BBS02-B Power Assist Stopped Working

[Rider]

I have over 4,000 miles on various BBS01/02’s. Today I hopped on my eCruiser to hit the bike shop Black Friday sales and after braking down a freeway overpass the electric assist didn’t kick back on. My first thought was that one of the brake cutoff sensors had stuck cutting the power, so I disconnected both of them. That didn’t work, so I powered the system off and on. No luck with that either. Finally I disconnected the throttle wire just as a precaution and still no power assist.

After pedaling for a while without power and thinking through what else it could be, I stopped and checked for the light on the magnetic sensor at the rear wheel. The light was on, so I cleaned the magnet surfaces thinking maybe it wasn’t getting a proper signal. No luck once again. After that I simply completed my ride without power.

Back at home I swapped out the color display with one from another bike and nothing. Now I’m thinking it must be internal to the motor.

PROBLEM:
No power assist ever kicks on. Only unusual thing I noticed is an odd drag coming from motor when the bike is moved backwards with power on or off. It is a tugging feeling from spinning the motor backwards that I never noticed before, but could have been there (?).

STATUS AND CHECKS SO FAR:
Battery has power
Display powers on fine
Rear wheel senor is clean, aligned and the red light is on
Displays proper speed when pedaling with power on
No assist even with brake sensor cutoffs discounted
No assist even with throttle unplugged
No change with different working color display

Anyone have an idea what it could be or what to check next? Is this similar to any problems that have already come up?

ADDED 11-30-2017:

- - - SWAPPING IN A GOOD CONTROLLER CONFIRMED THE CONTROLLER WAS BAD - - -

[Rider]

It appears to be the same problem as this thread:

https://electricbike.com/forum/forum/main-forum/trouble-shooting/48747-bbs02-stopped-working

I watched the video in post #12 and will go look at those connections now and report back.

[commuter ebikes]

*** This may end up as a double post. Lately when I go back into a thread post to correct something it gives me a notice that my post as "flagged" as span or something, then the post disappears. ***

Taken care of.

[Rider]

Thanks CE. I removed that, but I see there is a duplicate post so I edited it for removal.

Popped the controller off and looked under it. All the wires appear to be connected and sealed very well (see picture). In fact, there is plenty of grease on the reduction gear too, despite many claiming they are under greased from the factory.

Any other thoughts on what to check next?

[Rider]

From what I can tell with my limited diagnostics so far, it is the controller. This particular BBS02B was bought in August 2017 (less than 3 months old) and was said to have the "Latest upgraded 9 Mofets transistor BBS02B model with 25A output this is the updated version with If IRFB3077 mosfets fitted in the controller." Here is a picture of the controller stamp. Can you tell anything from it? Is it what the seller (not Luna) says it has?

CR R209.750.SN
CROF0214
1705160707

I use a 48V battery and seldom use throttle other than for a boost in level 4-5 of 9 when going up an underpass. This problem came up after braking on a downhill (not even under power), after climbing a freeway overpass in 2nd gear (1.68:1 - 42Tx20T less 25%) level 4 of 9 without any throttle. There was no strain on the motor when it failed at all.

Before I purchase a new controller (or get one under warranty) is the anything else I can check? Is there a way to check the controller through the wires that come out of it?

[Rix Ryds]

Sounds to me like your PAS hall sensors have failed. Hall sensors are notorious for failing, especially if they get hot, but I have had them fail for no apparent reason when the motor temp was less than 100 degrees F. Check for a 5v pulse on the black plug in the controller. there are 4 wires red is 5v, black ground, grey is speed, white is direction. with the plug still connected, to supply power to the sensors, you should see a 5v pulse on the other two wires when you pedal. Does the throttle work?

[commuter ebikes]

...Any other thoughts on what to check next?

If you hit a dead end, try removing and replacing individual functioning electrical components one by one.

Recently I completely rewired an ebike system (more intuitive harnesses and all new connectors). Upon testing it for the first time, I had no power. One by one, I pulled electrical components off of identical, running bikes. I continued removing and replacing electrical components until I found the problem (it was the wiring order of the 3-pin connector on the throttle). Had I begun my troubleshooting by unplugging the throttle, this would have isolated the problem more quickly.

First I removed and replaced the battery, only to have the same problem. Then the display, then the controller, then the multifunction switch, then two principal harnesses (multiconductor cables), and finally the throttle. Once I removed and replaced the throttle, all was well. The motor wiring harness and motor would have been next.

I like "remove and replace" because it is easy, albeit less sophisticated. I believe that it guarantees to fix your problem. A bonus is that you develop a collection of spare parts for scavenging or tinkering.

[Rider]

Sounds to me like your PAS hall sensors have failed. Hall sensors are notorious for failing, especially if they get hot, but I have had them fail for no apparent reason when the motor temp was less than 100 degrees F. Check for a 5v pulse on the black plug in the controller. there are 4 wires red is 5v, black ground, grey is speed, white is direction. with the plug still connected, to supply power to the sensors, you should see a 5v pulse on the other two wires when you pedal. Does the throttle work?

Thank you for chiming in. I know the motor wasn't hot or stressed. Up to the point it failed I was simply pedaling in 4 of 9 from 2nd to 4th gears. Wattage use ranged from 0 to about 500 when starting form a stop. The throttle did stop working as well, so I disconnected it completely.

Is the hall sensor inside the controller or inside the motor? So check the RED and BLUE wires while connected?

[JPLabs]

Motor drag when moving the rear wheel backwards is normal. The freewheel on the crank will spin the motor in reverse, so you feel the cogging from the magnets, only when the chain is turning the kit backwards.
So, that part is nothing to worry about, unless it is particularly hard to spin. Should still move pretty easily, but you definitely will feel some 'lumpy' drag.

FYI.

[Rider]

If you hit a dead end, try removing and replacing individual functioning electrical components one by one.

Recently I completely rewired an ebike system (more intuitive harnesses and all new connectors). Upon testing it for the first time, I had no power. One by one, I pulled electrical components off of identical, running bikes. I continued removing and replacing electrical components until I found the problem (it was the wiring order of the 3-pin connector on the throttle). Had I begun my troubleshooting by unplugging the throttle, this would have isolated the problem more quickly.

First I removed and replaced the battery, only to have the same problem. Then the display, then the controller, then the multifunction switch, then two principal harnesses (multiconductor cables), and finally the throttle. Once I removed and replaced the throttle, all was well. The motor wiring harness and motor would have been next.

I like "remove and replace" because it is easy, albeit less sophisticated. I believe that it guarantees to fix your problem. A bonus is that you develop a collection of spare parts for scavenging or tinkering.

Again, thank you for chiming in. I do have one other BBS02B just like this one that is working great with over 2,000 miles on it. I hate to open up a working motor, but if that is the "only" way to check a controller then I might not have a choice.

Is there any way to check a controller when removed from the motor stand-alone?

I agree, remove and replace is the way to go IF you have duplicate working parts. I have already swapped the display and control switch. Battery is good. I can try another throttle and main harness just to eliminate them. Swapping the controller out of my working motor is really something that I prefer not to do if I can help it. Wish there was a eBike co-op with good swap parts available just for this in my area (there's a thought for a local parts supplier or ebike shop - paint all the good swap test parts bright orange or something so no one will do the old switch-a-rou with their bad stuff).

I have been thinking of moving all the custom 29+ Sturmey-Archer 5spd disc brake Velocity Dually wheels and big Surly tires on this eCruiser to my Niner Jet 9 or a new Soma Juice belt drive frame build. Believe it or not, 29er wheels and most 29x2.3-2.4 or smaller tires will fit a Soma B-Side in the rear with the dropouts slid all the way back; that surprised me when I test fit it. And I have a Speciallized Compound Control 29x2.2 on order just for that reason (should fit both the Niner and B-Side rears). The Surly Extraterrestrial 29 fits the front on both rides just fine.

I really need to ID the problem, so I can at least try to use the 1 year warranty on this motor. Not sure how that will go with a Chinese seller. The warranty states buyer has to pay shipping to and from China. That expense may be more than the $100 a new controller cost (if that is what's bad). If it is something worse, then it might be worth it.

My last resort option will be to make this motor my "parts" motor and don't put any more money into it if collecting on the warranty is too much trouble. I really hate to do that.

[Rider]

Motor drag when moving the rear wheel backwards is normal. The freewheel on the crank will spin the motor in reverse, so you feel the cogging from the magnets, only when the chain is turning the kit backwards.
So, that part is nothing to worry about, unless it is particularly hard to spin. Should still move pretty easily, but you definitely will feel some 'lumpy' drag.

FYI.

It has obvious "lumpy drag." That is a perfect description of what it does, but it seems like it wasn't that strong before or I would have noticed it. I don't remember it on my other BBS02B ride either.

Wish I had a handy independent controller to slap in to eliminate that first. Isn't there a way to apply a power source to a standalone controller to test it?

[JPLabs]

I've notice my drag seemingly zero sometimes, and high other times. Figured out pretty quickly that what gear the bike is in makes a huge difference in the drag severity. So, again, probably nothing to worry you, there. If the motor was melted inside, plastic gear or worse, you would be able to tell, I think. It would be 'chunky' or get stuck some places, not just 'smoothly lumpy'. Like good turkey gravy.

[Rix Ryds]

OK, the fact that the throttle quit as well rules out the PAS hall sensors. However, there are three more hall sensors that are used for the three phases. These connect to the controller through a white plug that you can see if you remove the controller. This white plug is one of two problematic areas in the BBSxx series motors. I just helped a forum member "Gabriel' with his problem and it turned out to be the white plug. The first time I disassembled a BBSHD I carefully cut around the plug to free it from the silicon sealant, depressed the locking tab and gently pulled the plug loose. I was quite surprised to find that it had pulled one of the pins right off the board from below! When I went to repair it ALL of the pins on the board had 'cold' solder joints and pulled loose with ease. I'd be willing to bet good money you will find a problem with this white plug or the white socket it plugs into! Especially given that both PAS and throttle failed, the display comes on as expected, and you were riding within reasonable limits. Check it out carefully, I believe your problem is there! Good luck!

[Rider]

OK, the fact that the throttle quit as well rules out the PAS hall sensors. However, there are three more hall sensors that are used for the three phases. These connect to the controller through a white plug that you can see if you remove the controller. This white plug is one of two problematic areas in the BBSxx series motors. I just helped a forum member "Gabriel' with his problem and it turned out to be the white plug. The first time I disassembled a BBSHD I carefully cut around the plug to free it from the silicon sealant, depressed the locking tab and gently pulled the plug loose. I was quite surprised to find that it had pulled one of the pins right off the board from below! When I went to repair it ALL of the pins on the board had 'cold' solder joints and pulled loose with ease. I'd be willing to bet good money you will find a problem with this white plug or the white socket it plugs into! Especially given that both PAS and throttle failed, the display comes on as expected, and you were riding within reasonable limits. Check it out carefully, I believe your problem is there! Good luck!

Thank you RR! I am going to pull the controller off today, so the white plug will be getting disconnected. I did watch the video in a sticky thread on this forum for trouble shooting the BBS## motors. That was VERY helpful to see how it's done.

I think I will pull the entire motor and put in on the bench for easy disassemble...

Anyone interested in a converted to 29+ or 29 or 27.5+ or 27.5 or 26+ or 26 (your choice) "BBS02 READY" Electra Lux Aluminum 3-Speed cruiser with chain guard mounts? Original tires are like new and it takes 120mm or 135mm disc brake rear wheels! PM me if interested. I see a Soma Juice or Surly ECR coming my way if I have to take this one apart. ;-)

[Rix Ryds]

You're well on your way to having it repaired! Good luck!

[Rider]

I buttoned it back up and removed the motor from the bike. I decided not to mess with it until I hear from retailer regarding the 1 year warranty,

With that said, I did connect the battery once the unit was off and on the workbench. I went into the advanced settings and Error Codes, but there are no error codes listed ( the retailer asked me to do that first). When I hit the throttle I can hear a very slight "click" from inside the motor and the display only reads "26W" no matter what 1-9 level it is set to.

Does that bring any new light to identifying the problem? Thx.