Anti lock not working

[Terry Ivy]

Looking to buy a 1999 R1100RT with 41000 miles. Anti lock brake lights just keep flashing. Would this be an expensive repair?  Thx in advance 

[Claudio]

Hi Terry,

 

I assume they keep flashing after driving for a while (a slow steady flash after startup but before movement is normal). 

 

I would recommend arranging to take it to a shop to diagnose and estimate.  Before you invest more, a small cost to check it out would be sensible.  It is likely a bad sensor ($150-200 part) new, 50-75 used but it could be something more nefarious.

[szurszewski]

Could just be a bad/dying battery (common) but could also be a bad sensor, as stated above, or a bad abs unit. 

 

Have you done a test ride? The dash lights should flash at startup until the abs self test, which happens as the wheels start rolling. If you go for a good ride to charge up the battery, shut the bike down, restart and start riding again, do they (the abs dash lights) go off?

[dirtrider]

11 hours ago, Terry Ivy said:

Looking to buy a 1999 R1100RT with 41000 miles. Anti lock brake lights just keep flashing. Would this be an expensive repair?  Thx in advance 

 

Morning Terry

 

It could be expensive, or could be nothing to worry about  other than low system voltage after engine starting.

 

If it involves the ABS controller module then it could be expensive.

 

This might help you define the problem in more detail__

 

 

At key-on, the two ABS lights should flash together and should continue to do so until the ABS ride-off self-test is complete (self test doesn't happen until you start to ride the bike away), at that time both lights should  go out.

 

If the self-test fails, the dash lights will begin to flash alternately. The exact moment when they start to flash alternately is usually when the problem appears.

 

If_ it happens at key-on before you start the engine then it is usually a system that is tested at first power-up before engine is started.  (this would typically be the most expensive type of ABS failure)

 

If_ it faults when you start (crank) the engine it is usually a low  battery voltage problem. (usually just a low or bad battery)

 

If_ it faults when you ride the bike  away then it could be the ABS controller, or possibly a wheel speed sensor. (can't tell on this one as it might just be excessive wheel sensor gap, or bad wheel sensor, or cut/broken wire, or ???????) 

 

If you can tell us EXACTLY when the system faults (both lights start flashing alternatly) we can probably give you more info on what you are dealing with.

 

If your problem appears when you first start the engine then you might try riding the bike for a while (to fully charge the battery)  then turn the key  off, then try restarting the engine to see if the problem goes away. If it does go away then you probably need to look into a new battery, or modify the ABS system to do it's self test after engine starting.

 

There is also an ABS system RE-SET that you can do (re-sets a locked out ABS controller) but that involves a little more than just pushing a button as it involves removing the seat then using  a grounding wire on one of the under-seat test terminals, then holding the ABS button down for the required time period (you would need the sellers permission to do this re-set).  If the seller is OK with this let us know & I will give you the full ABS re-set instructions to do the re-set.

 

On the BMW 1100 bike the problem is 'usually' just low system voltage (low battery voltage)  signified by  the dash  lights starting to flash alternately at  engine cranking, or that the ABS system needs a re-set done (question then  is: why does it need the re-set).

 

  You might be able to use the failed ABS to bargain a significantly lower purchase price on the bike. If you get the ABS working before making the deal that bargaining power is probably then  gone.

 

[Michaelr11]

12 hours ago, Terry Ivy said:

Looking to buy a 1999 R1100RT with 41000 miles. Anti lock brake lights just keep flashing. Would this be an expensive repair?  Thx in advance 

 

Terry, you received great info from the above posts. You should give some feedback so that we can help with more specifics. Where are you located? You might get a local BMW rider who can help you look at the ABS closer. Is the seller individual or a moto dealer? Do they have anything to say about it? The R1100RT is a great bike, capable of a lot of miles. If it turns out to be the ABS module, it’s not that bad. There is a company that repairs that model, ABS2, for a very reasonable price and gives a five year warranty to the repair. There are also plenty of used modules around, condition somewhat unknown. Module Master is the repair company. I think they get $350 for the ABS2 repair.

[Terry Ivy]

Thanks for the info. It’s from an individual. He’s asking 3K

[Terry Ivy]

I bet it was the battery voltage. As a matter of fact he has a new battery on order. Thanks so much for the info. 

[dirtrider]

15 minutes ago, Terry Ivy said:

I bet it was the battery voltage. As a matter of fact he has a new battery on order. Thanks so much for the info. 

 

Afternoon Terry

 

Don't guess,  just see when (in the starting sequence) that  the lights change to the flashing alternately.

[wbw6cos]

The faults must be addressed, first, in order to re-set the flashing lights.  As D.R.___ points out, the specific sequence of the fault codes occurring can help point the direction to look for the issue and can, subsequently. help determine the cost/repair.

 

Sometimes it is a simple issue.  See if you can find out about any recent wheel removals.  Knowing the history of fluid changes can help, too; if done annually, then pump failure is lower on the probability scale, but still plausible.  By the way, Module Masters offers a 5 year warranty on their rebuilds.

 

Let us know what you find.  We are all watching with anticipation.

 

Cheers,

[dirtrider]

11 minutes ago, wbw6cos said:

The faults must be addressed, first, in order to re-set the flashing lights.  As D.R.___ points out, the specific sequence of the fault codes occurring can help point the direction to look for the issue and can, subsequently. help determine the cost/repair.

 

Sometimes it is a simple issue.  See if you can find out about any recent wheel removals.  Knowing the history of fluid changes can help, too; if done annually, then pump failure is lower on the probability scale, but still plausible.  By the way, Module Masters offers a 5 year warranty on their rebuilds.

 

Let us know what you find.  We are all watching with anticipation.

 

Cheers,

 

 

Afternoon wbw6cos

 

The OP is looking at an 1100RT, the 1100 (ABS ll) doesn't have an ABS pump as that antique ABS system uses a piston type ABS system.  

[Jim Moore]

That bike has great brakes, even without the ABS. Bargain him down some. See if the ABS is a simple, cheap fix. If not, pull the ABS relay and remove the bulb from the remaining flasher. Voila`, problem solved.

[dirtrider]

5 minutes ago, Jim Moore said:

That bike has great brakes, even without the ABS. Bargain him down some. See if the ABS is a simple, cheap fix. If not, pull the ABS relay and remove the bulb from the remaining flasher. Voila`, problem solved.

 

 

Afternoon Jim

 

I know some riders do that but I have always had a problem with doing that as neither ABS warning relay removal or warning light removal deactivates the ABS system (it just deactivates the dash ABS warning part of the system)

 

It isn't a big issue IF the ABS system stays broken but could be a problem for some  if the ABS suddenly starts working again as there is no dash tell-tail lights to show the ABS system is back on line & working again.    

[wbw6cos]

16 hours ago, dirtrider said:

 

 

Afternoon wbw6cos

 

The OP is looking at an 1100RT, the 1100 (ABS ll) doesn't have an ABS pump as that antique ABS system uses a piston type ABS system.  

 

Afternoon D.R.___,

Thanks for clarification.  I have ABS II on my R12C and the GS-911 has shown the fault code to be "16: ABS piston fault."  I have always referred to the ABS unit as the ABS pump, not really thinking about the difference.  They way I have cleared up ABS fault code issues on my C was relatively simple until the aforementioned code kept re-ocurring.  Spoiler alert:  I will be sending that unit out for a rebuild later on this year.  By the way, I have been riding with the flashing ABS warning lights on  for about 6 or 7 months; brakes are used old school style, for now.

 

I hope I did not skew any sound advice given to the OP.  My take on it was it may be a simple solution that may aid in the OP's purchase decision.  Too many sales listed with "ABS quit working" in the listings make me think the seller gave up without a proper analysis.

 

Best regards,

[Miguel!]

My new-to-me R1100RT had the ABS lights flash when I first got it from (a large and long established) dealer. The owner explained to me that BWM designed the ABS system to work at very close to 12V and a low battery voltage, caused sitting for weeks on end for example, would cause an ABS selftest failure and the ABS lights to flash. Why they chose two lights to flash alternately is still a mystery. And the ABS switch turns off the flashing lights for about five minutes and they come back on. Once the system test fails, the ABS doesn't reset till you power down and then on again. I found that if I ride a few miles, pull over or stop at a light, turn the key to off, then on again, the ABS will pass the selftest because the battery charged up. I now keep the battery on a tender in my garage and the ABS passes the self test every time. Just FYI. 

 

Best

Miguel

[szurszewski]

You are more patient than I am - when I had that issue and was putting off a new battery, I would ride a few blocks or so, pull the clutch lever, hit the kill switch, restart and roll on.

 

...I suppose pulling over would have been safer.

[SAS]

Even a new battery installed on an 1100 still needs to be on a trickle charger to prevent issues with the key on bite check of the ABS.  Remember you still have a clock running all the time at key off.  (If you have a clock installed).  Even sometimes after I leave the barn for a ride and stop along the way it may fault again but shut down and a restart usually does it rarely do I have to restart twice, but sometimes...……… it is finicky,  and annoying at times.   

[Jim Moore]

16 hours ago, dirtrider said:

 

 

Afternoon Jim

 

I know some riders do that but I have always had a problem with doing that as neither ABS warning relay removal or warning light removal deactivates the ABS system (it just deactivates the dash ABS warning part of the system)

 

It isn't a big issue IF the ABS system stays broken but could be a problem for some  if the ABS suddenly starts working again as there is no dash tell-tail lights to show the ABS system is back on line & working again.    

That's interesting. Thanks. Is there a simple way to disable the ABS? 

[dirtrider]

1 hour ago, Jim Moore said:

That's interesting. Thanks. Is there a simple way to disable the ABS? 

 

 

Morning Jim

 

Nothing real easy without accessing the ABS controller or cutting wires.

 

Disconnecting the wheel speed sensors will keep the ABS from actually doing anything but it will still power up & try to run it's key-on voltage checks (you just won't see the failures in the flashing dash lights) 

 

Nothing easy like a relay removal as the relay that runs the motor & piston shaft is under a cover on the side of the under-tank ABS controller & the ABS relay in the fuse box is ONLY for the dash light warning light control (doesn't effect ABS function).

[dirtrider]

7 hours ago, SAS said:

Even a new battery installed on an 1100 still needs to be on a trickle charger to prevent issues with the key on bite check of the ABS.  Remember you still have a clock running all the time at key off.  (If you have a clock installed).  Even sometimes after I leave the barn for a ride and stop along the way it may fault again but shut down and a restart usually does it rarely do I have to restart twice, but sometimes...……… it is finicky,  and annoying at times.   

 

Morning Szurszewski, SAS, Miguel

 

There is a fairly easy work-around & a more complicated work-around for the 1100 ABS ll low system voltage fault.

 

The easy one is_   next time you are under the tupperware (& possibly need to move the fuel tank slightly) just cut the green wire going to the ABS controller connector then install a couple of lengths of green wire on each pigtail end of the cut green  wire.

Then run those added green wires up to someplace convenient,  then add a N/C push button  momentary switch  (momentary switch contacts are closed until the push button is pushed to go open then returns to closed with button released).

 

With the added push button switch a simple push of the button forces the ABS to re-set it's key-on voltage check with the engine running & at full system voltage so if the ABS faults at starting, or after-start-ride-away, then a quick simple push of the button re-sets it turns the dash lights out (this can even be done while riding at speed).

 

The more complicated approach uses a relay in place of the push button with the relay triggered by the  charging alternator output so using this method  the ABS controller won't even try to do it's key-on voltage checks UNTIL the engine is running & the alternator charging  (this one works great & is seamless to both rider & ABS function but is more difficult to implement.    

The slight downside to this is the rider loses the ABS function if the alternator quits,  BUT, even without the relay, in most cases the ABS shuts down at first wheel lock ABS try as without the alternator working the system voltage drops to below the ABS controller function threshold as the high amp  piston shaft motor kicks in.

 

 

[Woodrider]

I have a 2004, 1150RT I found out the hard way that flushing the brake system is ABSOLUTELY CRITICAL! the servo assist pump when it fails CANNOT be rebuilt on the 04s  I did extensive research and ended up spending $2,000.00 for a new unit. The only other way out is to completely bypass the unit and go to completely mechanical braking system. After having the servo assist you don't want to go back trust me. Good news is the new unit is plug and play once installed it's like it never happened. Good luck G

[szurszewski]

54 minutes ago, Woodrider said:

I have a 2004, 1150RT I found out the hard way that flushing the brake system is ABSOLUTELY CRITICAL! the servo assist pump when it fails CANNOT be rebuilt on the 04s  I did extensive research and ended up spending $2,000.00 for a new unit. The only other way out is to completely bypass the unit and go to completely mechanical braking system. After having the servo assist you don't want to go back trust me. Good news is the new unit is plug and play once installed it's like it never happened. Good luck G

 

 

This is good advice for any braking system, but the OP has the previous generation of ABS, as stated above, and does not have the servo assist. 

[dan cata]

I would start the bike, ride it so that the battery charges, then reset the ABS error codes, see if that fixes the problem.

Then you can read the error codes using a 12V led or a regular LED + appropriate resistor, and depending on that, you can expect the bill. Either a sensor or the unit itself.

 

Dan.

[Miguel!]

43 minutes ago, dan cata said:

I would start the bike, ride it so that the battery charges, then reset the ABS error codes, see if that fixes the problem.

Then you can read the error codes using a 12V led or a regular LED + appropriate resistor, and depending on that, you can expect the bill. Either a sensor or the unit itself.

 

Dan.

How's that work Dan? Thanks. Miguel

[Paul De]

As DR and others have noted it is well documented quirk of the ABS system on the R1100RT.  It will fault out if it senses low system voltage which typically shows up at start up with a weak battery and is as cheap as a new strong battery and using a tender between rides.  It is a they all do that thing.  If current owner can't sort out the issue and you can't do the checks that DR outlined to determine the cause of the ABS error before you buy the bike, then negotiate a price based on a failed ABS system.  Or, move on.   

 

Although I have grown to really appreciate the value ABS on a M/C, if my '99 RT ABS unit failed I would be temped to go old school and eliminate it from the braking system. I have ridden the bike w/o the ABS system working when a front sensor when dead and was waiting on a part and found that the brakes worked fine, just had to go back to my pre-ABS braking skills.  The '99 RT has decent brakes and with SS brake lines the front brakes gives very good sensitivity and feedback  The rear brake will always feel a bit wooden but can lock up the rear tire with enough added peddle pressure.

[dirtrider]

54 minutes ago, Paul De said:

As DR and others have noted it is well documented quirk of the ABS system on the R1100RT.  It will fault out if it senses low system voltage which typically shows up at start up with a weak battery and is as cheap as a new strong battery and using a tender between rides.  It is a they all do that thing.  If current owner can't sort out the issue and you can't do the checks that DR outlined to determine the cause of the ABS error before you buy the bike, then negotiate a price based on a failed ABS system.  Or, move on.   

 

Although I have grown to really appreciate the value ABS on a M/C, if my '99 RT ABS unit failed I would be temped to go old school and eliminate it from the braking system. I have ridden the bike w/o the ABS system working when a front sensor when dead and was waiting on a part and found that the brakes worked fine, just had to go back to my pre-ABS braking skills.  The '99 RT has decent brakes and with SS brake lines the front brakes gives very good sensitivity and feedback  The rear brake will always feel a bit wooden but can lock up the rear tire with enough added peddle pressure.

 

 

Morning Paul

 

On the BMW 1100 ABS ll  'reaction piston' system--  that ABS system is slow to respond (ABS wise) & even slower to recover so it probably isn't a big loss to eliminate it. (the spinning shaft, clutches, chains, & moving pistons can only react so fast & that isn't very fast)

 

The BMW 1100 ABS ll works great on a smooth dry road (usually not really needed there) but it fails pretty bad on a dry road surface with chatter bumps, or on dry road with  loose gravel on it, as the slow response & rear anti-wheel-lift combine to not only prematurely release the rear braking pressure during hard braking but also prematurely release/reduce  front braking pressure  & that not only startles the rider but increases the braking distance.

 

On a real slippery road surface if you can get it to the ABS brake release point under control  then it will usually  prevent wheel lock-up but due to the slow recovery time you lose a lot of braking control.

 

There is a good reason that BMW went to the more complex & more expensive I-ABS system on the 1150 bikes. Using the servo pumps there was almost instant response & plenty of make-up fluid for an extended ABS event. The I-ABS system is probably the fastest motorcycle braking  system from  front hand lever initial movement to brake pad apply pressure  that I have ever ridden.

 

 The problem is, they didn't (probably couldn't)  design in any accumulation so not much back up if the servo system shuts down just before, or during normal barking, & definitely no ABS available if the servos shut down.

 

 

  

[Miguel!]

1 hour ago, Paul De said:

just had to go back to my pre-ABS braking skills

Paul, How do you brake differently with and without ABS?? Miguel

[wbw6cos]

Evening D.R. ___,

 

May be a rhetorical question, but is the ABS II the same through out the different model bikes?  R1100/1150 RT -vs- R1200C, etc?

Thanks for the knowledge.  It seems I am still learning about my C.

 

Best Regards,

[dirtrider]

nin

37 minutes ago, wbw6cos said:

Evening D.R. ___,

 

May be a rhetorical question, but is the ABS II the same through out the different model bikes?  R1100/1150 RT -vs- R1200C, etc?

Thanks for the knowledge.  It seems I am still learning about my C.

 

Best Regards,

 

Evening  wbw6cos

 

No way to compare as the 1150 bikes don't use the ABS ll system, the 1100 bikes  (except the 1100S) pretty well use the same basic system but it is calibrated slightly differently between the models.

The R1200C is a different animal as  pre 2004 uses a different system than post 2004. 

[wbw6cos]

Got it, thanks.

[Paul De]

10 hours ago, Miguel! said:

Paul, How do you brake differently with and without ABS?? Miguel

 

Hi Miguel,

 

I have always practice braking, including hard panic stops. Pre -ABS I learned to listen to my tires moaning before lock up and programed myself to include that sound into hard braking situations and would modulate to not lock up. While I still use those skills on an ABS equipped bike the weighting is not as high as it would be on an non ABS bike.  With ABS I will use that little piece of attention spent listening to my tires in a hard braking situations and apply it to some other aspect of riding aware.  It isn't like I go dumb and think ABS is all that and a bag of chips, but the computer manages wheel lock up well enough to give me opportunity to think beyond my wheels when needed most. I still am biased in that if the ABS system is activated  I still feel it is an operator error event and I review how that happened and how it could have been avoided - geeky me!

 

Back to Terry Ivy's question...to buy or not to buy, that is the question.