ST1100 ABS1 Traction Control Issues

[Garry_Coates]

I thought I should detail this separately for a different focus. I will say upfront that the only time I have noticed traction control has been to warn me of fast deflating tyres which I am eternally grateful. I have not had one of those since my ABS has not worked so I am not sure that it works as before.

In October I swapped the front T32 110/80 tyre to a new 120/70 GT version just before some trips. The rear T32 160/70 had about 1/3rd of it life remaining.

The weather conditions during the first trip where pretty bad: torrential rain, strong winds, land slides and lots of road debris.

I noticed when I had bad rear slides, leaning over, under power, the "TCS off" light would come on. It did not happen for slides off-throttle. As this was not behavior I wanted to reproduce I left it alone. The second trip was drier and the issue did not reoccur.

After 4000km I got the bike serviced this week and fitted a new rear T32 170/60 GT version to have a matched set.

On the ride on home in wet conditions and a bumpy road the traction control light kept flashing at me causing me to turn it off multiple times. I assumed the problem was running different profiles to oem.

On checking the bike I inadvertently made two changes at once because I wanted to get a ride in before the next rain session tomorrow:

1. Cleaned and reset the airgap on the rear wheel sensor

2. Changed the new rear tyre pressure from a little low 36psi to a normal 42psi

I went for ride tonight over the same (dryish) bumpy roads and more. It did not cause any problems for the traction control. I even spun the rear on some gravel a couple of times with the TCS light flashing but no errors. Spinning the tyre while upright on gravel is not the same as while leaning as the rolling radius changes. So the result is not conclusive.

In conclusion it may be that:

1. Having mixed profile tyres may cause TCS issues in some cases

2. Moving to the GT versions with different profiles may make TCS more sensitive to tyre pressures

3. I am quite happy with the GT versions and will stick to them subject to wear life.

4. All of this is guess work as I am not going out to power slide a 325kg (wet) bike to thoroughly test it.

Regards
Garry

 

[Upt' North]

I'm guessing, but don't know, this was probably the sensor.
I can't imagine 6 psi would make that much difference especially on a stiff carcus GT tyre, unless of course your gauge was way off as well.
Well done, it sounds all good now.
Upt'North.

 

[Uncle Phil]

FWIW, I've run the same rear on my ABSII ST1100s with no problem.
Can you pull the code to see what it is complaining about?
Check your sensors as I had one that had 'slipped' into the toothed ring and it made the system do 'interesting' things.
Also, loose/corroded battery cables or a battery that is on its way out can cause the ABS to lose its marbles.
If I had an ABSI, I'd send you a loaner TCS module but all of my stuff is ABSII.
You might look around at some breaker yards to see if you could get a TCS module and an ABSI module.
Also, I have seen the ABS/TCS switches get flaky and cause issues so you might give them a good dose of electrical contact cleaner.

 

[kiltman]

I experienced the flashing on my 97ABSII. It would flash when I went over a bump. The issue for me was the rear sensor was faulty. I replaced it with one from Happybikes in the UK and the flashing went away.
I also have been running the wrong size rear tire for years and it hasn’t caused the ABS or Traction control light to flash.
The only time I had the traction control engage was when I was on wet grass and I had wheel spin then the engine would decrease in power till I got a grip. Your mileage may vary.

 

[Garry_Coates]

Guys,
thanks for the feedback. I am really not fussed about it and provided this info as it was requested:
1. The only problem that I have had with TCS in 25 years is this, with the introduction different tyres with different rolling radius and profile. This is more evident when leaning.
2. The examples you provide are for the ABS2 model which has a different ECU, front wheel sensor and different front wheel rim size. Thats an apples to oranges comparison.
3. Just because 1 person has a problem and others different does not prove a general rule. It is only being provided for information.

Regards
Garry

 

[Erdoc48]

Yup, my 94 ABS / TCS lights have been flaky for some time- I can’t figure it out. Bike runs fine otherwise. I’ve sprayed the switches and have cleaned the sensors. Seems to help for a while, then the lights recur- old bikes, old bikes, old switches, old contacts- can be any of those I guess.

 

[wjbertrand]

I suffered a puncture on my '93 ABS I bike that resulted in a complete deflation whilst riding in the rain. The TCS light never illuminated in that case. I have seen it flash accelerating on bumpy pavement with less than idea traction, rain, sand, etc.

 

[Garry_Coates]

Hi wjbertrand, I believe you, as it is old equipment and was Honda/Nissan's early ABS/TCS motorcycle implementation. When rapid deflation happened, the bike would not accelerate (TCS adjusts timing) and a few seconds later I would feel a rear wheel shimmy. Happened 3 times so I knew what to expect. I cannot remember whether I saw the TCS light as I was bit engaged at the time trying to slow the bike down before the tyre left the rim.

Is your ABS/TCS system still running and original or has it been repaired?

Regards
Garry

 

[kiltman]

My understanding of the ABS system is that it calibrates the relationship of the front wheel to the rear wheel within the first 30 feet of travel and that’s when the ABS light goes out. So in theory it would account for the different tire size within the first 30 feet of riding and the ECU would base that data to determine if one wheel was spinning more than the other after that initial calibration.
I have also been led to believe that the front and rear sensor are interchangeable, the difference being the length of the cable is different between the two. Quite often it has come up in a method of troubleshooting if your sensor was indeed bad was to swap the front to the rear and see if the error code would be the same or the error code transferred to the other wheel.
Obviously I need to do some research when I get home to determine the differences between the two versions.

 

[Garry_Coates]

Hi Kiltman, I think you are applying 21st century thinking to a very early implementation of TCS/ABS. There would be a tiny amount of memory and processing power akin to a lunar module of the 70s. TCS is primarily controlled by the ignition module with input from the ABS ECU. Pull the ABS main fuse and nothing works.

From my understanding:
1. Riding the inital few feet enables the TCS to determine whether the wheel sensors are working normally and complete initial self-diagnosis. Not tyre calibration. Over 10kmh the TCS then regularly monitors operation (including self-diagnosis). Failure in the first few feet is most likely due to sensors or electronics.
2. This system would have been built to work with only one tyre spec for each wheel. This is because different tyres at various angles of lean, give a different rolling radius and different wheel speeds. It would be hardcoded to allow a certain amount of speed difference between wheels before engaging. Systems that allow for the use of different profile tyres are quite a recent thing. They are some now that allow programming changes to cater for tyre wear.
3. The 100+ pages in the workshop manual ABS/TCS sections are littered with warnings about use of incorrect tyre pressures and incorrect tyres. As well , the importance of cleaning the wheel sensor of material and ensuring it has not been damaged by the pulser ring. Bumpy roads are also mentioned but considering the state of our roads it has not been problem for me even riding dirt.
4. ABS/TCS troubleshooting Flowcharts suggest interchanging relays, fuses etc but I have seen no mention of wheel sensors. Norm (Canada) has confirmed the ABS1 modulators can be swapped with wiring changes
5. At $500AUD delivered, a failed wheel sensor would just hasten my removal of the ABS/TCS system but everything is good so far

I hope that this helps and suggest Chapters 16,19 and 23 of the workshop manual.

Regards
Garry

 

[kiltman]

Thanks Garry, this very helpful.
cheers
Robert

 

[wjbertrand]

Hi wjbertrand, I believe you, as it is old equipment and was Honda/Nissan's early ABS/TCS motorcycle implementation. When rapid deflation happened, the bike would not accelerate (TCS adjusts timing) and a few seconds later I would feel a rear wheel shimmy. Happened 3 times so I knew what to expect. I cannot remember whether I saw the TCS light as I was bit engaged at the time trying to slow the bike down before the tyre left the rim.

Is your ABS/TCS system still running and original or has it been repaired?

Regards
Garry

I no longer own the bike but I did put 150,000+ miles on it before i sold it and the ABS system was still working fine at that point. I ran into the new owner a couple years later and he said the bike was working great.

 

[Alberto]

sections are littered with warnings about use of incorrect tyre pressures and incorrect tyres.

I just broke bad and installed out of spec tires. Front with higher profile, back - with lower than recommended. ABS still works fine. Also started to thing, that first seconds of riding abs module not only sef- diagnoses, but also initiates by remembering speed difference between wheels.

 

[Garry_Coates]

Hi Alberto what year is your St1100? This TCS does not calibrate differences for tyre sizes/profiles. Its probably just the tyres being used are within the margin of what is allowable.

Current bikes like Africa Twin get around this problem by have a traction control multi step choice. Each step has a bigger margin for wheel speed difference before engagement.
People have then changed the front wheel from 21 inches to 19 inches and have gone through the TCS settings to find one that works.

Regards
Garry

 

[jfheath]

The shop manual indicates that not changing tyres at the same time may result in abs and / or tcs not working properly, due to the different diameter tyres between new tread and old tread. Its about 2% difference. In 1992, microprocessors were operating at around 20MHz. 20 million clock ticks every second. That is massive for the simple job it had to do.

I discovered a procedure for testing the sensors for the ABS II system. It isn't documented officially. It may work for the ABS 1.

I'll find a link to it. Its on here somewhere.

Article [11] - ST1100 - ABS Fault Finding | ST1100 Articles

Diagnosing a fault reported by the ECU on a Honda ST1100AY. ABSII ABS/CBS/TCS This information is taken from my own website - I wrote it up at the time - I am just revisiting it 13 years later. ABS The ABS is brilliant - it works. It gives a pulsing sensation through the brake levers -...

www.st-owners.com

Please let us know if something similar works for ABS I

 

[Garry_Coates]

Hi jfheath, the ST1100 ABS1 tyre diameters for a front 110/80 18inches and rear 160/70 17inches are close at 633mm to 656mm so the TCS expects similar wheel speeds with less than 4% difference. Going to 120/70 and 170/60 tyre set actually reduces the diameter mismatch to about half (10mm) which is less than 2% difference. I can understand that while the bike is upright its ok. What the rolling diameters are at various lean angles, profiles and tyre pressures is above my pay grade. I am sure there would be engineers that would have software to do this.

By the way a completely worn 160/70 is close to the same diameter as a new 170/60. Probably still larger.

That is a good article for reference. I had not seen the content on sensors before but can concurr with it. I can relate to your TCS problem.

Please note that the ABS/TCS warning button does much more than stop the light flashing. It turns off the ABS below 10kmh which is a speed it cannot self-diagnose. Very early on I had a ABS problem which I did not hit the button, being close to home. As I was pulling up behind some cars on a downhill, the ABS suddenly kept releasing the brakes. The bike bounced off the back a car with slight damage.

Honda Australia replaced both sensors free of charged when I talked to them directly. They knew exactly what the problem was. Never let anybody tell you something cannot happen because it has not happened to them.

Regards
Garry

 

[Alberto]

Hi Alberto what year is your St1100?

Hi Garry,
mine is 1994 model with ABS I

Please let us know if something similar works for ABS I

it seems like described ABS II behavior fits first version too. Maybe, both versions programmed with same logic, and main difference is mechanical (each modulator has two hydraulic lines to control).

 

[jfheath]

Please note that the ABS/TCS warning button does much more than stop the light flashing. It turns off the ABS below 10kmh which is a speed it cannot self-diagnose. Very early on I had a ABS problem which I did not hit the button, being close to home. As I was pulling up behind some cars the ABS suddenly keep releasing the brakes. The bike bounced off the back a car with slight damage.

Honda Australia replaced both sensors free of charged when I talked to them directly. They knew exactly what the problem was. Never let anybody tell you something cannot happen because it has not happened to them.

That is very interesting, and must have been frightening at the time. In my ABS II experience, I believed from what I had read in the manual that the system armed itself in the first few seconds of riding. I know that if it failed the tests, neither ABS or TCS were activated. I know this from living on a rough road and sometimes mine would fail to arm. I'd have to stop and turn off the ignition and set off again.

ABS is not supposed to operate at low speeds, so your experience is worrying. I would not have considered it as a possibility, but since ut obviously happened to you, I can imagine how this might have occurred. On the ST1100 individual wheel rotary speed will be determined from the pulsar ring and sensor information. If that develops a fault while riding, it doesn't actually recognise a fault unless the sensor stops sending signals. instead, it interprets whatever signals that it is getting - so I would guess that it thought the wheel was going fast enough, but was getting spurious signals. So perhaps a broken wire 'crackling' and sending rapid signals would indicate that the wheel was moving faster than it actually was, but the signals would be at irregular intervals indicating lockup. Clearly, I am guessing. But whatever the actual reason, it happened, it is interesting information, but it must have been frightening fir you at the time.

I don't recall ever testing whether or not ABS could be turned off with the warning light switch, so its interesting to know about that.

TCS does not normally operate at all below about 10km/h. When my sensor was failing, for a few days the system would arm itself ok, but fail sometime when riding - which made the engine cut the power - very alarming the first time that happened at speed. Normally this is a momentary cut until the back wheel is deemed to be no longer slipping. But when the sensor is failing the engine just splutters. - until you get below 5-6 mph. Open the throttle and it immediately cuts the power. Of course I played around with the TCS switch when my sensor was packing in. I didn't know it was a sensor fault at the time. I thought the switch was faulty!

The ABS releasing the brakes because it has detected a break in the pulses, but not recognising that your speed has dropped is a concern. Abs operates on whichever wheel is locked - it does not not need to compare pulses from each wheel for that, so presumably the other brake would work. But I have no experience of ABS I.

Using the information from people who back up claims by saying it has never happened to them ? Never. If there is a way that something can go wrong, at some point it will. And claims like that are always in the majority. In serious cases, almost by definition, there tend to be fewer people around that can make a counter claim.
eg You will rarely hear the opposing view to a comment like 'I never service my brakes and haven't had any problems'.

 

[Garry_Coates]

Forums are riddled with confirmation bias.

A confirmation bias results when researchers choose only the data that supports their own hypothesis. Quite often a sample size of 1.

Anyway great to talk to you. Bye now.

 

[Alberto]

When my sensor was failing, for a few days the system would arm itself ok, but fail sometime when riding - which made the engine cut the power

I had exactly the same problem when rear sensor failed. TCS started to cut engine periodically without a reason and finally threw sensor faulty code. When I started to investigate what is wrong to sensor - I easily pulled cable out of the it) Visually everything was fine, but cable totally rotten out inside, found a way to restore it instead of waiting a replacement: my sensor repairing. No any TCS issues since then at all. That's my personal experience.

also, one moment I noticed - TCS continue to work even if ABS fails with hydraulic issues.