Ultra Bee ER-138 code

[OliHo0pz84]

Hey guys, here to ask for some advice on a strange new issue with my Ultra Bee. I'm only about 400 miles in, riding mostly local trails, and kept it stock for now. Yesterday, after a really dusty day out, I started getting a strange problem.. The bike will power on fine, but the throttle will intermittently cut out, often after I chop the power and then try to get back on it. It feels like a safety switch being thrown, and occasionally it pops up with the code ER-138 on the display. I've looked it up and the error is listed as "MCU Regeneration Protection." I've already tried checking that the kickstand is up and cleaned the little bit of dust out of the brake lever sensors, but the issue is still there. Could the dust have messed up the throttle's Hall sensor, or is this error code a sign of a bad connection or maybe a BMS problem? Any troubleshooting advice before I drag the whole thing to the dealer would be appreciated. Thanks.

 

[Alan]

From what I understand, the ER-138 regeneration protection error indicates that the motor controller has picked up on some unusual regen braking conditions. This could be happening because of dust on the throttle Hall sensor or the brake sensor contacts, or it might also be due to loose wiring connections to the motor controller.

Make sure to clean all the sensor contacts really well using electrical contact cleaner and take a look at the wiring connections at the MCU. If you’re still having issues after cleaning everything, it’s possible that the motor controller might require recalibration or even need replacing under warranty if you’re at 400 miles.