BMW Luxury Touring Community banner

1 - 9 of 9 Posts

·
Registered
Joined
·
100 Posts
Discussion Starter #1
Hi, I just bought a 2002 LTC. I love the bike! Anyway, the brakes lights flash, actually the most left light flashes quickly, and the next light stays on. I have lost all "POWER ASSIST" to the brakes. They work, but I have to squeeze them very hard. Is this the classic ABS module failure, or do I have another issue? I just bought this on Weds, so am brand new to this forum. I will try and check fluid level at lunch time today, as apparently there might be related issues with level sensors.
 

·
Registered
Joined
·
1,243 Posts
The fact that you ask those questions makes me beleive that you do NOT have the owners manual or you have not read it. It contains 2 important sections:
1) What the fashing sequences (patterns) means for those 2 lights and how they should behave if everything is normal.
2) What is the "residual braking" mode and what precautions you should take.

The “Integral ABS” system of your K1200LT has electrical servo pump (or booster pump) built in the ABS unit. Without electrical power, or if any of the components inside the unit are defective, you will loose the extra “boosted” force. The braking force that remains is called “Residual braking”.

I am leaving in 5 minutes for the dentist, but I will cut-paste below details about item 2). Hopfully someone else will fill you on item 1) above.


Extract from the Owners manual of BMW motorcycles equipped with “Integral ABS” (2001-2009):
------------- EXTRACT --------------------------------------------------------
RESIDUAL BRAKING FUNCTION
Warning:
When the ignition is switched off, before and during self-diagnosis, or if the BMW Integral ABS fails, only a RESIDUAL BRAKING FUNCTION remains available for slowing the motorcycle.

When the RESIDUAL BRAKING FUNCTION is active, you must apply CONSIDERABLY higher pressure to the brake levers in question in order to apply the brakes, and lever travel is longer.

When the RESIDUAL BRAKING FUNCTION is active, the ABS function is unavailable in the
brake systems in question.

Warning:
When the RESIDUAL BRAKING FUNCTION is active, maintain a defensive riding style and proceed immediately to the nearest specialist workshop, preferably an authorized BMW motorcycle dealer.

Note:
When the RESIDUAL BRAKING FUNCTION for the front brake is active, it is advisable to set adjuster of the handbrake lever to position 4.
------------- END OF EXTRACT -------------------------------------------------
 

·
Registered
Joined
·
338 Posts
Just like Sailor explained.
The flashing light is for your brakes, the red triangle light means the computer is doing self dignostics--if all is well that should go out. The flashing light will remain untill the servo ( power brakes) kick in. You should hear a whirr sound. When this happens the flashing will slow down and will not completely stop untill the wheels are turning.
I would not ride the bike with the residual braking only, unless you drive very slow and give your self plenty of time to stop.
Just like the power brakes on your car.
 

·
Registered
Joined
·
1,243 Posts
This is the rest my previous post that I did not have time to finish.
---------------------------------------------------------------------------------------------
The following is applicable to I-ABS (Integral ABS) having the servo-pump (2001-2009).
The text below is part of a new tutorial video I am currently working on.

The IABS performs a self-diagnostic in 2 steps:

1) Every time you switch the ignition ON, the “ABS warning” light will flash 4 times per second (fast) and the “General warning” light will stay ON – this will last only a few seconds.

2) After this 1st diagnostic step is completed, the “ABS warning” light will change to flash every second (slow) and the “General warning” light will go OFF”. Both warning lights will stay in this state until the motorcycle moves to a speed of at least 3 mph (5 Km/h) – at which point the IABS can do the pull-away test and turn OFF the “ABS warning”. The pull-away check will complete the last step of the IABS diagnostic.

Additional NOTES:
---------------------------
During the 1st diagnostic step (after ignition ON), the IABS will run various checks including:

- the front brake lever is at rest (not pulled) and the brake switch has continuity,
- the rear brake pedal is at rest (not pressed) and the brake switch has continuity,
- the fluid level of the ABS unit reservoir(s) is above “minimum” mark,
- the rear or brake light bulb is not defective (on the K1200LT, the rear light assembly has 3 bulbs and ONLY the center bulb is monitored by the ABS-unit).

During the 2nd diagnostic step (moving), the IABS will make sure that both wheel speed sensors are responding correctly.

The IABS may generate a fault if the battery is weak, thus we avoid starting the engine before the first diagnostic step is finished. Reducing the load for this short period will give the maximum voltage possible to the ABS unit.

The "ABS warning" light and the "General Warning" light (triangle) have many possible combination of Slow-flashing / Fast-flashing or steady to mean various faults. The owners manual shows all possible combination that have a meaning. If you have a more recent K1200LT, the dash is a bit more fancy that the attached picture, but the concepts and the faults are the same.

A common fault is the "General Warning" light stays in a steady state (even after moving) which means that the rear center bulb (for tail-light) is defective.

The next most common fault is low fluid in one or both sections of the brake fluid container located under the seat (1999-2004 models) or the container built into the top of the ABS-Unit (2005-2009 models). This fault is shown as both warning lights being in flashing mode (slow or fast) even after you do the pull-away test.

*** DISCLAIMER ***:
This is the BRAKE-SYSTEM of YOUR motorcycle and it is CRITICAL to your safety. In case of doubt, please consult your BMW dealer.
 

Attachments

·
Registered
Joined
·
100 Posts
Discussion Starter #5
Thanks for the information, I shall proceed to get it fixed properly. One thing I did notice today while praticing tight turns, figure 8s etc in the near by parking lot is that IF I apply only the rear brake, as desired at slow parking lot turns, the brakes functioned with full power assist. When I used the front brake, poof, all power lost. Makes me think that the issue is in the front circuit somewhere.....
 

·
Registered
Joined
·
256 Posts
Another quick check, probably not in the book.

Switch the ignition on and leave the the engine off.

After the Power On test, you may hear a quick buzz when the booster energizes. Leave the engine off and apply pressure to the front brake lever to engage the booster pump, which should hear whining as long as you keep pressure on the lever. It only takes light pressure on the lever, one finger will do! The same should be true for pressing on the rear brake pedal.

If you don't hear booster pump whine with the ignition on and engine off, something is definitely wrong.

Best of luck.
 

·
Registered
Joined
·
426 Posts
Also, to make sure your ABS initializes properly, do not hold the bike in place with the brakes or have the brakes on when you turn the bike on. Do not touch the brakes until the computer has gone through its checks, the gauges all return to normal and the lights go to their steady flashing sequence. Then you can start the bike, once started, now you can grab a brake lever etc. If brakes are put on prior to self diagnosis and start up, it can throw the ABS off.
 

·
Registered
Joined
·
1 Posts
Thanks so much for All of your extremely informative posts. I’m curious if anyone is experiencing my issues. I just flushed out brake fluid after experiencing brake loss last year at end of season, due to low fluid in underseat reservoir.Flush went well, bled everything, I let bike go through the sequence, roll off, no lights, then about a mile or so down the road, triangle and fast flashing begins. I still have brakes for awhile but at some point they get real weak. I’ll let the bike sit and start the whole process again with the same results. BTW, bike is 2002 K1200LT
 

·
Wrencher Extraordinaire
2005 K1200LT
Joined
·
14,351 Posts
OK when it flashes fast there is a fault within the ABS unit and you need to have the fault code read by either a GS-911 unit or the dealers computer for us to help you further.

This system is also sensitive to a weak battery so a good readout of the voltage on the battery terminals with the engine OFF but the key ON will be helpful. Since it comes and goes I suspect a weak battery as the ABS unit does draw a large load.
 
1 - 9 of 9 Posts
Top