Bosch engine not engaging

[weons]

Hi there!

I've got a Batavus Ebike with a bosch active line engine (more details below). The display registers the current battery charge and the current speed when pedaling, but the engine does not engage even though everything seems like it should be working.

Specifications:
Batavus Milano E-go 2015
Bosch Active line - 0 275 007 032
Bosch display - 12700 020 906
Bosch battery 400w - 0 275 007 514

Problem solving:
Battery is charged
Display registers battery charge
Display registers current speed
Display changes mode and reacts to handlebar remote
Engine reacts and runs when "Walk" button is pressed on handlebar remote
Contacts between display and bike display holder have been cleaned
Battery has been soft-reset by holding the power button for 30 secs

I really don't understand why the engine does not engage when it should. The display registers the speed and the engine works with the "Walk" button. The battery works and I've cleaned the contact points of the display.
I have no yet opened the engine itself to give it a cleaning, but since the engine works with the "Walk" button, it doesn't seem like the problem lies there?

Does anyone have any idea of what might be wrong? My logic tells me that the signal from the display to the engine, telling it to engage, is getting lost somewhere.

 

[soundwave]

i think the only thing left is to take it to a bosch dealer so they can run diagnostics software on it and see if that can see what is wrong and try a firmware update and see if that sorts it.

if the controller has gone bad inside the motor then you will need a new motor as bosch dont sell replacement motor parts.

or peter may be able to help but limited spare parts.

The home of ebike motor parts -

Spare parts, bearings and repair service for most common ebike motors

www.performancelinebearings.com

 

[GLJoe]

Does anyone have any idea of what might be wrong?

The motor has a torque sensor built in. It won't start to give assist until it knows you are pressing down on the pedals.
Its possible there is a fault in that area.

 

[soundwave]

the torque sensor is bottom middle and plugs in to the pcb with the cable top right and it is held in place buy a castle nut on the left side of the motor.

 

[weons]

The motor has a torque sensor built in. It won't start to give assist until it knows you are pressing down on the pedals.
Its possible there is a fault in that area.

Thanks for your quick replies GLJoe and soundwave,

I'll try opening it up today or tomorrow when I get access to the tools to remove the pedal arm (?).
From the picture I'm assuming the torque sensor is the dark blue plastic thing along the bottom with the big purple smear on it. Is there an obvious way to tell if it's working or not? I guess if it doesn't spin when the crank is turning, it doesn't work

 

[MarcusT]

I'll throw something out quite simple:
Could it be the sensor? I know mine stopped receiving signal out of the blue. It had moved a few mm while riding

 

[weons]

I'll throw something out quite simple:
Could it be the sensor? I know mine stopped receiving signal out of the blue. It had moved a few mm while riding

Do you mean the torque sensor as GLJoe and soundwave mentioned?

I definitely think it's something along those lines

 

[soundwave]

id get the side off and have a look at its position and take it from there, could be just a loose connector pcb end

 

[GLJoe]

I'll throw something out quite simple:
Could it be the sensor? I know mine stopped receiving signal out of the blue. It had moved a few mm while riding

If it was the magnet and wheel sensor, how would :
"Display registers current speed "
Be happening?