PAS stopped working?

[Ilya]

Hey,

I have a 36V, 250W, ananda rear motor hub ebike , that's pushing just beyond 10 000 km. Today it abruptly just stopped outputing power during pedaling. No error codes. The "walk mode" works when I push that button, so the wheel spins, but it just won't give power when I pedal myself.

So I'm guessing it's a PAS problem? The wire is exposed to the elements close to the front gear wheels facing the street, but no apparent damage there. It's a three wire cable. I checked the connections at the control box embedded in the frame. Tried to open it to check voltages, but seems to be fused or glued shut. To do this I have to remove the battery as well, which complicates things even more. At the wire I could measure a low voltage of 0.2V between probable ground and the other two connections for some reason (no battery power). I was hoping to see changes while spinning the pedals, but no clear result. I also tried playing around with a magnet in the general area, without any effect. This is the sensor ( M5 EP1020750) : PAS Sensor för Elcykel Elinor/Elian/Elliot/Eladio which doesn't seem to be in stock (trouble finding replacements?)

Am I overlooking something? Could the issue be something else?

 

[Sturmey]

I have changed 2 PAS sensors on different bikes in the last few years. One was a Kingmeter sensor with the open magnet disc, the other was a KT compact type. In all cases, the bikes worked with 'walk assist' but the motor would not kick in when pedaling. I also had problems with the magnet wheel moving and widening the gap on the open disc type (when the chain came off etc)
It may be important to get the exact correct replacement as there is a difference in types (e.g Left or Right side) and in sensitivity and number of magnets etc.

PS. One thing that you can physically check is that the magnetic disk is actually turning when you pedal as they can loose their grip on the axle. Can be problems also if the bottom bracket bearings are very loose.

 

[E-HP]

Hey,

I have a 36V, 250W, ananda rear motor hub ebike , that's pushing just beyond 10 000 km. Today it abruptly just stopped outputing power during pedaling. No error codes. The "walk mode" works when I push that button, so the wheel spins, but it just won't give power when I pedal myself.

So I'm guessing it's a PAS problem? The wire is exposed to the elements close to the front gear wheels facing the street, but no apparent damage there. It's a three wire cable. I checked the connections at the control box embedded in the frame. Tried to open it to check voltages, but seems to be fused or glued shut. To do this I have to remove the battery as well, which complicates things even more. At the wire I could measure a low voltage of 0.2V between probable ground and the other two connections for some reason (no battery power). I was hoping to see changes while spinning the pedals, but no clear result. I also tried playing around with a magnet in the general area, without any effect. This is the sensor ( M5 EP1020750) : PAS Sensor för Elcykel Elinor/Elian/Elliot/Eladio which doesn't seem to be in stock (trouble finding replacements?)

Am I overlooking something? Could the issue be something else?

You can check your PAS sensor using a USB 5V supply. You'll need to be careful connecting to the pins of the PAS connector, at least for the +5V (I've seen people make a little probe extension with wire and heat shrink, and stuff like that). Check the second half of this video.

If the PAS is OK, then it could be the controller. If it's bad, then a good pic of where/how the stock one is mounted would be helpful.

 

[Ilya]

Yesterday I found a somewhat overpriced replacement Köp Ananda Hastighetssensor 550mm - Svart på HBS . Since it seems to be out of stock everywhere else I did not have much choice.

I've been using the bike anyway, which is a bit nightmarish, but at least I get to where I need to. Intended to work on it now, but out of the blue it just works, which is good in one way, but somewhat random and unreliable. The only thing I did, yesterday, was to lubricate the chain. I've been biking in frost and snow. Maybe dirt was obstructing something or road salt caused some corrosive damage. At least that should rule out a controller problem. Connections are likely good along with the wire, or I would have expected disconnections due to bumps and what not.

So if it stops working I will begin by cleaning the area, apply some oil. If it doesn't work then I'll just remove it and replace it with the new one, while troubleshooting the issue. I saw that someone here had added an arduino to emulate pedaling, which could be a convenient temporary bypass if things don't work. Removing the proprietary controller could be a better solution though.