Speedo/ABS Sensor FAQ
Please read the Disclaimer before attempting any work in this FAQ.
by Haakon##626 & Kristian #562

edited by Kristian #562

For the Classic refer Speedo Classic FAQ

 

My Speedo is not Working

 

Symptoms:

Q. Why does this happen.?

A1. The ABS/Speedo Sensor off the rear wheel feeds back to the Motronic and if the sensor goes (or maybe it's just covered in mud, so CHECK the Rear wheel first), it affects the Speedo.

A2. The Speedo itself has some poor Connections/Rusty or poor wiring. refer the Wiring Diagrams in the GS Documentation Section for the Speedo Connections to Cross-Check with the Photos Below.

 

Q. Is this common.?
A. How many instances do you need before it becomes common.? Yes. there are quite a few people who have had these symptoms. Here they are:

Solutions:

 

Q. How do I fix it myself.?

A1.  Check the ABS/Speed Sensor at the Wheel and at the Motronic. If you've checked all the connections and it STILL doesn't work, get it replaced by BMW. We might be able to find an aftermarket source of the sensor sometime in the future, but for the moment, that's the only option.

Connection at Motronic:

 

Connection at Wheel  (Sensor Detects Slotted Disk as is passes by):

Check for Mud, Sensor Mounting Bolts, Brake Disk & Sensor Disk Bolts

 

A2. You can't fix the Sensor Cable but you can check the pickup at the wheel. If cleaning it one of the solutions below doesn't work, get BMW to check/replace the ABS/Speed Sensor Cable for you. We will look at finding a source of a new OEM Sensor, but don't hold your breath.

A3. Get BMW to check/replace the Motronic for you.

A4. You can't fix the Speedo, but you can check the connections yourself. Get BMW to check the Speedo for you. Some riders have had the Speedo replaced TWICE and it still breaks down.

 

  

Speedo Losing Mileage?

Symptoms:

Solutions:

Well if you've checked your Sensor and Sensor Connections (See Above), checked for Rusty Speedo Connections, you might just have to go to BMW and tell them "it doesn't work." Sorry. We'll keep you posted.
 

Odometer Rounding Error?

Symptoms:

Solutions:

Well if you've checked your Sensor and Sensor Connections (See Above), checked for Rusty Speedo Connections, you might just have to go to BMW and tell them "it doesn't work." Sorry. We'll keep you posted.
 

Speedo or Tach Lags actual Speed/RPM

by Supertech

Q. I have a '01 F650GS, and I've noticed that in first and second gear under hard acceleration the engine revs up faster than the Tach needle moves. In other words I will hit the rev limiter while the Tach reads approx 6000 rpm. Also I have noticed the speedo will kind of lag behind on harder acceleration too, like it sticks around 50-55 mph too long, and then the speedo needle will "catch up" to the actual speed. Buck
A. I ride lots of these and I think it is the way they are.


My Speedo Buzzes?

Buzzing From around the Fairing/Speedo Area. Electrical/Speedo Problem?

Symptoms.

Answers That's quite normal - you often get those clicking noises.

Why, when I roll the Bike Back in Neutral with the Engine running does the Idle rise?


No-one's ever mentioned that when you reverse your bike, with the engine idling, the revs go up a lot. It's because of the Speedo ABS Sensor feeding back to the FI. quite normal!. Kristian #562

 

If I have ABS, is the Speedo run off the Front or the Rear Sensor?

Haakon#626 (Norway, F650GS)

Answer: REAR. I just checked, in the pouring rain.