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Discussion Starter #1
Hi, I started the bike and when I was waiting for the bike to warm up a throttle error showed up. I could not start the bike for 5 min. After that the error was gone, and I rode the bike for 10min, and I started it a few times with no issues. What does the error mean? Any ideas? I'm concerned something might be about to die. Thanks
 

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I would think, after reviewing the maintenance manual, that the error is related to the potentiometer that tells the ECU how much throttle is applied at any particular time.

If it starts to happen with increasing frequency, it is probably time to clean and inspect the connector (at the throttle body) or replace the sensor.

A TPS test and reset via diagnostics software could probably tell the issue.
 

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Discussion Starter #3
I'm not sure I have the right manual, where could I find it? In which page did you find the information?

Thanks
 

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Donsy provides the manuals free of charge at the top of each maintenance section.
There are multiple sections in the manual that describe Throttle Position and how it is used in the process of providing fueling to your bike.
There are multiple sections of the manual that describe how to set Throttle Position.
You need the diagnostic software to do it.

The manual I referred to is the Chassis Manual for Brutale 990-1090.
 

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Discussion Starter #5
This issue happened twice again, and I'm thinking about replacing the potenciometer, do you know the part number? Where can I buy it online? I have not been able to find the info.

Thanks!
 

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@jrebollo: After extensive searching, it appears the potentiometer (TPS) is part of the throttle body assembly on the B4 series. I cannot imagine that to be the case.

I'll let you know if I find more information. As for now, you can look at diagram G13 for the throttle bodies and you'll see the potentiometer in the center of the TBs.
 

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Discussion Starter #8
Thanks for looking into it. I also spent a good amount of time looking at the parts diagram and I came up with the same conclusion. Not sure why the don't have it as a separate item.
 

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Discussion Starter #9
Hi, It has been a few months since a started this post, but I was finally able to fix the issue and I wanted to share my experience. As I previously mentioned the bike was having some "Eng Fault Throttle" errors. The error would show up, and go away after letting the bike sit for a while (sometimes days). Initially, I thought the issue was a faulty throttle sensor, but since I could not figure out the sensor part number, and the throttle was failing only sometimes, which I could not understand, I decided to better understand the issue before replacing anything.

I read about JPDiag, and Guzzidiag, which you can download for free (the authors accept donations), and I decided to try these to better understand what was going on. Both diagnostic software were able to connect to the Brutale ECU, and read the data. While looking at the ECU values, I noticed that both the throttle sensor and the air pressure sensor were providing very low values when the bike was showing the error. Next, I removed the tank and I measured the voltage input to these sensors. They both had about 2.5v, instead of 5v. Both sensors are connected to a 5v output of the ECU. Finally, I left the multimeter connected, and I started moving the harness cables around, suddenly the voltage went up to 5v! One of the screws near the top of the engine was pushing into the harness, connecting the 5v wire input to the sensors to ground (I'm attaching a picture).

I still need to go for a ride (too much ice on the roads around here), but after I better protected the harness, and moved it away from the screw, I have not seen any errors. It took me a long time to solve the issue, but I did learn a lot in the process, and JPDiag/GuzziDiag are great.

Thanks
 

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Great work @jrebollo :yo:

Thanks for the update and resolution. A great exercise in proper diagnosis process. The 5v signal is an essential part of the system and your MV is not the only example I know of where compromised base voltage caused difficult to diagnose problems.

Glad you have it sorted ;)
 
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