BH Neo emotion torque sensor issues

[m0rt]

Hi

First time poster here. I have a bit of experience with Mid-drives and bike mechanics in general, but little experience with hub motors. Hoping someone can give me some advice on this.

I've recently come across a cheap BH Neo Emotion ebike 2014 model with a year old battery. It has a rear frame torque sensor which the derailleur is mounted on. When turning the display on, i get an error code 03 which according to a manual reads "TMM sensor: Check that the connection between controller and TMM sensor is correct. Check to see if the output of the TMM sensor exceeds the normal range, it must be 0,1V-3,5V."

I've disassembled most of the bike and checked that everything is properly connected. There was some moisture around the sensor plate. The screws holding the plate to the frame were tightened very hard, which i have loosened and tightened with <10nm force.

If this is not an easy fix, can it be possible to replace it with a cheap chinese cadence sensor? Maybe change the BB to a bottom bracket w/ built-in torque sensor? Will these kinds of sensors be compatible with the controller? (BH-MY15 Evo-W3618A). Any experiences / recommendations for a replacement sensor?

Thank you for your time

 

[AngryBob]

Torque sensors are generally NOT interchangeable, and that is with the most common type, mounted in the bottom bracket, which you do not have. Check the output voltages as suggested.

Whether it will take a standard cadence sensor will depend on the controller, and whether you can change to a standard controller will depend on the battery and motor having customized communications.

"Proprietary" components are a bad and evil thing, be more alert for these in the future.

 

[Voltron]

Those bikes happen to be pretty hard to diagnose, as the battery has to be off the bike to access the controller and wires, making it difficult to have it powered up while probing stuff.
Have you used a multimeter to check the voltages at the torque sensor yet?
It could well be it's just a broken wire on the way to the controller, so maybe continuity check on the three wires between the dropout and the controller plug inside after voltage check?

 

[Voltron]

Not sure if this is your exact one but it looks like you might be able to find one if it turns out not to be a connection issue.