Why would my ebike motor start running when brakes are de-pressed?

beanisboy

Pedelecer
Oct 30, 2019
47
1
I have just bought a smartmotion e-urban that is 7 years old.

Lovely bike, but it has a small fault.

When the brakes are plugged into the controller the motor starts running. It only stops when the brakes are pressed.

The throttle is also not working, which I don't mind, but maybe this is what is causing it?

All works as normal if throttle and brakes unplugged. When i plug in brakes but leave the throttle unplugged the fault occurs, and it also occurs when all three are plugged in.

Perhaps a new throttle will help? It seems the controller thinks the brakes are the throttle?

I've attached the spec for the bike in case that helps
 

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AGS

Esteemed Pedelecer
Feb 12, 2023
608
190
Maybe someone has been messing around with the wiring and connected the throttle connector to the brakes and brakes connector to the throttle.
 

beanisboy

Pedelecer
Oct 30, 2019
47
1
Maybe someone has been messing around with the wiring and connected the throttle connector to the brakes and brakes connector to the throttle.
Good thinking, but I have looked, and the throttle is a yellow connector and is in the right place.

So that maybe rules out the throttle as an issue. Also with the throttle unplugged the brakes still act like throttles - weird
 

AGS

Esteemed Pedelecer
Feb 12, 2023
608
190
Some controllers have the facility for brakes high or brakes low to operate.

As an example, brakes high need 5v to the input to cut the motor and brakes low need 0v to the input to cut the motor.

So that’s another thing to check if you have a multimeter.

Are you able to post a photo of the controller and wiring, specifically the throttle and brake connectors?
 
  • Agree
Reactions: flecc

beanisboy

Pedelecer
Oct 30, 2019
47
1
yellow is the throttle wiring, red are the brake wires.
The controller is obviously degraded, but seems to work fine.

All seem to be original, so I don't think faults in voltage would be an issue... or at least I'd hope not.

Also it's inetersting that both brakes make the bike do the same thing. Perhaps the controller itself is at fault? I di knew the model I would replace it
 

AGS

Esteemed Pedelecer
Feb 12, 2023
608
190
Crikey, that’s had a hard life. It looks like the cover for the rear brake switch is missing, does the switch operate properly?
 

beanisboy

Pedelecer
Oct 30, 2019
47
1
Ah, that's just a sticker or something that has faded, the cover is intact and the switch operates properly.

I am leaning towards it being the controller, because it's both brakes doing the same thing. And the issue occurs whether or not the throttle is plugged in or not.

So it's something weird about the brakes. And it happens whichever brake is plugged in, or whether both are plugged in.
As soon as either one is plugged in, the motor kicks in, and only stops when the brake is pressed

problem is - I imagine these controllers are specific and hard to get hold of?

Hard life yes! but I got the whole bike for £80 ! and the battery seems good, and the motor works well. It just needs new chain cassette and pads
And this problem fixing :D
 

beanisboy

Pedelecer
Oct 30, 2019
47
1
Ok, it must be controller - I just test rode it without brakes or throttle plugged in, and at one point it randomly didnt turn the motor off... so i had to stop and turn whole thing off and on again

I maybe need a new controller? Can I use an aftermarket one?
 

AGS

Esteemed Pedelecer
Feb 12, 2023
608
190
First of all try to identify what motor and what controller you already have. Again photographs posted on here help.
 

AGS

Esteemed Pedelecer
Feb 12, 2023
608
190
I’m guessing a bit here, but that looks like a Dashi display which is compatible with a Luishi controller. The controller may be integrated into the battery holder. If it is then the good news is all of this stuff is cheap to replace.
 

beanisboy

Pedelecer
Oct 30, 2019
47
1
I know the motor is 300w, or so says the PDF> But it just has the companies branding on it.
The battery is 36v 15.6ah
 

beanisboy

Pedelecer
Oct 30, 2019
47
1
Oh, and the top button on the display which on long hold turns the unit off and on. When pressed short press it turns lights off and on
 

beanisboy

Pedelecer
Oct 30, 2019
47
1
And finally, if this isn't too much info, when the throttle isn't plugged in I get error 34 which says faulty throttle (makes sense if it isn't plugged in)
But when brakes and throttle plugged in, i get error 34 only whn I press the brakes to cut the motor


Error codes read from this

Not sure - maybe better to replace everything unless it's just likely to get a faulty cable somewhere?
 

AGS

Esteemed Pedelecer
Feb 12, 2023
608
190
It doesn’t look like it has been hacked about and Ananda is proper motor/controller manufacturer. Even Smartmotion are still in business.

It’s not possible to diagnose what’s going on without a multimeter to check voltages across pins and continuity of the cables. And it’s even harder when you are trying to do it with waterproof connectors without proper test equipment.

So you will probably end up having to replace stuff. I guess now you know why you picked it up for £90.
 

beanisboy

Pedelecer
Oct 30, 2019
47
1
It doesn’t look like it has been hacked about and Ananda is proper motor/controller manufacturer. Even Smartmotion are still in business.

It’s not possible to diagnose what’s going on without a multimeter to check voltages across pins and continuity of the cables. And it’s even harder when you are trying to do it with waterproof connectors without proper test equipment.

So you will probably end up having to replace stuff. I guess now you know why you picked it up for £90.
I have a multimeter. But am not sure how to check things and where to look.

If I was to replace the controller, do you know which one will be a direct replacement? I cannot find a Luishi that has the same connections
 

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