Hall Sensor KT LCD5

[MistiK]

Hello
I bought an e bike off of fb marketplace. Gave it a test ride and it went great. I had to ride it home for about 40 mins. 20 mins into the ride it flashed now and again, info 3. As the battery drained it seemed to get worse.
When I got home I fully charged it and gave it a ride. I'm getting the error all the time now.
Display is the KT LCD 5, Controller is KT36/48ZWSRM-AKZ01, HL Downtube type battery 48v 13ah LNWLNW-22.04.29 is the closest thing that looks like a model number.
It will continuously happen with throttle and intermittently with PAS, some levels worse than others.
When I have the bike flipped over or I hold the rear wheel wheel up(with the motor) and apply throttle or pedal, it may flash once whilst getting to max speed but that's it. If I hop on, it happens without a doubt.
I followed the ebikes dot ca troubleshooting on testing a hall sensor. The 3 sensor wires all fluctuated between 0 and 5 whilst rotating the wheel. I did notice though, 2 of the wires were in sync and the other was not. E.G. 2 wires show 5v at once, the other 0. Rotate a bit and the volts reverse. Is that normal?
I checked for continuity from the controller end of the plug to the male endof the round plug that connects into the motor. All was good.
My settings are as follows:
P1 - 100
P2 - 1
P3 - 1
P4 - 0
P5 - 12
C1 - 02
C2 - 0
C3 - 8
C4 - 0
C5 - 10
C6 - 5
C7 - 0
C8 - 0
C9 - 0
C10 - n
C11 - 0
C12 - 4
C13 - 0
C14 - 2
L1 - 0
L2 - 0
L3 - 1

The plug is definitely all the way in.

Wires and pins all look great from controller to motor plug. It had ~120Ks when I bought it.

Attempting walk mode flashes the error for a solid minute at least until it clears to home screen.

PAS1 Will flash 03 when I first start riding briefly but then nothing until between 15-20Ks and it'll flash every other minute, it depends how hard I'm pedalling. PAS2 seems to be the same. And then it gets progressively worse until PAS5.

Throttle is hard to describe, when first starting, from a low speed it'll work fine until ~15Ks. Then it's flashing error on and off constantly. If I go from cruising in PAS fine and switch to throttle (or throttle + pas) the motor will run but won't actually do anything and I slowly lose speed

Not sure where to go from here as so far it seems the tests conclude that the hall sensor is fine. I would appreciate any help as I bought this to commute for work. This is also my first time using a multimeter and whilst I have an interest in it, I don't actually know that much about electronics.

Thanks in advance.

 

[amberwolf]

followed the ebikes dot ca troubleshooting on testing a hall sensor. The 3 sensor wires all fluctuated between 0 and 5 whilst rotating the wheel. I did notice though, 2 of the wires were in sync and the other was not. E.G. 2 wires show 5v at once, the other 0. Rotate a bit and the volts reverse. Is that normal?

They should all change independently, so you get a pattern like this (random google find)


If two of them always read the same, for all six steps, then you probably have wire damage in the motor cable that is allowing them to short together. That's usually at the exit from the motor axle, a scrape or a pinch. It can sometimes be a pin bent over in the connecting cable so that two are touching each other.

That should cause a fault all the time, so I don't know why it's different in different modes, etc.

 

[MistiK]

They should all change independently, so you get a pattern like this (random google find)
View attachment 351243

If two of them always read the same, for all six steps, then you probably have wire damage in the motor cable that is allowing them to short together. That's usually at the exit from the motor axle, a scrape or a pinch. It can sometimes be a pin bent over in the connecting cable so that two are touching each other.

That should cause a fault all the time, so I don't know why it's different in different modes, etc.

Thank you for the info. I've just tried this again and I can't get row 2 and 3 to show up. It's a little painful on my own so I'm going to give another shot to make certain with the wife helping me.
A short in this sense basically just means there are 2 or more wires exposed, somewhere, and they're touching together, is that correct? Thank you.

 

[MistiK]

I did a thorough check and I'm unable to get the 5th row [0 - 1 - 1] to appear. Every one keeps telling me it's a short, so I did the following to try and short it out myself; throttle held down and jiggled, bent, twisted and tugged the plug and leads at the same time. With the throttle down I used a spanner to tap the controller and the axle.
Nothing happened, the error only occurs when it's first turned on and then throttle applied (bike upside down) or if I'm on it.
I changed c5 to 9 and 8 and the bike didn't like it at all, threw the error up and refused to work.
I do note as well when using the multi meter I found a spot where all 3 sensors had no voltage and errored out.
Thanks.

 

[amberwolf]

Thank you for the info. I've just tried this again and I can't get row 2 and 3 to show up.

I'm not sure what you mean by this. Does it mean there is no result at all on the motor position that should give those patterns? Or that you get a different pattern?

If you draw your own table up of your results, just like that one, you'll probably see the pattern.

A short in this sense basically just means there are 2 or more wires exposed, somewhere, and they're touching together, is that correct?

Essentially, yes. The short (short circuit) means that there is enough of a connection for either of the sensors that are unintentionally connected together to ground the connection of both. So you will get more 0v readings than you should, and on those two wires you'll get the same reading at the same time on both wires.

The short itself can be anywhere between the actual sensors and the controller's circuit board. The most likely place is at the axle-wiring exit of the motor, since that's the most commonly-damaged part of the whole wiring path.


If it was just a failed sensor, you'd have one wire stuck at ~5v or at ~0v, or at some voltage between them, but since you are always seeing the same voltage at the same time on two of them, that would be a short.

The only other way you'd see the same reading at the same time would be if the two sensors were in the same slot, or are in equivalent slots reading the same set of magnets for a single phase, instead of slots that let them read separate phases. That's only possible as a factory defect or a bad repair, it shouldn't be possible if the system was working and then just isn't.