ERROR CODE 21: Recently took delivery of a new Bafang BBS01B mid drive. When first test driven the speed sensor worked fine on my C965 display which came new with the Bafang drive. I got speed and mileage readings. I then added a kickstand to the bike and accidentally crimped the speed sensor cable. When code 21 displayed, I first checked the location of the magnet...at 5mm it was fine. The sensor cable was not cut by the crimping but the copper of the black wire was exposed and possibly grounded to the frame? The red and white wires were fine. I repaired the cable and checked continuity of all three wires = fine. The speed sensor still does not work...still getting code 12. The three levels of pedal assist and the throttle work. The error code clears each time I pull the brake lever and shut off the motor.
With the display turned on, I checked the voltage of the red, black and white wires at the female plug end of the sensor cable where it connects to the sensor itself. Black to white = 0 volts. Red to black = 0 volts. Red (negative) to white (positive) = 64 volts. It seems 64 volts is not possible from a 36 volt 13 ah battery pack coupled to a 36 volt 250 watt BBS01B drive?? I checked my volt meter. It measured a 1.5 volt flashlight cell just fine on the DC setting and when switched to AC, measured our house current fine at 118 volts. So I assume the 64 volt DC reading was accurate.
Can anyone help me??
With the display turned on, I checked the voltage of the red, black and white wires at the female plug end of the sensor cable where it connects to the sensor itself. Black to white = 0 volts. Red to black = 0 volts. Red (negative) to white (positive) = 64 volts. It seems 64 volts is not possible from a 36 volt 13 ah battery pack coupled to a 36 volt 250 watt BBS01B drive?? I checked my volt meter. It measured a 1.5 volt flashlight cell just fine on the DC setting and when switched to AC, measured our house current fine at 118 volts. So I assume the 64 volt DC reading was accurate.
Can anyone help me??