Hi Folks,

Well, my bike is somewhere on its 600 mile route from its old owner to me here in Scotland. To say I'm excited at the prospect of the imminent arrival of my late Christmas present is an understatement!

One thing I've been thinking about is the ABS. The ABS 'brain' has been removed but the remaining hardware is still in place and the brakes function well (but without ABS). I am wondering whether to try and reinstate the ABS (as presumably it is a valid safety feature) or if this will be more effort than its worth.

I've searched but can't find any posts related to this. I believe the ABS brain is a black box beneath the seat but suppose that reinstating a fully functional system will need more work than plugging in a new one. Perhaps new sensors? I'm not familair with the bike or such a complex electrical system. Anyway, I think my questions are:

- Is the ABS worth having?
- Is the ABS generally problematic?
- What BMW part is the ABS 'brain' if I want to obtain one?

Any pointers to relevant information sources would be much appreciated

Many thanks
Dave

Hi Dave, If you go into the down load section [having obtained the password from Crazy Frog -Bert] there is info there, also under the wheels and frame section.

There are those who appose the system as being a problem area and those who swear by it, I have it on mine and really did not appreciate it untill a dog ran out infront of me chasing a ball, it was then that I found the benefits. Against is the cost off parts and weight some here have removed the system and the bike is none the worse for it, the final decision will be yours. I like it but if it fails big time and the expense is too much I would not hesitate to remove it.

Just my opinion.

BIG D

Thanks BIG D. I'd like it working but there are financial and technical competence limits!

Thanks for the pointers, I'll chase those up

All the Best
Dave

Hello Dave, My 1992 K100 16V was born with ABS, but the PO had the dealer remove it, as there were high costs in maintaining it.

I am not able to comment too much on the technicalities, but unless you remove other components than the brain box, you will get alarms etc. I was quoted >£ 1200 to restore it, and decided not to.

Wheteher the dealer was on the up and up or marginally competent, I do not know.

Hi,

Thanks for that information Agerbundsen and a warm welcome from Scotland to Denmark. Having looked in to it a little further there is a Japanese gent who can fix or sell me a new ABS 'brain'. It's about £185 for a replacement. Of couse that could be just the start of it if it's another £1000 to sort completely! That said I guess a lot of that cost you refer to could be Dealer labour. As a first step I will need to wait and see what parts should be there, which are present and what is missing.

Having followed BIG D's advice I did discover the recommendation to inform your insurer if ABS does not work and so have told mine. Good advice and not something I'd thought of Probably the most important step while I consider the options.

Best wishes
Dave

First lets see where you are, do you have the modulators on the bike? There should be one on each side. There is no question that Tosi can sort a dead ABS unit or indeed sell you a repaired unit, I was looking at his site a few days ago and he had one for sale then. Assuming the modulators are working connecting up the replacement brain with DeoxIT on each electrical connection will restore ABS function to your bike. ABS can be a life saver have a read of http://www.ibmwr.org/prodreview/abstests.html When the brain on mine died I ran through the full diagnosis and then got Tosi to repair it, postage to and from Japan was quick and the unit performs flawlessly If I were in your position I would buy an ABS brain from Tosi and get it fitted ASAP. His site is http://bmwk10075abs1fix.web.fc2.com/

Regards,
K-BIKE

Thanks for the reply K-Bike. I agree there are benefits with ABS. A while ago I did a driving skills course with a car with switchable ABS and tried the same moves with and without it activated. With ABS you were able to brake and steer around an object in your path that you impacted with it turned off as the the wheels locked and you were unable to steer effectively.

All of the hardware including modulators is present. One of the relays is disconnected but present so only the brain is missing (something I am familiar with myself at this festive time of year). The multi pin plug for the brain is also present. The ABS reset button on the dash may not work according to the previous owner - I will need to investigate when the bike arrives mid next week. Tosi contacted and awaiting his reply.
Best regards
Dave

MT350Explorer wrote:Thanks for the reply K-Bike. I agree there are benefits with ABS. A while ago I did a driving skills course with a car with switchable ABS and tried the same moves with and without it activated. With ABS you were able to brake and steer around an object in your path that you impacted with it turned off as the the wheels locked and you were unable to steer effectively.

All of the hardware including modulators is present. One of the relays is disconnected but present so only the brain is missing (something I am familiar with myself at this festive time of year). The multi pin plug for the brain is also present. The ABS reset button on the dash may not work according to the previous owner - I will need to investigate when the bike arrives mid next week. Tosi contacted and awaiting his reply.
Best regards
Dave

Nice one Dave, Aberdeen will be rocking in the new year I presume all the best.

BIG D

Cheers Big D. There may be a wee dram or two consumed over the next day or so - stranger things have happened!

All the Best to you and yours

Hi Dave,
Just a clarification for anyone else reading this later when riding the ABS reset button only cancels the flashing for a timed period and it then re-starts so you have to cancel it again and again on a long ride.

Resetting the ABS is done at the small unterminated socket by the ABS brain (usually found with a blanking plug fitted) and then using the reset button, ignition switch and a temporary shorting link.
Regards,
K-BIKE

Well, I'm in the process of getting the oarts I need together to recommission the ABS. In the pile of old garage receipts thatcame with the bike is a diagnotcic report from BMW. It states the 'front pressure modulator' is the source of the fault. Could anyone tell me if this is this the left hand or right hand side modulator (when seated in the saddle?).

I suspect this is the part I will need to source. Once I have the brain installed which should be next week I will do the diagnistic check myself but suspect it will come up with the same error as above.

All the best
Dave

Its the one on the left.

Today I had all the bits to fit the ABS brain and new ABS rocker switch.

Took the tank off as below - as discussed on th 91 4V there is enough length in the fuel lines to give you good access without having to disconnect them. A stack of old wheels made a good stand!



Changed the ABS (and Hazard) rocker switches. Everything else looked fine - dirty but serviceable. Used some contact cleaner on the new connections and a few of the old ones were remade with it too. The relay box held a surprise - a new ABS relay in a plaastic bag! Brilliant . I plugged it in and then put the fuel tank back in place.

The ABS brain I got from Tosi in Japan. Less money than Motorworks but more than a breakers. One key difference is Tosi offers a 12 month warranty and I have no doubt he would honour it. So I plugged that in - again using contact cleaner, took a deep breath and went for a ride. I can't believe it - the ABS functions as it's supposed to! . Usual flashes etc on start up but then no warning lights. of course it might be a different story tomorrow! I still need the brain holder as that was also missing.

Anyway, fingers crossed that's the ABS reinstated.

A couple of queries though:

There are two ports oin the photo (3 including the ABS); one blue and one black - what are their respective fiunctions?


Also the ABS wire looks to me to not be routed correctly (held by white tie wraps to the fork). Where should it go?


Thanks all for the help and advice - fingers crossed that's a job well done!

Best
Dave

About the two connectors: the one with a blue cap is the ABS/Motronic diagnostic plug.
The modified black connector is for the sidestand switch, which apparently is history on yours.

The sidestand switch is known source for problems, but afterall it is a safety device.
It could save you when having a toughtless moment someday.
More than 30 years ago, before every bike had switch like this (or spring retracted stands),
a device like this would have saved me from spending three weeks at the hospital.
On my 1100 I have a bypass connector (like yours) in the ducktail, if the switch becoming
less cooperative along the road (usually fixed with some WD40, to get the mechanism moving again).

About the front sensor wiring: on my 1100 it`s laying closer to the rear center of the slider with
black zip ties, then routed under fork brace cover and zip tied to the brake hose.
Tip: first zip tie is through a hole in the sensor bracket, which gives a neat and clean installation.

Inge K.

"black zip ties"

Inge, you are my hero!

blakey wrote:"black zip ties"

Inge, you are my hero!

Got rid of all your white ones yet?

Inge K.

yes...grumble, grumble...

Inge K. wrote:About the two connectors: the one with a blue cap is the ABS/Motronic diagnostic plug.
The modified black connector is for the sidestand switch, which apparently is history on yours.

The sidestand switch is known source for problems, but afterall it is a safety device.
It could save you when having a toughtless moment someday.
More than 30 years ago, before every bike had switch like this (or spring retracted stands),
a device like this would have saved me from spending three weeks at the hospital.
On my 1100 I have a bypass connector (like yours) in the ducktail, if the switch becoming
less cooperative along the road (usually fixed with some WD40, to get the mechanism moving again).

About the front sensor wiring: on my 1100 it`s laying closer to the rear center of the slider with
black zip ties, then routed under fork brace cover and zip tied to the brake hose.
Tip: first zip tie is through a hole in the sensor bracket, which gives a neat and clean installation.

Inge K.

Thanks Inge, that's really useful information.
Where is it best to disconnect the ABS wire so I can re-route it pls?
Thanks
Dave

By judging the picture, I don`t think you need to disconnect the wire to reroute it.
Anyway, the connector you should find under the tank.

Inge K.

Guys

Please could anyone advise, is this the holder for the ABS brain I need for my 91 RS? At the moment the brain is held in place with tie wraps as it and its holder were missing when I got the bike.

http://www.ebay.co.uk/itm/bmw-k-100-rs-plastic-cover-ABS-/400172875736?pt=UK_Motorcycle_Parts&hash=item5d2c297fd8

or is this it?

http://www.ebay.co.uk/itm/bmw-k-100-rs-plastic-box-ABS-/400172612121?pt=UK_Motorcycle_Parts&hash=item5d2c257a19

Or is it neither or both?!

Thanks
Dave

Neither of them, the pictures just shows some plastic parts from a -89 with ABS
(which have the ABS ECU in the ducktail, as one of the pictures shows a tool tray).

The part you need looks like this.

Inge K.

Terrific, thank you Inge. I'll have to keep looking...
Best regards
Dave

Hi Guys

Just dropped the bike - putting the main stand on an uneven surface and over it went. I'm afarid there was some Sunday blaspheming. The ABS fault lights are now flashing. Can anyone think of a connection between the two events? It dropped on to its right side. I've checked the connections at the wheel sensors and the brain looks fine. Any simple ideas to try before I embark on the full diagnostic route?

I've learned a few things though:
- I will now finish the job of putting down hard standing (paving slabs) at the front of the house
- I can pick the bike up on my own - just.
- The fairing mirror popped off as it should and very little damage to anything
- My glass fibre fairing repair took the brunt of the impact and is unnaffected - that repair is bloody strong

Thanks
Dave

That's a bummer Dave, I had a little "Aw Bu@@€r!" moment mysel on a forecourt recently, with audience !

The best way to pick up the bike is with your back/backside to the seat in a squat position, with the side stand extended hold the grab handle with one hand and turn the handlebars to towards the ground with the other (covering but not applying the front brake if you can). move the bike slightly backwards and stand/walk backwards up as it moves allowing it to roll upright. It's more technique than strength, there are some you tube clips on it.

Good to hear the repair held up. Cant advise ont he ABS as I don't have any exerience of that.

88.

Cheers 88 - stuff happens eh and we all learn good lessons from mistakes. Of course it won't happen again ( ) but I'll be sure to pass on your advice to fellow riders. LOL.
Best
Dave

Could it be that your battery didn`t appreciate to lay on the side?.....lost electrolyte through breather?
ABS is sensitive to low voltage..........would then usually start to flash when you hit the starter button.

Easy test is...turn off the ignition a couple of seconds while on the move...and start in gear.
(without engaging the starter motor, and get a drop in voltage).

Inge K.

I have connected an analogue multimeter and am getting dips as I should but there seems to be a continual series with no pause so am having difficulty interpreting what this means?

Thanks Inge I tried that but no joy.

Low voltage should give code#5....sorry, can`t help you with this one.......have you tried a reset?

Inge K.

Amabout to try a reset but wanted to estrablish if I could what teh fault code was, if genuine.

It could be that continuous dips is 12 'flashes' according to the text below. Just wondering if covering the throttle body stubs could be realted in any way as that also was done just before the ABS faukt developed
ABS-II Fault Codes

Code Fault
3 Front Wheel Speed Sensor
4 Rear Wheel Speed Sensor
5 Low Battery Voltage
6 ABS Relay in ABS Hydro Unit
7 Control Unit (mounted to side of Hydro Unit)
8 External Influence or Wheel Sensor Gap Incorrect
9 Unknown
12 Piston Fault (This can be Mechanical or Electronic in nature)

MT350Explorer wrote:ABS-II Fault Codes

Code Fault
3 Front Wheel Speed Sensor
4 Rear Wheel Speed Sensor
5 Low Battery Voltage
6 ABS Relay in ABS Hydro Unit
7 Control Unit (mounted to side of Hydro Unit)
8 External Influence or Wheel Sensor Gap Incorrect
9 Unknown
12 Piston Fault (This can be Mechanical or Electronic in nature)

You got ABS-I....haven`t seen that code 12 in any ABS-I code list....

Inge K.

I've reset and been for a ride; all is fine, thanks for the help Inge, appreciated as always. Let's put it down to a sensitive ABS system!

Is it ABS 1? I am confused by the brain code which is 2.5 so I assumed the ABS was ABS 2. So it is ABS 1 with an ABO 2.5 brain; OK, Got it.

http://bmwk10075abs1fix.web.fc2.com/#LA

Best regards
Dave

Nice that you got the problem solved....especially when it`s related to safety.

All ABS I got the modulators mounted at the footrest bridges.
ABS II have both modulators incorporated in one unit which is under the seat.

Inge K.

MT350Explorer wrote:Hi Guys

Just dropped the bike - putting the main stand on an uneven surface and over it went. I'm afarid there was some Sunday blaspheming. Dave

You now must be bought to account for this GO WASH YOUR MOUTH OUT WITH BEER you horrid sinner and with each mouthful you will be gradually bought back to the fold now go and repent many times.

Luckily I dropped it at the weekend and was able to fully absolve myself in the expected way Father Freak.

With penance like that being dished out there could be a spate of K bikes falling over

MT350Explorer wrote:Hi Folks,

Well, my bike is somewhere on its 600 mile route from its old owner to me here in Scotland. To say I'm excited at the prospect of the imminent arrival of my late Christmas present is an understatement!

One thing I've been thinking about is the ABS. The ABS 'brain' has been removed but the remaining hardware is still in place and the brakes function well (but without ABS). I am wondering whether to try and reinstate the ABS (as presumably it is a valid safety feature) or if this will be more effort than its worth.

I've searched but can't find any posts related to this. I believe the ABS brain is a black box beneath the seat but suppose that reinstating a fully functional system will need more work than plugging in a new one. Perhaps new sensors? I'm not familiar with the bike or such a complex electrical system. 

Now I realise this is an old post but it has been very useful to me as I am in a similar situation to OP. Bought my bike in Hexham and was told at the time that the ABS had been 'disconnected'. After reading all about the safety features of it, I now want to be able to connect it back up. One question I had was - will my bike fail an MOT test if the ABS is attached but not working?

Also wondering if you got it all working in the end, Dave.

My black box seems to be there and so are the cylinders on either side of the bike with ABS written in red. I'm going to check to see if there are any missing relays which, I'm guessing, is the way to disconnect it?

Hi,


I believe it is all about the cost - once it is reasonable, it's a definite yes. I had ridden 2 very similar bikes (both Rs though) - one without and one with the ABS - and it is a hell of a difference. Wouldn't go for a bike without ABS & dual brake system again.

Thanks 

Thanks Björn

I guess everything BMW is quite expensive. Being a Scotsman, if there is going to be a cost to fix it - it will remain unfixed lol. I just wondered if I was in luck for it to be something simple like a disconnected relay or other plug, but I'll find that out once I've followed the expert instructions, on this forum, on how to remove my petrol tank.

This is the place to get the ABS computer fixed. http://bmwk10075abs1fix.web.fc2.com/
Follow all the testing procedures first because you might do what I did and send a good one over to get fixed.

All the other ABS bits are available on fleabay try to get modulators from a working bike as some have been lying around for years and wont work.

Nice one RicK - no wonder though he doesn't do the integrated one

Good luck Alibear - hope it is only a relay or something.

The integrated ABS was not introduced until the 1994 version of the K1100. The K100RS 16v had the 2.2 version of the original ABS.
The 2.2 computer from my 1993 K1100lt was sent to Tosi some months ago and was tested after it would not reset.

RicK G wrote:The integrated ABS was not introduced until the 1994 version of the K1100.

K1100's did have ABS II from 1994 model year.

iABS aka ABS III (which I guess is the one Björn have in mind) was first time used on the K's from ~ 2001 on the K1200's.

Inge K. wrote:iABS aka ABS III (which I guess is the one Björn have in mind) was first time used on the K's from ~ 2001 on the K1200's.

Precisely. And also on the R1150RT (2001 onwards) which I ride at present. A dream when it works, a nightmare when it breaks....

A nightmare to maintain also ...?....from what I've heard/read.

Well, changing the brake fluid is a "little" tricky.... TBH, it's a pain - a small price worth being paid once every 2 years for the additional safety. Nothing else needs to be done about it, really.

Inge K. wrote:iABS aka ABS III (which I guess is the one Björn have in mind) was first time used on the K's from ~ 2001 on the K1200's.

Oh gods, just realised what a well educated person you must be, spelling my name correctly

Even though I don't mind being called Bjørn which is probably easier with your home keyboard layout... Some of my official papers are showing that way. Still the same groany and hairy creature, whatever the spelling is

Björn wrote:Even though I don't mind being called Bjørn which is probably easier with your home keyboard layout...

I live so close to the Swedish border that I have a dual language keyboard .

Hi all you knowledgeable brikers. I eventually managed to find how to lift petrol tank on my K100 up far enough to gain access to the relay box. Didn't want to risk taking it off completely just yet, since I read that the K100 fuel pipes are a bit short and not sure how to disconnect them yet.

Anyway, there doesn't seem to be any relays missing or unplugged, all present and correct, but there was a plug and a socket which, at first, I thought might have meant to be joined together. On closer inspection though, I saw that they were completely different types, so I'm guessing they must be there for something else plugging into?

I'm going to try to include some pictures I took to see if any of you will be able to identify my problem from them.


The two mysterious plug/sockets.


The black box under my seat.


This aluminium box is underneath the other one and immediately above the battery. Any thoughts?

All plugs/sockets/leads/relays seem to be connected and no orphan wires hanging loose, but my ABS is definitely not working. Don't know if it's related, but I discovered (when I ran out of petrol on the motorway last Friday evening) that the petrol warning light doesn't work, neither do the hazard warning lights, the switch on the dash does nothing (haven't check to see if the auxhiliary socket is working yet)

Any help on this frustrating problem will be much appreciated.

About the mysterious sockets/plugs.....if they are round and one black and one
white....they are for the factory alarm and extra euqipment.

It would have been a bit easier if one could see your pictures.