2005 R1200GS ABS modulator

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r75boxer
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2005 R1200GS ABS modulator

Postby r75boxer » Sun Nov 05, 2017 11:47 pm

Hello all. I'm contemplating purchasing a gently used 05 R1200GS. The bike's been checked out by a reputable local shop specializing in BMWs and all is well save for the ABS modulator. The mechanic said if I don't want to go the expense of fixing/replacing it I could just ride it as is. I put this question to Ced in a private email (his response below) and he suggested I post it to the group. Does anyone have experience with this year and model that could help? I've ridden mostly without ABS so really don't have an issue with it working or not UNLESS only residual braking is what is left to stop this hefty beast. Thanks.

Kevin

Message from Ced:

Hi Kevin,

I'm not well up on the R1200 bikes but suspect that the 2005 R1200GS may use the iABS-1 system.

From Largiader's 'ABS Faults' article:
"Integral ABS (iABS)
If you normally get a whining noise when you apply the brakes, and notice that they are power-assisted, you have iABS........."
If the above applies to your potential bike then it has iABS-1 fitted.

Here is a link to Largiader's article: http://www.largiader.com/abs/absfault.html

The biggest danger with a faulty iABS-1 system is that, should the iABS-1 fail, then the ABS reverts to a 'Residual' braking mode.
This can occur in one or both wheels and, should it occur, the 'Residual' braking mode leaves very much to be desired in terms of stopping power.

On the GS models only, I believe that the ABS system can be switched Off at the handlebar but this may only apply to the REAR brake so you need to check this out.
Also, this likely only applies to an ABS system that is working normally - a failed system may only be working in 'Residual' mode on one or both wheels and the ABS 'Off' switch may therefore be ineffective.
Try a post on the forum for those that have got this bike model to get this info confirmed.

On all other models equipped with iABS-1, the ABS cannot be switched off.
It could be dangerous to ride a bike with a faulty iABS-1 system as the braking can be dramatically reduced.
If the iABS-1 system is faulty and a repair is uneconomic or, there is no trust in this system, then the system servo Modulator needs to be hydraulically disconnected from the bike.
This is comparatively simple to do and the cost varies from £0 to £200 depending on how you go about it.

What is VERY important is that you should try and retain the Electronic Controller sub-module fitted to the servo Modulator as long as this sub-module is working OK.
The reason for this is that it allows the rear brake and tail lights to function normally without having to cut/modify any of the Modulator wiring - the existing Modulator connector is just re-plugged back into the Electronic Controller sub-module and the electrics will work as normal without any modification.

Some K-bikes using this ABS system also have the speedometer controlled by the Electronic controller sub-module so for these K-bikes it is ESSENTIAL that the sub-module is retained or the speedo will not work.

The Electronic Controller sub-module has to be re-packaged into a waterproof container as the servo Modulator wll be discarded.

If you are thinking of replacing the 'pooched' servo Modulator then the cost to do this for a new BMW warranted unit is around £1800.
Be careful with using a used unit as I think that they may be coded to the bike model so you would be safer getting one from the same model of bike as yours.

If you are buying the bike from a dealer, then consider getting the dealer to do the 'servectomy' BEFORE you buy the bike if that is what you intend re the ABS.
However, ensure that he does NOT cut any wiring as above!
Many people remove the iABS-1 system even if is not faulty because of its unreliability and what they consider to be an unsafe system on failure.

Hope that helps!

Ced.
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Re: 2005 R1200GS ABS modulator

Postby Jaythro » Mon Nov 06, 2017 4:27 pm

You cannot "just" ride a Servo ABS bike, The Servo is basically a torque amplifier

Think of it as a pair of Binoculars ... When you look through the lens correctly, it helps you see further (corresponding to the servo unit Braking normally)

Now if your servo fails? You are basically in a position where you are "looking through binoculars from the wrong side" i.e. Your marginal input on the brake lever cannot produce sufficient braking effort to stop you from high speeds

There are 4 circuits

Master cylinders to unit 1 front and 1 rear "Control circuits"

the from the ABS unit to each calliper again 1 front and 1 back "Wheel Circuits"

Your input form the master cylinders is amplified through the ABS unit and with e servo function disabled (any fault code does this) You simply cannot generate enough power to stop the bike safely from say 100kmh

It is really better to read the fault codes It "could be something as simple" as the speed sensor has metal filings on it from the Final drive*** it cannot clearly read the pulse from the Pulse ring while the wheel turns ( *** Please note if it has copious filings? The FD needs examined!!! It may be on a mission to fail at this point!)
If it is a damaged sensor wire then the sensor can simply be changed

BUT If it is a catastrophic Failure? It is simple to remove the system But you would loose ABS function "but" would actually have properly functioning brakes!

In a quick form:- you re pipe the bike brake lines as per a normal bike

From the ABS Unit. You remove and seal up the Electronics box and refit it to the loom and mount it on the bike again (try to make sure it does not suffer too much Vibration!! Damp the mount with foam rubber or rubber strip ?)

You will still have 2 flashing lamps, on a 1200GS you can just blank out the LEDs with Tape or nail varnish or whatever method you like
"Put your Ass on a motorcycle and ride with an attitude and the "Grim Reaper" will ride in your shadow!"

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Re: 2005 R1200GS ABS modulator

Postby Jaythro » Mon Nov 06, 2017 4:34 pm

The bike's been checked out by a reputable local shop specializing in BMWs and all is well save for the ABS modulator. The mechanic said if I don't want to go the expense of fixing/replacing it I could just ride it as is.
P.S. That rings a rather loud alarm bell in my mind!!!
"Put your Ass on a motorcycle and ride with an attitude and the "Grim Reaper" will ride in your shadow!"

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Re: 2005 R1200GS ABS modulator

Postby r75boxer » Mon Nov 06, 2017 5:00 pm

Thanks for your thoughts. The mechanic is reputable and I've used him for years to do work, as have many others. He would have a code reader so I am certain he as done this diagnostic. The GS is not his but rather a client that has had it serviced there for years. So, no alarm bells sounded (but I will talk to him again, and again if need be).

My preference, since I am not to keen on going through all the expense of the install for a used modulator (and new is out of the question), is to remove said unit and re-pipe as you suggested.

Kevin
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Re: 2005 R1200GS ABS modulator

Postby goldenoldy » Mon Nov 06, 2017 5:55 pm

Hi Kevin. I’ve a 2005 RT 1200. My unit failed( wizzey sound brakes), first the rear then the front. You are left on these bikes with absolutely useless brakes. No matter how hard you pull them on there is very very little there. I had the unit removed by Roy Gardner’s at a reasonable cost.The main dealers don’t do this type of work. When I took mine in he had about five bikes going through the process. Apart from having to relearn convential braking techniques due to the original being a shared system on the front lever it’s been a surprisingly good move. My insurance made nothing of it. And the bike lost about 12/14 kilos I believe. Now don’t get me going about the fuel strip failures!!
Brian

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Re: 2005 R1200GS ABS modulator

Postby r75boxer » Mon Nov 06, 2017 5:59 pm

Thanks. I'll have to bone up on the fuel strip failures before I can comment on that. Maybe I should hang on to my 02 R1150RS?

Kevin
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Re: 2005 R1200GS ABS modulator

Postby Mike D » Mon Nov 06, 2017 7:16 pm

I recall on at least some of the R1200GS that the ABS is switchable. If that is the case for the 2005 model, perhaps that was what the mechanic was alluding to? (I'm being generous here :neutral: )

Mike

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Re: 2005 R1200GS ABS modulator

Postby Galactic Greyhound » Mon Nov 06, 2017 7:31 pm

I thought that was the case as well Mike.
However, if the ABS servo has failed then switching Off the ABS may not resolve a 'Residual' brakes issue.
Ced.

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Re: 2005 R1200GS ABS modulator

Postby Jaythro » Mon Nov 06, 2017 11:01 pm

05 GS will have "likely" a float level system

until the "MU" (model update which was 2006 models
Thanks. I'll have to bone up on the fuel strip failures before I can comment on that. Maybe I should hang on to my 02 R1150RS?

Kevin
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Re: 2005 R1200GS ABS modulator

Postby Jaythro » Mon Nov 06, 2017 11:05 pm

Too Generous When they fail they fail

For me its a love hate relationship I love how they work and how the ABS works, I hate the way that some day it will fail I just hope its not when I need them most!!!

When you De-acticate for off road you still have full power servo just no ABS function
I recall on at least some of the R1200GS that the ABS is switchable. If that is the case for the 2005 model, perhaps that was what the mechanic was alluding to? (I'm being generous here :neutral: )

Mike
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Re: 2005 R1200GS ABS modulator

Postby Jaythro » Mon Nov 06, 2017 11:08 pm

I thought that was the case as well Mike.
However, if the ABS servo has failed then switching Off the ABS may not resolve a 'Residual' brakes issue.
Deacticatiing ABS for off road use just switches off the ABS component

Whatever fool thought it was a good idea to have full power servo with no ABS off Road needs a kick in the behind, Half power would still be too much!!!
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Re: 2005 R1200GS ABS modulator

Postby r75boxer » Mon Nov 06, 2017 11:14 pm

Thanks to everyone for their input. Much appreciated. I will call the mechanic tomorrow to find out more about fault codes etc. (his shop is closed on Mondays). I'll also get the serial number so that I can figure out exactly what sort of braking system the GS came with. Stay tuned.

Kevin
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Re: 2005 R1200GS ABS modulator

Postby Mike D » Tue Nov 07, 2017 1:00 am

When you De-activate for off road you still have full power servo just no ABS function
Thanks for clarification Jaythro. I haven't worked on that model GS, so wasn't fully conversant with the effect of the switch on the servo/ABS. I agree that that servo operation and no ABS would be interesting (putting it mildly!).

Mike

Yes - but if the ABS is faulty you may not have 'full power servo' and are working with permanent 'Residual' braking!

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Re: 2005 R1200GS ABS modulator

Postby Jaythro » Tue Nov 07, 2017 9:45 am

Yes - but if the ABS is faulty you may not have 'full power servo' and are working with permanent 'Residual' braking!
Absolutely correct Mike If there is a detected "critical" Fault Code the system won;t initialise the servo assistance at all
Low fluid (in the ABS unit) and rearbulb failure will illuminate a lamp to tell you there is a non critical fault

but instead of allowing the circuit that is working to power up and stop you safely? The engineers just designed the system to turn off!! ](*,) Obviously those people had never ridden a motorcycle!!! :evil:
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Re: 2005 R1200GS ABS modulator

Postby Galactic Greyhound » Tue Nov 07, 2017 10:07 am

When you De-activate for off road you still have full power servo just no ABS function
Thanks for clarification Jaythro. I haven't worked on that model GS, so wasn't fully conversant with the effect of the switch on the servo/ABS. I agree that that servo operation and no ABS would be interesting (putting it mildly!).

Mike

Yes - but if the ABS is faulty you may not have 'full power servo' and are working with permanent 'Residual' braking!
Sorry Mike!!! My Moderator priveledges caused me to foul up your post with that last paragraph comment I made!

I do apologise. :oops:
Ced.

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Re: 2005 R1200GS ABS modulator

Postby P-K » Tue Nov 07, 2017 11:39 am

I used to have an '03 plate R1150R with the servo ABS.
Let me just tell you, that when the modulator fails, the "Residual" braking is virtually useless.
If it fails whilst you are riding, it leads to the biggest "Ohh Sh*t" moment you have ever had.

I speak from bitter personal experience.
Phil,
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Re: 2005 R1200GS ABS modulator

Postby Mike D » Tue Nov 07, 2017 3:08 pm

used to have an '03 plate R1150R with the servo ABS.
Let me just tell you, that when the modulator fails, the "Residual" braking is virtually useless.
If it fails whilst you are riding, it leads to the biggest "Ohh Sh*t" moment you have ever had.

I speak from bitter personal experience
The first time is occurred on my R1150RT, I was in Friday rush hour traffic on the M6 - my bum was nibbling the buttons off the seat! If it wasn't for the roadworks providing an escape route then I would have probably hit the back of the truck in front.

Mike

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Re: 2005 R1200GS ABS modulator

Postby r75boxer » Tue Nov 07, 2017 8:00 pm

Hello all. So, I just got off the phone with the mechanic. The fault that showed up stated: 'ABS motor rear defective'. The original owner has been riding it regularly, just without ABS.

So, according to the mechanic, who took the bike out for a good run, the 1150s have a different setup that result in only 60% braking (so-called residual braking) when the ABS fails. The 1200s revert to non-ABS too but with 100% braking. He has retrofitted a number of 1150s with a bi-pass kit from the UK but never for the 1200s because it isn't necessary.

Kevin
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Re: 2005 R1200GS ABS modulator

Postby Mike D » Wed Nov 08, 2017 12:30 am

The 1200s revert to non-ABS too but with 100% braking. He has retrofitted a number of 1150s with a bi-pass kit from the UK but never for the 1200s because it isn't necessary.
Not very experience on the 1200 series then is he!

The early 1200's had exactly the same servo system as the 1150, including the abysmal residual braking. This only changed around 2007/8 when the later ABS motor was fitted. This was a totally different (and safer) system. Not without its own problems as the motor brushes can stick leaving the bike with no ABS, but at least normal functioning hydraulic brakes.

Mike

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Re: 2005 R1200GS ABS modulator

Postby Jaythro » Wed Nov 08, 2017 12:39 am

I seriously think I would be walking away from that bike!!!

If that's what he "knows" and he is a respected BMW Mech???

I would wonder have the services been done correctly??

MikeD 2006 onwards is the next Evolution BMW ABS (the one with sticky brushes)
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Re: 2005 R1200GS ABS modulator

Postby r75boxer » Wed Nov 08, 2017 1:18 am

Now you got me thinking ... again. I double checked with my local BMW Motorad dealer and he [independently] said that residual braking would be 100% on this year and model. So, no issues? Is it possible that the NA bikes were different? Somehow I doubt that particularly when we're talking about at least a year before the ABS changed.

Kevin
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Re: 2005 R1200GS ABS modulator

Postby Galactic Greyhound » Wed Nov 08, 2017 1:34 am

Now you got me thinking ... again. I double checked with my local BMW Motorad dealer and he [independently] said that residual braking would be 100% on this year and model. So, no issues? Is it possible that the NA bikes were different? Somehow I doubt that particularly when we're talking about at least a year before the ABS changed.

Kevin

Kevin,

Your mechanic is talking about the iABS-2 or later system.

I believe that your 2005 R1200GS is fitted with the iABS-1 system which is the same system as fitted to the R1150 bikes and will therefore suffer from the 'Residual' braking problem if any part of the servo Modulator has failed.

The 'Residual' braking is a failure to produce the required hydraulic pressure at the Wheel circuit/s due to the inability of the servo Modulator to produce the required pressure.
This can occur on the Front, Rear or both Front/Rear Wheel circuits depending on what has failed in the servo Modulator.
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
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Re: 2005 R1200GS ABS modulator

Postby r75boxer » Wed Nov 08, 2017 1:40 am

I think you're right (as before). He must be painting all 1200s with the same brush. He did say that the front was still working, if that's possible.

It may be prudent to take Jaythro's recommendation and walk away.

Kevin
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Re: 2005 R1200GS ABS modulator

Postby Galactic Greyhound » Wed Nov 08, 2017 2:12 am

Kevin,

2005 R1200GS (early), ABS Modulator Generation 1 [iABS-1] (up to 08/2006) BMW Part Number: 34 51 7 698 296.
http://www.realoem.com/bmw/enUS/showpar ... Id=34_1409

2005 R1200GS, ABS Modulator Generation 2 [iABS-2] BMW Part Number: 34 51 7 715 109
http://www.realoem.com/bmw/enUS/showpar ... Id=34_1650

Look at the links to see pics of the Generation 1 [iABS-1] and Generation 2 [iABS-2] ABS Modulators to see what is fitted to your intended bike.
It is possible that BMW may have switched some US bikes to the Generation 2 [iABS-2] to avoid possible litigation in the US re the iABS-1 failures but this is not clear from the RealOEM website for the data given.

There might be a clearer result if the VIN is input into the RealOEM Serial Number Search box (http://www.realoem.com/bmw/enUS/select) and an examination made of the 'BRAKES/MECHANICAL-HYDRAULIC COMPONENTS' Parts List to see what Modulator was fitted to that VIN.
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" onclick="window.open(this.href);return false; - It works!

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Re: 2005 R1200GS ABS modulator

Postby r75boxer » Wed Nov 08, 2017 2:17 am

You read my mind. I left a message with the shop for the VIN.

Kevin
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