[art.kondakov]

Good day everyone.
2020 riding season for me started with very strange problem. I was taking away my 2015 ABS Scout from local dealer when noticed that ABS lamp still lighting even after 200 meters of riding. I returned back and asked for some help. Mechanic connected laptop to diagnostic port, find couple of errors (nothing interesting, "low voltage" etc) in ABS module, erased them and we ride a bit again. Nothing was changed - ABS lamp was still on. Next step - connect laptop and push bike forward for couple of meters. We noticed, that only front wheel speed was shown in diagnostic tools - something about 3 km/h. But rear wheel speed was 0. Mechanic said it could be something wrong with rear wheel speed sensor, but sensor looks fine. Unfortunately due to all this coronavirus problems dealer completely has no time to make a deep diagnostics for my Scout and recommended get back in couple of weeks. Well, the only problem that ABS definitely doesn't work now, that's sad, but everything other is find. Next day I disconnected sensor and cleaned contacts (is was a bit dusty), nothing changed. Cable looks unbroken.
Right now I'm clueless. I'm pretty sure that problem couldn't be complicated - something like broken fuse, but I'm not good in electrics. So if anyone can help me finding the real reason why ABS module cant's get data from rear wheel speed sensor - I'd very grateful to know it.

 

[MOMZ]

Do your brakes work at all?
Or is the the front the only the single brake that functions upon application?

 

[art.kondakov]

Do your brakes work at all?
Or is the the front the only the single brake that functions upon application?

Front and rear brakes works good, but without ABS (dealer's mechanic even blocked rear wheel on low speed while testing).

 

[Chief Signguru]

Take either compressed air, or high pressure water and clean that sensor. My Chief did it. The mechanic diagnosed it as that. After 4 years, I do it every time I wash it, not ever a repeat of the problem.

 

[MOMZ]

Well then you should/could still ride your Scout.
Not every motorcycle has ABS, nor does every rider want ABS.

After this pandemic subsides, I'm sure a dealer could properly diagnose the issue correctly and fix the problem. (most ABS issues require a system bleed procedure that most of us cannot perform properly in our driveways)

 

[RACNRAY]

The correct diagnosis is in the op's original post...."0" speed from rear sensor...so you have a bad sensor. You are not the first and not the last to have a failed speed sensor.

RACNRAY

 

[Chief Signguru]

Start with the simple fixes first...
Sensor dirty, dusty, grit
Battery cables, electrical connections, etc.

Then if you're at an impasse, the dealer will diagnose and replace the defective sensor.

 

[art.kondakov]

Battery cables, electrical connections

I only took a look at connector of sensor under the bike. I don't know where are cables goes next. But I want to check them anyway

 

[XGC75]

Interesting problem. I work in controls. Most often, issues like these are in the connection/harness. Not necessarily things you can see, either. For example, the crimp to one pin may be bad or the pin is not fully seated into the connector. If you have some time on your hands, trace the cable back to the ECU and do a little "wiggle" of each pin (in and out, not more than ~ a few kilo of force) at every connector between the ECU and the sensor.

 

[art.kondakov]

I think I must give some updates for people who also have troubles with rear sensor.
After couple of months sensor mostly work than not. I suppose this caused by better weather - warm, dry and so on. At the beginning of the season temperature was about 5 celsius and rains were almost every day. Some times at may, when was rainy too, ABS light didn't turn off for a while. So maybe this problem could be related to wiring, not sensor. I've checked connectors under the bike twice, they are fine. We need to go deeper...