GS-911 and ezCAN User Forum

General Category => Technical => GS-911 => ABS related issues => Topic started by: ManxGS on January 25, 2017, 09:08:05 PM

Title: Another ABS problem
Post by: ManxGS on January 25, 2017, 09:08:05 PM
Good evening everyone. This is my first post so go easy on me. :D I've a beautiful 2004 R1200GS with only 2700 miles on her. She sat for 10 years in a dry garage and apart from dust wanting cleaning of her she's showroom.  New battery and a service and we're off. 250 miles later and I have to leave her outside overnight, it rains and when I go to start her the next day, ABS failure, warning triangle, and no servo on the rear circuit.  911 reads 1 code present. 
24972 Pressure in rear wheel circuit too high.   when I read live data, battery 12.36v, pressure front circuit 18.17bar, rear circuit 47.11bar, and when I press both levers front operates motor but rear does not, and the live data says front not operating and rear is?????   weird.
Any help will be greatly appreciated.
Title: Re: Another ABS problem
Post by: Alexm1 on January 25, 2017, 11:17:17 PM
ManxGS, the first thing to try would be a full brake system bleed, both wheel circuits and control circuit. The fluid will likely be quite contaminated so you need to ensure the system is fully flushed.
Probably not contributing to your problem but worth thinking about is the OEM brake lines, they are likely soft and replacing them with braided lines will improve the brakes performance.
Title: Re: Another ABS problem
Post by: ManxGS on January 27, 2017, 09:27:32 PM
OK. Fluid all changed and no nasty's found. Same problem persists. What I can't understand it the pressures recorded on live data with all the nipples loose. Front 18bar, rear 62bar. Also the data shows that the front switch isn't working yet the light and motor runs, and the rear switch does work yet the motor does not run.  Should there be any pressure reading when idle?? :(
Title: Re: Another ABS problem
Post by: Alexm1 on January 28, 2017, 11:15:50 AM
I am missing something here, "all nipples loose", do you mean open? And you are still getting pressure readings?
Check the switches physically and electrically if you are able, get them out of the equation.
What colour was the control circuit "old" fluid?
Have you performed the brake pressure test?
Title: Re: Another ABS problem
Post by: ManxGS on January 28, 2017, 11:24:07 AM
Yep. All nipples open, all of them just incase there was some trapped pressure in the circuit somewhere. How do I test the pressure sensors? are they inside the ABS block or outside on the circuit somewhere? The fluid looked like fresh out of the bottle.
Title: Re: Another ABS problem
Post by: Ghiribizzo on January 30, 2017, 12:35:34 PM
Inside the abs block. As Alexm1 said - have you tried the bleed test on GS911? What did it say?
I'd expect a problem as you normally need to press very hard on the pedal to get the pressure up and hold to see if it maintains it.
But if the 'apparent' fault is over pressure (even if there isn't any in reality...) then the pump wont run and well - i *think* you would not be able to complete the bleed test.
Keep us posted.


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Title: Re: Another ABS problem
Post by: Ghiribizzo on January 30, 2017, 12:38:49 PM
I also wondered about brake lines. Ive changed plenty originals where they ballooned up - hoses coming apart internally. They can also fail where they wont release built up pressure. But you were able to get fluid through the rear wheel circuit?


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Title: Re: Another ABS problem
Post by: Old goat on January 30, 2017, 04:11:31 PM
Hello ManxGS
I hate to be the bearer of bad tidings, but your symptoms are exactly the same as I had on my 2005 R1200RT with the same electrically-assisted  iABS-1 system. I could not resolve it by any amount of flushing and clearing fault codes and I learnt that what I had was typical of a failure of the ABS unit, presumably of the rear brake pressure sensor though that was never made perfectly clear. The unit is not serviceable: BMW do not supply parts and there seems to be no one (in the UK at least) able to overhaul them. BMW abandoned this system after 3 years (I think) and so the bikes with it are now old and interest must be waning. Faced with the absurdly high cost of a new unit I had the ABS system removed so that the bike now has conventional non-assisted braking. I much prefer the brakes now. They are just as powerful but without the grabby operation of the assisted operation. It was done by Sherlocks and the result is that everything still works (speedometer, self-cancelling of direction indicators ...) and there are no brake warning messages, but there is course no ABS. You also lose the warning triangle in the instrument panel. The ABS unit (separated from the hydraulic parts) is retained and will reveal fault codes to a GS911, but these no longer matter. The cost on my bike was less than £450 – I think it varies a bit according to model. They did it in the day and lent me a bike while it was in.
The alternative approach is second hand unit, but it will be expensive and there will always be the fear of another failure.
Good luck
Title: Re: Another ABS problem
Post by: ManxGS on January 30, 2017, 11:43:45 PM
Inside the abs block. As Alexm1 said - have you tried the bleed test on GS911? What did it say?
I'd expect a problem as you normally need to press very hard on the pedal to get the pressure up and hold to see if it maintains it.
But if the 'apparent' fault is over pressure (even if there isn't any in reality...) then the pump wont run and well - i *think* you would not be able to complete the bleed test.
Keep us posted.


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Forgive my ignorance, and I've looked it up, but how do I perform a bleed test via GS-911? Cant find anything specific on the menus. I am beginning to think its defiantly electronic rather than mechanical. I did suffer a low battery problem last week and I tried to start without success. Hence the new battery. Came to work on the bike tonight and low and behold when I turned on the ignition both motors in the ABS unit ran, you can hear a definite twin motor note when all is fine during its self test. Leaned over and pressed the rear lever, motor ran. Hooray I cried. Plugged in the 911 and readings were nominal. 5 mins later all bad again. Spent all night then re-bleeding testing micro switches wiring and so forth. I'm done in.
Title: Re: Another ABS problem
Post by: Ghiribizzo on January 31, 2017, 01:36:12 AM
I'll get back to you tomorrow. GS911 is not 'here'...
When you say you were re-bleeding - can I ask how you did it?


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Title: Re: Another ABS problem
Post by: ManxGS on February 01, 2017, 12:39:42 AM
Just the best I can do with bleeding it manually via the levers, as the rear circuit motor won't run it's a little tricky but the front runs so primes up fine.
Title: Re: Another ABS problem
Post by: Alexm1 on February 01, 2017, 01:25:54 AM
ManxGS, I suspect you are not following the procedure for bleeding Abs brakes. The is a good write up on the ibmw site. Suggest you get it and try again.
Title: Re: Another ABS problem
Post by: ManxGS on February 01, 2017, 02:50:10 PM
I'm certain I'm not following procedure Alex, I've no motor to run up the rear circuit, but the front is running and bleeding fine. I've a known good ABS unit coming tonight to try, so I'll update with the results of that test.
Title: Re: Another ABS problem
Post by: Ghiribizzo on February 01, 2017, 06:54:35 PM
Sorry i was busy - didnt get back to you... did you try the brake pressure test on GS911?


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Title: Re: Another ABS problem
Post by: ManxGS on February 01, 2017, 10:38:25 PM
I didn't my friend. No obvious option on my GS-911
Title: Re: Another ABS problem
Post by: Alexm1 on February 01, 2017, 11:25:27 PM
I'm certain I'm not following procedure Alex, I've no motor to run up the rear circuit, but the front is running and bleeding fine. I've a known good ABS unit coming tonight to try, so I'll update with the results of that test.
The correct procedure is done with the battery removed and thus no motors running. You are wasting your time and money replacing an abs unit before you bleed it correctly. It is of course your time and money to waste as you want.
Title: Re: Another ABS problem
Post by: ManxGS on February 01, 2017, 11:43:39 PM
This guy seems to say very different about the battery. I thought these boards were supposed to help. I'm proper confused now.

http://www.ukgser.com/technical/nick/Brake%20bleeding%20(All%20BMW%20EVO%20systems,%20'04-'07).pdf
Title: Re: Another ABS problem
Post by: mike d on February 02, 2017, 01:09:11 AM
Quote
The correct procedure is done with the battery removed and thus no motors running.

Sorry Alexm1 never heard of that method before for the servo ABS system.

ManxGS the following shows the GS-911 bleed function is available on the PC/laptop version, but not on the wifi Web version

http://www.hexcode.co.za/products/gs-911/iabs-can

Mike 
Title: Another ABS problem
Post by: Alexm1 on February 02, 2017, 04:07:19 AM
I'm certain I'm not following procedure Alex, I've no motor to run up the rear circuit, but the front is running and bleeding fine. I've a known good ABS unit coming tonight to try, so I'll update with the results of that test.
The correct procedure is done with the battery removed and thus no motors running. You are wasting your time and money replacing an abs unit before you bleed it correctly. It is of course your time and money to waste as you want.
ManxGS, sorry, I did not mean to confuse you. It is me that is confused! I have a k1200 with iABS and I have been giving you advice about a completely different brake system. I jumped in without reading the question, again sorry.

Found this procedure, I hope it is the correct one for your bike

http://advwisdom.hogranch.com/Wisdom/service_abs3.pdf

Title: Re: Another ABS problem
Post by: ManxGS on February 04, 2017, 12:06:52 PM
Good morning. Update so far. Another known good and fault free unit removed from a GS and fitted.  Tried to bleed up and the same 1 motor startup is heard and no rear servo motor runs. The front one will run for about 5 or 6 lever pulls then stops. I read the codes and it's 24971, and description is now that the front circuit pressure is too high. Live data shows circuit pressures bouncing around the 50bar range again. What could possibly be on the bike that can affect the ABS units so much? Do they get controlled by the bikes ECU and not just their own one?
Title: Re: Another ABS problem
Post by: ManxGS on February 07, 2017, 12:11:09 AM
More tests done. Now it's been bled the best we can. Two iABS units with about 50000 miles use difference with now identical faults. No rear motor and internal pressures almost equal to each other. Unit put back on it's own bike, codes cleared and it works perfect.   What could possibly be wrong with my bike please????
Title: Re: Another ABS problem
Post by: Jughead on February 07, 2017, 01:54:38 PM
More tests done. Now it's been bled the best we can. Two iABS units with about 50000 miles use difference with now identical faults. No rear motor and internal pressures almost equal to each other. Unit put back on it's own bike, codes cleared and it works perfect.   What could possibly be wrong with my bike please????

Have you checked things like the rear brake switch and the contacts on the brake light (globe)?

Does the brake light work properly?  Some of the older bikes (1100/1150) used the tail lamp in the event of the brake lamp failing.  That is why I ask the question.  Do not just check that the brake globe lights up.  Physically remove the globe and check the contacts on the globe as well as in the fitting.

On certain of the older models, depressing the rear brake pedal whilst turning on the ignition, disabled the ABS.  So if the rear brake switch is not adjusted correctly, the system will think the brake is being depressed during the ignition on cycle.

The switch needs to be adjusted in such a way that the brake light comes on almost simultaneously to the pressure being applied to the system, if not fractionally before.  If pressure is applied to the ABS system and the brake light has not yet come on, it will generate errors.

Lastly, does the rear master cylinder work and return smoothly?  The same master cylinder is used on the early 650 ('00 - '07) and these often corrode inside, causing them to bind.  In the event of this happening, the brake light will go out (since it is operated purely by the foot pedal position) but since the master cylinder is slow in returning, the pressure is still maintained in the ABS unit, and thus registers an error.
Title: Re: Another ABS problem
Post by: ManxGS on February 08, 2017, 12:25:31 AM
Cheers Jughead. All those things tested. All perfect. Fault is still that the rear motor wont engage. Put it all back together and went for a ride to see how it goes. Brakes well on the front and ok on the rear. No ABS though. Bizarre codes when I got back though. Still the pressure too high in the rear, but now front headlight unit faults. low beam high beam and park, yet no disenable or noticeable lighting faults.  I'm still definitely thinking it's electronic/ECU failure.
Title: Re: Another ABS problem
Post by: schuppi on February 08, 2017, 01:31:09 PM
Hello
You wrote: Another known good and fault free unit removed from a GS and fitted.
And then the same fault readings?  Strange things.
Did you ever opened the cable harness? Maybe there is a cryptic short cut which lets the motor run?
Title: Re: Another ABS problem
Post by: ManxGS on February 27, 2017, 11:01:13 PM
Decided to give up, put it all back together, bleed it as best I could and run it for a little while. Two days in and everything started working fine. two day later and it's gone back to the same fault. Properly stressed with it.
Title: Re: Another ABS problem
Post by: ManxGS on April 14, 2017, 11:04:08 AM
OK. After much deliberation, I've decided that I'm going to remove the pump unit and run the bike with non assist brakes. I was wondering if anyone has done this and if there is a kit available somewhere? If not, getting the lines made should be straight forward, but its the warnings on the dash that will drive me mad.
Title: Re: Another ABS problem
Post by: ManxGS on May 27, 2017, 12:24:21 PM
OK. Further update is the ABS is now bypassed. Wish I'd done this sooner. The brakes are so much more user friendly. No sudden grab or headlights dimming on night runs. Rang the lads at MotorWorks and they sent me a kit to bypass the pump unit. The unit has to have a modification inside to remove the power to the two pump motors but the ECU within it must remain as it controls the speedo. Then I removed the dash unit, broke it down and blanked out the red LEDs indicating the Brake failure warning and the red triangle, but the amber LEDs remain to light up the warning triangle when the fuel level gets to reserve.   I'm a happy biker again.
Title: Re: Another ABS problem
Post by: mopedi on August 31, 2017, 11:54:50 AM
Do you have your removed modulator for sale?
Title: Re: Another ABS problem
Post by: ManxGS on September 01, 2017, 06:54:45 PM
Do you have your removed modulator for sale?
Do you mean the ABS unit complete?
Title: Re: Another ABS problem
Post by: mopedi on September 01, 2017, 09:14:54 PM
I presume you are using electronics to get tacho working or you upadted computers with non-abs one with some rewiring.
Do you have anything left from complete units?
Title: Re: Another ABS problem
Post by: ManxGS on September 02, 2017, 08:38:30 AM
I presume you are using electronics to get tacho working or you upadted computers with non-abs one with some rewiring.
Do you have anything left from complete units?
The complete unit stays on the bike. The control unit within the ABS pump is needed to supply signals to the dash for the speedo to work and also for turn signal auto cancel.    I do however have a complete second hand one I purchased to try and see if that would work. I did not so its for sale if you wish.
Title: Re: Another ABS problem
Post by: mopedi on September 02, 2017, 11:26:29 AM
You have second unit for sale. It would be perfect if you can send me values of pressure sensors and readout of module errors wit ECU info.  Where are you coming from? What would be the price for unit?
You can connect this spare unit to your R1200GS and read informations by GS911 by following steps:
1. remove + lead from battery
2. remove fuel tank
3. Disconnect ABS electronic cable and connect it to spare abs unit
4. connect + lead to battery
Note: if spare abs unit is coming from another R1200GS than you may expect just short start of both abs motors (about 1 second). If spare unit is defect or ECU NOT coded to R1200GS than you may expect both motors running continuously once you switch on ignition. Please not that brake fluid will come out at abs wheel connectors while motors are running and if any brake fluid was left in abs unit.
5. connect gs911 to your bike, turn on ignition and read ABS unit data

To connect your own abs unit following steps 4, 3, 2 and 1 with oposite functions as explained in steps.
 
Title: Re: Another ABS problem
Post by: ManxGS on September 02, 2017, 12:42:18 PM
You have second unit for sale. It would be perfect if you can send me values of pressure sensors and readout of module errors wit ECU info.  Where are you coming from? What would be the price for unit?
You can connect this spare unit to your R1200GS and read informations by GS911 by following steps:
1. remove + lead from battery
2. remove fuel tank
3. Disconnect ABS electronic cable and connect it to spare abs unit
4. connect + lead to battery
Note: if spare abs unit is coming from another R1200GS than you may expect just short start of both abs motors (about 1 second). If spare unit is defect or ECU NOT coded to R1200GS than you may expect both motors running continuously once you switch on ignition. Please not that brake fluid will come out at abs wheel connectors while motors are running and if any brake fluid was left in abs unit.
5. connect gs911 to your bike, turn on ignition and read ABS unit data

To connect your own abs unit following steps 4, 3, 2 and 1 with oposite functions as explained in steps.
 
You can make me an offer for the unit :)    I'm really happy with the setup I've got now so I'm not going to go through pulling the bike apart again to get those readings I'm afraid.  PM me if youd like some more details, pictures postage etc.
Title: Re: Another ABS problem
Post by: mopedi on September 02, 2017, 12:51:30 PM
I can not give you an offer without knowing its mentioned report. Without report I would  assume its bad and  with bad status the  price range would be in 100eur+shipping costs.
Title: Re: Another ABS problem
Post by: ManxGS on September 03, 2017, 07:07:35 PM
I can not give you an offer without knowing its mentioned report. Without report I would  assume its bad and  with bad status the  price range would be in 100eur+shipping costs.
I've sent you a private message.
Title: Re: Another ABS problem
Post by: Valentin on November 02, 2017, 09:27:33 PM
Hello to everybody !
I have a trouble without ending with my abs . I have K1200RS made in later of 2001. I change abs with other from BMW R1100S from 2005, wich model have same ABS pump and electronic board.
I do, bleeding secvence, and I connect battery. The trouble is:
When I turn the engine key switch the electric motor make a self control. But, don't stop. Electric motor for rear part still continue work. The front part servo work ok. When I use front breake the noise from electric and servo work ok. The rear electric motor noise don't stop, and the intonation of it don't change when I push levier for rear break.

Maybe someone from you can help me with any information about this.
Thank you very much, and sorry for my poor englese,

Title: Re: Another ABS problem
Post by: mopedi on November 03, 2017, 09:02:58 AM
Valentin, just to clarify your configuration, you have K1200RS with servo type of ABS so called iABS. As you mentioned "I change abs with other from BMW R1100S from 2005, wich model have same ABS pump and electronic board."
What do you mean by replacing K1200RS ABS with R1100S ABS?
There are at least two big differences:
- K1200RS ABS modulator is mounted vertically while R1100S is mounted horizontal so bleeding ports are different as well as braking fluid reservoirs. Bleeding process will not be successful with horizontal modulator being mounted vertically and you have to replace oil reservoirs too.
- electronics are differently coded which will result in permanent servo motor running when ignition is on - probably your case?!
It would be the best if you can get GS911 tool and send me/us report (memory readout and reading of pressure sensors) with original K1200RS ABS and original R1100S ABS than I can guide you with some steps .
Title: Re: Another ABS problem
Post by: Jughead on November 04, 2017, 09:04:20 AM
Hello to everybody !
I have a trouble without ending with my abs . I have K1200RS made in later of 2001. I change abs with other from BMW R1100S from 2005, wich model have same ABS pump and electronic board.
I do, bleeding secvence, and I connect battery. The trouble is:
When I turn the engine key switch the electric motor make a self control. But, don't stop. Electric motor for rear part still continue work. The front part servo work ok. When I use front breake the noise from electric and servo work ok. The rear electric motor noise don't stop, and the intonation of it don't change when I push levier for rear break.

Maybe someone from you can help me with any information about this.
Thank you very much, and sorry for my poor englese,

You need to take your bike to a BMW dealer.  They will "marry" the ABS to the bike.  Without doing that, the ABS will NOT work.