Bafang Throttle only works from stopped position.

[Vw-73]

Throttle works from only a stopped position. After peddling the throttle is unresponsive. While coasting the throttle will not work until at a complete stop.
The throttle previously worked under both rolling and stopping. Any ideas?

 

[m@Robertson]

Which Bafang motor are we talking about? The initial assumption will be its one of the mid drives but Bafang has hub motors with throttles, too.

Has anything changed between the time it worked normally to the present? Did you use the programming cable to change any settings?

If 'no' I would swap out the throttle for a new one to see if that fixes it. They are cheap.

If you have a programming cable and some sort of software to get at the motor's internal settings, I would post pics of your settings here.

 

[Vw-73]

Thanks for your reply. Yes this is the 500 watt mid-drive. No programming changes have been done. The throttle is original and did work in both riding situations. Could be throttle but isn’t it simple reostat type device and should be working in both situations if it works in just one?

 

[m@Robertson]

Thanks for your reply. Yes this is the 500 watt mid-drive. No programming changes have been done. The throttle is original and did work in both riding situations. Could be throttle but isn’t it simple reostat type device and should be working in both situations if it works in just one?

"the 500w mid drive" unfortunately only narrows it down by a little. Are we talking about a BBS01/BBS02, or one of the newer in-frame motors? If its a BBSxx that would definitely make things cheaper and easier to diagnose as that is a motor with a UART interface that uses absolutely generic components. If it is the newer M325 version of the BBS02, or one of the in-frame motors, things are much more difficult as you are dealing with CAN bus and parts are not widely available.

As to the rheostat etc... Maybe. Ordinarily on a Bafang motor you want to work your way up the ladder in a process of elimination that starts with the cheapest fix to the next most expensive and so on. Plus, parts can interact. In particular since the motor controller is in the middle of it. To diagnose this from cheapest to most expensive solution, you'd want to first replace the throttle, then the PAS sensor. Then the wiring harness. Then the display (you would want to pick something cheap like a DZ40 that can be had for around $30). At that point you have replaced everything but the motor controller, which is next - and last - on the list.

If your assumption of the rheostat being an on/off switch is correct, then you have only one place to go to repair the problem and thats immediately jump to replacing the motor controller. Which you want to avoid unless forced to do so. Be methodical.

If I were to guess, I'd say its most likely the controller or the display, in that order. But I've seen enough of these to know not to jump ahead of the line and start out on the cheap.