New controller will walk assist, but not throttle

[LisaMiza]

Hi! I've been lurking through threads here over the past few months to better understand my DIY Ebike project. As someone who prefers to fix and repurpose rather than dispose of electronics, I may have taken on more than I initially bargained for! I'm hoping to find some knowledgeable individuals, even if it's just a straight up "you done goofed" from a fellow nerds.

I own a Danish brand SCO E-bike with a Promovec drivetrain from the mid 2010s. The bike was built on a cheap supermarket bike platform and shares similarities with Aldi models that use similar electronics. The thing that started my months long saga, was that my bike started stuttering instead of driving, leading me to suspect the controller was faulty. After trial and error, I replaced it with a new SL-QX041KZ controller from amazon (which I initially thought was a KT controller).
Unfortunately, this new controller displays an Error 7 "Motor" error according to its manual.

My current setup looks like this:

The wiring is still in disarray lol
The battery cells and BMS were replaced some years ago. It's 36V. The motor is hall-less, and I recently installed a new PAS controller on the left side (not pictured). The setup allows me to activate the walk-assist, which enables the bike to run without throttle input from either the PAS or a makeshift throttle wire solution.

I've double-checked my settings on the display, but I'm still stumped. Specifically, I want to know if the new controller is incompatible with hall-less motors. Any guidance or advice would be greatly appreciated!

Thanks for taking the time to read and help me troubleshoot

 

[indianajo]

The PAS pickup could be defective or have a different pinout than the controller expects. There is usually one +5 v, one ground, one sensor input. I can usually spot the +5 and ground with a DVM. Fashions in pin arrangement change over the years, and I have no experience with 2015. I electrified in 2018.
The throttle input could be defective or have different pinout than required instead. One +5 v, one ground, one signal to controller. Some analysis could help.
Brake inputs could also be stopping the controller from responding. My 2018 controller required +5 v input to stop the power. Later ones require an open contact between the two wires to stop the power. IE brake input has to let current flow to allow the motor to run.
Some controllers require an enable to run. Something called "door switch" wire has to have battery hot to it before the controller will operate. I install a toggle switch in a pill bottle (to shed rain) under the seat. These controllers, I pick up the battery hot from the alarm power connector.
Failing that a new controller could help, or either of the sensors. If you want to save time, a power wheel kit with a new motor, wheel, pas pickup, throttle, controller, all bought at the same time, should be compatible. Or if you are good at lacing wheels, a motor kit less the wheel. Those, the only thing you wire up is the battery hot and return. Motors without hall effect rotation sensors are obsolete.

 

[PedalUma]

I strongly think it needs an internal motor cleaning with fresh synthetic grease. I work on eBikes professionally all day, everyday. The grease gets dried and dirty causing sputtering. It is mechanical, not electric. One test this theory is to see how freely it rolls backwards.

 

[PCeBiker]

After trial and error, I replaced it with a new SL-QX041KZ controller from amazon (which I initially thought was a KT controller).
Unfortunately, this new controller displays an Error 7 "Motor" error according to its manual.
,..The setup allows me to activate the walk-assist,

I think that the "Error 7 Motor" means that your controller isn't receiving Hall sensor data?

,.. Specifically, I want to know if the new controller is incompatible with hall-less motors.

I think that you need a sensorless controller. (Not to be confused with a brushless controller. )

This is your wiring harness for your controller,..

It not only has a Hall sensor connector, but it also has an intelligent identification wire.

I'm almost positive that your controller can't "see" the motor so it's not working?
I don't think the intelligent "learning" wire will work if there are no Hall sensors in the motor for the phase wires or speed sensor magnets ?


You know that your motor is working, because it works in walk mode, so I think a new controller/display will get your ebike going.

I found this smaller sensorless KT controller on Amazon, but it's got the waterproof connectors,..
(It says "with Hall" but that's referring to the PAS sensor.)

It doesn't need to be a KT controller, and I'm thinking that a lot of the functionality of a KT controller/display won't be available to you anyway without Hall sensors or speed sensors in your motor, so a cheaper KT display is probably all you'll need.

Or another motor controller/display combination for a sensorless motor.

The sensorless controllers/displays tend to be square wave and cheaper as well, but AliExpress has a lot more to offer, and you can find one with the correct connectors for your motor.

I found this sensorless KT controller but you would still need a KT display to go with it.

https://a.aliexpress.com/_mP8WDEf

 

[Slaphappygamer]

With the new set up, you mention that the motor works only in “walk” mode. I had that same S866 display on my scooter. It defaulted to “non-zero start”. This means that the scooter had to be in motion before throttle would be enabled. Try spinning the motor, then using the throttle. These is a setting that you can enable “zero start”. Then your throttle will always be active.

But as PCebiker mentioned, you may have to try the “intelligent recognition” wire. Since you can enable walk mode, then maybe the wheel spins in the correct direction. The way “intelligent recognition” works is, BE SURE THE WHEEL, AND PEDALS, CAN SPIN FREELY, then connect the green mating wires together. You can do this before or after you power on the bike. This will make the wheel spin. If it spins backwards, YOUR PEDALS WILL SPIN. Once good spin direction has been achieved, then you just unplug the “intelligent recognition” wires and tuck them away.

I should also mention that my controller was also “Brainpower” and worked with my direct drive motor. “Intelligent recognition” worked well. Then again, my motor has hall sensors. I don’t know if “Intelligent recognition” works without hall sensors.

 

[PCeBiker]

I don’t know if “Intelligent recognition” works without hall sensors.

I'm guessing that it won't work without hall sensors ?
Sensorless motors have no outputs to analyze.
I'm speculating though. It'd be cool if it does work.

 

[harryS]

You bought a brainpower controller AND the S866 display, First time you power up the display, you do it with the two intelligent jumper wires connected. The controller will inspect the sensor and phase wiring and turn the wheel forward. Then you disconnect those jumpers, insulate the ends, and never connect again, The controller has done its "intelligent learning".

Walk mode should work, Pas should work, Throttle too.

If throttle won't work it's usually because the new throttle's wires don't match the connector. Pedal assist sensors have the same issue, but are complicated by need to orient the disk in the right direction on the pedals. It can face the wrong way,

Walk mode demonstrates that the controller - motor wiring is understood by the controller. Running a motor is pretty complex and walk mode proves all is well. I use walk mode to prove my controllers work, when I get into situations where throttlr and pedal assist are dead.

 

[PCeBiker]

You bought a brainpower controller AND the S866 display,

Walk mode should work, Pas should work, Throttle too.

Walk mode demonstrates that the controller - motor wiring is understood by the controller.

Does that mean the e-bike should work?
Will the controller/display operate a sensorless motor?

 

[LisaMiza]

Oh waow That's a lot of responses! Thank you all! Time to respond

 

[LisaMiza]

The PAS pickup could be defective or have a different pinout than the controller expects. There is usually one +5 v, one ground, one sensor input. I can usually spot the +5 and ground with a DVM. Fashions in pin arrangement change over the years, and I have no experience with 2015. I electrified in 2018.

I have both newly bought PAS and controller, so I really hope the pinout would be the same. I did try and rewire with breakout cables with my old PAS, but that one is on the right side anyways, so i'm not sure if the controller would ever like it. I think it sends an inverted signal if on the right side, no?

The throttle input could be defective or have different pinout than required instead. One +5 v, one ground, one signal to controller. Some analysis could help.

I've tried jumpering all the pins in all manner of ways on the throttle wires, but I don't have a throttle as I won't find that useful

Brake inputs could also be stopping the controller from responding. My 2018 controller required +5 v input to stop the power. Later ones require an open contact between the two wires to stop the power. IE brake input has to let current flow to allow the motor to run.

That is in fact correct. I think that break is shorting somewhere in the handle bit. Sadly i've also tried having no break attached too, and no change

Some controllers require an enable to run. Something called "door switch" wire has to have battery hot to it before the controller will operate. I install a toggle switch in a pill bottle (to shed rain) under the seat. These controllers, I pick up the battery hot from the alarm power connector.

My manual says nothing of such, however, there is a jumper wire thing that if unplugged stops the display from turning on. But maybe? I doubt it since it can run in walk-assist

Failing that a new controller could help, or either of the sensors. If you want to save time, a power wheel kit with a new motor, wheel, pas pickup, throttle, controller, all bought at the same time, should be compatible. Or if you are good at lacing wheels, a motor kit less the wheel. Those, the only thing you wire up is the battery hot and return. Motors without hall effect rotation sensors are obsolete.

It's what I honestly would have done if I had the money. New frame too so I can actually get one that's big enough for me
For now I have more time than I have money, and I don't even have that much time

Your comments are very much appreciated though! Thank you ❤

 

[LisaMiza]

I strongly think it needs an internal motor cleaning with fresh synthetic grease. I work on eBikes professionally all day, everyday. The grease gets dried and dirty causing sputtering. It is mechanical, not electric. One test this theory is to see how freely it rolls backwards.

I can hear that it's not even sending power to the motor nor any movement when I try with it in the air. But as a matter of facts I actually opened it up last month. Here it is if you're curious:

It was fun to take apart, but I didn't spot any mechanical problems with it. ran fine just fine

 

[LisaMiza]

I think that the "Error 7 Motor" means that your controller isn't receiving Hall sensor data?

I think that you need a sensorless controller. (Not to be confused with a brushless controller. )

Yeah i think you're right in it just giving up since there's no Hall data. But as I understood from both the listing and the interwebs is that most, if not all, controllers can handle sensorless motors, no? Since it would be getting data about the current and whatnot even from one with sensors it should be able to say "alright, I don't have all the data I want, but I guess this seems right". Or is that outdated information?

Or another motor controller/display combination for a sensorless motor.

The sensorless controllers/displays tend to be square wave and cheaper as well, but AliExpress has a lot more to offer, and you can find one with the correct connectors for your motor.

That might very well be my way forward. I ain't about to drop €200+ on a new motor/wheel. I really just need something cheap to tie me over with until i can get a new frame and completely DIY.

 

[LisaMiza]

With the new set up, you mention that the motor works only in “walk” mode. I had that same S866 display on my scooter. It defaulted to “non-zero start”. This means that the scooter had to be in motion before throttle would be enabled. Try spinning the motor, then using the throttle. These is a setting that you can enable “zero start”. Then your throttle will always be active.

But as PCebiker mentioned, you may have to try the “intelligent recognition” wire. Since you can enable walk mode, then maybe the wheel spins in the correct direction. The way “intelligent recognition” works is, BE SURE THE WHEEL, AND PEDALS, CAN SPIN FREELY, then connect the green mating wires together. You can do this before or after you power on the bike. This will make the wheel spin. If it spins backwards, YOUR PEDALS WILL SPIN. Once good spin direction has been achieved, then you just unplug the “intelligent recognition” wires and tuck them away.

I should also mention that my controller was also “Brainpower” and worked with my direct drive motor. “Intelligent recognition” worked well. Then again, my motor has hall sensors. I don’t know if “Intelligent recognition” works without hall sensors.

Mine is on Zero start, but i did also try and push the wheel to see if that helped. Sadly it did not.

the “intelligent recognition” wire

I already did make sure to have it learn, in fact tried many times after fiddling with settings. Still only walk assist.

Then again, my motor has hall sensors. I don’t know if “Intelligent recognition” works without hall sensors.

Yeah... I think I goofed. I don't think it'll work with a sensorless motor sadly
At least I can give that, and the controller on to my partners bike so they can get a diy ebike too later on. So it's not a complete waste

 

[LisaMiza]

You bought a brainpower controller AND the S866 display, First time you power up the display, you do it with the two intelligent jumper wires connected. The controller will inspect the sensor and phase wiring and turn the wheel forward. Then you disconnect those jumpers, insulate the ends, and never connect again, The controller has done its "intelligent learning".

Walk mode should work, Pas should work, Throttle too.

If throttle won't work it's usually because the new throttle's wires don't match the connector. Pedal assist sensors have the same issue, but are complicated by need to orient the disk in the right direction on the pedals. It can face the wrong way,

Walk mode demonstrates that the controller - motor wiring is understood by the controller. Running a motor is pretty complex and walk mode proves all is well. I use walk mode to prove my controllers work, when I get into situations where throttlr and pedal assist are dead.

It's all very weird, isn't it? Like, the controller very much understands how to send power to the motor. But anymore than walk assist it just never tries. It's honestly being kinda mean to me lol

 

[LisaMiza]

I'm guessing my next step would be to get another controller, one with no Hall connections. But are they still a thing? PCeBiker did post one, a KT one, so maybe go for that?

 

[indianajo]

I'm guessing my next step would be to get another controller, one with no Hall connections. But are they still a thing? PCeBiker did post one, a KT one, so maybe go for that?

Well, I bought used front 350 w bafang motors from batteryclearinghouse.com for $36 each, with hall effect sensors. Look around, Sensorless motors are from the dark ages.
Post #4 has a picture of a controller with a master switch input, which is jumpered. That must be shorted to run. The red wire labeled "hall effect" is totatly bogus. The red 14 ga wire is usually paired with the black 14 ga wire and is the hot from the battery. Those conical connectors are called "bullet" connectors at auto supplies.

, but I don't have a throttle as I won't find that useful

Controllers requiring or programmed to require a throttle, will error and refuse to work without one. Instructions for reprogramming controllers are hard to find. It took me 4 years to receive instructions of how to reprogram my 2018 controller. Amazon is not a knowledgeable vendor. There are none IMHO in the USA. I buy controllers stocked in the USA on ebay, but only ones with a picture of the connectors clearly labeled in English, not Chinese. Perhaps you can find a knowledgeable vendor in UK. IMHO a motor+controller+brakehandles+pickups+wireharness from a vendor that does not know very much may be cheaper. At least such a vendor has to guarentee it all works together, unless it takes more than 30 days for you to install it and ask for your money back. If buying a kit, make sure you buy the freewheel with it, or be prepared to buy one separately on ebay or gumtree. I have never been able to remove a used freewheel that had been installed more than a few months, and the ones that did come off I used anti-sieze compound on the threads when I installed it.

 

[PCeBiker]

Yeah i think you're right in it just giving up since there's no Hall data. But as I understood from both the listing and the interwebs is that most, if not all, controllers can handle sensorless motors, no? Since it would be getting data about the current and whatnot even from one with sensors it should be able to say "alright, I don't have all the data I want, but I guess this seems right". Or is that outdated information?

The way I understand it, is that any controller can power any motor, but it needs to be programmed to do it, or it needs to program itself to do it.

Here's what I think is going on, but I'm just speculating.


When you connect your green jumper wire, the controller sends a safe signal to the motor to get it spinning, then analyzes the Hall sensor data to try and figure out what motor it is hooked up to.

I think that in your case, the controller has no way to analyze any feedback data, so it's stuck with only walk mode speed and power that would be safe for any motor that it's connected to?

Maybe there's a way to over-ride everything and just get it to send power to the motor in some way, but I don't know about any of that?

That might very well be my way forward. I ain't about to drop €200+ on a new motor/wheel. I really just need something cheap to tie me over with until i can get a new frame and completely DIY.

I'm almost positive that the controller for a sensorless motor will work for you.


Here's the info from that link,..

And here's the wiring diagram for it,..

So it's got connections for a PAS sensor and speed sensor (magnet stuck to your wheel)



The sinewave version for a "sensored" motor has an input for what looks like a single Hal sensor ?

I would have thought three motor sensors. One for each phase wire ?

It does get kinda expensive after adding shipping, a 1-4 cable, and a display though.


These are most of the KT displays that are available,..

These are the cheapest ones,.

But those two aren't programmable.

If you get a programmable display, you can adjust all kinds of stuff, specifically the PAS sensor input to set it up for left side or right side installation, as well as input the number of magnets on the PAS sensor.


I'm pretty sure this is the cheapest programable display available,..

I went with the fancy expensive one.
You can get a horizontal or vertical version, with or without a USB port, and with or without waterproof connectors,..

If you get the KT display that you like and want to spend the money on, you can transfer it to your next build project.

It's all very weird, isn't it? Like, the controller very much understands how to send power to the motor. But anymore than walk assist it just never tries. It's honestly being kinda mean to me lol

One thing that I'm not sure about is using a "regular" KT controller to operate your sensorless motor?
You might be able to just set up any KT controller to operate your motor without any motor Hal sensor data?

I'm not sure about that, and being as there are two distinctly different KT controllers available for a motor with or without Hal sensors makes me wonder if you NEED a sensorless controller??


If a regular brushless KT motor controller/display will work on your ebike motor, then you can purchase something that can work with your next project.

If you don't go too powerful, you won't strain your bicycle components, or battery.

Too much power will kill your battery WAY quicker, and that shortens the life of your battery and motor.



Another thing to keep in mind is that the throttle, PAS sensor, speed sensor, and 3 motor phase sensors are all HAL Sensors, so you need to be aware of what you're buying and what "sensor" they are referring to.



Maybe @harryS or @m@Robertson knows if a regular KT controller can work with a sensorless motor?

I'm just not sure about that?

 

[PedalUma]

The classic diagnosis is that if walk assist works, the controller is good.

 

[LisaMiza]

So something amazing happened.
Look what I found that someone is throwing out...

A sensored Dapu 9 pins 250w 36v motor!! (From googling I think it might be the same OEM as mine)
However. There are a few issues.

1. I have no idea who is throwing it out yet, so I don't know why they're throwing it out
2. Because of no. 1. I don't know if it's shorted
3. It's in a 24 inch frame.

Could I adapt it to a 27'' wheel as I have? It's very much smaller than mine, physically. So I would need other spokes.
It'd be a new adventure, but it sounds fun. Although, I have not looked into how hard it is to swap front motors xD