Speedo Failure

[timeandtide]

IIRC I had 4 speedo sensors on my twin cam (non ABS)
Bought it in 2012, just under a year old, nearly 2K miles.
Great bike, sold 10 ish yrs later circa 57K apart from its appetite for speedo sensors!

 

[dicktheleg]

IIRC I had 4 speedo sensors on my twin cam (non ABS)
Bought it in 2012, just under a year old, nearly 2K miles.
Great bike, sold 10 ish yrs later circa 57K apart from its appetite for speedo sensors!

Mine has no ABS too.

Strange I can’t find a fault logged with the GS911 though?

 

[Santa-2512]

When i feel better, ill fire up the other fuser, and dig out some paperwork, and see what ican find
Rigjt now all ifeel like doing is crawling back into bed and either sleeping or dying

 

[dicktheleg]

When i feel better, ill fire up the other fuser, and dig out some paperwork, and see what ican find
Rigjt now all ifeel like doing is crawling back into bed and either sleeping or dying

Ta Santa.

Speedy recovery mate.

 

[Mistacat]

Probably no help as the only GS wiring diagrams I have are all ABS and the speed sensor is wired to the ABS ecu.
The only non ABS Diagram is for a R1200R non ABS and the speed sensor is wired to pins 51 & 31 on the ZFE ( central electronics unit).
As they are a twisted pair it should be easy to identify the wires on the ZFE.

 

[dicktheleg]

Probably no help as the only GS wiring diagrams I have are all ABS and the speed sensor is wired to the ABS ecu.
The only non ABS Diagram is for a R1200R non ABS and the speed sensor is wired to pins 51 & 31 on the ZFE ( central electronics unit).
As they are a twisted pair it should be easy to identify the wires on the ZFE.

Much obliged. Ta.

 

[dicktheleg]

Just tested the abs / speed sensor as per the YouTube video, LED lights so I know wiring is intact but fails to flash when wheel is rotated.

Looks like a new sensor is required!

I also checked supply voltage from the controller and that's fine.

 

[dicktheleg]

New (used ) sender bought off eBlag.

Its a genuine BMW unit and its fitted, Speedo working fine now.

Princely sum of £28.50p

Result.

 

[Joca]

I'd be happy to take the old sender /sensor of you, if you are willing to send it. I repaired the wire on mine a couple of years ago and was stumped that wire broke at a point that had no movement.
I'm curious as where it failed.

 

[dicktheleg]

Hi Joca
You’re welcome to it but I’ve tested it and there are no breaks in the wiring but the actual head has failed and doesn’t pulse as it should.
ATB
Rich

 

[Slipperyeel]

Hi Joca
You’re welcome to it but I’ve tested it and there are no breaks in the wiring but the actual head has failed and doesn’t pulse as it should.
ATB
Rich

Send it to Joca!

I too want to know what the hell goes wrong with them!?@#£&!

Sent from my SM-S908B using Tapatalk

 

[Santa-2512]

I'll save you the bother

The inductive field breaks down


Its just a coil and a magnetised chunk of steel , i cant remember the physics bit, but i believe the magnetic field diminishes over time and thus fails to register the variations in the field

 

[Slipperyeel]

Ok....but why would one last 11yrs and the new, OEM, replacement last just 18 months?

Would an unused magnet loose power just sitting in storage? I mean, if the new replacement I bought was from stock the same age as my bike, could that explain it?

I don't know any where near enough about electronics to answer this stuff.

Sent from my SM-S908B using Tapatalk

 

[Mistacat]

I'll save you the bother

The inductive field breaks down


Its just a coil and a magnetised chunk of steel , i cant remember the physics bit, but i believe the magnetic field diminishes over time and thus fails to register the variations in the field

You seem to be describing Passive analogue sensors.
I was under the impression that BMW had come out of the dark ages and used Active digital sensors for this application.

 

[Kenny Rodkiss]

I pulled one to bits.
It's a small magnet with a couple of linked ic chips stuck to it.
Post in thread 'Speed sensor' https://www.ukgser.com/community/threads/speed-sensor.368939/post-5344229

 

[mikeyboy]

You seem to be describing Passive analogue sensors.
I was under the impression that BMW had come out of the dark ages and used Active digital sensors for this application.

Ive lost a lot of interest over the last 10 years in electronics Chris,
So in your language,a PAS is what I’d call a simple AC generator?
Whilst a ADS would be utilised when traction control etc is in play?
So a lot more advanced.

 

[Mistacat]

Ive lost a lot of interest over the last 10 years in electronics Chris,
So in your language,a PAS is what I’d call a simple AC generator?
Whilst a ADS would be utilised when traction control etc is in play?
So a lot more advanced.

Mike, I think that sums it up.
I understand that the Active sensors are more stable regarding heat and RF interference plus they are more accurate.
Things move on but unfortunately you can get the occasional semi conductor failure in all devices.