99 Front ABS Sensor bolt

Joined
Jan 12, 2017
Messages
11
Location
Greenwood, Indiana
Bike
99 ST1100A
Anyone know what bolt holds the front ABS sensor on and best place to get replacement. My ABS light came on and would not go off, started troubleshooting and found sensor dangling due to no bolt. I see a few on partzilla I could try but wanted to check the wealth of knowledge here for any advice...Thanks!
 
Partzilla should list the bolt size, or they used to, Menards, auto parts store . Menards has a good selection of stainless steel metric bolts. The rear sensor is most likely the same size, match it.
 
What I am looking for is the bolt for the first pic with the hole above bleeder cap. The back looks to be mounted in a different orientation.
 

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If I understand it is the bolt that holds the front sensor to the caliper.
If that is it, it is the same thread size as the one that goes into the anti-dive but of a different 'shoulder' configuration.
There is also an 'alignment' bolt that pokes through the sensor bracket to keep it aligned.
If that is it, it is 90106-MAJ-G40 6x16 (part 32 on the list).

1747589156534.png
 
Yes that is the size and I was able to get one and get the sensor attached however I don't believe it is aligned correctly since cannot get the ABS light to go out. In the process noticed I need front tire so will need to take to shop and hopefully they can align sensor when putting wheel back on.
 
Yes that is the size and I was able to get one and get the sensor attached however I don't believe it is aligned correctly since cannot get the ABS light to go out. In the process noticed I need front tire so will need to take to shop and hopefully they can align sensor when putting wheel back on.
Do you have the 'locating' bolt (33 on the diagram) through the top hole of the sensor bracket?
Check the sensor to make sure it doesn't have a deep groove worn in it.
Check the gap between the sensor and the toothed ABS ring.
Look closely for broken wires also.
If the ABS is flashing it will throw a code that will tell you what is the issue.
The retrieval sequence -

To recover the fault code
  1. Turn ignition off
  2. Hold down the ABS/TCS indicator light switch below the left hand fairing pocket.
  3. Turn on the ignition while keeping the switch held down and watch the ABS warning light on the dash.
    • Note that the warning light has a wider lens beneath which are two bulbs. In my case, the left hand bulb lights at this point, the right hand bulb remains off.
  4. After about 5 seconds, the warning light goes off. At this point (within 1 second), release the warning light switch. The ABS warning light should begin to flash.
    • The flashes consist of one long flash, followed by a number of short flashes. Count the number of short flashes.
  5. Do not press the warning light switch again, unless you wish to clear the problem codes. Instead, turn the ignition off. This leaves the same problem codes in memory.
    • Note that the system will cycle through two sequences and then repeat.
  6. What the Fault Codes Mean (1996 and onward).

    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)
7. To clear the fault codes:
  • Follow the procedure above to retrieve the problem codes.
  • Press the ABS / TCS indicator light switch while the indicator light is flashing.
Credit to @jfheath IIRC for the details. ;)
 
Do you have the 'locating' bolt (33 on the diagram) through the top hole of the sensor bracket?
Check the sensor to make sure it doesn't have a deep groove worn in it.
Check the gap between the sensor and the toothed ABS ring.
Look closely for broken wires also.
If the ABS is flashing it will throw a code that will tell you what is the issue.
The retrieval sequence -

To recover the fault code
  1. Turn ignition off
  2. Hold down the ABS/TCS indicator light switch below the left hand fairing pocket.
  3. Turn on the ignition while keeping the switch held down and watch the ABS warning light on the dash.
    • Note that the warning light has a wider lens beneath which are two bulbs. In my case, the left hand bulb lights at this point, the right hand bulb remains off.
  4. After about 5 seconds, the warning light goes off. At this point (within 1 second), release the warning light switch. The ABS warning light should begin to flash.
    • The flashes consist of one long flash, followed by a number of short flashes. Count the number of short flashes.
  5. Do not press the warning light switch again, unless you wish to clear the problem codes. Instead, turn the ignition off. This leaves the same problem codes in memory.
    • Note that the system will cycle through two sequences and then repeat.
  6. What the Fault Codes Mean (1996 and onward).

    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)
7. To clear the fault codes:
  • Follow the procedure above to retrieve the problem codes.
  • Press the ABS / TCS indicator light switch while the indicator light is flashing.
Credit to @jfheath IIRC for the details. ;)

I will need to take another look. What I noticed in my pic above was the missing bolt that goes through the fork and appears to hold the sensor. I couldn't find a diagram showing that or if it was correct. It seems to be but doesn't hurt to take step back and reevaluate.

Thanks for the code instructions. I had been following the article posted which told me it was a front sensor fault. After clearing and attempting to gap I only get one long flash repeated.
 
Sometimes if your battery is about to die it will do 'funny' things to the ABS system.
My guess (and it is only a guess) is that flopping around inside the wheel either broke some wires or broke the sensor.
OEM sensors seem to be made out of 'unobtanium' but there is an article on this site about someone who 'retrofitted' a generic one and got it to work.


It's ABSI but the sensors are the same as ABSII IIRC.
Happy Bikes in the UK used to provide 'upgraded' ones.
I just sent them an email to see if that is still the case.
 
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Sometimes if your battery is about to die it will do 'funny' things to the ABS system.
My guess (and it is only a guess) is that flopping around inside the wheel either broke some wires or broke the sensor.
OEM sensors seem to be made out of 'unobtanium' but there is an article on this site about someone who 'retrofitted' a generic one and got it to work.


It's ABSI but the sensors are the same as ABSII IIRC.
Happy Bikes in the UK used to provide 'upgraded' ones.
I just sent them an email to see if that is still the case.
I found the instructions on page 86-87 of the owners manual and took off the front mudguard (fender) and sure enough because the sensor mounting bolt fell out the pulser ring rubbed a groove through the sensor. So may have to go the alliexpress route or without ABS.
 
I'm still waiting to hear back from HappyBikes in the U.K.
They have a good solution that was under $100 + shipping if they still offer it.
The bike brakes fine without the ABS but you have to deal with the 'lights'.
There are a couple of connections you can undo to turn them off as IIRC you cannot remove the bulbs.
Sometimes you can find the sensors on EBay but not very often.
 
I'm still waiting to hear back from HappyBikes in the U.K.
They have a good solution that was under $100 + shipping if they still offer it.
The bike brakes fine without the ABS but you have to deal with the 'lights'.
There are a couple of connections you can undo to turn them off as IIRC you cannot remove the bulbs.
Sometimes you can find the sensors on EBay but not very often.
I found them on eBay and purchased one so will see how it goes. It was around $175 with shipping.
 
The ST1100ABS brakes work perfectly well without ABS operating properly. I rode mine for about a year like that - when I broke the bracket trying to remove the rear sensor. It was stuck. I put the wedge shape of a tiny screwdriver blade between the casting and the sensor to try to pry it upwards. I gave it the tiniest of taps with something no bigger than a toffee hammer - I means I know that cast alloys are fragile so I was careful. Everso careful.

It snapped off.

But in the UK - ABS not working is not an MOT failure. They do not test for it.
The only time that mine ever kicked in was when I was testing that it worked - braking hard at 30mph approaching and riding over a wet manhole cover.


I'll add the link to my ABS info page. UP has already quoted some of it - but there is a nice bit at the end that isn't documented anywhere else. I found it by accident. A test to see whether the ABS unit is receiving the signals from the sensor and pulsar ring.

 
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The ST1100ABS brakes work perfectly well without ABS operating properly. I rode mine for about a year like that - when I broke the bracket trying to remove the rear sensor. It was stuck. I put the wedge shape of a tiny screwdriver blade between the casting and the sensor to try to pry it upwards. I gave it the tiniest of taps with something no bigger than a toffee hammer - I means I know that cast alloys are fragile so I was careful. Everso careful.

It snapped off.

But in the UK - ABS not working is not an MOT failure. They do not test for it.
The only time that mine ever kicked in was when I was testing that it worked - braking hard at 30mph approaching and riding over a wet manhole cover.


I'll add the link to my ABS info page. UP has already quoted some of it - but there is a nice bit at the end that isn't documented anywhere else. I found it by accident. A test to see whether the ABS unit is receiving the signals from the sensor and pulsar ring.

Thanks John! I appreciate your write up and used it to diagnose. It showed the front ABS fault which once I investigated and found the bolt to be missing was obvious. Unfortunately, the lights came on while on a ride where I was 400 miles from home so grooved the sensor out pretty good. I thought about simply going without ABS but would rather have it working if possible.
 
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