Brake failure (GS)

[tinos]

I have a GS 07 with 11000 miles and the brake failure light came on, on the dash.
The bike is fitted with I ABS and braking has become very weak. The local agent are saying it may be the ABS or the ECU. Has anyone come across this problem?

[marc]

'07 bikes came with iABS II. But "weak brakes" sounds like an iABS system (power assist) failure. If the ABS unit fails with iABS II you degrade to normal, non-ABS brakes. Weak brakes would not be a symptom. What is the manufacture date of your bike?

For iABS (whizzy) brakes the first things to look at are the two brake switches and the fluid level in the ABS unit. Also, when was the last time the brakes were bled?

[tinos]

Originally Posted by marc

'07 bikes came with iABS II. But "weak brakes" sounds like an iABS system (power assist) failure. If the ABS unit fails with iABS II you degrade to normal, non-ABS brakes. Weak brakes would not be a symptom. What is the manufacture date of your bike?

For iABS (whizzy) brakes the first things to look at are the two brake switches and the fluid level in the ABS unit. Also, when was the last time the brakes were bled?

Tks for your reply. It is a July 07 bike with 11000 miles. I changed the fluid 2 days ago after the light went on.How can I check the fluid in the abs there is no bleed valve, but i blead the system out when I changed the fluid, after this the brakes were still weak. A question, if I bypass the abs by connecting the line comming from the levers and connect it to the line going to the wheels and not removing the wires from the abs,(i mean leaving the abs connected and just bypassing the lines, what can heppen? After driving the bike can the bikes ecu shut down? TKS.

[marc]

A bike built in 0707 will have iABS II. iABS II doesn't have fluid in the ABS unit. If the ABS unit is bad the bike should act like a bike without ABS save for a blinking light. If you've got weak brakes I'd look at the usual problem areas.

How are your brake pads?

Are the pistons in the calipers moving when you apply the brakes?

Are you seeing any leaks around either of the master cylinders or the various banjo bolts?

Any bulges in the brake lines?

Is the weakness limited to just the front, just the rear, or both brakes?

I guess what I'm saying is to ignore the ABS for now and get normal hydraulic braking function. If you still have the ABS error once you've got normal braking you can then worry about what to do to get your ABS back.

[pdxrmccgs]

If your brakes are "squishy" you may still have air in the brake line.

There are some pretty good videos on you tube on ABS service.

If you have access to GS-1 or GS 911 you might see if there are
any error codes that help you.

To get up close and personal with ABS it takes some effort to build
a understanding and a knowledge base. There is quite a bit on the forums on
various flavors of the ABS system.

Good luck.

[tinos]

Originally Posted by pdxrmccgs

If your brakes are "squishy" you may still have air in the brake line.

There are some pretty good videos on you tube on ABS service.

If you have access to GS-1 or GS 911 you might see if there are
any error codes that help you.

To get up close and personal with ABS it takes some effort to build
a understanding and a knowledge base. There is quite a bit on the forums on
various flavors of the ABS system.

Good luck.

I have on order and should be at me in 2 days time a GS-911, will see the results.
I did an oil change and bleed the system out, what I will do next is check the calipers may be I have a jammed one. Tks for your info.

[pdxrmccgs]

Here is a google search site that might help...lots of stuff.

BMW R1200 GS brake bleeding - Google Search

[tinos]

Originally Posted by pdxrmccgs

Here is a google search site that might help...lots of stuff.

BMW R1200 GS brake bleeding - Google Search

Hi Guys,

First of all thanks for all your help,

Mechanically (hydraulically) all looks fine.
I had the Bike tested at the dealer and they told me that the ABS unit was faulty / fried.

I have managed to find a 2nd hand unit for a decent price and purchased it.

To install the new (used) abs unit do I need to code the ECU with GS911 or is it plug and play (and clear any faults).

[tinos]

So,

I got a replacment abs module (used) and installed it on the bike, bled the brakes, tested with gs911 inc output tests and a brake bleed.

1 fualt keeps coming up that the abs unit needs coding to the vehicle.

BMW Malta say that they cannot code the module as it is used and "locked" to the other bike.


WHat do you guys think?

I have GS 911 and BDM tools to read / write the BMS-K ecu.

Cheers

[pdxrmccgs]

Tinos aka martin aka James Aquilina aka Piranha Performance...

What you are attempting has been problamatic. There are
few if any verifiable forum posts claiming any degree of success.

The "bonding" I suspect is a rolling encrypted algorithm to defeat
what you are attempting.

I doubt any BDM stuff will get you into the ECU.

I would try to evaluate the original module as to whether the
problem is electrical or mechanical and proceed from there.

Unless your bike was pulled out of the surf from a shipping accident
it has way to low miles for ABS total failure.

Good luck and let us know how it works out.