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-   -   F650GS ABS light and speedo problem (http://www.horizonsunlimited.com/hubb/bmw-tech/f650gs-abs-light-speedo-problem-30438)

Ekke 6 Nov 2007 08:56

F650GS ABS light and speedo problem
 
We are in Istanbul at the moment and are getting some help from the Horizons Unlimited community to try and repair a problem with Audrey's F650GS. I would like to get some feedback though to see if anyone else has encountered this problem.

2001 F650GS with about 38,000 km. During the recent ride down through Serbia and Bulgaria Audrey was using her electric vest a bit as well as the heated grips. The ABS light came on and the speedometer stopped working properly. Every now and then the speedo would come on and then shut down again. She has not used the vest for a couple of days but the problem persists.

I've heard that the 1100 and 1150s can have an ABS light come on if the battery is low. I can understand that if that happens right from the start but this happened while riding on the highway. Is it possible that the charging system on the F650 can't handle an electric vest? Seems kind of odd really especially on the highway. On my airhead I usually shut down the vest and grips before I get into town (even with the Omega 400W system) and I've never had a problem.

We are taking it to a repair technician today who might have an idea but any and all input would be appreciated.

juddadredd 6 Nov 2007 14:41

Hi Guys,

You should have NO problems running a heated vest, heated grips and the parking light and low beam (always on) all at the same time. (I run 180w of lights 2 * 35 HID Twin Main and Low together and my 2 * Halogen Fogs with no problems

Do you carry a Volt meter to check on the batteries charge? if so is it steady and does the bike fire up first time?
Have you checked the Batteries connectors to make sure they are tight and made sure they are covered with conductive grease?

Have you checked the batteries water level?

How is the Vest connected to the bike?
Does the light come on only when the vest is on?
............After checking the above we can rule out the Battery.........
Once that’s ruled out we can then check the ABS

An ABS sensor can be checked simply by spinning the wheel and checking for an output voltage. A sensor that is open circuit is failed. If the air gap between the sensor and toothed wheel is too great the voltage will be low

And the SPEEDO is still RUN from the REAR, even if you have ABS, so make sure it’s clean and that the rear tire sensor bit is mud free..

Those are the exact checks that I would make if I was on the road with you. Now I would also remove the front of the light housing and look for wires that are broken frayed or generally not where they should be, as it's seems to be intermittent fault that’s where it will be if it’s wiring based

But please let me know what you find, as I keep a Database (sad I know) of things to help me diagnose my little Dakar when she’s poorly





f650.com says

The ABS warning light sequence includes different flash sequences for different errors. These are known only to BMW (at present). The simple rule is, if the light is on you have full non-ABS braking, but may not have ABS. When the ignition is keyed, the ABS will test its components (you will hear clicks etc. as the modulators fire) and should reset if disturbed by a minor fault. If all is well the ABS light goes out. ABS cannot test its sensors fully until above 15kph. Below this speed you may not have ABS. Most systems do work down to about 7kph. The light will not come on again if both wheels decelerate in a normal way. Stoppies or wheelies may be logged as ABS faults and bring the light on.

Flashing at a frequency of once per four seconds indicates the ABS has been switched off by the user. You need to turn the ignition off and back on in order to re-enable ABS

Ekke 6 Nov 2007 18:50

Rear ABS sensor fouled by raın and mud
 
The dıagnosıs at Istanbul BMW was that the heavy raın we had been rıdıng through combıned wıth the dırty roads caused the rear ABS sensor not to be able to read the trıgger wheel correctly. Everythıng seems to be workıng fıne now.

Perhaps ıt ıs only a coıncıdence that Audrey uses her electrıc vest when ıt ıs cold and raınıng and that ıs when the problem happens. I guess she should try rıdıng ın cold and dry condıtıons! I suggested hookıng up a blow dryer to the sensor so that Audrey could just dry off that poor lıttle sensor when ıt got too wet and dırty.

:eek3:

juddadredd 6 Nov 2007 20:28

Hi,

Great stuff dirty sensor, I've even updated my database to that it now has a higher ranking on the list (it now comes before check the wiring connectors), if only BMW would publish their guide for fault finding.

You could try to move the sensor a little further away from the trigger wheel and please also check to make sure that it is still sealed, as there are two wires inside that connect when they get water on them both, a small piece of tape will keep it sealed so that it doesn't happen again.

And unless your running a sealed battery, check the water level if you are running the heated vest for any period of time.

Lee @ f650ridetheworld.com

Walkabout 6 Nov 2007 20:45

Quote:

Originally Posted by Ekke (Post 157892)
The dıagnosıs at Istanbul BMW was that the heavy raın we had been rıdıng through combıned wıth the dırty roads caused the rear ABS sensor not to be able to read the trıgger wheel correctly. Everythıng seems to be workıng fıne now.

Perhaps ıt ıs only a coıncıdence that Audrey uses her electrıc vest when ıt ıs cold and raınıng and that ıs when the problem happens. I guess she should try rıdıng ın cold and dry condıtıons! I suggested hookıng up a blow dryer to the sensor so that Audrey could just dry off that poor lıttle sensor when ıt got too wet and dırty.

:eek3:

Hi,
Interesting.
Is that the diagnosis for both the intermittant speedo and the ABS warning light or just the latter?

Thanks,

bmbiker 7 Nov 2007 09:53

Same problem on mine with the speedo
 
I have encounted the same problem on my bike.

It first packed up on the Karakoram Highway in Pakistan. At the time we were going through wet, dirt sections of road. I noticed the speedo would flicker back into life after it dryed off.

It has done it a few times more since then but always on a combination of wet dirty roads. Just give it a clean and dry off the sensor.

Cheers

Jim

Ekke 7 Nov 2007 10:15

Just out of curiosity...
 
How does the non-ABS F650GS speedometer work? Does it still have a toothed wheel and sensor or is it completely different?

A little aside:

I notice in my reply above that the "i"s aren't dotted since I wrote it on a Turkish keyboard. Might want to keep that in mind in case you use "i" in your password....

:stormy:

juddadredd 7 Nov 2007 12:29

Hi,

All modern speedos work in the same way

Sensor and Teeth, that way you can combine ABS with the Speedo, cuts down on costs but it does mean that both can get screwed up. Did you check to make sure that the sensor is watertight otherwise it WILL happen again.


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