Brand new to this forum and already needing something. Been into ebikes for about 3 years now, bought a 2017 FLX hardtail with an Ultra motor, then later converted a Scott HT into a BBSHD beach cruiser for my wife. Was not sure whether to put this in Bafang Midrive Kits, moderator please place this where it belongs. Anyway, I'm seeking insight in diagnosing what I think is a failing or out of calibration torque sensor on my 2017 Ultra (MM G510 12) with a DC P18 display. It is right at 5850 km and has been ran in stock trim at 48v nominal. All was fine up until about 2 weeks ago when: 1) PAS became reduced by about 50% at all selected power levels compared to prior, while throttle control is unaffected, 2) And lately PAS is completely missing and zero watts output is indicated on the display without throttle input.

I split the motor 3 days ago to freshen up the grease and checked all the external and internal electrical connections at this time. All appeared fine, and no signs of overheating. I have the cable and the software to check/change motor parameters, but it seems odd that they would change on their own and the slow death of the system leads me to suspect a hardware failure. To make matters worse, I am unable to locate a replacement torque sensor at the time of this writing. A buddy who is the regional distributor of Bafang Ultra equipped bikes says he has had 2 Ultra TS failures, both occurred during warranty and the motors were replaced but had to be sent to The Netherlands for inspection. It can be surmised that this is a relatively infrequent failure item, and I would much rather have it be a controller problem, they are readily available. The motor ran after re-assembly, but poorly as before, but now zero PAS. I did not disassemble the TS as shown in this forums Tech Knowledge section, I thought it was a sealed unit.