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Stromer ST2 - drive error code 0X210002

Posted: Mar 29 2021 6:07am
by Mocha2021

I hope someone here can help me. I purchased a used Stromer ST2 that has less than 120 miles on it. It has the latest update on firmware. The bike is a 2016. It is no longer under warranty. Took it out for a ride and as soon as the power is applied to the Omni display, i encountered a drive error 0X210002. Tried to reset by taking out battery, wait 10 min and put battery back in same issue. Took the controller out to visually inspect, i don't see anything obvious. I suspect the hub motor (Syno drive) may be the problem. I removed the wheel and torqued to 20N-m. Still same issue. There are two connections. One for the power to the hub motor. The other is a small quick connect for low level hall sensors. Does anyone have a pin out of this connector. I am trying to see if the hall sensors are working and also make sure there is no broken wires, pins.

If anyone have seen this fault and remedy please let me know. It is an expensive bike and I am trying to make it work. I saw at the Stromer NL site, the controller may need to be replaced. problem is I do not know if this would solve it and that the controller is about 300 dollars on ebay with no guarantee. Is there a way to eliminate the controller being the culprit.?

Worse case, if the hub motor is good (not sure how to check the bldc, phase to phase resistance is consistently low i.e. 0.4 ohms), can I just purchase a generic 48VDC, 1000W controller and make it work.? It is a nice and light frame, it would be good to solve this problem. I appreciate any help any one can provide.

This would be the first time I rode this bike since purchased.


Re: Stromer ST2 - drive error code 0X210002

Posted: Mar 30 2021 3:48pm
by Firedog
I have several ST1 hub motors. Those have the controller inside the hub which sometimes failed. I opened the hub removed the controller and brought the 3 phase and 5 Hall sensor wires out to a 30A generic controller and its a great bike.

I believe the ST2 has the controller in the battery area so the phase and hall wires are already out,and replacing it with an generic controller should work fine. You'll loose the stromer display and torque sensing PAS unless the new has similar

Re: Stromer ST2 - drive error code 0X210002

Posted: Apr 04 2021 6:50am
by Mocha2021

Thank you. I checked all CAN bus node connections and point to point on all wiring to the motor. No problem found on connectors. I did see a blue wire that come down to the hub motor had a knick on it and was exposed. That may have shorted the controller board. When I follow the cabling, it came from a Higo connector at the hub motor. I assumed as you mentioned that the hall sensors and temperature sensor would be in this connection. A little more details about the motor. It is an ST2-HM-01 and do not have a controller built in to the hub. I searched the forums in the EU but not able to find much about the wiring for this connector.

Power side to the motor connection is Green, Yellow and Blue (standard colors I think). The motor is a 48VDC BLDC made by TDCM. I could not find any infos on the Syno Drive which is what this motor is.

Anyway, when I short the green/yellow together (disconnect from controller), it took a lot of effort just trying to move the wheel. Similarly, the other two phase combinations. This seems to indicate that the coils are ok. Not sure if resistance measurements would do anything here.

I started to check the Higo. The wiring colors are not "standard". The cables look like factory molded cables 6/Conductors. They are:


I am hopeful someone would know where these connected to. I am almost certain they are for the Hall sensors and Thermistor but not sure the color code. I am assuming that

Black - DC common
Red - +5VDC
Orange - Thermistor
Blue, Brown, Yellow ( Hall sensors).

Going by this assumptions, I am getting strange voltage on the blue, brown and yellow wires. My understanding is the Hall sensors are Honeywell 461R. That seems to indicate there is reverse polarity protection, so I tried to swap the + and - still not reading correctly on the assumed hall signals. I am reading zeros on all hall phases with no changes when the wheel is rotated. When swaping the + and - wires, I would read 4.5VDC on all hall wires?

At this time, I have not tried all combos yet, but just reading the impedance between the phase to ground, they are consistent. I am hoping someone who has knowledge of the wiring colors to help with ID the hall phases. Hoping not to have to pull the hub motor apart to get the wire code.

I am hoping just to convert the controller to a generic one so I can make use of the bicycle. I will need to change all wiring for PAS, display, light.... but that ok. Another option is to change the hub motor if it is bad, but this is a through-axle wheel, not sure if there is an generic off the shelf replacement. I dont think I can even change the front wheel to a hub motor wheel due to the through axle design. Best can hope for if none of these option work, probably a mid-drive.

Any inputs or help point the way would be most appreciated. This bicycle is complex in the controls (CAN) which I have no way to access. Even the battery is CAN bus integrated. Anyone had any luck with reusing this battery (blue case) with other systems that are non CAN? It is a nice design and powerful, would be a shame not able to use it.



Re: Stromer ST2 - drive error code 0X210002

Posted: Apr 05 2021 2:23am
by Firedog
First, figure out which of the small wire is the thermistor. Usually it's 10K ohms at room temp between thermistor wire and black.

I would suggest that you get a "ebike tester" (~$15). It will tell you if the halls and phase wire output is normal and if the controller has any problems. Testing halls with a meter; I have a bit of trouble with that since the output is the opposite or what one expects and very hard to "see" combos. If all halls are dead, that usually because either the common red or black is broken (sometimes red shorted to the case). Of course you could fried all 3, but I doubt it. The motor will run w/o the halls but not start as smoothly.

Go to and you can learn how to test the controller for blown Mosfets. If the controller fails or you can't use it for other reasons, consider a cheap 36/48v 17a ($15) controller for testing. It has a "learning mode" and will automatically sense the battery voltage, if sensored (halls) and the best phase wire timing. Those controllers give quite decent performance at 48 to 54V and have cruise control, but no PAS or meter connections. If the motor is like my ST1's, it's really nice with a 30A controller and would probably handle even more power.

Batteries with Uart or Canbus use that to more accurately report AH used to the display. You will loose the battery display, but my experience is those batteries still work and the BMS functions properly.

Re: Stromer ST2 - drive error code 0X210002

Posted: Apr 06 2021 5:57am
by Mocha2021

Thank you Firedog for all your inputs. I just realized that by testing the Hall Sensors without a controller and just a 5VDC power supply required pull up resistor to get a reading from the transistor. Once i added 10K ohm to the circuit, all the hall sensors are working properly. So the hub motor is ok as far as the tests I can do externally.

I also checked the mosfets on the controller by checking to phase to ground and phase to power, all three phases look suspcious since the readings are not what i had expected. The controller may just need replacement.

At this point, I am tempted to buy a controller and put it in to try. Is there reliable place on the internet where I can purchase refurbished/tested controller for Stromer ST2? My fear with buying on ebay is that the controller is not tested and at 300 USD, that is a bit of a gamble. Additionally, there is a security feature, if I buy a preowned controller, how would I reset the lock code if one was programmed in.

I can use a generic controller now that I have the wire identified and hub motor look to be ok. I can make use of the rest of the peripheral but the battery has an energybus CAN system which would not enable the output to the battery without the Stromer controller online. Is the only way to use the battery is to disassemble and install a new BMS? or is there a way to send a PDO packet to the battery to enable it or even through hardware interface.?



Re: Stromer ST2 - drive error code 0X210002

Posted: Apr 06 2021 10:26am
by Firedog
You searched for the that error code? I had no trouble finding lots of guys with the same error.

You now seemed intent on repairing the ST2 not using a generic controller. Great idea, I can help much with that.

Controllers can be repaired. If you can't test the controller's mosfets, go back to Grin and learn how. Failure is almost always a dead short to ground or Batt+. I've never seen all of 'em fail. Mosfets can be replace....again watch & learn how. Since the display lights up the 5V on the controller is probably OK. The only other thing I can think of is something wrong with the torque sensor, throttle or brake switches. causing the controller to give the error. Sometime unplugging one at a time will start the motor

Good luck, Over and out.