Jump to content

OK ..Here is an exception to the "there are no really stupid questions" rule ...


Recommended Posts

Sorry I can't find an answer in the bike's rider manual nor Clymers ... and yes I tried to search this forum and others too ...


I have just acquired a new to me 1992 K100RS in wonderful condition ... And I can't for the life of me figure out the ABS system.


Really stupid question number one.


There is this big switch on the dash which says "ABS". What they heck is that for? It doesn't seem to actually do anything when I push it. Why would there be a switch? My cars don't have "ABS switches"?


Second ... I have flashing ABS warning lamp and the triangle lamp (rear tail light failure/.). How does one go about doing a "reset" on this? If you tell me it is that switch ... please tell me how to operate that switch.


The brakes work just fine ... haven't hit any ABS type situations in which they might kick in ... to figure out if that in spite of my lack of familiarity with them they work at all ... but I would like to get the annoying flashing to stop at least as it drives me rather crazy.



(I have owned BMW motorcycles continuously since 1977 and currently have three a couple R airheads and now this K ... but this bike is the first with ABS.)

Link to comment

The switch on the dash is a disable-button of some sort. (Either disables ABS, or disables all the warning lights about ABS)


Flashing ABS Warning light:

Depends on what/how they're flashing. On the R11xx series, if the two lights alternate, that usually indicates a low-voltage found at system start, which means your battery is getting old.

Link to comment

Yes previous owner mentioned that ... and when I test drove (late late last fall) that did indeed work.


On Saturday had it up to highway speed and the light just keeps going and going and going ...


In between these two events I had changed out the battery and I presume I must "reset" the ABS some how. Nothing is mentioned in the rider manual ... Clymer says leave it alone and take it to your dealer if anything is awry.


Funny you can pull the pistons out or completely disassemble the steering head ...


But for heavens sake leave that ABS alone.

Link to comment

Turning on the ignition should get you a steady warning (triangle) light and flashing ABS light. After starting the bike and before riding away apply both the front and rear brakes, both lights should flash. Upon riding away if the lights do not go out you have a problem, anything from sensors to the ABS computer. All the switch does is stop the light from flashing and being quite so annoying. The warning light will also stay on steady if you have a burned out bulb. I lost the ABS computer shortly after my warranty expired and it was rather expensive bncry.gif. Starting with a weak battery sometimes causes the system to act strangely. This is all on a 95 k75 which I think works the same as yours.

Link to comment

Now that is very useful elwoodpone.


So my lights continue to flash (problem #1) and my switch has no effect on their flashing (problem #2).


Or they could be inter-related and maybe even something about the switch.


Yes the K75 and my bike ABS systems should be very similar.


As far as I know I may never have applied both the front and rear brakes simultaneously quite possibly even when riding the bike. So you may have something there for me to try.


Thanks thumbsup.gif

Link to comment

The brakes do not need to be applied simultaneously, actually not even before you start out. The lights should go out any time you have been moving and both brakes have been appled in any order.My ABS switch has never failed but most of the other switches have gunked up or failed entirely at some point but that shouldn't affect the warning light operation. You might try measuring the gap at the wheel sensors. I think there is a diagram on the fork with the proper #.Beyond that I'm lost as I said with mine it was the comp. and I was told alot of them failed for no good reason--other than the BMW "you tried to start it with a low battery" excuse.

Link to comment

I may well be the switch. They previous owner seemed to have a problem using water on the bike. The bike was "clean" as in he polished every surface ... but in every crack where ever there is a crack was dead bug guts from years ago I'm sure.


I covered up the gauges and switches and blew bugs out from around the headlight with my power sprayer and off the bars and grips.


Note to self ... take out switch and clean ... and measure gap as denoted on the fork (somewhere) ...


All else fails I guess I will have to take it into my BMW guy (not a dealer but a specialist 3rd party repair place who does awesome work at non inflated prices ... ).

Link to comment

You might call ahead to a dealer & ask if the box can be directly connected to diagnostics. It is easily accessable (and removeable) back in the tool kit area.Just went out and checked the gap it is 0,6 - 0,65 mm. Good luck.

Link to comment

Oh, I'm sure it can be hooked up to diagnostic tools. At their prices however I just hope I get a kiss too ... or I will feel somehow "used" ... lmao.gif



Link to comment

There is a way to manually reset the abs on the 1st generation abs models, which I don't remember off hand, but I think I saw it here: http:/www.ibmwr.org/ktech.


If, after you reset the abs, it starts to flash again, you may have to take it to the dealer for diagnostics.


The abs also has a relay under the seat which may be bad, it's in with all the other relays.


Good luck!



Link to comment
You might call ahead to a dealer & ask if the box can be directly connected to diagnostics. It is easily accessable (and removeable) back in the tool kit area.Just went out and checked the gap it is 0,6 - 0,65 mm. Good luck.
It might be useful to visit http://www.ibmwr.org - and view the ABS writeups in the K-Tech sections. There is extensive information on diagnostics and repair of the ABS-I systems.


Save yourself a trip to the dealer..


And worth doing an ABS reset with the instructions you'll find on that site.

Link to comment

OK thanks guys! I don't know why I never thought of http://www.ibmwr.org ... I have the whole site saved on my computer in-case the site goes down it is so good ...


I will try the reset procedures from there and hopefully that works!



Link to comment

One more thing to check which could cause your problem. Verify that both the front and rear brake levers actuate the brake light. If you have a bad switch (the foot brake switch is known to fail, most likely from it's dirtier environment) your ABS will not reset.

Link to comment
  • 2 weeks later...
I will try the reset procedures from there and hopefully that works!

Well?? I was wondering how this story ended! grin.gif

Link to comment

The ABS switch on the dash is not to disable ABS. All it does is this: when you have an ABS fault, the two ABS light blink on and off. Pressing the switch makes the lights stay on. I guess the thinking was that the blinking (until you could correct the fault) was distracting, so they put a switch in to stop the blinking. Really dumb in my opinion, but there you have it. And yes, there is a way to reset ABS using a piece of wire and the unconnected connector under the seat. I think ibmw.org has the details. I've done it successfully but can't remember how at the moment.



Link to comment

If I remember correctly from my K75, there is a three wire open plug behind the right cover. Put a piece of wire in the middle socket and ground it to the frame, then turn on the key but don't start the bike and hold down the ABS switch on the dash for 20seconds. Then remove the grounded wire and try riding the bike, as soon as you get above 3 to 5mph the ABS should reset.

It's been awhile since I had my K75 but I believe that is the sequence. Keep a piece of wire in your tool kit, since any time you run the battery down or remove the battery you will have to reset it this way..

Dave thumbsup.gif

Link to comment

I have determined that this is definitely due to my replacing the battery with a new one.


I have tried the 20cm length of wire trick. With no success. So I phoned the previous owner to ask if he had any suggestions.


The PO said that the 20cm length of wire trick never worked for him ... but he did have success using an analogue multimeter instead. So far this hasn't worked but I haven't had time to try every variation on the theme.


Because it is a simple reset (due to the battery replacement) I am determined to fix this myself as I will no doubt encounter it again and again.


Someone in one forum or another mentioned that the ABS likes a voltage which is somewhat higher than 12 volts to be happy. And that a sealed battery might be the answer.


Maybe it wasn't such a good idea to buy a cheap Chinese battery ... dopeslap.gif

Link to comment


This topic is now archived and is closed to further replies.

  • Create New...