05 R1200RT Servo Problems/Removal

My 05 1200RT has started having brake servo problems. The first time was in rush hour traffic in San Francisco. The brake warning started flashing and the rear brake pedal was extremely hard, but the front brakes seemed to work fine. I was able to get to a safe spot and after turning off the bike and restarting it the fault cleared. All was well for about 15 miles and it did it again. A second restart cleared the problem and I made it home. GS-911 shows a "high-pressure" fault.

On my last ride, this occurred several times, sometimes with the rear brakes and sometimes with both brakes. I'm now more than a little concerned about my safety.......

It seems like my options are either have the dealer fix it, which aside from the hassle of an intermittent problem, looks like it will cost ~$3K or more (the nice weather makes everything cost more in CA), or remove the system.

I've spent a fair amount of time searching for information on removing the system and it looks pretty easy on a non-CANBUS bike, but I haven't found anything for a CANBUS bike.

Can anyone help me out with a procedure? (Any chance just re-routing the hydraulics to bypass the ABS system would work, although causing alarms?)

Thanks, Mike

promptcritical said:

My 05 1200RT has started having brake servo problems. The first time was in rush hour traffic in San Francisco. The brake warning started flashing and the rear brake pedal was extremely hard, but the front brakes seemed to work fine. I was able to get to a safe spot and after turning off the bike and restarting it the fault cleared. All was well for about 15 miles and it did it again. A second restart cleared the problem and I made it home. GS-911 shows a "high-pressure" fault.

 

On my last ride, this occurred several times, sometimes with the rear brakes and sometimes with both brakes. I'm now more than a little concerned about my safety.......

 

It seems like my options are either have the dealer fix it, which aside from the hassle of an intermittent problem, looks like it will cost ~$3K or more (the nice weather makes everything cost more in CA), or remove the system.

 

I've spent a fair amount of time searching for information on removing the system and it looks pretty easy on a non-CANBUS bike, but I haven't found anything for a CANBUS bike.

 

Can anyone help me out with a procedure? (Any chance just re-routing the hydraulics to bypass the ABS system would work, although causing alarms?)

 

Thanks, Mike

Morning Mike

You can by-pass the ABS servo controller & plumb in conventional brake lines from master cylinders to brake calipers. This won't mask or turn off the dash warning light though.

If your remove the entire ABS servo controller you will lose your speedometer & brake light. Easy enough to get the brake light back working with new brake switches, or a relay to reverse the present switch control input/output. On the 2005 you might have to run a separate taillight circuit to the rear. But still no operational speedometer.

You can remove most of the ABS servo system but retain the electronics box that is bolted to the ABS servo controller as that should condition the speed input & drive the factory speedometer & should allow brake light/tail light function (you will need to build a block-off plate to seal that electronics box from moisture). You will still have a dash warning light so will have to mask or disable that somehow.

If you don't need a functional speedometer or functional cruise control (ie ride with a GPS for speed indication & don't have or use cruise control) then the ABS removal is much easier.

Thanks!

If I re-plumb the hydraulics to bypass the servo, what do I do with the in/out lines into the servo controller? Can I just block them off? Just drain all the brake fluid out of the servo?

Mike

promptcritical said:

Thanks!

 

If I re-plumb the hydraulics to bypass the servo, what do I do with the in/out lines into the servo controller? Can I just block them off? Just drain all the brake fluid out of the servo?

 

Mike

Morning Mike

That is a good question. You don't really want to leave anything open & unplugged, if a servo would ever come on it would spray paint removing brake fluid all over the place.

If you drain the servo reservoirs then the dash light will definitely stay on due to low fluid level warning (you could probably jumper the reservoir level sensors if you drained them).

If you leave fluid in the controller & plug the lines then the line plugs must be very high pressure capable. (maybe plug them with threaded coupling/plugs where the lines terminate at original junction blocks) --you probably don't want to cut or damage the original metal lines as they are expensive if you ever decide to repair the ABS system.

If your dash light stays out then just plug the inlet & outlet lines. If the dash light is lit even with the ABS controller still plugged in & fluid reservoir sensors jumper then unbolt the ABS controller electronics box & unplug the internal servo motor tape then bolt the electronics box back on (this should prevent the servo pumps from ever running).

Thanks DR!

If I could figure out how to do it, it seems like removing power to the servo motor(s) would be the best alternative if that doesn't trigger alarms or other problems. Since the servos are fairly high power, is it a safe assumption their power comes from the two plugs on the left hand side of the ABS/servo unit and not the multi-pin connector on the right (#7 not #3 in the attached pic)?

Mike

Thanks DR!

 

If I could figure out how to do it, it seems like removing power to the servo motor(s) would be the best alternative if that doesn't trigger alarms or other problems. Since the servos are fairly high power, is it a safe assumption their power comes from the two plugs on the left hand side of the ABS/servo unit and not the multi-pin connector on the right (#7 not #3 in the attached pic)?

 

Mike

Evening Mike

#7 (both) are the reservoir fluid level sensor connections. All the power (12v B+) & (12v Ign switch B+) goes in through the #3 connector.

Removing power to the servo motors will not sound any alarms be will put the dash warning light on.

Starting to understand the term "The Oracle".....

Looking at the attached (rudimentary) writing diagram, it seems the two level sensors are wired in series, so is it safe to assume that I jumper across both #7 connectors and drain the fluid the alarms won't come on and I don't have to worry about having a high pressure plug on the lines?

Specifically, with no fluid in the unit, nothing should trigger the servos to turn on, but if they did, would that be a problem (trip a breaker, cause a fire, etc)?

Starting to understand the term "The Oracle".....

 

Looking at the attached (rudimentary) writing diagram, it seems the two level sensors are wired in series, so is it safe to assume that I jumper across both #7 connectors and drain the fluid the alarms won't come on and I don't have to worry about having a high pressure plug on the lines?

 

Specifically, with no fluid in the unit, nothing should trigger the servos to turn on, but if they did, would that be a problem (trip a breaker, cause a fire, etc)?

 

Evening Mike

You can jumper across the level sensors & that should satisfy the low fluid level warning but I can't say for sure if the servos will stay completely off. It's possible that a brake switch input could trigger a servo run (main servo pump output pressure is controlled by the ABS controller internal pressure switches & reaction pistons). I guess without testing I can't give you a positive on the servos not coming on (they just might). You might be able to test this by (just) unplugging a brake switch then seeing if a servo pump will come on. This should give you brake switch discreet with no pedal or lever initiated pressure on the internal pressure switches (the brake switches are reverse logic so are N/C & go open at brake lever/or/pedal apply).

I'm more familiar with the 1150 (non CanBus) era I-ABS systems where the brake switches report directly to the ABS controller. On the early 1200 I-ABS bikes the brake switches report to the ZFE (chassis) module then on to the ABS controller over the CAN (CanBus).

Your biggest worry is a possible servo pump run with fluid in the system & improperly plugged brake lines (fluid spray issues).

If you jumper the reservoir low fluid sensors that could allow servo pump run even without fluid in the system so (if they come on) you would be running the servos with no fluid to lube the pumps (might eventually lock the pumps up)

I'm kind of navigating in uncharted waters here as I haven't ever (just) by-passed the ABS controller & left the servo pump part in the bike connected to power on an early 1200 I-ABS bike.

If it wasn't for the speedometer & cruise control part then you could probably just unplug the main ABS controller connector. If you try to just remove the B+ 12v circuit going to the ABS controller (leave the 12v ignition circuit unmolested) I'm pretty darn sure that you will get a dash failure light triggered by a controller motor circuit voltage low.

Even so you still might get a dash warning light if the ABS controller gets a brake switch signal but the pumps won't come on in response (I just don't know for sure on this)-- wouldn't take long to test it though.

Bottom line-- you need the ABS electronics (powered up) to process the wheel speed output signal & send the processed speed signal out over the CAN to the speedometer & ZFE electronics.

Thanks! Much appreciated! Off to gather parts......

Mike, there is an excellent you tube video on the absectomy procedure, follow that and you can't go wrong. You will need to repurpose one of the brake lines to connect the rear brake master cylinder to the connection at the front of the swing arm. Also turn the manifold block near the forks upside down and cut off the locating tit.

All the best, your brakes will be better, more charge in your battery and the bike a couple of kgs lighter.

Dave Glen

Australia

Mike,

I know I am replying and waking up an old post, but I may be heading down the same path on removing the ABS/Servo unit, keeping the circuit board end to keep most things happy.  I was wondering if you have any input on how this turned out?  Any lingering issues, maybe some suggestions?

Gary

I removed the servo/abs some months ago from my 05RT. Solved the warning light issue by splitting the instrument housing and painting over the flashing LEDs with black nail varnish. All is working fine, and I ride most days.

Glad to hear!  It is great to know that others have had good experiences with it without the booster.

I almost went that route, but I decided to order the RH Electronics Second Life "Lite".  It is a replacement for the standard electronics on the ABS pump assembly, which still has a functional warning light that can be set to do one of four options during first start up.  They also sell the full version, which includes the electronics box plus a plate to make replacement easy as you just hook up the existing lines and avoid any front and rear line rework.  The lite version is cheaper and I found that you can purchase front (34327682345) and rear (343227671408) jumper lines from the R1200ST, non-abs model, for the front and rear.  The front is easy, just remove the two lines to the abs, install the jumper.  The rear jumper to the rear master may not fit perfect as the cylinder mount is in a slightly different location from the swingarm pivot.  I still think the jumper line could be tweaked to work.  If not, I will repurposed an abs unit line.  I will need to shorten, rebend, and reflare it.  The issue is BMW's special plug and clip into the jumper location near the swingarm pivot, like the abs line connections, so you need something to maintain that connection if you want to make it look as intended.  I had hoped to have the parts by now, but shipment from Germany on the RH unit can be over 3 weeks to the US.  I ordered the "brake pipes" from Max BMW, unknown when I will get them.  Contacted them by email, after receiving a confirmation, no response.  I will have to give them a call and see if any of the parts had to be ordered from BMW, which is likely.  This whole Covid thing is messing everything up.  For now, I am taking the time to do some other preventitive maintenance.

My main concern is the future of selling or trading in, will all of this be a plus or minus on value.  A dealer would probably look at it as a minus or even a risk if they don't put it back to factory.  Probably a good reason to keep all of the parts to put it back.  A private purchaser, if they understand the ABS history on the RT, may look at it as one item they shouldn't have to be concerned with.

I may get ambitious in my retirement and look into what it takes to rebuild the pump assembly!  Since mine leaks and didn't appear to have any pressure switch problems, it may just be some piston seals or something not too serious.

@Chester RT what happens when something goes wrong on your bike and the system would try to warn you but you will not see the warning light because it's painted black?

@Tech1 please keep us posted how the second life kit works out for you. That is my go-to option if my ABS unit fails. Regarding the dismantle of the unit, I recall seeing someone pulling it apart. I am certain it was the same unit as ours and what is fitted to the R1200 CL/CLC as well. I don't have the time right now to go through my bookmarks, but will do when I get home from work.

Ok, looked through my bookmarks and found the following:

and

Good luck.

On 3/23/2018 at 2:24 AM, promptcritical said:

Thanks! Much appreciated! Off to gather parts......

4 years on, I know......but I'm intrigued and I've just bought 1 with the same issue, did bridging the level sensors put the light out?

14 hours ago, warbler 675 said:

4 years on, I know......but I'm intrigued and I've just bought 1 with the same issue, did bridging the level sensors put the light out?

Morning warbler 675

What year is your 1200? There is a BIG difference in braking function & operation between the 2005 (I-ABS) 1200RT info in this thread & the later (2007 up) 1200RT (I-ABS gen2) motorcycles.

Thanks for the input DR

  I've just bought a 2006 RT, it was cheap because appears to have typical issues.

ABS/servo is mechanically bypassed with flashing dash lights, TBH I haven't stripped to have a look, it has tape on the dash.

O2 sensors I believe, have some sort of  eliminator/resistor.   Much better to replace, I would have thought?

Owner complained of parasitic battery drain. I've measured this at 55mA, slightly high, I know but it's baltic in the street, so I didn't really hang about to let it settle. I think the starter is lazy, got a S/H one coming, that I'll bench test/strip before fitting.

Seeing a BM indy guy tomorrow for a rear tyre and a look over, who I'm sure has software & knowledge so will be better informed.

Again, thanks for getting back to me, bikes been a zero degree street since I bought it, lithium (isolated) battery holds 12.6 V but wouldn't start without jump off my big alternator van, running. Manana, manana. (hoping for a couple of degrees temp)

Afternoon warbler 675

ABS/servo is mechanically bypassed with flashing dash lights, TBH I haven't stripped to have a look, it has tape on the dash.----  Does your speedometer still work? 

O2 sensors I believe, have some sort of  eliminator/resistor.   Much better to replace, I would have thought?---- You should address this as the 1200 Hexhead doesn't have a very defined open loop map.  

Owner complained of parasitic battery drain. I've measured this at 55mA, slightly high, I know but it's baltic in the street, so I didn't really hang about to let it settle. I think the starter is lazy, got a S/H one coming, that I'll bench test/strip before fitting. ---- Does that motorcycle have a factory alarm? If so there is a 4.9Ma draw even with the alarm turned off (even more with it activated).

Normal key-off parasitic draw is 2.5-3.0 Ma (no factory alarm) but you have to test for that correctly as you can't JUST unhook the battery cable then hook up your voltmeter. You need to allow the bike to sit after key-off for about 1/2 hour,  THEN hook your voltmeter up between the battery post & cable end, THEN disconnect the battery cable. (this prevents onboard modules from coming alive & skewing the reading). I usually disconnect the (+) battery cable, then install a decent gauge jumper between the battery post & the removed cable end, then hook up the voltmeter, then allow it to sit for the 1/2 hour, THEN unhook one end of the jumper & take my readings. 

Seeing a BM indy guy tomorrow for a rear tyre and a look over, who I'm sure has software & knowledge so will be better informed.

Again, thanks for getting back to me, bikes been a zero degree street since I bought it, lithium (isolated) battery holds 12.6 V but wouldn't start without jump off my big alternator van, running.---- You might try bringing the headlight on for short while before trying to start (sometimes this load will warm the battery enough to give you a short engine cranking).  See if headlight will come on if you hold the flash-to-pass (or whatever it is called in your country). That works on some Hexhead bikes. 

Thanks for the flash to pass tip, 

I'll let you know how it goes.

Oh, speedo works.

26 minutes ago, warbler 675 said:

Oh, speedo works.

Evening warbler 675

With the speedometer working then the wheel speed sensors still go through the ABS module so it knows you are moving. 

If the brake light inputs still go through the ABS module then it will difficult to mask the dash fault-light as the ABS module will see brake input but the internal pressure sensors will show no pressure increase. Plus the servo pumps will not run so it probably won't pass the ride-away test. 

If you disconnect (and properly terminate) the CAN (CanBus) at the ASB module  that might keep the dash light out but you will then lose your dash speedometer/odometer reading.

I'm just not sure on how to mask that dash fault light short of some sort  complex ABS module masking circuitry or cutting one leg of the LED warning light.     

I have been watching the discussion and thought I would mention that these issues are what the RH Second Life Kit address.  It replaces the BMW ABS/Servo controller board with a circuit board that maintains the functions of the brake lights & speedometer and alters the function of the warning lights.  Negatives: no abs (you already have it bypassed), cost (but less expensive than a new oem servo for sure), availability from Germany(?).  Positives: no warning lights (not sure if it passes thru speedo or brake light issues?), removal of the abs/servo for less weight, and my primary reason I did it, long wait time just to find out if it could be repaired by Module Masters.  I would have had to either buy a replacement at almost the total value of the bike in good working order or wait a minimum of 6 months for repair.  I have put about 1.5  riding seasons on it (maybe only 8K miles), with no issues.

Snow overnight, so postponed further investigation until Monday.

Baulked at the cost of the 2nd life kit so far.

Yeah, that is why I did the "lite" kit and made my own bracket that used the BMW fastening locations and rubber mounts.  After struggling with the rear brake direct line I was starting to think that I should have just spent the money to retain all of the factory lines, but I got it working well.

I will watch to see what you find out.

I have an 05 model RT   and was aware of this issue.  Then on YT I noticed this vid,which maybe of help to whoever!    also in the UK     Motorworks sell a bypass kit...     

Quote

I have an 05 model RT   and was aware of this issue.  Then on YT I noticed this vid,which maybe of help to whoever!    also in the UK     Motorworks sell a bypass kit..

Morning Phil

I quit watching at the first signs of using copper tubing for brake lines as using copper tubing for brake lines demonstrates a total lack of brake system understanding. That is a dangerous thing to do as copper tubing is not rated for braking type pressures. 

17 hours ago, dirtrider said:

Morning Phil

 

I quit watching at the first signs of using copper tubing for brake lines as using copper tubing for brake lines demonstrates a total lack of brake system understanding. That is a dangerous thing to do as copper tubing is not rated for braking type pressures. 

 

  

I questioned copper tubing too when I watched the video.  I decided to look into the source of where he bought the hardware and look up the brake line and adapter.   Have a look here:  https://www.motorworks.co.uk/rigid-brake-line-bra89991-1.html and https://www.motorworks.co.uk/brake-hose-adaptor-bra79297-3.html .  No mention of the tube material but it has a copper color to it.  After looking into brake line material, it is probably seamless copper-nickel (NiCopp), now a common replacement brake line material and is rated for DOT approved for hydraulic brakes.  You can also check this out:  https://4lifetimelines.com/blogs/knowledge-garage/are-copper-nickel-brake-lines-safe .

With how familiiar you are on other BMW models, you may have been aware that the rear coupler adapter was availabe that didn't require the special BMW clip retained brake lines.  I wish I knew.  I spliced my rear brake line to retain the original adapter, although not really visible, I know it is there and it is a little kludgy.  I ordered the brake line and adapter, have not installed them yet.  If I see an issue, I will report back!