Err code 28, console sluggish


New Member
Hi everyone,
I have a BionX powered e-bike which has been giving me some trouble lately.
Notice I have two batteries:
a) the original one with a working DC output for the headlight
b) a spare one I got second-hand, whose DC output doesn't work (so no headlight...)

If I enable diagnostics on battery a), I get error code 28. Also, the console does not seem very reactive (it looks like I have to press each button several times for it to work).
What I actually find most annoying is the fact that every time I change the support level +/-, the motor just freezes for a fraction of a second (as long as I keep the button pressed) and then resumes its support.
Kind of a hiccup at every change of settings.
Also the screen goes a bit blurry sometimes.

On battery b) (where the headlight has never worked before), I now get some feeble light out of the headlight every time I press some button on the console, for a few seconds.
I've also seen error code 22 sometimes.

So the only explanation I could find for this behavior would be a short-circuit between the CANBUS and the DC output. Would that explain this behavior?
I visually inspected the connector on the battery rail and it looks OK.
But I haven't tried any resistance measurement yet. Any idea what pins I should look at?
If I remember correctly, this kind of behavior started after I went out in the rain one day.
Perhaps there's some water shortening the pins within the connector in the battery rail, or someplace else?

Any suggestion would be highly appreciated!


New Member
The blurry display, sluggish buttons and the rain suggest water in the display console.
Take it to a dealer to swap consoles as a test first to confirm this.

If you are out of warranty, and you confirm the problem is the console there is not much to lose and everything to be gained by opening it up and checking for moisture inside. If you find any, use a hair dryer to dry it off and gently scrape off any obvious corrosion. You can see how to open it here:öffnen.33900/ although the text is German your browser should have a translate option. Note the case will need to be glued back together.

If you are still in warranty though, Bionx should replace it since it should be able to tolerate rain.


New Member
Hi whitexkr,
thanks for your reply!
Actually I also have a spare G1 console I got with the battery (I essentially got a spare kit for the price of the battery alone), so I assume I could try that.
The warranty is long gone so I'd go with opening up the console if it turns out that's the real cause of the problem. But I'd like to make sure of that first. ;-)

I'm still convinced there's something wrong with the wiring though, perhaps some cable got damaged or some connection got wet.
This flickering of the headlight with the 6V-incapable battery, that I can't explain with a fault at the console. Or am I wrong?
Are there any basic checks I could perform at the battery connector (or anywhere else, for that matter) to make sure there's nothing obviously wrong?
As for the external (6V/12V) power, I could not find any documentation but I believe the two pins involved at the battery are the motor's ground and the D-Sub chassis.

Again, any help would be highly appreciated!
Thanks again!​

Ann M.

Well-Known Member
@iurly , are you sure it's a G1 console? that wouldn't work with the later, G2 systems that support the 6V port. The early consoles were vulnerable to moisture damage, so whitexkr's suggestion is a good one.

A pretty extensive post was made on EBR about accessing the Console Codes which may be of value to you.
Error code 28 indicates that there is a problem with the 6V port; Error code 22 is an indicator that the motor controller circuit board has a problem; that will require opening the battery where the primary controller is and possibly the motor.
Nycewheels has an excellent list of what the(Link Removed - No Longer Exists) for a G2 console mean. Plus, they have a link to email BionX about the issue.
A dealer would be able to run diagnostics using BionX's program and make recommendations about what needs the repair.


New Member
I don't get the question.
The console I have on my bike is a G2, and I have a spare G1 from a second-hand kit which I bought separately.
Apart from the 6V (which I don't care about right now), that should work with my system, right?

In the end, I'd like to figure out what the problem is (assuming it's a single fault).
I have a spare kit I could use (G1 console, 36V battery wihout 6V output, motor and cablings).
I already tried replacing the battery using the spare one, and the whole system actually failed this morning.
First I was cycling with no assistance, then a few minutes later the whole system would turn itself off after a few seconds.

I guess as a last resort I could just replace the motor and console, and if that still fails it would mean it's the cabling, right?
(Which was my suspicion to begin with). I would also proceed with this (Link Removed - No Longer Exists).
Any suggestion on how to proceed further with this investigation?

Thank you!

Ann M.

Well-Known Member
If that G1 system is the original I2C programming, none of those components will work on the newer G2 systems and there is no way to upgrade that firmware. If it is the later type coding, then the firmware version has to match on each component for them to be swappable. You need to have a BionX dealer with the BBI program to upgrade the firmware on the G2 components, that's not something you can manually do at home. (Sorry!)

One additional benefit to having the dealer do the firmware upgrade is that if there is any other issue with the system, they can get BionX on the phone while doing the diagnostics. When the kit is plugged in to the BBI, BionX in Canada can see all the data via the internet and a lot more than what the dealers do.


New Member
I'm pretty sure the G1 system is the new CANBUS, as it is part of a kit whose battery works with the stock G2 system I have on my e-bike (apart from the 6V/12V output). I haven't checked the firmware version though.

Apart from the incurring costs, I'm a bit reluctant to bring the bike to a dealer since I did some tweaking with the system (i.e. max speed) with a CANBUS thingy and I assume they wouldn't be enthusiastic about that, so I would have to revert those changes.
I would leave that as the last resort ;)
Thanks again!


New Member
thanks again for your support.
In the end I disassembled the battery rack. I had a look at the wiring of the D-SUB connector (all covered in silicone or some other transparent glue) and did not find anything suspicious except for some (barely noticeable) moisture or grease on the plastic cover.
I cleaned all the connectors (battery<->motor and battery<->console) a little bit. Nothing fancy, just some blowing and rubbing with a paper napkin. And then I put it all back together.
Then I re-made the 6V connections (front and back lights were connected through some rusty fastons which I replaced) and now it's all working perfectly, good as new. No errors, no more stuttering when changing assistance level, no trembling feeble light coming from the headlight (with the battery which doesn't support the 6V port).
Quite honestly, I did not find anything "wrong" which I could have fixed by doing this (i.e. no rust, oxidation, dust, nothing!).
Even with the 6V wires, the inner cooper was maybe a bit rusty I guess, so at worst the connection to the headlight might have been just loose. But there was definitely no room for a short circuit between those cables and anything else (i.e. the frame).
So I really don't know what the problem was to begin with. Unless this loose connection to the lights was throwing the whole system off.

I fear I might have just moved the cables around a little bit, thereby moving some loose contacts around.
What can I say? It works for now. I just hope it doesn't hit me again any time soon.

Thanks again for your help!