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Throttle-By-Wire


Dragonstale

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Dragonstale

Has anyone experienced this problem?  Bike it’s a 2021 NC750X.  Riding normally about 3,000 rpm.  Suddenly the rpm’s dropped to idle speed and throttle didn’t work, check engine light came on.  Was able to start bike and throttle worked normally for about 500 feet then same issue.  Got bike home and 24 hours later I went and checked it and now the check engine light was off and bike operated normally.  Has anyone else had this problem and if so is there a way to reset computer manually?  Any suggestions will be appreciated.

Jay in York, PA USA

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Andy m

Welcome to the forum.

 

There is no such thing as a reset, that's just dealer talk for clearing the error memory to hide what they don't understand. 

 

You sound like you have an intermittent problem which will be in one of the physical parts, either the twist grip assembly or more likely the wiring loom. Also check the battery, nothing likes low voltage and modern batteries are **** . Don't fall for the "it's electrical and scary and full of demons and must be a design fault" voodoo, it just isn't the case. If you can't find anything you want someone to put an OBD reader on and watch the throttle reading. Should be smooth and able to go from any reading to any other. 

 

I have not seen a 2021 NC. Is it really a wire from grip to ECU? Mine (2016) was a bowden cable and TPS. TPS's are cheap rubbish with moving parts, so an obvious failure possibility. They can be tested with a multi meter, just a three wire potentiometer that usually fails by going open circuit. 

 

Andy 

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baben

The recall  was for an ecu issue so it might well be that but my money is with Andy, especially the battery connections. Dodgy connections can cause all sorts of problems. Oh but one thing Andy got wrong - electrickery is voodo/black magic - trust me on this.

Edited by baben
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  • Haha 3
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Xactly

Doesn’t ride by wire simply move the tps to the twistgrip, eliminating the need for a throttle cable. Still a potentiometer isn’t it?

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MatBin

Battery/connection problems? On a 1 year old bike?

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baben
14 hours ago, MatBin said:

Battery/connection problems? On a 1 year old bike?

Quite possible!

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Andy m
15 hours ago, Xactly said:

Doesn’t ride by wire simply move the tps to the twistgrip, eliminating the need for a throttle cable. Still a potentiometer isn’t it?

Could be, but could also be a shielded magnet type thing. Big square wave goes in, stretched or compressed square wave comes out. Only varies with the control position not temperature and there are no moving electrical contacts. You only get 255 throttle positions because its digital, probably less because some will be allocated to errors, but given the signal eventually ends up in a computer anyway it hardly matters. Failure is still going to be battery, loom, sensor, electronic hardware, software, in that order. 

 

Andy 

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listener
28 minutes ago, Andy m said:

Could be, but could also be a shielded magnet type thing. Big square wave goes in, stretched or compressed square wave comes out. Only varies with the control position not temperature and there are no moving electrical contacts. You only get 255 throttle positions because its digital, probably less because some will be allocated to errors, but given the signal eventually ends up in a computer anyway it hardly matters. Failure is still going to be battery, loom, sensor, electronic hardware, software, in that order. 

 

Andy 

 

Going by the diagrams I've seen of t-b-w actuators they usually have around six to eight wires coming from them.

Two would be power and ground, the others I think are connected to two potentiometers.

 

But as you say, they might be Hall sensors like with ABS.

Or it could be a Gray encoder disk.

 

 

  

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