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Discussion Starter #1
Hi to all. 2014 F4. As soon as 2 years warranty expired abs light starts popping up, ones in a while in the beginning but more and more often. After a few months it lights up EVERY time I start the bike. Abs doesn't work anymore. No errors codes found (dealer said). I am a mechanic myself, have a motorcycle shop, always trying to fix things myself if possible before paying big bucks to MV dealer. Any help with this issue will be greatly appreciated.
 

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Hi,
on mine the ABS lights and then goes off after I have started moving. Its looking for valid signals from both wheel sensors. First thing I would do is check the distance between the sensor and the slotted disc. I'd set it for mid range to start with and the see from there. Make sure the sensor is clean too.

The ABS module has its own diagnostics which can be checked by the dealer. I thought that the ABS stores its errors i.e if either of the pressure sensors fail, but I might be wrong.

.
 

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Do you have a DropBox Account - if you do you can download the Workshop Manuals form my link and go through that - https://www.dropbox.com/s/78lprzohhbv7rws/mv_agusta_ f4_y13_s_r_ft_rr_workshop_manual_ed3.pdf?dl=0
If you look at page 284 through 286 of the F4 workshop manual ed.4 shows how to check and adjust if required the clearance between the sensor and phonic disc.

Page 193 shows the wiring diagram (top right hand corner N°18 & 54)

http://www.mvagusta.net/forum/showthread.php?t=165833&highlight=diagram


The sensors are 2 wire versions and without an oscilloscope you will struggle to test the sensor its self, as you really need to see the waveform not just voltage changes.

Also check the ABS fuses Page 216

The dealer can check the 2 sensors and the internal pressure sensors of the ABS module using the TEXA Page 227 to 232. It is worth checking the connector and the condition of the wiring just in case.

I have ECUStudio so I can see the individual wheel speeds so it helps me check check operation.

As I said I'd check that the sensors are positioned correctly first.

What are the exact faults conditions?
I tried creating a fault, regardless of the method, fuse or sensor, the ABS light came on at start up (as expected) and the instead of going off after a few metres a large warning triangle filled the dash board screen with "ABS Fault". Is this what you are getting?

Is the ABS in Normal, Race or off mode?

How do you know the ABS is not working?

Cheers
 

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Discussion Starter #7
Thank you Donsy for manual and Dansoarr. All that I have is a small yellow light in the upper side of dash which supposed to go away when I start moving. It never goes away now, it is lit up all the time. I guess ABS doesn't work because of that but I am not really sure if it ACTUALLY stop working. I never had a big triangle warning on the screen and dealer said there is no fault codes in the memory. Ill try to adjust sensor and check plugs and connectors. I will let you know. Thanks a lot.
 

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Thank you Donsy for manual and Dansoarr. All that I have is a small yellow light in the upper side of dash which supposed to go away when I start moving. It never goes away now, it is lit up all the time. I guess ABS doesn't work because of that but I am not really sure if it ACTUALLY stop working. I never had a big triangle warning on the screen and dealer said there is no fault codes in the memory. Ill try to adjust sensor and check plugs and connectors. I will let you know. Thanks a lot.
Tosha,
just a quick silly question, is the ABS turned off in the dash menu?

If it has been set to Off accidentally, then the light will remain lit. If the ABS is set to Normal, then the light will turn off. From memory if the system is in Race or Off then the light will remain on to inform you that the system is not in the factory Road / Normal setting.

If the ABS system is faulty then the triangle should come up.

Its worth a quick check to see what the setting is. At the very least i would change the setting to Off, check it, then to Race and check again then to Normal and check again. The ABS works on the front and rear, so if you want to check the operation of the system and you are nervous of locking the front, just try to lock the rear on good dry smooth tarmac (clutch in). No ABS = Locked up and skidding, ABS = no lock up and a little juddering.

Good luck

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Discussion Starter #9
Abs in "normal" and "race" settings behaves the same, simply stays lit all the time. I did not switched it off. Like I said in the beginning the light comes on ones in a while. After restarting the bike it usually disappears. Then it become more and more often and finally it's just stays on all the time. It's like something gradually become inoperable, sensor may be. Weird.
 

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Cross-reference the part number...
 

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Hello
I hope you don't mind me jumping in with an ABS issue

I went for a mountain ride yesterday for the first time in a while. Half way back my brakes became soft and doughy. At this time the orange ABS light started to go on and off. Then the "ABS RACE" on the screen started flashing. No error and no big triangle but the ABS light and ABS RACE writing were flashing madly.
I will be careful and get it fixed but this brake failure caused me to drift in to oncoming traffic. It was a very close call.

Can anyone shed some light on what is going on?

Thank you
Clay
 

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Hello
I hope you don't mind me jumping in with an ABS issue

I went for a mountain ride yesterday for the first time in a while. Half way back my brakes became soft and doughy. At this time the orange ABS light started to go on and off. Then the "ABS RACE" on the screen started flashing. No error and no big triangle but the ABS light and ABS RACE writing were flashing madly.
I will be careful and get it fixed but this brake failure caused me to drift in to oncoming traffic. It was a very close call.

Can anyone shed some light on what is going on?

Thank you
Clay
I guess the first thing is to ask if they are still spongy with the ignition off?
Again with the system set to ABS off?

Disconnecting the ABS module electrically 'should' restore the basic brake function, as, unless you have a valve fault in the module. Likewise setting the ABS to Off should have the same outcome.

If you are not getting the large triangle on the dash that covers everything up, then the ABS module is still talking to the rest of the system. The Bosch system works independently of the main ecu, but shares sensors. If you are getting the ABS light flashing, then I'd start by inspecting the ABS sensors to see if they are clean and undamaged.

For the system to go spongy and the lights to flash it suggests that the module may think the wheel is locking or close to it.

If you have to ride, I would set it to ABS off. If you disconnect it electrically you will get the warning triangle all over your dash.
 

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Thank you mate
You have replied to a couple of my issues lately and are a great help.

I will test the bike with the ABS off and see how we go and check the sensors.
 

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Hey Tosha
Did you have any luck with your issue. Yes the photo shows that your sensor if melted. I have been having issues with my 2013 F4 as well
I disconnected the rear sensor at the connector and all my issues have disappeared. I have ordered a new sensor and hope that it is the problem
I believe the sensor you need is part number 8000B7768 and yes it is the same for the 14 F3.

Hope you have this all sorted by now
 

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Discussion Starter #18
Problem solved!!

I replaced rear sensor with one from F3 and it did not help. I lost hope but some time ago my horn started acting weird and I decided to replace it. I removed front black cover that covers horn and found where my problem with ABS was hiding from me! The wire for front sensor was broken and since that wire was in insulation (like a cloth tube) it was unnoticable. But I saw suspicious cloth treads in two places on that tube and when I cut it open I found broken wire. I soldered wire back together and that was it!!! Obviously a design flaw because wire was broken after 2 years from handlebar moving right and left. Only 10K miles on the bike. I am glad my horn went bad otherwise its very hard to find the solution to that problem.:laugh:
 
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