ABS warning lights!

[Andyman]

I bought my r1150rt 2002 last October, I rode it home a journey of around 150 miles, all was good when i got home everything working as it should. I then garaged it connected to a Optimate charger via the accessory socket on the left side of the bike.

A few weeks later i added an LED tail light as my wife had said it was difficult to see you ahead in the dark, all connected up and working great. A few days ago i decided to go for a ride, the Gen light was on and the ABS light was flashing at 4hz a second, these i thought would go off once i start moving down the road. When they didn't go off i stopped and turned off the ignition, switch back on making sure no brakes are on, including pushing the lever away from the handlebar incase it was triggering the switch for the brake light, moved off still the same lights still on. There are no brake lights remaining on when away from the bike and both light bulbs work fine, I am wondering if it is anything to do with the wheel sensors!

I have loads of service history with the bike when i bought it, just before i collected it, the paperwork states fully service, discs, pads and new tyres. Not sure what to check next, but have looked up ABS delete threads to remove the servo.

[dirtrider]

10 minutes ago, Andyman said:

I bought my r1150rt 2002 last October, I rode it home a journey of around 150 miles, all was good when i got home everything working as it should. I then garaged it connected to a Optimate charger via the accessory socket on the left side of the bike.

A few weeks later i added an LED tail light as my wife had said it was difficult to see you ahead in the dark, all connected up and working great. A few days ago i decided to go for a ride, the Gen light was on and the ABS light was flashing at 4hz a second, these i thought would go off once i start moving down the road. When they didn't go off i stopped and turned off the ignition, switch back on making sure no brakes are on, including pushing the lever away from the handlebar incase it was triggering the switch for the brake light, moved off still the same lights still on. There are no brake lights remaining on when away from the bike and both light bulbs work fine, I am wondering if it is anything to do with the wheel sensors!

I have loads of service history with the bike when i bought it, just before i collected it, the paperwork states fully service, discs, pads and new tyres. Not sure what to check next, but have looked up ABS delete threads to remove the servo.

 

Afternoon  Andyman

 

Adding rear lighting (brake or tail) usually doesn't cause the ABS light to come on or stay on. Now removing  rear lighting load (like using a higher resistance bulb, or removing a bulb, or having a burnt out bulb,) can cause the GENERAL warning light to ramain on but NOT flash the ABS light. 

 

As a rule when you have the 'general' warning light lit & the 'ABS light' flashing at 4 hz that points to either the ABS module not doing it's ride-away test, or failing the ride-away test, or a stuck servo motor.

 

So, first thing, look the bike over for the possibility of a mouse chewing on one of the wheel sensor pigtail wires, also look for other signs of mouse damage to the wiring  (even under the seat). Also look for the front wheel sensor wire to have been rubbing on the front brake rotor.

 

If no wire damage found then verify that the front brake lever & rear brake pedal are fully returning to the out stops (a slightly sticking brake lever or brake pedal can cause a failed ride-away test).

 

Next, turn the ignition key to on (do not start the engine), then allow a few seconds for the fuel pump to momentarily run & shut off  (all should be quiet).  Then apply the front brake lever & listen for the ABS module pump to start & run (should get louder the harder that you squeeze the brake lever)--  Does IT??????

 

Then do the same with the rear brake pedal-- apply the rear brake pedal & listen for the ABS module pump to start & run (should get louder the harder that you press the brake pedal)--  Does IT?????? 

 

Then ride the motorcycle a short ways & see if you can tell if you have both front lever and rear brake pedal power braking assist. (should have both). 

 

If you can tell us any more info based on the above info then we can hopefully help you pin down your problem a little better.  

[Andyman]

Hi, 

I have front ABS module but not rear, riding i have full front brake and only risidual rear braking

[dirtrider]

13 minutes ago, Andyman said:

Hi, 

I have front ABS module but not rear, riding i have full front brake and only risidual rear braking

 

Afternoon  Andyman

 

I don't fully understand your answer. When you say "I have front ABS module" are you meaning full power (servo) assist using front brake lever?

 

With rear in residual-- is that sitting still or when moving? Or try the rear brake test again but use your foot (or an assistant) to spin the rear wheel during the test.

 

 

[Andyman]

Hi dirtrider

When riding the bike i have full power servo assist on the front and i can hear it working, when riding the rear brake makes no servo sound and hardly slows the bike down, I rode the bike for a couple of miles trying the brakes.

[dirtrider]

Just now, Andyman said:

Hi dirtrider

When riding the bike i have full power servo assist on the front and i can hear it working, when riding the rear brake makes no servo sound and hardly slows the bike down, I rode the bike for a couple of miles trying the brakes.

Afternoon  Andyman

 

OK, that helps.

 

Couple more questions-- Do you have a decent feeling rear brake pedal (ie not a soft feeling pedal apply  or excess travel???)

 

I presume that you have (already checked)  that the brake light comes on with ONLY rear brake pedal apply?? (does it?)

 

 

 

 

[Andyman]

Hi dirtrider

 

Yes the rear brake pedal feels good not spongy and the rear brake light only comes on when the foot pedal is applied, all a mystery, my first bike with ABS

[dirtrider]

1 minute ago, Andyman said:

Hi dirtrider

 

Yes the rear brake pedal feels good not spongy and the rear brake light only comes on when the foot pedal is applied, all a mystery, my first bike with ABS

 

Well!-- You are finding the bad side of the BMW I-ABS system. It gets difficult to diagnose at home once past the general malfunctions.

 

You could have a low ABS module rear reservoir BUT that usually gives you  a general warning light  and the ABS light flashing alternately at 1Hz. (this doesn't fit your light flash sequence).

 

Without as GS-911 or dealer computer it is somewhat of a guessing game as there are no easy (at home tests).

 

At first thought it is sort of pointing to stuck rear servo motor or failed internal pressure sensor for the rear braking circuit, (neither an easy fix at home).

 

Next suggestion is to ride the motorcycle on a very rough road (like closely spaced chatter bumps) while using the rear brake to see if that will help free up a stuck rear servo motor (if that is even your issue) 

[Andyman]

Thanks dirtrider, I can certainly try the bumpy road test, there is a disused airfield up the road from me where they flew Lancasters during WW2, concrete runway and very bumpy!

 

I think if that doesn't sort it out i will go for the ABS delete option and fit stainless steel hoses while i'm at it. I need reliability, not a liability.

[dirtrider]

More-__ 

 

I lost my Internet for a few minutes___

 

If you can't get it working by riding the motorcycle on a rough road you can also try bumping (light pounding on)  the ABS module with a rubber mallet or rawhide mallet while using the rear brake pedal with the key on.  

 

There is also the possibility that you have failed the rear internal pressure sensor (difficult to diagnose at home).

 

You might also try calling ModuelMasters  Phone 208- 892-0764 as they are very good with the BMW ABS systems. 

 

As for removing the ABS system, that will also  take some wiring changes & a relay added as your brake lights work through your ABS module & your lever/pedal brake switches work reverse logic (go open with brake apply). Not difficult, just something different that needs to be addressed during ABS removal. 

 

You will end up with a great feeling & good modulating braking system that is great to ride with, just kind of a pain to remove. 

 

 

 

[Andyman]

I have thought about removing the LED tail light i fitted as everything worked alright before i fitted that, just to see if it makes any difference.

[Andyman]

I just had a thought about you saying the brake lights work via the ABS module. When i wired up my aux tail light i used the hot feed from the tail light, but i used a ground wire which i found attached to the battery negative terminal, does the tail light ground go via the ABS module and the way i wired it make any difference?

[dirtrider]

55 minutes ago, Andyman said:

I just had a thought about you saying the brake lights work via the ABS module. When i wired up my aux tail light i used the hot feed from the tail light, but i used a ground wire which i found attached to the battery negative terminal, does the tail light ground go via the ABS module and the way i wired it make any difference?

 

Evening Andyman

 

Just the power side goes through the ABS module, the ground side does not directly go through the ABS module. 

 

Even with a rear lighting issue you should still have power assist from both front & rear, your no rear power assist more points to the ABS module having issues.