Problem of vicious ABS, and its resolution

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gapiob

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Note : in this post, I try to describe how we managed to find the error of abs, and this in an English not too fake ... I hope that is comprehensible.

Since Three weeks, a member of fjr-passion-gt forum, (a French forum) had an issue with it's ABS.
A permanent red light on its board, and ABS signal stay highlighted. And this, since the last revision.

He took his motorcycle to yamaha, who at the end of 2 hours, just made a purge, and nothing solved ...
They were content to tell him that the system ABS was dead (ECU ABS + hydro).

In short, yamaha did nothing, and just looking to make cash ....
Overall, it is very likely that both will lose at the same time. Moreover, a failure of the ABS pump is rarely visible by the ABS ECU ... And this one is very simple to test.
So with another member of the Forum, it is proposed to go home Friday evening... Objective to give back this damn ABS.

Ok, So Saturday around 6pm, they arrived at home. We discuss 3 minutes of his problem..
And first good news, speed is displayed... So ABS ECU and rear ABS sensor cannot be broken...

Well, we start... First step, What does the ECU ABS tell us?
As explain in the Workshop manual. (in french sorry)
debug_11.png

We look at the oscilloscope on pin 9. Cool, to the scope we find 2 error code, the 25 and the 41.
Good, but overall this helps us not very much ... it just tells us that the ECU is still functional. (The ABS sensors had already been checked)

Then checked at the terminals of the various connectors in connection with the ABS ECU if there are none that seem curious ... And the bingo, D connector has these 2 lines to the ground ... curious
So what's the use of this connector? In fact according to the electrical plan it allows to power the ABS engine, nothing else ... and the presence of voltage is also present at the terminals of the ABS ECU. So finding a mass here is really strange... there, we take an idea...


abs_212.jpg

This line goes up to the fuse of the ABS engine. The fuse is good ... snif, it would have been too simple ...

Well we continue our recovery towards the source of the problem. And there is not much between this fuse and the battery ... Normally nothing according to the plan ... After verification, no voltage to the bornes du fusible!!!How is this possible ????? Simply if the block on which the fuse (and the starting relay) is mounted is upside down ...
This is one of the only item on the FJR or there is no keyway, and when the latter is mounted upside down, nothing prevents the start of the bike ... there's just the damn fuse Which finds itself at the mass instead of being at + 12v ...

Puts it back in the right direction, and there ... everything works normally, the first time.

It remains to celebrate this victory !!! And of course, it was with rhum!

dsc_1010.jpg


 
Funny I had to replace my starter relay and I put it in backwards or as you say upside down. Same issue, the extra fuse in the relay can really throw you off when reinstalling the relay.

 
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