Bafang m400 mid drive no pedal assist???

[vincent]

Weird problem, m400 was working fine , shop had to change the battery slide out and now the pas does not work
bike turns on fine, display seems to act fine

put second controller in and added throttle, throttle works fine but pas still doesnt..??

i dont know where the pas sensor or whatever is on this bike
guessing all bafang mid drive are the same but maybe not since this is torque based

tern has been slow to get back with us

writing Anna at greenbikekit now to see if she has any input

any suggestions would be great

thank you

 

[Surly]

Sounds clutchy or PAS sensory - when you turn the pedals with the power off can you feel the pawls engaging to turn the motor or is it kinda limp? You should feel resistance. If no resistance it's clutch, otherwise sensor.

I've not been inside an M400 so i have no idea if PAS sensor is an easy repair.

Is this your new bike?

 

[vincent]

This is the tern and I don’t know what got messed up, it only has maybe 130 miles on it and I put three 20-25 mile rides on it right after I got it and it was fine


I’m guessing something got unplugged or pinched


just looked up the torque sensor and showed it to them so he’s going to go back in there and check it out- look for wires pinched etc


Good news is with the 350W controller I bought from Green bike kit the throttle works and my Nuvinci IGH is on the bike and ready to go

Caveat- on an m400 throttle only works from 6mph and up, you cannot use it from a standstill but I knew that before I bought it
Not as big a deal on a lighter bike like this although I do wish it worked from a stop


had an M600 for a while and the throttle was like that and I did fine with it


I’m sure we will get it figured out, hard to find much info on the M400


Will keep this thread up to date about what the problem was when we get it fixed

 

[shroffman]

This is the tern and I don’t know what got messed up, it only has maybe 130 miles on it and I put three 20-25 mile rides on it right after I got it and it was fine


I’m guessing something got unplugged or pinched


just looked up the torque sensor and showed it to them so he’s going to go back in there and check it out- look for wires pinched etc


Good news is with the 350W controller I bought from Green bike kit the throttle works and my Nuvinci IGH is on the bike and ready to go

Caveat- on an m400 throttle only works from 6mph and up, you cannot use it from a standstill but I knew that before I bought it
Not as big a deal on a lighter bike like this although I do wish it worked from a stop


had an M600 for a while and the throttle was like that and I did fine with it


I’m sure we will get it figured out, hard to find much info on the M400


Will keep this thread up to date about what the problem was when we get it fixed

@vincent was this ever fixed? I’m currently in a very similar position right now. I have a bike with a mid drive Bafang M400. Originally it was a 250w, but I changed the controller to a 350W and upped the battery from 36V to 48V. All was working fine until I tried to install a throttle, now the PAS does not work but the throttle does. I have already tried replacing the controller and torque sensor but still am only left with a. bike with a working throttle but no PAS.

 

[vincent]

They thought mine just turned out to be a loose wire connection , they are not sure exactly what it was but went through and replugged everything and it has been fine since

Wonder if maybe pas needs to be unplugged and then put back together to reset with the new controller since mine did the exact same thing after the controller change and throttle added
Must be some kind of sequence so resetting going on..??

I would unplug and replug all the connections
Hope you get it going

 

[Tars Tarkas]

While unplugging and plugging things back in, a little dielectric grease, Boeshield, or ACF-50 on all of the connections would probably be a good idea too.

TT

 

[Gionnirocket]

While unplugging and plugging things back in, a little dielectric grease, Boeshield, or ACF-50 on all of the connections would probably be a good idea too.

TT

Not to be applied to the actual copper connection points but the plastic/rubber housing of the connector to protect against the ingress of moisture/contaminates
Dielectric = Non conducting

 

[J.R.]

I've been using dielectric grease for more than 40 years for work, home, auto, MC, marine, ebike..... It's often misunderstood. Electrical snap connectors, mechanical connections where there's metal to metal, the grease doesn't restrict the flow of current. There are conductive greases available, but it is dangerous to use where the connectors cannot be completely segregated.

Motorcycle manufacturers and marine manufacturers use dielectric grease on their connectors due to the harsh and wet environment where the products are used.

One of the better explanations:

 

[Tars Tarkas]

Not to be applied to the actual copper connection points but the plastic/rubber housing of the connector to protect against the ingress of moisture/contaminates
Dielectric = Non conducting

You DO use it on the contacts, absolutely. It doesn't interfere with the metal-to-metal contacts at all. It cleans them and protects them from corrosion. The tiniest patina on the contacts can stop the flow of electricity. These products prevent that. This also protects from water intrusion to help protect the connections from future problems. I've used all of the products I've mentioned for years with great success.

TT

 

[Gionnirocket]

You DO use it on the contacts, absolutely. It doesn't interfere with the metal-to-metal contacts at all. It cleans them and protects them from corrosion. The tiniest patina on the contacts can stop the flow of electricity. These products prevent that. This also protects from water intrusion to help protect the connections from future problems. I've used all of the products I've mentioned for years with great success.

TT

I'm glad it's working for you, but...
I'm just expressing my personal experiences along with everything I've ever read on protecting electrical contacts from the manufacturers literature. Always keep contact points dry, clean and free of any contaminate (anything dielectric)
I'll also add that this was what I was told from Boeshield directly.
You might get away with it with new connections that are tight and remove any substance from the contact point as it mates. Boshield told me if you get any on the metal to mate the connection a few times to remove it from the actual contact point.
This becomes problematic with even slightly worn connections. Do this to hi current connections and you can really have a problem

I've been using dielectric grease for more than 40 years for work, home, auto, MC, marine, ebike..... It's often misunderstood. Electrical snap connectors, mechanical connections where there's metal to metal, the grease doesn't restrict the flow of current. There are conductive greases available, but it is dangerous to use where the connectors cannot be completely segregated.

Motorcycle manufacturers and marine manufacturers use dielectric grease on their connectors due to the harsh and wet environment where the products are used.

One of the better explanations:

I've been using it for decades myself and with great success but In the manner I described. And as far as I can tell the manufacturer's you mentioned implementation is as l described as well.
The video is interesting but also leading to a not so accurate conclusion. If I were applying it to the stab connector as in the video I would mate it first and then encase it in grease. It would be equally protected and with 0 contamination of the contact points. If you ever used those, they don't mate as tight the second time around and it gets worse with each cycle. It's not that it won't work on day one with a new connector as it will typically push the grease out of the way... it's down the road with vibration.

The stuff is awesome and has a million and one uses. Just this week I lubed the seals on my display connector (I open it frequently to progam). On the pivot point of my espresso machines' froth wand and to lube the rails on a sliding shower transfer bench for an elder relative. Tons of aquarium applications as well. (I use a food grade silicone grease)

 

[J.R.]

I'm glad it's working for you, but...
I'm just expressing my personal experiences along with everything I've ever read on protecting electrical contacts from the manufacturers literature. Always keep contact points dry, clean and free of any contaminate (anything dielectric)
I'll also add that this was what I was told from Boeshield directly.
You might get away with it with new connections that are tight and remove any substance from the contact point as it mates. Boshield told me if you get any on the metal to mate the connection a few times to remove it from the actual contact point.
This becomes problematic with even slightly worn connections. Do this to hi current connections and you can really have a problem



I've been using it for decades myself and with great success but In the manner I described. And as far as I can tell the manufacturer's you mentioned implementation is as l described as well.
The video is interesting but also leading to a not so accurate conclusion. If I were applying it to the stab connector as in the video I would mate it first and then encase it in grease. It would be equally protected and with 0 contamination of the contact points. If you ever used those, they don't mate as tight the second time around and it gets worse with each cycle. It's not that it won't work on day one with a new connector as it will typically push the grease out of the way... it's down the road with vibration.

View attachment 150233

View attachment 150234


The stuff is awesome and has a million and one uses. Just this week I lubed the seals on my display connector (I open it frequently to progam). On the pivot point of my espresso machines' froth wand and to lube the rails on a sliding shower transfer bench for an elder relative. Tons of aquarium applications as well. (I use a food grade silicone grease)

My comment was in support of both of you, but really was just a general comment to anyone that may need some info on dielectric grease. I'm also really happy with modern silicone dielectric grease over the white dielectric grease that use to be sold decades ago. Lasts much longer and easy to use.

 

[Gionnirocket]

I gleaned that from your comment.. but my reply was also to others that quoted me.
Curious to your experience with the motorcycle and marine manufacturers you mentioned.. Do you see the grease on the contacts or just the connector shell?

 

[Tars Tarkas]

I'll just say that if you don't have a good mechanical connection, ain't nothin' gonna work. These products will help with making the connection clean and therefore reduce any unwanted ohms. The dielectric grease (or other product) will get pressed out of that connection and become a barrier to moisture, corrosion and debris. So, I guess in a way, I'm agreeing with you. The grease will only be a problem is the contacts aren't connected.

TT

 

[Gionnirocket]

I'll just say that if you don't have a good mechanical connection, ain't nothin' gonna work. These products will help with making the connection clean and therefore reduce any unwanted ohms. The dielectric grease (or other product) will get pressed out of that connection and become a barrier to moisture, corrosion and debris. So, I guess in a way, I'm agreeing with you. The grease will only be a problem is the contacts aren't connected.

TT

I agree... The connection needs to be mechanically sound in all cases.
I don't know about the AFC product as the silicone grease and Boeshield have always worked well enough for me.. but they do not clean contacts and I strongly recommend that you do not use it for that purpose.
Contact Cleaner should be use to remove any patina or contaminates. Fast drying and leaves no residue.
If the product doesn't facilitate a better connection (such as conductive grease) then it need not be there and in most cases you can just as easily protect the contacts from moisture by sealing the connector plastic/rubber body the contacts are in_cased in.
This is one of those cases in my opinion where less is more... Your electron flow may vary

 

[vincent]

wondering if you ever got this fixed

 

[J.R.]

I gleaned that from your comment.. but my reply was also to others that quoted me.
Curious to your experience with the motorcycle and marine manufacturers you mentioned.. Do you see the grease on the contacts or just the connector shell?

Connectors are getting better every year it seems. So many these days use O rings and seals that only a little lubrication is required. The ones on my newer 125HP Mercury 4 stroke are like that. Maintenance free really. The Harley I've owned for 33 years, the connectors are antique and I do use dielectric grease on the entire connector plugs. These are blade and or barrel type, metal to metal, so no issues with resistance. I've read of people even using it on spark plug wires. I'm not sure that has any benefit. There are a few areas on my ebikes where I use dielectric grease. One area I would use it every time is with dissimilar metals. If by chance a manufacturer mixed copper, steel, aluminum in their connectors, electrolytic corrosion can form from acidic humidity or rain, fusing the metals together. Dielectric grease works for protecting the connectors from moisture and it works as an anti-seize lubricant.

 

[Ravi Kempaiah]

Weird problem, m400 was working fine , shop had to change the battery slide out and now the pas does not work
bike turns on fine, display seems to act fine

put second controller in and added throttle, throttle works fine but pas still doesnt..??

i dont know where the pas sensor or whatever is on this bike
guessing all bafang mid drive are the same but maybe not since this is torque based

tern has been slow to get back with us

writing Anna at greenbikekit now to see if she has any input

any suggestions would be great

thank you

I will be visiting Bafang factory next month and we do have strong contacts there!
Let me know if there is anything I can do to help.

 

[vincent]

Mine is fine now for months but I don’t know about shroffmans bike, hopefully they will come back and let us know

 

[shroffman]

Thanks for all the help guys. Eventually I fixed my issue, I did pull apart everything again and double checked everything was fine. The fix was, I had the battery attached all this time whilst working on my bike and all I did was remove the battery and attach it again, and suddenly everything worked!

 

[vincent]

ahhh, that is great though! always good when it is something simple
for all i know mine was the same thing, maybe they need to be reset somehow by pulling the battery off..

glad you got it fixed!