Hall sensor error kt lcd5

MistiK

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3:41 AM
Joined
Apr 16, 2024
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Location
Australia
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 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.
 
The general consensus is that it would be a hall sensor problem, since it is not a new bike, wire chafing or pinching could be an issue. There is an odd fellow on YouTube, Hightech//lowlife, Hall Sensor Testing, he will show you how to check the wiring, initially with the wheel still on, so you can see if the problem is outside the hub or if you have to go inside to the phase wire board. I know it sounds like being thrown in off the deep end but you won't hurt anything mucking about back there to check a few things. Other people with similar problems have had it turn out to not be the controller. Let us know what happens. I'm a bit out of my depth on this one too.
 
Here's what I did: changed c5 setting to 8 and 9 (lowering current). The bike didn't like it at all. Threw the error, wouldn't go at all and took a bit for it to get back to "normal".
Retested voltage at the plug
I was shown a picture of how hall sensors should test/change independently of each other, resulting in 6 configurations of different states of the sensors. I got all but one to show up.
I found a position for the wheel that showed 0v to all 3 sensors, this obviously caused the error and wouldn't go at all.
Not wanting to cut the lead to look for a short, I thought I could purposely cause one myself. With the throttle applied I twisted, pulled, tugged, bent the lead in various places especially where the zip tie was tight and where the lead enters the hub.
I also used a spanner to tap the axle and controller. This didn't lead to anything.
Does this still sound like a short and should my next move be looking inside the hub?
 
This is not my area of expertise but you said you had 1 sensor not show up. I'm guessing you may have a break on the hall sensor circuit board, or simply where they connect. There are a number of videos on checking the board or replacing it. If it were me, I would now watch a bunch of videos until I felt comfortable and then I would open the hub. I wish I could be of more help but I have not yet had this particular problem.
 
A second thought, you said you had a dead spot on the wheel? Maybe someone could chime in here if they know whether a loose or lost magnet would cause this.
 
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