS works absolutley fine as I regularly test it to make sure (safely of course - I'm good with brakes [

]), as long as the light doesn't illuminate during an MOT I should be fine

Neil Haughey · Jul 12, 2007

Blooming heck I hope not! I am frustrated enough that the 17th seems to be booked up, I was really looking forward to getting on the track again.

sawood12 · Jul 13, 2007

Mine came on intermittently when I first got the car and sometimes I notices a buzzing coming from behind the dash - anyway the chap I bought the car off didn't use the car much and I use it as a daily driver and gradually the frequency deteriorated and now it hasn't happened for a couple of years now. I put it down to one of those things.

dlknight · Sep 10, 2007

Arghh !!! the plague of the ABS warning lamp.... mine has now been lit constantly all day (stopped for a few hours and returned to find it lit again). Maybe Scotts car has passed on this strange phenomenon

Dave K.

andymorris · Sep 10, 2007

I know the feeling ! Took along time to figure mine out until I took it to RPM and it was simply the tyre sizes were incorrect ! Put on by the previous owner.

Suffolk944 · Sep 10, 2007

Well guess the avoidance of such frustrations is some consolation for those of us who dont have ABS. [8|]

TK2015 · Sep 11, 2007

ORIGINAL: Diver944

This could be the beginning of a long frustrating process [8|]

Our S2 started intermittently lighting the ABS warning lamp a few years ago. I did all the usual checks on the sensors and the wiring, then gave up and have now had three seperate independants look at it and none could find the definitive cause. One took the risk to fit another ECU which seemd to cure it, but a few weeks later it started doing it again []

The ABS works absolutley fine as I regularly test it to make sure (safely of course - I'm good with brakes []), as long as the light doesn't illuminate during an MOT I should be fine

Ditto for me [8|]

Wiggling the connectors behind the discs seems to help - or maybe I just feel better for doing something [

]

The problem definitely seems worse in damp conditions or if the car has been standing for a while. I've checked all of the earth straps for corrosion and they're good. The sensors test out OK on a scope, so I'm guessing a connection problem somewhere between the sensor and ECU on one of the circuits. It could take a very long time to find as the problem's intermittent [

]

zcacogp · Sep 11, 2007

ORIGINAL: TK
It could take a very long time to find as the problem's intermittent []

The curse of the intermittent fault ... just out of interest, has anyone tried to use a commercial data logger to try and capture information from intermittant faults? Theoretically it could be possible, but I have never had the kit to play with to try it out.

(Having said that, threads like this make me very nervous as I know mine is OK ... for now ... )

Oli.

Neil Haughey · Sep 11, 2007

In theory if you just want to sample some analog circuits you can use a decent soundcard and write some fairly straightforward software yourself, obviously you would have to sort out the analog interfacing circuitry as well. Creative Labs have a software library that interfaces with all their latest high end cards that makes it just about as simple as possible.

The best Commercial Of The Shelf (COTS) cards these days have amazingly good spec's and real world capability. I have managed to get better the 80dB real dynamic range from a COTS Sigma Delta analog to digital converter card. This sort of technology only a few years ago was costing £10K+ per card. If you can put up with sampling rates that are factors related to pro Audio (i.e. CD sampling rate) then cheapo Creative cards etc. can do the job.

If its more modern car with CANbus then you can get interface boxes to convert from CAN to serial and such like so you can log all the data on the bus with your PC, again I would be looking at how good or bad the supporting documentation / software is since this is what will cost you time more then anything.

Hilux · Sep 13, 2007

The best Commercial Of The Shelf (COTS) cards these days have amazingly good spec's and real world capability. I have managed to get better the 80dB real dynamic range from a COTS Sigma Delta analog to digital converter card. This sort of technology only a few years ago was costing £10K+ per card. If you can put up with sampling rates that are factors related to pro Audio (i.e. CD sampling rate) then cheapo Creative cards etc. can do the job.

If its more modern car with CANbus then you can get interface boxes to convert from CAN to serial and such like so you can log all the data on the bus with your PC, again I would be looking at how good or bad the supporting documentation / software is since this is what will cost you time more then anything.

`kin `ell Neil.....................

..................wassallthatabaht [&:]

Neil Haughey · Sep 13, 2007

sorry I got carried away this stuff crosses right over into my day to day work and I get pretty excited about how easy it is getting these days to do some pretty flashy systems. When I started about 15 yrs ago I had enough of a nightmare just getting some simple Rs232 devices to talk to the PC properly. Now with a Creative Labs box it takes about 30 minutes to write some software in C/C++ that will sample data (analogue to digital) and write it to disk in a format like wav. Labview makes it even easier but if everyone used Labview ppl like me might be out of a job!

tref · Sep 14, 2007

Er... so in otherwords, take a complicated system (ABS) with an even more complicated monitoring system which doesn't work sometimes (ABS light), and use an even more complicated system to find out why it doesn't work sometimes...(ABS Monitoring System monitoring system).

should have started with take a system that works (brakes)... and add a system to make it work intermitantly (ABS)...

Tref... hoping his ABS never stops working...

Neil Haughey · Sep 14, 2007

I never said that building a high resolution data acquisition system to test the ABS warning light circuit was a good idea. Come to think of it is a bad idea because there are many more exciting things one could do with some nice electronics and the time to make use of it.

Hilux · Sep 15, 2007

In me old westy and ginetta I didnt even have a servo [

]

Keep it simple I say...................

Neil Haughey · Sep 15, 2007

I wonder if ppl are starting to copy the major race teams and fit sensors all over the car. I was looking yesterday for MEMS accelerometers. They cost something like $2.50 each now for OEM, cheap enough to cover the car in the things but then making sense of all the data is still a major issue I believe.

zcacogp · Sep 15, 2007

I think that a major demand for accelerometers is in running stability management and yaw-control systems. When they are that cheap, couple it with the brake-control systems already there for ABS, run it all through a small computer and - hey presto! - you have a full stability management programme (and a car that is hateful to drive. My experiences of both a Mitsu Evo with stability management and a Boxster with PSM have both told me that there is no substitute for the seat of my pants. In so many ways.)

Oli.

sawood12 · Sep 15, 2007

I agree with you Oli. A skilled driver behind the wheel of a well sorted simple chassis will thrash the pants off a PlayStation car any day of the week. There are millions of parameters to consider and electronic stability systems can only monitor a handful and they can be tricked so are not infallable (the number of Evo's and Scooby's skidding off track at my last trackday proves that). So far there is only one computer that is able to process millions of parameters instantaneously - the human brain (married to a human bottom in this case). It's going to take a bit more that 50yrs and Bill Gates to better Millions of years of evolution.