SW900 Won't Go Into Program Mode

Killerchaos7

100 µW
Joined
Nov 24, 2021
Messages
8
Hello out there to all of you guys.

So, after finally getting a battery to come in for my ebike conversion kit amongst other necessary preparations, I installed it and did a little test with my bike. Seems to work really great with loads of power (didn't really ride it; I just had the bike propped and tested the throttle to make sure that it responds like it should). My only issue is that for some reason, when I try to enter program mode on the SW900, the computer never switches to it. It just stays on the screen as shown below in the image. I read the manual where it says to hold both the up and down arrow buttons at the same time for a few seconds until it changes, but nothing happens, so I can't set the parameters like the wheel size, speed limit, zero start/non-zero start settings, etc. I can make it to where you see the different speed settings (max, avg, and such), headlight on and off, switch between TRIP and ODO, setting the PAS levels from 0-5; things like that, and that's as much as I'm able to do.

I suppose my questions are why would my computer behave this way, and how does one go about fixing it?
 

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Did the display come with the controller as a set? If not, it may not have compatible firmware, even if they are the "same brand". If they are not the same brand, they probably won't work together, as there isnt' a standard for these things yet (probably never will be).

For example, I have a few of LS (lishui) controllers and a few Kingmeter displays that came with them, but the displays from one controller don't do the same things on a different controller, and vice-versa. The most common problem is they simply don't read any data from the wrong controller, or they read what little they do incorrectly. Like they may display the wrong speed, or not respond to assist-level changes, etc. The battery level meter seems to always work, but it might display the wrong level if it is a display meant for a different voltage system (I think all of mine do correctly display the batteyr level, but it's been a while since I looked at them).


Another problem is taht some controllers simply can't have any of their settings changed, so they either wont' even go into programming mode from the display, or you can't actually change any settings once in that mode. :(


In either of these cases, there isn't anything you can do about it, other than to replace either the controller or the display with a compatible unit, or replace both of them with a set sold together that you know will be compatible.
 
If they did come as a set, then there could be something wrong with the connection between controller and display, such that one cannot receive data from the other one.

Assuming your kit doesn't use waterproof plugs, then you can measure the data lines on each side of the connector to verify this isnt' happening. If you can try this I can describe the procedure.

If it has waterproof plugs, that's really hard to measure without cutting into wires, so the best bet is to simply unplug and replug the connectors, making sure they are correctly lined up and have no bent pins, and ensuring it is very firmly and completely plugged in (some are a bit hard to fully seat).
 
amberwolf said:
Did the display come with the controller as a set? If not, it may not have compatible firmware, even if they are the "same brand". If they are not the same brand, they probably won't work together, as there isnt' a standard for these things yet (probably never will be).

For example, I have a few of LS (lishui) controllers and a few Kingmeter displays that came with them, but the displays from one controller don't do the same things on a different controller, and vice-versa. The most common problem is they simply don't read any data from the wrong controller, or they read what little they do incorrectly. Like they may display the wrong speed, or not respond to assist-level changes, etc. The battery level meter seems to always work, but it might display the wrong level if it is a display meant for a different voltage system (I think all of mine do correctly display the batteyr level, but it's been a while since I looked at them).


Another problem is taht some controllers simply can't have any of their settings changed, so they either wont' even go into programming mode from the display, or you can't actually change any settings once in that mode. :(


In either of these cases, there isn't anything you can do about it, other than to replace either the controller or the display with a compatible unit, or replace both of them with a set sold together that you know will be compatible.

I'm not sure what, exactly, constitutes as a "set" in this case, but all I know is that this was bundled with the controller that I had in the kit. It's as you say: there isn't a standard for something like this, and I agree that it may never be the case given how many different applications can use the same model.

That sounds rather aggravating if this is actually a common issue where you can supposedly have incompatible devices even if it actually seems like they'd work together just fine. It seems even more irritating and suspiciously bizarre for someone to not be able to set their parameters based on their build. Now that would make zero sense if you had to change a major component that would ultimate affect the functionality of these ebikes. I rather not be stuck looking at KMPH instead of MPH all the time, or have the ability to allow a bit of a delay before taking off with the throttle instead of being stuck with instantaneous wheel-standing power lol. One should be able to ALWAYS make any necessary changes with their ebike build through the programming settings especially in the case of PAS controls. Hopefully, this isn't my issue, as farfetched as it may sound, but it also sounds like something certain companies will do just so you can't somehow screw up a setting with your motor, which is understandable, but still...

If push comes to shove, then I can always just order another SW900 from Amazon and see if that does anything different. For now, I'll try to keep troubleshooting with any and all other methods given here.
 
amberwolf said:
If they did come as a set, then there could be something wrong with the connection between controller and display, such that one cannot receive data from the other one.

Assuming your kit doesn't use waterproof plugs, then you can measure the data lines on each side of the connector to verify this isnt' happening. If you can try this I can describe the procedure.

If it has waterproof plugs, that's really hard to measure without cutting into wires, so the best bet is to simply unplug and replug the connectors, making sure they are correctly lined up and have no bent pins, and ensuring it is very firmly and completely plugged in (some are a bit hard to fully seat).

I'll be honest, but I have no idea if these standard connectors are even the slightest bit waterproof. What I can definitely say is that I have the display connector hooked to the correct one on my controller, so I know it's not that. I'll have to try the connect and reconnect method later, though. I'm about to head into bed, and I just don't feel like fiddling with this thing so late at night haha.
 
Well, now... To anyone out there reading this, it would seem that amberwolf's method actually worked! I seriously can't believe that it did haha! Unplugged and replugged the display connector from and to the matching one on the controller respectively, powered it on, and actually managed to get into the settings! I honestly thought for sure I had that thing plugged all the way in there. There's VERY little room to push it any further, so I honestly thought I had a good enough connection.

With that out of the way, I'll be able to do a proper test with my ride but after Thanksgiving dinner, though. One of my parameters was set at 48v, so that was already wrong (my setup is 72v 3000w and is working with a 72v 25ah battery). Everything else was mostly correct for what I needed it to be save for a couple of PAS settings. I also noticed that my battery meter now correctly shows how much capacity it really had (showed 5 bars (full) but really only 3).

Thanks for the simple suggestion there, amberwolf. Saved me a headache and likely $60-$70 from buying a replacement display lol.
 
Killerchaos7 said:
I read the manual where it says to hold both the up and down arrow buttons at the same time for a few seconds until it changes, but nothing happens

I just read the manual for a KT-LCD8, and it explicitly says to press up+down within 5 seconds of powering on to get into settings. SW900 looks similar to KT series displays, so maybe the same is required?
 
Comrade said:
Killerchaos7 said:
I read the manual where it says to hold both the up and down arrow buttons at the same time for a few seconds until it changes, but nothing happens

I just read the manual for a KT-LCD8, and it explicitly says to press up+down within 5 seconds of powering on to get into settings. SW900 looks similar to KT series displays, so maybe the same is required?

Wasn't the case for me. I kept thinking that maybe I was too slow at one point. I've watched several YouTube videos on how to enter into this mode, and some people had left their displays on standby for a good several moments before going into program mode.
 
Killerchaos7 said:
Thanks for the simple suggestion there, amberwolf. Saved me a headache and likely $60-$70 from buying a replacement display lol.

You're welcome. :)

Almost every time, problems are caused by connection issues, in any situation where wires or connectors of any kind could possibly be involved. (which is...everywhere. :lol: )
 
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