ABS brakes not initializing or initializing when moving

[d_klingensmith]

Problem: 98 R1100RT approx 80K miles. At the start of the season, ABS brakes worked fine. After a few rides, a brake fault (alternating flashing lights) thrown and ABS quit. No "flashcode" per LED test procedure. Does reset with the grounding of pin 2 on the connection. Now the problem is that even though the lights are blinking correctly, when I pull away, the lights continue to blink, and I don't get the normal "marbles in a tin can" sound as the brakes initialize. Another few times, while riding and the ABS was working correctly, I hear the marbles, and feel a slight brake application, this may happen several times in quick succession, and then the ABS brake failure - lights blinking alternatively.

 

Had the bike to the local dealer who put it on the computer. They reset the error and said all was fine. The brakes worked correctly until a few miles from home, and then the same problem - the brakes tried to initialize while riding at about 60mph and then the alternating lights.

 

Any and all help and suggestions greatly appreciated.

Thanks,

Dave Klingensmith

[dirtrider]

Evening David

 

Seeing as you had the dealer put it on their computer this should be fairly easy to figure out.

 

 

What code or codes did they pull up?

 

[d_klingensmith]

D.R.

 

Thanks for the reply.

 

The dealer said there were no codes, and speculated that it may have been a "one time" drop in voltage that set an error code that has to be cleared by the dealer's computer. I don't believe him since it did the same thing on the way home - I had been moving for about 20 minutes and was actually on a freeway when it happened again. I reset the code by the grounding procedure, and the brakes initialized when I pulled out of my garage, only to go into the multiple reinitialization/error code by the end of the driveway. I called the dealer when I got home, and all he would say is that it would cost about $2K to change the computer and ABS pump and he wouldn't gaurantee that even would fix it. The dealer tech did say he ran all of the suggested diagnostics and did a "stress test" and everything checked out fine. Needless to say, I'm not impressed with the dealer's service department.

[KDeline]

Welcome to my world.

[Linz]

Well, I'm not sure whether I'd recommend to you what I did but, when my ABS-Servo pump failed (and it did fail) on my R1150RT, I bought a used unit on Ebay for $200.00 which was "in perfect working order".

 

I fitted it myself, the bike has done around 2000Kms since and it's working fine.

 

My alternative was to pay the Australian price for a new unit $4038.16 plus fitting or, to remove the ABS unit off it altogether. My replacement ABS unit was off a later model bike and the rather savage braking when using the rear brake has been substantially reduced.

 

I have no idea how long it will last for but I'm pleased I took the road I did. I'd look for a good used replacement, especially since the ABS units on the 1100's were not as prone to having problems as the 1150 units.

 

Linz

[Alfred02]

Over AUS4000,- dollars?...ouch.

I hope mine doesn't Kark it.

[Jim Moore]

I called the dealer when I got home, and all he would say is that it would cost about $2K to change the computer and ABS pump and he wouldn't gaurantee that even would fix it.

For that kind of money I'd probably pull the ABS relay and unplug the remaining light. I rode my RT a long way like that.

[Phil50]

I recon Linzs' solution is best. Are there any specialist BMW bike breakers in Aus?

 

 

[dirtrider]

Morning David

 

 

I guess I have a problem with your dealer’s observation.

 

If your unit had an ERROR CODE that had to be cleared that should have shown on his equipment.

 

Now the ABS controller can have a failure without setting a code as not all controller failures trap a code.

 

In any case, with no failure code(s) shown to the dealer and no flash code(s) available to you that usually means your ABS failure is not something normal like sensor gap, or low voltage, or ABS relay power.

 

An ABS problem like you presently have is very difficult to find on the ABS-2 system.

 

Start by going over both front & rear wheel sensors for being pulled too tight at zip ties, look for stretches or possible abraded areas. (kind of a long shot as you aren’t getting a sensor failure code)

 

Otherwise see if you can get some new brake fluid in the system including bleeding at the ABS controller. Then (if) you can get the ABS to work, while it’s working, go out on a gravel road and get into some low speed ABS events (be very careful when doing this). See if you can get the thing to ABS on rear then on the front. Maybe exercising the ABS controller pistons can move some crud and allow future correct operation.

 

While you have the tank off to bleed at the ABS controller maybe slide the cover up that covers the ABS power relay and verify the wires are tight and no obvious oxidation visible.

 

Otherwise if you can’t get the system to set correctly at every ride off you will probably have to disable the ABS system, or install new (or good used) controller, or take yours apart hoping to find a repairable problem (very low probability of success with this one)

 

[ElevenFifty]

Check your brake light ... make sure the contacts are clean and it is firmly seated. I chased an intermittently occurring ABS light for several days caused by a slightly loose brake bulb

[dirtrider]

Morning ElevenFifty

 

He has an 1100 with the ABS-2 system. It doesn’t control the tail/brake light like your 1150 I-ABS (wizzy) system does.

 

[Bob_Minor]

I went through this with a '96 RS some years ago. After a couple of trips to the dealer and a useless change of the ABS relay the dealer told me pump or brain, we're not sure which. In either case it was big bucks. I pulled the whole system and re-plumbed the brake lines to make it a non-ABS bike. With a 13 year old RT it makes no sense to fix the ABS with new parts.

[Michaelr11]

Problem: 98 R1100RT approx 80K miles. No "flashcode" per LED test procedure.

Using an LED to check for ABS codes, I can't get the code to show on the LED when I apply the one lead to the negative terminal. But, if I apply the lead to the positive terminal I am able to get the code to display on the LED. Try to view the fault code using the + instead of the negative.

[Michaelr11]

There's a good write-up on the ADV Rider website on disassembly and clean out of the ABS2 pump unit.

http://advwisdom.hogranch.com/Wisdom/BMW%20ABS%20II%20D&A.pdf

See if you are getting a fault 16 and you might want to try opening up the piston chambers and cleaning them out. I did this on my R1100RT and it's been working okay for 4 months now. I did have to have a piston pressure test of the ABS at the dealer after I did this work; once I did that the fault cleared and didn't return.

[d_klingensmith]

Michaelr11, and Everyone,

 

Thanks for all of the suggestions. I'm going to really dig into the bike tomorrow. I'll check all of the wiring first, and then if I don't find anything, I'll go into the piston chambers.

 

I'll let you know what I find...

 

Thanks.

[Jaguar]

I had ABS issues with my 2007 R1200R. The ABS light was on and off at different times until it came on for good and would not turn off. So I took it to my local BMW dealer. He said, if it was the ABS pump, it would cost around $2400 parts and labor. So I told him to check it out. If it was something minor, to repair it. If it was the ABS pump, DO NOT REPAIR IT. I refuse to pay $2400 for a new pump. Just disconect the warning light on the dash, I'll pay whatever shop fees and I'll ride my bike as a non ABS bike.

So the dealer called a couple days later and said that the ABS pump was dead. I said, do not fix it, I'll pick it up tomorrow. He said that he just spoke with BMW of North America and that they said they would pay for 75% of the bill. They would get me out the door for $600 parts and labor. So, needless to say, I got a new ABS pump installed.

Could BMWNA be thinking "liability"?

[AndyS]

...Could BMWNA be thinking "liability"?

No, just good will, and I'd say it was good will too.

 

Andy

[Danny caddyshack Noonan]

I'll go into the piston chambers.

 

I'll let you know what I find...

 

 

I did that last year with some temporary relief. Make sure the whole top area is clean and look for parts (I can't recall which) that come off with the cap.....maybe an o-ring and a spring.

[Phil50]

I had a similar experience 3 years ago. My warranty had run out a couple of years earlier but the dealer said they would ask BMW if they would provide parts as a goodwill gesture. They agreed and I got a new servo/ABS modulator (cost around 1200 GBP) free of charge. I just paid the labour charge and for the fluid used.

 

Interestingly the tech guy could not find a stored fault on my bike but he then did some tests and was so struck by the results he came to find me in the showroom for me to see the massive (almost unbelievable) pressure to my front callipers. Which probably explains why residual braking was working so well when I rode the bike to the dealer with the fault light on and no whirring from the pump.

 

Cheers

 

Phil

[d_klingensmith]

Well, at least some news, maybe not progress. I checked all of the wiring and didn't find any pinches, breaks or anything unusual. Took the tank off, and was going to dig into the pistons, but unfortunately, I don't have a socket to fit the fittings to get access to the pistons. (my sockets are all too thick to fit into the recess. I'll be lookin for a socket to fit.) Hitting that roadblock, I did take out the bleeders and flushed the brakes with new fluid - lots. I did notice the inside of the front piston under the bleeder was dirtier than the rear. I cleaned what I could, bled the brakes multiple times. I've got great brakes, just not abs. Tested, and no change. I reset the lights by the grounding method, and the brakes did initialize and work for about 50 ft. I did get the front and rear ABS to kick in before the system initialized when moving, and then the blinking lights again and no ABS.

 

Today, I triple checked the rear wheel speed sensor, and it seemed a little big on gap. I removed one of the shims and put it into tolerance. Checked the whole way around the wheel and it was good. Tried to reset the error code and it would not reset. Rode the bike around the block and tried to reset again. No luck. I checked and now I'm getting a 4 flash code - rear wheel speed sensor fault. I can't get the system to reset with the grounding method. I did put the shim that I had taken out, back in, and cleaned the connection for the back sensor. Still cannot reset the alternating lights, and still get the 4 flash code on my led tester.

 

Any additional ideas out there? What are the symptoms if a wheel speed sensor is going bad? If I can't figure it out soon, what is the best way to configure the bike so the abs isn't working? Remove the relay, or just cover up the flashing lights with tape?

 

Thanks for all the help.

 

[Danny caddyshack Noonan]

Dave

I was playing with my sensors this weekend and found the following. A DMM with Hz capability doesn't seem to be able to pick up the sensor. Neither series or parallel got me anywhere. I did show 135 Ohms on each. Then, while reading that, I spun each wheel to see what would happen. The digital reading fluctuated a good Ohm or two about the 135. That may, possibly, be a way to check your sensors.

 

BTW, the way I did this was to take some 14 or 16 gauge multi-strand wire, about 4 inches long. Pull out somewhere around four strands from each. Then using needle nose pliers, slip each over a pin in the sensor connector.....carefully. With a bare wire on each end, you can alligator to your DMM or analog meter.

 

You can also do the Ohm reading while screwing with the wire harness to see if it goes open transiently.

 

Keep trying the reset. Mine seems to be a bit finicky with the grounding and resetting.

 

IMHO, I wouldn't worry too much about the socket. If you have a wrench that'll fit, I think you'll be fine. The caps are bore seals not face seals so, exact torque isn't important to sealing.

 

 

[Michaelr11]

The top of the ABS Hydro pump unit, just under the bleeders requires a 6 point 22mm deep socket to grasp those nuts. They are recessed so the end of the socket has to be thinned for it to fit into the recess where the nut sits. If you have a lathe or a nearby machine shop this can be done in a few minutes. When I did mine, I used a hand file and it took me at least an hour by hand to trim the socket until it fit.

 

I would also suggest you go to your dealer and have them run a piston pressure test on the ABS, and then have them clear the fault code. The pressure test runs the piston up and down through more travel than it normally goes. It will probably fail the pressure test, but might very well run okay once the code has been cleared.

[tpfeffer]

Has anyone had success in disassembling and reassembling the ABS Hydro Unit?

[Clive Liddell]

The same as others above my ABS failed in the middle of a 4500km trip and the flashing lights accompanied me all the way home.

 

After much deliberation and resetting only to have at fail again some 50 meters down the road I have decided to unplug the ABS relay (stops the top flashing light) and cover the bottom light with black tape.

 

I remain well aware of my present lack of ABS and apply extra caution in certain conditions.

[tpfeffer]

Clive - thanks for the resposne.

 

I am in the middle of trying to diagnose the cause and attempt to fix my ABS fault and looking for forum experience on what has worked for others. Especially, I am curious whether anyone has successfully "fixed" the problem by disassembly and cleaning the actuator.

 

Curiously, I found the gap between the ABS sensors and the sensor ring less than the minimum of 0.018 inch using the go/no go gages that came with the tool kit. I had to insert a 0.003 inch shim to the rear and two shims totaling 0.006 inch to the front sensor. Afterwards, the rear gap was fairly consistent all around the perimeter and within limits. However, the front gap varied from too tight for the minimum gap gage in one location to too loose for the maximum gap gage 180 degrees around the ring. Perhaps that is the cause of my codes but why it would occur after 10 years is beyond me. I wonder if anyone has attempted to remove high spots from the sensor ring with judicious sanding???

 

I bled the brake fluid at the actuator. I was kinda hoping to see gunk come out which would signal the cause of the problem, but it was clear and with no air. Oh well.

 

I have opened the housing for the ABS Motor relay and am trying to decide how to get it apart. The exploded view diagrams make it appear that the relay plugs into a socket, but that isn't readily apparent when I look at the actual device.

 

Any suggestions or advise is welcome. I am NOT going to spend the +$2000 to replace the actuator. So, unless someone comes up with a good recommendation, I am likely to partially disassemble the actuator to "clean" it as documented by others on the AdvRider forum. At this point, I haven't got much to lose.

[Michaelr11]

Has anyone had success in disassembling and reassembling the ABS Hydro Unit?

Yes. I did. I followed the write-up on the ADV Rider Hall of Wisdom, then had the dealer run a piston pressure test. No faults for 4 months. Permanent fix? Probably not. I expect that the ABS2 Pump will fail again. At that point I'll either do the same fix, or I will replace the pump with a used one - There are about a half-dozen of them right now on ebay with prices from $250 to $600.

[tpfeffer]

Has anyone had success in disassembling and reassembling the ABS Hydro Unit?

Yes. I did. I followed the write-up on the ADV Rider Hall of Wisdom, then had the dealer run a piston pressure test.

Michael,

Just to be sure, you say you fixed the ABS pump, but do you mean the procedure on the hydro unit (actuator) of removing the bleed nipples, ball, spring, valve body, and piston?

 

Did you find any visual evidence of dirt or debris that would cause the piston to stick that you cleaned? How did you "clean" these parts?

 

I presume you DID NOT drain the brake fluid first. Did you have any problem bleeding the system?

 

What is the purpose of the piston pressure test? I understand it "works" the piston through a wider range of motion that it would normally experience in operation. Is this test required or recommended??? Did the brakes function OK before the test...that is, were you able to ride the bike to the shop or did you trailer it?

 

Anything I need to watch out for that is not covered by the procedure?

 

Lots of question. I appreciate your help.

[Danny caddyshack Noonan]

I have opened the housing for the ABS Motor relay and am trying to decide how to get it apart. The exploded view diagrams make it appear that the relay plugs into a socket, but that isn't readily apparent when I look at the actual device.

 

Tom

once the slide cover has been lifted off the relay, pull the relay straight out. Do not remove the hex nuts. Once out, the relay can be removed from it's socket by removing the two Torx screws. One holds a wire lug and the other just keeps it in the socket.

 

I took mine out and tested it with battery power to make sure it was working.

 

Total time: 5 minutes. I rank it as a single Chef's Hat job....as opposed to 5 Chef's Hats for very difficult.

[tpfeffer]

Peter

Did you happen to get any resistance measurements across the coil?

[Danny caddyshack Noonan]

didn't think about measuring the coil. Just wanted to see if it clicked.

 

BTW, it's $130 or so.

[Michaelr11]

Michael,

Just to be sure, you say you fixed the ABS pump, but do you mean the procedure on the hydro unit (actuator) of removing the bleed nipples, ball, spring, valve body, and piston? Yes.

 

Did you find any visual evidence of dirt or debris that would cause the piston to stick that you cleaned? How did you "clean" these parts? Very little, but there was a little discolored brake fluid that never got flushed during a bleed. I cleaned the piston itself and the well that it sit down in - with brake parts cleaner on a rag for the piston, with brake parts cleaner on a Q-tip for the well.

 

I presume you DID NOT drain the brake fluid first. Did you have any problem bleeding the system? No, I left the brake fluid in the lines and left the master cylinders closed. The ABS pump is the highest part of the rear brake circuit, so opening the top of the rear circuit lets the brake fluid drop down towards the caliper and the rear master. It took some pumping and some vacuum to get the air out of the rear circuit after it was closed up.

 

What is the purpose of the piston pressure test? Is this test required or recommended??? Did the brakes function OK before the test...that is, were you able to ride the bike to the shop or did you trailer it? After I finished cleaning he pistons and closing it up, I bled the brake lines to make sure there was no air in the lines. I had very firm pressure at both front and rear brake levers. But, no ABS - it still was failing the initial test and throwing an ABS Hydro fault code. I tried resetting it, but it would throw a new fault as soon as I rolled away. It was only after the dealer pressure test that the fault code stopped. I rode the bike to the dealer, good brakes just no ABS.

 

If you want to take a chance without cracking open the ABS, just try having the dealer do a pressure test. But you have to insist that they force the pressure test more than once. The computer will do a pressure test as part of it's process when it reads the fault code. Make sure they look at the menu and there is a way for them to manually do another pressure test.

Anything I need to watch out for that is not covered by the procedure?

 

Lots of question. I appreciate your help.

[tpfeffer]

didn't think about measuring the coil. Just wanted to see if it clicked.

FYI, I measured 22.3 ohms which seems to be in the ballpark. Thanks for your help.

[tpfeffer]

Thanks Michael, you have been a lot of help.