Slightly losing mind; 30H error

[Clyde]

I built my son an electric kickbike back in 2020 (Bafang 500w front hub motor in the 100mm rear dropouts), and he had a wreck last Summer. We put the bike away while he healed up, and did a little refurb (internal cable routing, moved the controller into the battery bag) last month to get it ready to ride again. As soon as we got it together, though, the display started showing a 08H error (Hall sensor fault). I first replaced the motor cable, figuring I'd pinched it while routing it under the deck, but no joy. Replaced the controller next, but still no joy, so rather than disassembling the motor to replace the bad Hall sensor I just bought another bare motor to swap into the wheel.

On completing that task the 08H error was resolved, but now I get a 30H error (display communication error). Thought it might be the p850c display, so ordered a new one, but I still get a 30H, even swapping in a new wiring harness. The display powers on, and stays on, and I can scroll through PAS levels, but the throttle and walk-mode aren't working. Thought it might be down to not changing the voltage from 48v to 52v on the new display, but the old display was correctly set and has the same behavior. I've now replaced literally every Bafang part on the bike aside from the throttle, and still can't get it to work.

If anyone has any ideas I'd be grateful to hear them!

 

[tomjasz]

30H is often a controller fail. You've done everything else.

 

[Clyde]

30H is often a controller fail. You've done everything else.

Thanks, but I've even swapped in a new controller. Frustrating...

 

[tomjasz]

Thanks, but I've even swapped in a new controller. Frustrating...

Throttle tested?

 

[Clyde]

Throttle tested?

Neither the throttle nor walk-mode work, but the error persists regardless of whether or not the throttle is connected.

 

[harryS]

Must have been a short in one of the two original harnesses that blew out either the Rx or Tx circuits. Test them to see that all five pins at the display end are isolated from each other.

This is the diagram for a BBS02 middrive. but maybe your display harness side is the same for the hubmotor. I believe they do use the P850C in the mid drive kits.

Many controllers will work without a display. For this bafang, the P+ is tied to PL at the display connector to do that. Hard to do though because it's male pins.

 

[Clyde]

Must have been a short in one of the two original harnesses that blew out either the Rx or Tx circuits.

Would a new harness resolve that, or do you mean it blew out those circuits on the display and/or controller?

 

[harryS]

I would check the old ones first. You have two? Continuity and isolation,

 

[tomjasz]

Neither the throttle nor walk-mode work, but the error persists regardless of whether or not the throttle is connected.

But have you tested the throttle? Electronic gremlins are weird.

 

[Clyde]

But have you tested the throttle? Electronic gremlins are weird.

So I have two controllers, two displays (p850c), a brand new motor cable, and brand new display cable. I've tried all possible combinations, and all result in a 30H error. On the original display it comes up immediately, while it takes 8-12 seconds for the error to appear on the new display. Throttle doesn't work on any of the combinations. Baffling.

 

[tomjasz]

So I have two controllers, two displays (p850c), a brand new motor cable, and brand new display cable. I've tried all possible combinations, and all result in a 30H error. On the original display it comes up immediately, while it takes 8-12 seconds for the error to appear on the new display. Throttle doesn't work on any of the combinations. Baffling.

Test the throttle?

 

[Clyde]

Test the throttle?

If you mean test it with a multitester, then no, I have not, but neither the original nor the known-working throttle from my other bike induce the controller to power the motor, nor does engaging walk-mode via the display controller.

 

[wwwbingcom]

Did you manage to get it sorted? I guess because you changed the controller before changing the display, your "new" controller may have been tripped by the old p850c display...

 

[Benny boy75]

did you manage to get to the bottom of it , my mid drive unit was displaying a 30h error i tried a new display and a new controller and finally a main cable the fault 30 has gone to be replaced by an 08 fault

 

[tomjasz]

did you manage to get to the bottom of it , my mid drive unit was displaying a 30h error i tried a new display and a new controller and finally a main cable the fault 30 has gone to be replaced by an 08 fault

This from my old tech support notes,

FYI, I just had an HD in for troubleshooting from (redacted), A new motor and a new controller would not correct the 08 error. We finally unplugged the PAS circuit and error went away, I get many 08 situations and the hall sensors are always good. Now we may know what is causing the problem. We suspect the PAS circuit is pulling down the 5v pwer to the point that it triggers an 08. When I replaced the PAS circuit all is well.