Bafang bbshd motor not working error code 08

[Midlifecyclist]

Hi,

I have two bbshd kits that I bought from China.

When the first one arrived I installed it without any problems and the bike performs really well.

So I ordered a second kit (this one for a 100mm bb) and before installing I took the opportunity to grease both motor units with mobilgrease 28.

I installed the second unit, turned it on....no problem. With the bike in a cycle stand I touched the thumb throttle and the rear wheel turned a fraction and then the motor stopped.

The display then showed "Controller Report Error 08".

Following information from various Google searches I have checked all the obvious causes and everything is fine.

I finally decided to check the controller, so I swapped the one on the faulty unit with the one on the working bike together with all leads and display. This gave the same 08 error message.

So, the fault lies with the motor core, probably the Hall sensors(?).

Beyond this point I'm out of my depth.

The seller in China has said I can send the unit back for repair, but given the cost of return, the length of time it might take, and, probably more importantly, the fact I've opened the unit up...... it's probably not worth the effort.

So..... I'd welcome any advice as to how to fix the problem?

I can buy a replacement motor core from the US, but the postage is $80....!!!!

Thanks

 

[Deleted member 4366]

Error 8 is hall sensor - most likely the connector not making proper contact. On mine, there was silicone sealant holding it off, so I had to scrape it all off from around the connector to get it to sit down properly.

 

[tommie]

Error 08 Hall sensor: Sometimes corresponds with grinding noise: Check the motor plug to make sure it is connected properly, unplug and replug. May happen if the motor has been unplugged. Check that the plug pins are not bent. If not Needs to be sent in for repair. If you are a true DIYer you can open it and check if the hall sensor board is still fixed in place

 

[Midlifecyclist]

Thanks both for your replies.

I have dismantled the drive unit to access the hall sensors and board. All looks fine.

There is quite a bit if silicone on the sensors themselves, but I don't see that it would be the cause of the problem.

I'm assuming that either the board and or a sensor(s) is at fault.

I'm getting someone who knows more about these things to have a look later today.

I'll report back once he's been.

If it is the board, is it available as a spare?

Thanks again.

 

[Midlifecyclist]

So....
Did a rather basic test of the Hall sensors.
This involved using a 9v battery to power the hall sensor circuit board in the motor core.
The armature was removed and a magnet was used to "trigger" the hall sensors in turn and the output signals were monitored.
The results showed that all the hall sensors responded to the magnetic, but it wasn't possible to tell if these were of the same magnitude.
It was also found that at least one of the phases was working. With the motor reassembled it was possible to get rid of the 08 error message but rotating the chainring backwards and turning the unit back on.
With the display not showing a fault, the thumb throttle would make the motor kick through a phase and then stop. Error message 08 would then be displayed again.
I'm assuming that the fault lies either in a hall sensor (or 2) or the hall sensor circuit board itself.
Think the first thing to do is check for dry joints on that board. Failing that, replace the hall sensors and if still not working, get a replacement board (if available...).

Cheers.

 

[JohnnyBBadd]

Interesting. Keep us posted.

 

[Midlifecyclist]

Well...

I'm delighted to say that replacing the Hall sensors cleared the fault and the bike has now been reassembled and is working.

All I need is a break in the weather and I'll be heading to the trails for a shakedown.... Can't wait..

 

[tommie]

good job.

btw where did you get your spares from?

 

[Midlifecyclist]

Hi tommie,

RS Components online.
Part Number 8223771
90p each delivered!!!

I ordered 6, just in case I messed it up, but only needed 3.

The original ones weren't particular well installed, however if you've got a good soldering iron with a fine tip (or in my case a mate) it's not a difficult job to replace them if they're playing up.

Care must be taken with the circuit board as they are unavailable as a spare.

Cheers

 

[Midlifecyclist]

 

[Midlifecyclist]

 

[Midlifecyclist]

Tested then Silicone applied.

 

[Mike Eatough]

Tested then Silicone applied.

Midlife, thanks for this thread & great descriptive pictures your symptoms & diagnosis steps are EXACTLY like mine. I should receive the hall sensors today. I can't wait to install them. One question, were the sensors difficult to extract (glued) from the core slots? Do you have any idea what caused your sensor issue in the first place?
Mike Eatough

 

[Deleted member 4366]

Yes, they're glued in. In the one I did, one came out easily with the hall pcb, the second needed a bit of levering to get it out with the pcb, and the third was so tight that it broke off, but I was able to lever it out of it's slot afterwards.

 

[Midlifecyclist]

Midlife, thanks for this thread & great descriptive pictures your symptoms & diagnosis steps are EXACTLY like mine. I should receive the hall sensors today. I can't wait to install them. One question, were the sensors difficult to extract (glued) from the core slots? Do you have any idea what caused your sensor issue in the first place?
Mike Eatough

Hi

Yes, they're glued in. In the one I did, one came out easily with the hall pcb, the second needed a bit of levering to get it out with the pcb, and the third was so tight that it broke off, but I was able to lever it out of it's slot afterwards.

Hi Mike,

As d8veh says they come out with the circuit board, hopefully with just a bit of gentle and even prising. If they are a bit stiff, chop them off, remove board and leaver out.

No idea why they fail.... Probably just low quality control standards.

Hope all goes smoothly. Great sense of satisfaction when the motor runs again!

Cheers.

 

[Deleted member 4366]

A crank-drive can't lose heat as well as a hub-motor can. Look at all the finning on the Bosch CX motor, then compare that with a BBSxx. Maybe that's the problem.

I've known of quite a few instances of hall sensors failing on a BBSxx and had to fix one for a friend. Mosfets pop regularly too, but that seems to be related to water ingress. It's possible that the water affects the hall sensors too, or it could be that a misfire from water in the mosfets causes the motor to go very hot, which boils the halls.

 

[Deleted member 4366]

I forgot to mention that you can make a test lead for the BBSxx halls using a 5S lipo balance connector. It's the same connector with flying leads. You can then use a meter to test them or wire them to an ebike tester. IIRC, you still need to remove the motor from its outer cover to be able to rotate it by rotaing the metal helical gear directly. I should have made a note of the pinouts when I did it!

 

[JohnnyBBadd]

Guys. Thanks so much for this - it's really useful info. I've got error 12 on mine at the moment, with similar presentations - motor works for a bit, then cuts out, then works again... I've been advised to run the battery completely flat and then re charge in case of a faulty cell, but its probably the controller which I can get from Green Bike Kit (bought spares from them before - really good service). Can't pretend not to be disappointed in the motor's reliability so far. It's only done C1300 miles and I had to replace a chewed up nylon gear at about 500 miles. Saying that, I use it predominantly for XC in all sorts of weather, so it does get used hard.

 

[Deleted member 4366]

Don't waste your time running down the battery. That wouldn't solve anything even if there was something wrong with the battery. It would only make it worse. If the battery were faulty, the display would go off. As long as the display stays on, the problem is elsewhere. Other guys that got error code 12 had water in the motor. I'm not sure of the meaning from memory, but i think it's abnormal current, which normally means mosfet problems.

 

[JohnnyBBadd]

Hi d8veh, thanks for your reply.

I'm inclined to agree with regard to running the battery down, but I'm at the stage of ruling things out at the moment. (it's done now anyway) I've stripped the motor down and there was no sign of water ingress, or rust. Can I purchase the mosfets from RS? If so, do you know of a part number?

The other option is to buy a replacement 'motor only' and have the original one for spares...

Adendum: Mosfets are here