95 ABS/TCS with ABS problem

Joined
Jun 23, 2005
Messages
3
Location
San Jose, CA
My 95 ST1100A was tipped over by my neighbor's car. Rather than contacting me, he and his wife attempted to hide their mistake, by lifting it back upright. They managed to do so, but it took six tries, and the first five created more damage to the right side of the bike.

Their insurance paid $4500 to repair the broken tupperware, right mirror and other damage. I had a small local shop repair it, because the dealer(s) weren't interested in working on a 95 bike.

A month later the ABS light came on a few times. I pressed the ABS switch to steady the light, and it seemed to be Okay the next time I started it. After a few weeks it started blowing the 20A fuse at the bottom of the ABS fuse box. I've replaced the fuse a few times, but it blows as soon as I press the starter button.

I've used the bike for months, but that light is annoying and pressing the ABS button is wearing the lettering off the button.

I purchased a Honda's ST1100/A and general shop manual a few weeks after purchasing the bike in 1995. I've searched everywhere looking for the shop manual, because I remember seeing a diag chart and codes, but I can't locate my ST1100 manual, just the general shop manual.

What are the steps to access the codes? I found references to a site (http://www.pan-europe.utvinternet.ie/guides/abs-tcs_fault_codes.htm), attempting to access that URL simply times out. Looks like the site/page is dead.

Thanks
 
OP
OP
Joined
Jun 23, 2005
Messages
3
Location
San Jose, CA
Progress report:

I located a detailed code extraction procedure on www-st-riders.net:

Notes:

o The ABS indicator light indicates the problem code by the number of times it blinks.

o The problem code is not cleared when the ignition switch is turned OFF during output of the problem code. However, output cannot be restarted by turning the ignition switch ON. Restart the output by following the problem code retrieval procedure.

o After retrieving the problem code, write it down. Clear the problem code after problem resolution.

Retrieval Procedure: (Indicator Light 1 is on the left, 2 is on the right when viewed from the riding position)

1. Turn the ignition switch OFF.

2. Turn the ignition switch ON while pressing the ABS/ TCS indicator light switch. The ABS indicator lights 1 and 2 should come ON.

3. Hold the ABS/TCS indicator light switch pressed (for approximately 5 seconds). The ABS indicator lights 1 and 2 should go OFF.

4. Release the ABS/TCS indicator light switch immediately (within 1 second) after the ABS indicator lights go OFF. Output of the problem code starts and the ABS indicator light 1 blinks. (ABS indicator light 2 remains OFF). Count the number of blinks and refer to the list below:

Blinks Fault
-------------------------------------------------------------
1 Faulty front modulator crank angle sensor system
2 Faulty rear modulator crank angle sensor system
3 Faulty front modulator control motor system
4 Faulty rear modulator control motor system
5 Faulty front wheel speed sensor system
6 Faulty rear wheel speed sensor system
7 Faulty power circuit
8 Faulty ABS control unit (ECU)

Code Clearing Procedure:
Press the ABS/TCS indicator light switch during output of the problem code (while the ABS indicator light 1 is blinking). The Problem code is cleared and the ABS indicator lights 1 and 2 come ON and stay ON.



Following this process I extracted a code. During step 4 I heard a buzzing/racketing sound from under the right side of the front fairing. I didn't hear anything from the rear, nor does the code indicate a fuse is blown.

ABS light #1 flashes one long flash followed by one short flash.

Does it attempt to reset stuck relays by rapidly switching them?
Is there a chance it wont blow the lower 20A fuse in the ABS fusebox after running the code extraction procedure?
 
Joined
Sep 4, 2013
Messages
8,110
Location
Cleveland
Bike
2010 ST1300
I can't help you with specific answers to your questions - I have a newer bike and have never delved into the mysteries of the abs system. However, blowing a fuse usually indicates a wire has been shorted to ground (e.g. the positive wire was squeezed against the frame and the insulation broken so the copper wire is touching the frame). It can also mean you have an overloaded circuit, but since the bike was knocked over and you sustained significant damage, I would suspect the former.

The first thing I would do, (before trying to decipher codes) would be to visually follow the abs wires along the outside of the frame, looking for damaged wire. This might be a useless suggestion - having been inside my bike, I have seen how thick the wiring harness is and how well hidden it can be. However, you are looking for damage that might have been done by the bike toppling over, and/or by the mechanic replacing fairing pieces. I would think that damage to the wiring harness inside the frame members can be ruled out. Another area I would examine would be the abs sensors themselves.

I bow to more complete knowledge and experience of other riders on this site.

Good luck!.
 
Joined
May 18, 2014
Messages
86
Age
61
Location
Danville, California
Bike
2002 ST1100A
STOC #
8795
I'm not super mechanically inclined, but what SMSW said makes sense. If you need it, I have the Honda service manual. I can try copying and/or scanning the electrical diagrams and e-mail them to you
 
OP
OP
Joined
Jun 23, 2005
Messages
3
Location
San Jose, CA
Thanks for the links to wiring diagrams. I wish I could locate that official Honda service manual I purchased back in 1995. I've looked everywhere for it.

The wiring diagrams show "light switch" within each ABS modulator assembly. What's a "light switch"? I doubt it's a really a switch controlling a light bulb. Is it really a diag motor run switch intended to cycle the motor within the modulators during testing and brake bleeding?

It looks like I could remove one ABS modulator relay at a time and trigger each modulator to determine which one is blowing the 20A fuse. Maybe attempting to run it in reverse might loosen anything jamming it.
 
Joined
Jun 3, 2006
Messages
3,512
Location
British Columbia
Bike
2021 RE Meteor 350
See if you can find and send a PM to Norm, a member on this board. He is the ABS modulator man.
 
Joined
Sep 13, 2011
Messages
30
Location
Norway
Hi.

The 4 years i have owned my ST1100A '94, i have had a couple of faults related to the ABS.

First time, the front modulator started to make a code from time to time, which i could reset. - After the winter i could not reset it anymore, because it had blown the fuse. Replacing the fuse just ended up in a new blown fuse.

I removed the front tupperware, and managed to open the modulator so i could remove the rotor. (Without removing any brake-hose ). It was stuck / seized in the stator-house . - Cleaned it all well, and mounted everything back again.
This was some years ago, and it have been ok since.


The other time , the rear modulator was messing up, making a code.
Removed the white plastic on the modulator, where the "light switch" is. The switch needed to be cleaned and adjusted. After that everything was working again.

The "Light switch" on the modulator is controlling the start / stop of the modulator- pump, making pressure. -(Sometimes when you drive, you hear a short buzzing )

When you start your bike, the modulator is running a kind of test-cycle. This cycle make the pressure come and go, so the switch opearates a couple of times.

When my "Light switch" was not working, i heard a buzzing that lasted some seconds longer than the other modulator. Then the fault code appeared.

Kairo
 
Last edited:

Norm

Vendor
Joined
Aug 26, 2007
Messages
351
Location
Chilliwack, B.C., Canada
Bike
KLR650
STOC #
8030
I the limit switch on the ABS1 modulator is not correctly adjusted, there may be a code set despite that the modulator functions correctly, unfortunately the ABS will be disabled by the system. Maladjustment may also cause a non-functioning modulator to pass the self test which is bad news.

A seized pump can draw over 20 amps so fuse blowing is often a modulator failure. Unplug the 1/4" spade lug connector on the pump to see if that stops the fuse blowing so as to localize the problem.

I remembered to record two modulator numbers to day, from a 1992: front- MY3F1521; rear MY6R1853. Unfortunately sent some others off without remembering.
 

Norm

Vendor
Joined
Aug 26, 2007
Messages
351
Location
Chilliwack, B.C., Canada
Bike
KLR650
STOC #
8030
I can't find the thread but somewhere we were discussing ABS1 modulator identification by casting number. I usually don't remember to check the numbers because trying to get them turned around and shipped back after repair.

Here are two numbers from a European 1992:

Front: MT3F3099
Rear: MY3R3077

If someone recalls the thread, here or some other site, please let me know.

Norm
 
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