Bafang M400 - Powers up but nothing else

[AllRounder]

This is very similar to another in the forum but with some. subtle differences...

I have 2 bikes with Bafang M400 , one is C07 display, the other C10 display

The issue:
Bike powers up with no fault codes but does not deliver power,

Discovery:
Backing lights work (no onboard head or tail light to check)
No power to motor when pedalling,
No power to motor in Walk mode (but the "Walk" is displayed and 2.5km/h is registered with bike stationary),
No brake cutouts fitted to bike (hydraulic brakes),
Gear change sensor LED is normally off and lights up when gears are changed

When pushed backwards, the shuddering can be felt from the from crank area (in the motor??)

any ideas are appreciated?

 

[AHicks]

Re: shuddering when pulled backward, that's a normal function. I could go into more detail if you like, but it would have nothing to do with your issue.

Your bikes were working OK when this happened, or these are both new installs?

 

[AllRounder]

Re: shuddering when pulled backward, that's a normal function. I could go into more detail if you like, but it would have nothing to do with your issue.

Your bikes were working OK when this happened, or these are both new installs?

I have several M400 bikes and none of the working bikes shudder when pushed backwards. Can you please go into the more detail so that I may understand more of the reasoning for the shudder.

The bikes that have stopped working are both about 1500 kms from new

 

[AHicks]

Re: shudder. There are clutches built into the motors that allow the motor to uncouple when coasting - allowing you to coast freely, with no drag from the motor. If the bike is rolled backwards, this clutch SHOULD engage the motor, and you will feel the motor "coging" as the armature moves past the magnets.


No idea why the other bikes aren't doing this.