Need help diagnosing an acceleration problem

[BDC]

Have had a recent series of issues with my BBS02 that I've put ~500 miles on. Earlier this week I was riding to work on my normal commute and about 5 minutes into the ride an Error 4 and Error 21 appeared on my C961 display and everything stopped working sans those two messages being displayed on my unit. I rode the rest of the way to work with no power. At the end of the day, I unplugged and re-connected the throttle (after seeing an Error 4 is related to throttle homing issue (?)) and had also made a minor adjustment to my speed sensor (Error 21). Turn the bike on, and the display comes on normally and then randomly turns on and off...when its on I was able to adjust/increase my pedal assist but throttle wouldn't work at all (display would occasionally read Error 4 still). Pedal assist continued to work even when the display would be "off" and not show anything.

Fast forward to the next day. I go to ride...and display doesn't turn on at all, but the pedal assist that I had it set to the night prior remained engaged and gave me a boost on my commute in....but with a catch. Now it would occasionally accelerate on it its own as if I was pressing the throttle despite not using the throttle (and it not even being connected). Gave me quite the scare sitting at a stop sign and having my bike lurch forward while I fumbled for my brakes!

It has since been intermittedly throttling/accelerating on its own and also remains on pedal assist level 2..when I unplug the battery and then plug it back in, I can turn my display on for about 5 seconds where I can then adjust the pedal assist and am then locked into that for the rest of my ride or until I unplug the battery again. I've tried disconnecting my throttle while riding (and prior to turning the ebike on) with no changes...I've unplugged my C961, which stops the random accelerating/throttling (and pedal assist) but essentially turns the ebike back into a regular bike. Looked at wiring from the C961 and Throttle all the way to (but not inside of) the controller and didn't see any shorts/kinks/creases/damage.

Any thoughts on what might be going on or what I should check out next? Is this likely a controller problem? An issue caused by my C961 possibly failing? Issue caused by a jealous person placing a curse on the bike causing me to accelerate at stop signs and unexpectedly while going through turns? Thanks so much for any thoughts or advice!

 

[indianajo]

If you bought it from a local shop, you're in luck. Drop it off and wait for them to call you.
If you bought it on the internet, you need to replace some things.
I'd scrap them all, controller, display, throttle, PAS sensor. Wiring too. Uncontrolled acceleration is dangerous. You might get away with not replacing the motor & battery, but maybe not. I think Luna supports the bbs02 but maybe not.

 

[John from Connecticut]

If you bought it from a local shop, you're in luck. Drop it off and wait for them to call you.
If you bought it on the internet, you need to replace some things.
I'd scrap them all, controller, display, throttle, PAS sensor. Wiring too. Uncontrolled acceleration is dangerous. You might get away with not replacing the motor & battery, but maybe not. I think Luna supports the bbs02 but maybe not.
I've been having trouble with all this ****ese **** with bad solder joints or sensor or microcontroller failure. 2 year old maytag washer only fills 3". 1 year 50 week old Samsung 32" TV won't turn on remote or pushbutton. 1 week old Dewalt drill/impact-driver/battery/charger won't charge the batteries. No US made substitutes available. Rode the bike over 28 miles RT to Dewalt recommended service shop today, only Dewalt refuses to pay them. No power used this trip, was suitably worn out when I got back. Lucked out on the bike motor/controller/throttle, from a $189 ebay kit, has worked 18 months now with the only fault it stopped working in a pouring rain. Then started again when it dried out.

I completely agree with 'indianjo. The kind of problem you're describing can be extremely difficult to troubleshoot, if at all. Unless you or
a shop can recreate the failure, 'repair' it by doing ??? and then create the failure again by 'undoing ' the fix there is no way to know if
the problem has truly been solved. ....And to have unexpected uncontrolled accerleration is not an option !

As indianjo wrote, I'd scrap everything less the motor and battery initially....Agreed. This not the time for a 'science project' unless you or the
shop can repair and then recreate the problem as above....If I were to take a wild guess. A potential trouble source could be a bad ground,
a cold solder joint that conducts 'most of the time', a poorly crimped connector that appears solid, a bad trace aka 'wire' on the controller
board etc etc etc. Just a few failures that cause the dangerous intermittent you're experiencing...Good luck

 

[tomjasz]

Every so often I forget myself and think 5 years and thousands of BBSxx support emails and hundreds of calls qualify me as a source of BBSxx series motor support.

 

[AHicks]

What's your point Thomas? Do you have a suggestion?

From the descrition of all the erratic behavior, I'm thinking the wire harness is damaged somewhere. Or possibly a connector has pulled partially loose or become corroded. That's something that can be easily checked out before condemning the bike to weeks in line waiting to be worked on by somebody who may or may not know what he's doing.

 

[tomjasz]

What's your point Thomas? Do you have a suggestion?

From the descrition of all the erratic behavior, I'm thinking the wire harness is damaged somewhere. Or possibly a connector has pulled partially loose or become corroded. That's something that can be easily checked out before condemning the bike to weeks in line waiting to be worked on by somebody who may or may not know what he's doing.

Sorry. I responded with a litany of possible solutions only to read posts indicating that respondents knew better. I gave up and deleted the responses. I’m not interested in having pissing matches over the solutions or directions I know to be valid. Out of frustration I simply deleted and offered the OP to help through my support contacts. You’re correct. I’ve sorted the same issue scores of times in my customer support years. But it gets frustrating reading critical comments when my only intent was to provide help, the same help I offer anyone contacting our shop. I’m to busy to argue. Be assured I respond to any PM for help.

 

[indianajo]

I would suggest BDC take his bike to your shop in Winona MN. But he lives in Keene NH.
Cost of all the parts I suggested, $250? $300? cost of one ambulance ride to the emergency room, $500?
It is not worth the risk of a sudden acceration accident, IMHO. Flaky computer systems is the bane of our existence, and field wiring is maybe 1/5 of the problem.

 

[BDC]

Sorry. I responded with a litany of possible solutions only to read posts indicating that respondents knew better. I gave up and deleted the responses. I’m not interested in having pissing matches over the solutions or directions I know to be valid. Out of frustration I simply deleted and offered the OP to help through my support contacts. You’re correct. I’ve sorted the same issue scores of times in my customer support years. But it gets frustrating reading critical comments when my only intent was to provide help, the same help I offer anyone contacting our shop. I’m to busy to argue. Be assured I respond to any PM for help.

I tried doing a few of things that I recalled from your post prior to it getting deleted. It gave me a great start after work today to begin trying to figure out what is going on. From what I recall...you had asked about a number under the C961...I see a 20180903 number with V.1.2.6 under that...and 67 under that. Unsure of the meaning behind it all, but possibly it is significant.

I brought the bike into my garage and used a flashlight to really inspect every inch of the wiring. You were right, I needed to look a bit closer. There is a tiny nick on the speedsensor cable. I moved that around some and started the bike up with the rear tire off the ground...display does the same as before (if I hit power, it comes on for a few seconds then turns off and says Error 4), but the random acceleration has stopped....at least in my mini-trial. The pedal assist was still working even with the display not showing anything, so that is significant but, at least for the moment, no random acceleration.

I think I recall a few other questions from the initial post. I do use the throttle, but not very frequently. Used it more in July when it was hot out so I wouldn't arrive to work too sweaty, but lately its been pretty much always set on pedal assist 2. Vanilla programming, didn't make any adjustments since I had got the unit from Luna. The day this all happened, it wasn't wet or raining but was appreciably colder than usual as the the Fall is really starting to come upon us.

I forgot the other many questions and thoughts you had, but the things I could remember appear to be fruitful in terms of possible idea of what is going on (maybe an issue with the speed sensor wire?). Thanks so much for the initial lead on how I can begin troubleshooting. Please let me know if you have any other thoughts/ideas!

 

[tomjasz]

I would suggest BDC take his bike to your shop in Winona MN. But he lives in Keene NH.
Cost of all the parts I suggested, $250? $300? cost of one ambulance ride to the emergency room, $500?
It is not worth the risk of a sudden acceration accident, IMHO. Flaky computer systems is the bane of our existence, and field wiring is maybe 1/5 of the problem.

Oh for crying out loud. That’s near th price of a bare motor. Again, no one suggested the OP continue to ride.

I tried doing a few of things that I recalled from your post prior to it getting deleted. It gave me a great start after work today to begin trying to figure out what is going on. From what I recall...you had asked about a number under the C961...I see a 20180903 number with V.1.2.6 under that...and 67 under that. Unsure of the meaning behind it all, but possibly it is significant.

I brought the bike into my garage and used a flashlight to really inspect every inch of the wiring. You were right, I needed to look a bit closer. There is a tiny nick on the speedsensor cable. I moved that around some and started the bike up with the rear tire off the ground...display does the same as before (if I hit power, it comes on for a few seconds then turns off and says Error 4), but the random acceleration has stopped....at least in my mini-trial. The pedal assist was still working even with the display not showing anything, so that is significant but, at least for the moment, no random acceleration.

I think I recall a few other questions from the initial post. I do use the throttle, but not very frequently. Used it more in July when it was hot out so I wouldn't arrive to work too sweaty, but lately its been pretty much always set on pedal assist 2. Vanilla programming, didn't make any adjustments since I had got the unit from Luna. The day this all happened, it wasn't wet or raining but was appreciably colder than usual as the the Fall is really starting to come upon us.

I forgot the other many questions and thoughts you had, but the things I could remember appear to be fruitful in terms of possible idea of what is going on (maybe an issue with the speed sensor wire?). Thanks so much for the initial lead on how I can begin troubleshooting. Please let me know if you have any other thoughts/ideas!

I’ve messaged you with my contact information. I’ll happily guide you. I’m just not willing to debate with those that either can afford $3500 bikes and $60 shop time, or sensationalists with zero experience with BBSxx series motors.

Wonky results like you are experiencing are typically wiring/connector/harness issues. Get a replacement throttle. They’re cheap. There’s a thread here where several helpful fellas posted some throttle trouble shooting. https://electricbikereview.com/forums/threads/thumb-throttle.27436/page-2#post-222785