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2003 K1200GT - Brake warning, ABS shutdown

jrmull

New member
I had my first ABS failure that lasted about two miles running around town.

No strange noise, no leaks seen, just a dead brake like an old 1960's drum brake power.

Brake warning light flashing, so I knew something was a wrong. Nothing scary in particular. I was near home, so pointed that direction. A few miles later, everything returned to normal. Full brake power, power assisted front and rear. Continued my journey, then it happened again a couple miles later for a short 200 yards or so. Then back to normal. Weird.

Temp 45 outside today in Chicago.

GS-911 tool reports no faults. No faults to clear, No ECU engine complaints. More weird.

I thought possibly the rear brake fluids were over the MAX and too full. Tonight I lowered them to the middle of Max Min line. Fluids were changed about 200 miles ago. Right now brakes are firm and strong. Front brake reservoir is full possible too high as I can't see a line in the bubble. I didn't lower that one but could. I know it is not empty just at the top of the bubble viewer.

Air bubble in the ABS controller? Temperature change in the 50s vs 30s prior days? Reservoirs too full the problem? April 1st joke on me? Is this a common event?

Thanks for your suggestions.
 

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All brake systems, not just the wheel circuits, were recently flushed and bled?

The failure mode you describe sounds more like an electrical issue in the brake system, like possibly an ABS control module that has a loose, dirty, or corroded connection or connector. That would be the inexpensive fix, just removing/cleaning/reinstalling the connector. If it is not a connector, the you could have a problem in the ABS module itself and that’s an expensive replacement. Module Masters in Idaho *might* be able to rebuild a malfunctioning ABS module.

Good luck,
DG
 
Did you check both chambers in that reservoir?
attachment.jpg

Also I would double check the reservoir on the handlebar.
With clean fluid it may be hard to see the fluid line.
It might be too low instead of too high.
Look when turning the bars left to right or just remove the cap.
 
Thanks for the ideas. The second to last picture is the rear inside reservoir. The line is hard to see but at the Max line.

I will pull out some fluid on the handlebar to be able to check it, but I think it is full. Also check the connector once I find the location. That electrical sounds like the most likely. Bike is dry and indoor stored but can corrode. It sounds like having the reservoirs too high is not an issue. I wanted it normal filled anyway.

See if it reappears today.

john
 
The only reservoir that is monitored is the duel reservoir on your bike. Both need to be full or past full or they can throw a fault. Some will throw a fault at the max line or if the fluid is just below it. Check the floats in the duel reservoir.
 
Normal behavior from a too-low reservoir is to trigger the constantly flashing and alternating dash warning lights but to NOT drop into residual braking mode, where no boost activity is present. My money is still on an intermittent electrical issue (dirty or corroded connector block, loose or broken wire, etc.) or an impending failure of the ABS module. Still hoping for the former,

Best,
DG
 
51 outside today. Rode for an hour mixed travel, no failures today. I checked the handlebar reservoir and it was full above the window. I lowered the level to see it sloshing in the window turning the wheel. I don't have to guess anymore at least.

Regarding the float, the orange float is in picture 1 before I lowered the fluid line to middle of Max/Min. The float it is not floating on the top of the line. It is in the middle. Is that normal? Not sure it if matters but it flops around doing something. Not stuck in place.

For the ride, no faults seen. We have several slowdown humps in the side streets that I let the bike bounce a little. Just in case something is loose. Nothing found.

If someone can, forward any pictures of connectors that I should pay special attention to. I will do some ABS youtube research too. I recall a large monster connector on the side of the ABS. Max has a new part for $3k. ouch. Well lets hope for something different.

34 51 7 685 801 PRESSURE MODULATOR, PARTIAL INTEGRAL ABS $2937.81

I haven't monkeyed with that area yet but I do have ambitions to change the brake lines into stainless steel one. The handlebar brake line is pinched turning left due to risers being added but original brake line. It needs another inch or so on that line. Yesterday's failure occurred going straight and recovered same direction. I hadn't noticed it before, but I don't think it is related. I guess I can save my money on that project until the fault settles down.

Just wait and see for a constant outage. When it did go out, power assist was missing and the lever was mushy. Integrated was missing too where the front brake did not activate the rear. Stopped like an old 60's car that went through a water puddle, if you know the feeling. Once it recovered, the brake line was sharp and crisp. Nice hard braking when working. Rear brake the same. Hard when working, mush when not.
 
51 outside today. Rode for an hour mixed travel, no failures today. I checked the handlebar reservoir and it was full above the window. .

Did you check with the handle bars straight or turned to the left.
The manual shows turning the bars to the left when checking.
Top of the circle is the min mark.
 
Picture 1, Far left turned. Window full.
Picture 2, Centered wheel, small visual bubble
Picture 3, Far right turned, window line center

To remove the fluid, I turned to the left which makes it level (on the center stand too) take out the screws and extract. I pulled out a small amount (1 oz) about. Before, I could turn it far right and not see a line (or I don't recall one). When Centered, I couldn't see a line. Now I see a small line on the upper part to make me comfortable. The clutch side is similar visually for inspection.

No drips on floor or bike, so I don't think I am leaking fluid. Now with the ability to see the level in the window, I can check after rides any changes.

What is the story about the orange float. Purpose, position of the float for a working bike? Mine is in the center of the reservoir even though too full originally.

Not worried about the price of a new ABS unit, I have a plan B and plan C. Plan B is Buy a donor 2003 GT bike (same price). Plan C is find a Cliff. Always good to have a plan. Again, thanks for your ideas.
 

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ABS shutdown today after having the bike on the side stand visiting friends for an hour. I rode it about 200 yards, then shut off the bike. Kept the bike level with me sit-in on it, started it again and drove off. Light cleared and stayed clear for another 30 mins riding.

Maybe that orange float in the rear is flagging an error. A second person suggested corrosion on a connector as a likely. I guess I will take the plastic off and clean connectors next rainy day.

Advise welcome.
 
Maybe have a load test done on the battery.
One trip to California and back I would lose ABS every couple days.
The bike always sounded like it was starting fine but when I returned from the trip I had the Kansas City shop check the bike and the load test failed.
With a new battery my problem went away.
On my bike I did not lose the servo brakes, just ABS.
 
Maybe have a load test done on the battery.
One trip to California and back I would lose ABS every couple days.
The bike always sounded like it was starting fine but when I returned from the trip I had the Kansas City shop check the bike and the load test failed.
With a new battery my problem went away.
On my bike I did not lose the servo brakes, just ABS.

Lee,
You are absolutely correct to bring this up - this is often a forgotten item in troubleshooting iABS problems (ABS with servos).

Using an appropriate DC Amp clamp multimeter, I found out these 2 servo motors can create a system wide spike of 30 AMPS when running (front brake lever will activate both servo motors). This is a LOT of amps if battery is not strong AND the conditions are near engine idle RPM (lowest point of charge for alternator).

Unfortunately many users / owners do not understand this has nothing to do with being fully charged or not. An old / weak battery will create all sorts of subtle problems on a modern fuel injection vehicle - even more so on these power-hungry iABS models (iABS mainly installed on 2001-2006 for USA market).
 
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What is the the meaning of servo vs ABS ? I guess I am just lumping the two together. I know my 2003 K1200GT has "linked" brakes where front and rear work together using the front lever. ABS to me is generically the wheel will not lock up but chatter to stop without skidding.

What I see in normal mode is "power assisted" front brake power and ABS action as needed.

When the Brake warning light set off like this morning, I did not have power assisted. The front brake was mushy and like an old drum brake. Same with rear. Front brake did not have the whine and rear link.

So Servo means power assist?

Regarding my battery, it is a new MotBat 22amp fully charged in the 13.1 vt range. On a battery tender too. I will look next time at my battery meter that is attached when it occurs again.

Can someone send me a picture of your orange rear float inside the rear reservoir? Mine is dead middle of the tank. I am thinking the sensor there is reading low due the float not floating to the top. Makes it worse when on the side stand. I am going to side stand the bike for a while as see if that gets a consistent fault.

FYI using the GS-911, no faults are found.

ABS-N : -
Controller Type : ABS Brakes
Controller Name : ABS-N
Part No. : 076643651600
HW Version No. : 0
Coding Index : 0
Diagnostic index : 7565
Manufacture Date (YY/MM/DD) : 1025-40-04
Software Version No. : 5
Manufacturer : Reinshagen / Delphi
No Faults found :
 
A couple of thoughts.
Not certain, but I doubt that there is an ABS fault mode that results from too full reservoirs. Too low? Certainly. Too full might results in an overflow or leak, but I doubt it can fault the system.
The e-brakes we have on our bikes are more than linked ABS. The hydraulic circuits that originate at the control points (front and rear levers) don't communicate directly with the calipers. The fluid you pump by activating either brake is sent to the module, and the module takes that signal and translates it into a boosted signal that gets sent to the calipers.
It's designed with its own Plan B in the form of back-up "manual" braking should the electronics fail. That's the numb, 60's car drum brake response you've felt.

As others have suggested, the nature of your failures doesn't scream "hydraulic" to me. The intermittency sounds more electrical. That said I'd also run a quick check of the ABS wheel sensor gap as they could be set right on the edge, and are subject to slight movement in the course of a ride.
 
Thanks Jeff for the details on manual mode.

As you and other guys suggest, I will pull off the panels and review through the connectors related to the brakes. Also fill back up the rear reservoir. I see the rear fluid tank is a $140 part to replace if the float inside is somehow sticking or not floating.

On the education positive side, good to experience basic roadside problems. I see tons of similar ABS warning light concerns others have had. From low battery, low fluid, brake lights out, rear brake sensor, wheels dirty on the ABS sensor.

Time to dig in.
 
At $140 I'd have a real hard time stepping up to a new one. If mine leaked or was somehow damaged, I'd check the used parts sites for options.
If the float were simply not working, I'd be tempted to somehow lock it in an upper position, and live with it. It's only purpose is to warn you of low fluid levels. You can do that yourself by simply remembering to look at it.
Immaterial, as I doubt yours is the source of the problem.
 
When was the last time this bike had a complete brake system flush and bleed, either by a dealer or by following the DIY procedure available on the internet? The boosted brakes, aka “whizzy” brakes, require a very specific procedure to flush and bleed the brake system. Part of that process is a final pressure test that requires the dealer MoDiTec equipment or a GS911. Dealers charge $180-250 for the job and it’s worth the money if you have a good dealer with a tech who’s been around long enough to have been to service school on these systems.

Don’t worry about your fluid reservoir; if both sections are well above Min they are not the source of your problem, as a low fluid level will only trigger the alternating lights and will not shut down your boost pump. And if you overfill the reservoir, it can relieve excess fluid on its own through the hoses attached to the caps—it’s not unusual to see that happen when the caliper pistons are pushed back to install new brake pads.

The concerning issue you have is the complete shutdown of your boost system. Usually that’s an electrical issue as mentioned previously, a bad ABS module or module connection, or a problem in the boost pump itself. If this were my bike, I’d be starting by cataloging the light sequences you’re getting. From Anton Largiader’s website:

Gen OFF, ABS ON = Only residual braking in both circuits.
Gen OFF, ABS flashes at 1Hz = ABS not available. Pull-away test not completed.
Gen OFF, ABS flashes at 4Hz = Only residual braking function available in both circuits. Self-diagnosis not completed.
Gen ON, ABS off = Tail light/brake light defective.
Gen ON, ABS flashes at 1 Hz = At least one brake circuit without ABS.
Gen ON, ABS flashes at 4Hz =At least one brake circuit in residual braking function mode.
Gen AND ABS flashing alternately at 1Hz = Fluid level in Integral ABS too low.

That may give you a pointer in the right direction. Also, if this were my bike i’d be running it to my favorite trusted technician to have a flush/bleed/pressure test done as a baseline, and in case there is an air bubble in the ABS boost unit.

Good luck,

DG
 
When was the last time this bike had a complete brake system flush and bleed, either by a dealer or by following the DIY procedure available on the internet?

The first post said 200 miles ago. Since he mentioned the front reservoir I took for granted he did a full flush and bleed.
If the full flush was not done this would be my next step.
Even if it was done, I would be temped to do it again.
 
Problem solved. Rear brake micro switch not pushed. I adjusted the stop screw up higher to make it click when no pressure is on the pedal.

The GS-911 diagnostic tool didn't help in this situation. No fault codes even though the ABS was shutdown. I sent an email to GS911 support asking for some User usage pointers. I see some values on realtime mode but not an ABS fault code I would expect.

Anyway, nothing to do with the float inside the tank. Nothing about the bike on the side stand. Good news is I did purchase some electrical cleaner and electrical grease for shop material as I touch many of the connections. Good to clean them and prevent corrosion.

I did poked a small screw driver to look for a stuck float. They were ok and floating. Remove that from the theory list. I did top off the reservoirs over max. I was testing the side stand theory as the reason for the fault. That test led me to a way of consistently getting a failure, then ABS working then failure again. I did read some tips on the rear brake stop screw. I checked to see if the pressure plate slipped out of position, etc. I already had some problems with that screw and the brake light being on while riding.

I pulled up on the brake pedal it insure the micro switch was touched and turned on the ignition. Good slow flashing light. Turning off, when I push the pedal down and slowly released, the stop set screw didn't fully retract click the micro switch. Ignition on, fast flashing light and no ABS.

Lessons learned. Thanks for the assistance.
 
Good to hear you found the problem and it didn't cost big bucks to fix.
Thanks for the update.
 
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