Flashing abs light

Joined
Jun 17, 2018
Messages
10
Location
England
Sorry to bring this topic up again, i have read through the previous posts and followed advice given but i am struggling to resolve this problem.

I have a ST1100 CBS/TCS/ABS 2001 ex police bike with 55k. I have spent the winter replacing the alternator, swing arm, pads, coolant, discs, and tyres. once put back together took it for a ride and the red abs light flashed when riding. I looked into this and tried the following.

-cleaned front and rear abs speed sensors. checked clearances
-bleed front and rear callipers.
-checked and cleaned all fuses
-checked and replaced abs control unit.
-checked ECU
-audible sound of abs module initiating when turning key on
-checked and cleaned main earth.

Checked callipers after heavy front and rear braking and in both front and rear callipers the centre piston has compressed, therefore i am thinking that the CBS system/ABS front and rear modules are working.

When trying to find out fault code using previously mentioned procedure in other threads, no code is displayed. All is normal until the bike moves and then flashing starts. Put bike on centre stand and disconnected rear sensor red light then stand on. So unsure if this is identifying the rear sensor or general abs warning that abs system is not working. Reconnected started flashing as normal. Tried to remove rear sensor, absolutely seized in so unable to remove.

Also have read conflicting information from different threads concerning the flashing being normal or not?? so does anyone no if it is meant to flash when moving or not.??
Also if it is not and as it flashes when on centre stand with rear wheel rotating does this point to rear speed sensor?

Any wisdom would be greatly received !!
 
Be very gentle trying to remove the sensor. The mounting bracket has been known to break easily.
 
Can a resistance check be made on the sensors ? And the output of the sensor checked/measured when spinning the wheel ?
 
Have you done the procedure for clearing a code. When mine starts flashing I press the ABS switch and get the solid red light. When I’m stopped I turn the bike off then turn the ignition on whilst holding down both the traction control and ABS switches. Turn off the ignition and then start the bike again, that usually clears the light flashing.
 
Thanks everyone for your reply and help;

i did clean and replace the earth, the battery is good with 12v, i also disconnected the rear cable and cleaned with contact spray, so i don't think it is any of these things causing the problem.

Removing the rear sensor will be a nightmare and could cause more damage so will try and avoid that. Testing the continuity would be a good idea, but not sure if it would work at the rear sensor as the end is a magnet, but i will have a go.

The ABS and TCS buttons don't clear the fault or give me a fault code, not sure why, they could be defective. Will see how much they cost to replace.

Does anyone no what the flashing means? is it a diagnostic test signal? should pressing the abs button re set things? therefore indicating defective switch.
 
Yes the flashing light indicates a trouble code, you need to be able to retrieve the code to diagnose the issue. It can appear the switches don’t do anything. With the engine running, when you press the TCS switch is there an amber light come on at the extreme left of the ignition light cluster?
i’ve attached A photo with instructions on how to retrieve the codes and reset the computer. Have you tried this? You need to get those switches operating, that maybe part of your issues. Try again to retrieve the codes and then we can guide you through the process to resolve the issues.
E555F60C-1E51-4552-B01B-96C04EF24D1E.jpg83BAFADD-F0F1-4C8D-B4A8-044931543482.jpg
 

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Thanks kiltman, very useful information. Thanks for taking the time to upload those pictures. If possible could you send me the second photo again I would like to see info in table.

When turning the key all the dash lights light up as they should. The TCS light does not come on when pressing the button. The abs fault finding procedure also does not work when pressing the abs/tcs warning button.

I will into this this and track back the cables and see if anything is wrong. Sounds strange that both buttons have stopped working. Anyone else had this problem?
 
This may be of use. https://www.st-owners.com/forums/showthread.php?158284-ST1100-ABS-Fault-Finding&highlight=

My experience of problem finding on an ABS/CBS/TCS 2000 ST1100. Not the same problem that you are having, but the info may be useful.
Including a video of finding the problem code.

Post #1

And Plus 1 on that sensor bracket fragility issue. I was being very careful. I put a driver between the flange and the bracket. A really very tiny tap to try to ease the sensor up. I knew that cast alloy was brittle. But I was surprised when it snapped clean off.
 
Thanks John, useful link I did find it previously when searching the We for information.

Today i I traced the abs/tcs warning button and the tcs button back to there connectors, cleaned and tested for continuity at the female/battery side. Both ok. Then the switch side, abs/tcs warning switch was ok, tcs switch however did not seem to work. Had a look at wiring diagram, doesn’t seem to be much between connection tested and abs module unit and tcs/ignition control unit whatever and wherever that is. Also not sure where to find the earth for the switch’s.

Have ordered some replacement switch’s to see if they are the problem.

Anyone think of something I am missing?
 
Thanks kiltman, very useful information. Thanks for taking the time to upload those pictures. If possible could you send me the second photo again I would like to see info in table.

When turning the key all the dash lights light up as they should. The TCS light does not come on when pressing the button. The abs fault finding procedure also does not work when pressing the abs/tcs warning button.

I will into this this and track back the cables and see if anything is wrong. Sounds strange that both buttons have stopped working. Anyone else had this problem?
here,s the requested picture. This is for the Gen 2 ABS 1996 models and later.
F093691F-9706-4E24-907A-FBA989745F45.jpg
 
Then the switch side, abs/tcs warning switch was ok, tcs switch however did not seem to work.

If I remember correctly, the TCS switch isn't a switch as such. It is a 'push to make' or 'push to break' type switch. Probably the former. I think that all it does is to send a pulse to the ECU. It doesn't stay in the same position. Certainly on my 2000 model, the TCS was always on when the ignition was first turned on - regardless of what state it was in when ignition was turned off.
 
Thanks John, that’s good info. When I turn the key on and it finishes the initial sequence the red abs and red tcs stay on, I am also unable to turn the tcs on or off. Got some second hand switch’s coming. I hope that will fix it but will not hold my breath!!
 
Another shot in the dark.... check the main ground from the wiring loam. It's located on the frame by the folding grab rail on the left side or the left rail that holds the pannier. Make sure it's fastened properly.
 
Yea I did check and clean that main earth. I take it the switch’s are earthed there as well?? Hard to say looking at wiring diagram
 
Probably a dumb question, but it sounds like the bike was apart for service. Were the connectors to the panel switches plugged back in or plugged in securely? I know from experience if they are unplugged the system will blink the error light and of course you would not be able to retrieve any codes with the switches disconnected. From the thread it seems you've traced the cables to the other end but I couldn't tell if you confirmed at the panel?
 
I had similar issues where it would just flash but never report a code error, i tried the code clearance many times and really struggled with this. I kept trying to clear the code process as outlined in the thread above.

My feeling is that my machine had not completely exited the diagnostic mode and is actually reporting the spin test results, ie flashing with a constant beat when in motion to indicate that input from the ABS sensors front and rear. Easy enough to validate the theory.

Put on the stand and spin the rear wheel with the ignition on and the engine not running (then jack front up and check the front), if it starts flashing its not completely exited from the diagnostic mode. It would be a quick test which might move you along one step. How this would come about i am not sure, bad ABS switch so you cannot exit from diagnostic mode but if you have turned ignition off you should be out of this mode, anyway easy enough to check.

Also doing this might induce an error report (vast differences between input values front and rear ABS sensors) when on centre stand and spinning tyres by hand, which might start continuous flashing (even with wheels not spinning) and when you go through the Diagnostic mode you should then get an error code, but an error code now would probably be encouraging.

In the following video you can see me kicking the tyre round as part of spin test.

https://www.youtube.com/watch?v=vQ4cOCnUrmo&index=3&list=PL46dElEFxNELB6XdsFk-Joay7mRTf296O

Hope you get to the bottom of it..
 
Cheers Dean and WJbertrand, I will carry out that procedure later, thanks also for the video.

There has been some progress!

The second hand switches arrived this morning and they have changed things!! went through the diagnosis test and got code 2 (rear crank sensor system) and code 7 (electrical system ). So now if I do the same diagnostic test I get a very slow flash when stationary and when moving.

If I start up as normal I get a red abs and tcs light constantly on. Progress!

Couple of questions my good people:

- I can see the sensor at the bottom of the rear module, do i take the hole thing of to get to it or try and do in situ?
- How easy is it to re fit module, is bleeding done from calliper only?
- i ve read you can use a front sensor if you extend cable?
- Can you strip and clean the module?

Thanks everyone for your help.

I am off camping for the weekend so back on comms monday
 
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