ABS sensor problem

[Santa-2512]

Having an odd problem with my ABS sensor(s)

Ive noticed a few times that i have no speedo on various trips.

so over the last week or so have started to spin the rear wheel as i turn

the iginition on to see if the sensor is working ...

Now this is where it gets odd.

Tried checking the connection to see if its a poor joint ... all seems ok ...

The concensus on here, is that if the rear ABS sensor fails, the front will

take over, so no biggy in terms of speedo function, the only issue, is the

ABS fault, which will flag.

Not an issue for me the bikes had a servoectomy, so ABS function speed

sensing only.


Now whats odd is first run in the morning i turn the ignition on, spin the

wheel, and the speedo works. press the starter and start the engine.

spin the wheel, and the speedo is dead!

Come the PM trip home, exactly the same routine. turn on spin the

wheel, and the speedo works. start the engine spin the wheel, and the

speedo still works.. !!

So now i have a quandry ?

Is it the rear ABS sensor thats failing.

And / or is the front ABS sensor allready defective hence no speedo at all?

The the question is which sensor do i replace? if at all??

If my front sensor is good, and the rear defective, why isnt it doing the

rear /front speed sensing transfer,

Or is it because i've had the snip the sensing transfer magic isnt working?

Looking at motorworks, they want from £25 to £60 for sensors depending

on model etc,.

Now why would i pay £60 for a rear sensor, when i can get use the front

sensor for £40??

Or could it be somthing else?

 

[Deleted account 190920001]

Have you pulled the rear sensor to see if it is covered in metal paste from your FD? It's easy to do if you haven't.

 

[comberjohn]

Not very scientific, but it nearly always seems to be the rear sensor that fails. Maybe to do with the environment it lives in.
Had a fall light on mine one time, just after I'd had the front wheel out. Hadn't made sure that the front sensor was fully into the hole on the forks and it was too far from the ABS disc. Only needs to be a fraction too far out for it to throw up a fault.

 

[Santa-2512]

I had the sensor out, when i did my FD oil change .

Yes there was some debris (paste) on it but not a lot, i may whip it out again to check ...

cant prove it, but it never failed until it was removed

 

[Paul C.]

Check your f/d oil....

 

[Santa-2512]

Check your f/d oil....

For what? missing abs electrons? signals floating on the surface?

 

[Bendy toy]

If the oil was really messy you may already have problems with the final drive gears.

The rear ABS sensor is used as the speedo sensor. If the speedo starts to work after a couple of miles you have a wiring fault at the back. If you disconnect the back sensor the bike will immediately use the front so speedo works immediately. In both cases you will have an ABS warning.

 

[Santa-2512]

If you disconnect the back sensor the bike will immediately use the front so speedo works immediately. In both cases you will have an ABS warning.

Erm Nope. just been and tried the bike .... spin rear wheel, speedo works ... disconnect sensor spin rear wheel no speedo

spin front wheel no speedo connect rear sensor speedo works ...

As i said in my first post , the bikes' had the snip, so i cant see anything brake related on the dash

 

[Bendy toy]

Sorry had not got the point about "the snip"

Mine was intermittent for quite a while. A new rear sensor cured it.

Check the sensor connectors and connecting wires.