Not getting pedal assist power, and intermittent throttle response

[CorbtheBorg]

Just like the title says, having no power via pedal assist when riding. Throttle works intermittently. Anyone have this problem? I checked all wires and connections. Magnet is on the spoke in proper position. Getting speed reading from the display when wheel is turning. Kinda stuck and not sure what to do. Here’s a picture of the magnet in position and over view of bike.

 

[Ann M.]

@CorbtheBorg; something happened when you uploaded the images and they do not display properly. I've deleted the old attachments so you can try again. Please make one image full size and the others, select Thumb. All thumbs will view at full size when clicked on.

Without seeing your images I can't say for sure that there's not an issue with the PTS sensor; occasionally they are faulty or not aligned closely enough. Combined with the throttle issue this is most likely a faulty controller; however, I do suggest that you check that all of the connectors are snugly fitted to the controller. With the bike in a stand or carefully turned upside down (use a small box or block shoved under the stem to keep the handlebars off the ground) turn the bike on and wiggle wires gently while turning the cranks or using the throttle. This may indicate that their's a wiring harness problem which could still be associated with a faulty controller.

A couple of other questions:

• Is this a new bike? If so, contact Biktrix immediately for warranty help.
• How long have these issues been going on?
• Was it a sudden start to the problem or gradual? (as in the pedal assist sorta worked or had worked fine prior to this issue)
• If it was a sudden start to the issues, do you remember riding over some bad potholes or super rocky road? Or riding one or more times during heavy rain?

All of these will help diagnose what's happening with your bike and I know it's a bummer to not have your ebike running right!

 

[CorbtheBorg]

Thank you for you help Ann. I’ve contacted Biktrix and sent them emails. Roshan’s advice was to check magnet placement on the rear wheel. It appears to be in place. I mailed him back with pictures and haven’t heard anything yet, this was earlier this week. The bike is brand new less than 100 miles on it. It was in a local bike shop for about two weeks already waiting on parts via warranty for an unrelated issue as well. No rain only shine and I’ve ridden it on bike path only, nothing wild yet.
I’ll do as you suggest and wiggle the connects but they are all attached and in place. I was riding with my wife downtown for about ten miles when it suddenly started happening. So it was working all day no problems then bam.
Definitely a bummer as I was using it to commute for about a week before this latest issue.

 

[rich c]

Either battery connections or wiring connectors when something works intermittently. Make sure the battery isn't rattling around, and the battery connector is not slightly melted and making a good connection.

 

[Ann M.]

I know that was a long 10 miles back home! Yes, the magnet alignment is pretty critical. One other thought; if you're comfortable with a voltmeter, measure the battery voltage on the bottom of the pack. Be careful to not let the test leads touch while you're measuring and the battery might need to be turned on to get any reading. Low voltage from a bad set of cells could also trigger what the throttle is doing but probably not the assist issue.

 

[Barry S]

Does your bike have the GearSensor attachment that cuts the motor briefly when shifting? If so, check that connection too. It's usually spliced in on the rear shifter cable just before the derailleur.

 

[CorbtheBorg]

Looks like all the connections are secure and in original working condition. I did find some error codes on the display I’ll post the picture below. There is a gear sensor and it’s got a flashing green light and is looking properly fixed to the bike. I don’t have a voltage meter but I can tell you under throttle alone it has full power and can get you to speed no problem. The brake cutout sensors work

 

[dadoftwinsfml]

Here are the bafang error codes: https://electricbike.com/forum/foru...rs-and-kits/bbshd/7747-bbshd-bbs02-error-list

I looked up the ultra manual and it uses the same codes.

Looks like speed sensor may be the culprit despite what you're seeing? I recall reading in some other forum that the speed sensors can go bad and that some ebike parts site sold more bafang speed sensors than any other component. IIRC someone said they always had an extra one on hand.

 

[CorbtheBorg]

Wow fantastic information! I’ll head down that rabbit hole tonight. Thanks for finding that for me.
Great username btw

 

[CorbtheBorg]

Well spoke with Roshan and he was a bit stumped by the error codes. Apparently when the speed sensor goes out it gives a warning message on the display. My codes I had to access through the information prompt while on the display. He said he would contact Bafang to see how to trouble shoot it. Bikes been down a week.

 

[Barry S]

Wondering if those are old codes that got created during pre-shipment testing since nothing new popped on the display for you. Thinking along the lines of PC boot-up errors that get logged but don't clear out unless manually done. I'd clear those codes if possible and see if they regenerate. Just a thought.

 

[CorbtheBorg]

I don’t recall them being there while I was thumbing through the different prompts...plus the bike was functioning properly before the codes appeared. This is an interesting thought though. Is there a way for the end consumer to delete codes and see if they regenerate???

 

[Barry S]

Not finding anything using Google. I think the display may have its own battery in order to maintain accumulated miles and other settings, so disconnecting it from the power source probably won't reset it.

 

[roshan]

Err 30 is a generic error code that bafang uses as a catchall.
Err 21 is for speed sensor.

As mentioned on our call, I'll ship you a programming cable and software with instructions on testing the torque sensor. I believe that might be the culprit. Either way, it's covered under warranty and worst case we'll ship you a replacement motor.

 

[CorbtheBorg]

I appreciate you sending that over to me I’ll be waiting eagerly. Ready to get this nut cracked.

 

[CorbtheBorg]

Just a brief update if anyone is interested. I was sent the cable and diagnostics were done with Roshan and Bafang. It was determined that it is the torque sensor causing the malfunction. Roshan said he was going to send out the replacement motor free of charge and I will send my defective motor back to Bafang. I’m waiting on that now and am keeping hope alive that I can get this straightened out. I think patience is a virtue. I’ve been watching YouTube on how to pull crank apart and trying to bone up on how to videos about motor swap. Should be interesting. Here’s a pic of the diagnostic screen that was used to determine the problem.

 

[Brad in NC]

I experienced similar problem with my second biktrix, a Jugg HD Classic, within 20 miles of riding new. What I found was that the metal bushing nut supporting the electrical connector on the battery was loose allowing random disconnection of the battery from the integrated bracket. I disassembled the battery in order to push the electrical connector through sufficiently to reattach and tighten the bushing. I also found the bushing loose on the bike side and tightened it also. I was lucky and had a second bike to help isolate the issue (worked on my bike but not wife’s). Used locktite blue on all and haven’t had another issue.

Pic below is of the bike side bushing (the metal around the plug). It has a mate on the battery.

Also, worth checking is the following. In the attached picture you’ll note a missing bolt in the center of the picture. This bolt came loose and became lost after about a hundred miles of riding my Jugg FS. I was unaware but enough wiggle was allowed that the battery was performing intermittently - i could stop and jam it all back together but any bumps would stop assist. I purchased at hardware store, and replaced the bolt to secure the end cap, and used loctite. No recurrence after a fair amount of bumpy gravel and single trail riding. Bolt is a Button Head Cap Screw, Metric, M3-.50 x 16. Good Luck!

 

[CorbtheBorg]

Wow ok I’ll double check that. Was your screen not functioning due to the battery being a loose connection?

 

[Brad in NC]

Wow ok I’ll double check that. Was your screen not functioning due to the battery being a loose connection?

Correct, display would also shut down. Total loss of power.

 

[CorbtheBorg]

Great trouble shooting Brad. Thanks for sharing that. I went and checked my connection and battery. Everything is tight. I should be receiving my motor soon and I’ll post some updates. I’ve got my order confirmation but not tracking numbers yet. I’ll check with Roshan Monday if it’s in the mail.