Author Topic: Magic Pie 4 Display shows error 9 and usb programming not working  (Read 379 times)

Offline Cloudy

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Hello, I have bought second hand what I think is a Magic Pie 4 motor. It has "2018" on a sticker on the hub body. I have the motor running at 14s battery (54.6V), both throttle and regen work as expected.

I would really appreciate some help with this older motor. In particular:

I would like to change settings with the USB cable that came with the motor. I have installed the windows software, but am unable to connect to the motor when plugged in. I get the error : Fail to open serial port COM09600. I have tried both USB ports on my laptop and get this error regardless. How do I connect the software?

I have a display that came with the motor, this is not showing "error 9" and 0km/hr speed when the motor is spinning. How do I make this one work?
« Last Edit: November 29, 2025, 11:29:49 PM by Cloudy »

Offline Bikemad

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Re: Magic Pie 4 Display shows error 9 and usb programming not working
« Reply #1 on: November 30, 2025, 01:50:08 AM »
Hi andto the forum.

Do you know if everything was working correctly before you purchased it?

Try to connect using the following sequence which typically enables a successful connection:
1) Connect the USB lead. (Vector controllers use a USB lead fitted with a five pin connector)
2) Open the programming software.
3) Select the correct COM port from the dropdown option box (was showing as COM 16 on your screenshot).
4) Click the “Connect” icon and wait for the timeout error.
5) Then connect the battery power!!
The controller should instantly connect and the relevant parameters should automatically be uploaded and displayed.

If it is unable to connect, power off and then disconnect the 10 pin connector on the controller and see if you are then able to connect by repeating the previous steps.

If you are still unable to connect with the USB programming lead, try plugging in the display back in (with the 10 pin control harness connector still unplugged) to see if the battery gauge is reading higher than before. You might also see "ERROR 2" with the throttle disconnected.

If the controller will still not connect successfully to either the programming cable or the display unit then I suspect there may be a problem somewhere within the controller or its external wiring. :(

The MP4 and MP5 wheels are identical except for the controllers and there are 2 versions of the BAC-601 displays which only work with the specific controller. Early versions were used for SP4 & MP4 and later versions were used for MP5, MP Edge and SP5.

Unfortunately, I don't know how you can tell the difference between the MP4 & MP5 controllers or the BAC-601 displays to confirm that you have the correct version to match your controller.
My original Smart Pie 4 controller had a MP5 sticker on it, but was not compatible with the MP5 Bluetooth dongle.  ???



I also have A BAC-601 display on my MP4 but it does not work with my MP5.  :(

I presume you must have a 13S battery (13S x 4.2V = 54.6V) as a 14S battery would be 58.8V fully charged. ;)

Alan
 

Offline Cloudy

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Re: Magic Pie 4 Display shows error 9 and usb programming not working
« Reply #2 on: December 01, 2025, 02:10:03 AM »
Hi Alan, Thanks for taking the time to write such a detailed response!

I was successful in connecting the programming cable. I simply had to select COM16, in the drop-down menu next to the "Connect" button. Thanks for the tip.

Unfortunately I was unable to get the screen working, it powers on and shows "error 9", the three button controls for it allow me to change PAS mode, but nothing useful is displayed when the motor spins. I'm not sure if this means I have an incompatible screen or what the issue is. The previous owner never installed the motor on a bike but may have bench tested it. The screen does look like it has been used, but the motor is still mint.

My battery is 14s, but I charge it up with a 13s charger to approximately 54.6V. Sorry, I should have been clearer about that in my original post.

I've been able to increase the battery current setting from 25 to 30A
Max Power is now about 1500W as measured by my battery B.M.S. I'm pretty happy with the motor performance and it has reasonably good torque at low speed. I've left Max Phase Current at 70A (maximum allowed setting).

Over Voltage Protection - Reduced from 62 to 61V. I was unable to set this below 61 for some reason? It's a little weird this cannot be set below 61V, but maybe not a big deal as my B.M.S should cut out at around 58V anyway

I see no settings for Motor or Controller Temperature protection. Do you know if this motor/controller will overheat or is there inbuilt temperature protection? I intend on going up some very big hills!

Max Forward Speed, default setting is 380rpm, the software does not let me upload any changes to this setting?

Regen was a little abrupt, and I was able to adjust it by reducing EBS Phase current from 70 to 60A. Default regen returns up to 1200W to the battery when braking. I'm unsure if this rate of charge is sensible in the long run for my 8p14s battery made of 18650 cells.

I reduced "Decel Level 1 (rpm)" from 65 to 20 but I could not say for sure if this changed anything. Do you know what this setting does?

Offline Bikemad

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Re: Magic Pie 4 Display shows error 9 and usb programming not working
« Reply #3 on: December 02, 2025, 01:11:57 AM »
Unfortunately I was unable to get the screen working, it powers on and shows "error 9", the three button controls for it allow me to change PAS mode, but nothing useful is displayed when the motor spins. I'm not sure if this means I have an incompatible screen or what the issue is. The previous owner never installed the motor on a bike but may have bench tested it. The screen does look like it has been used, but the motor is still mint.
It does sound like the display might be the wrong version for your controller.

I see no settings for Motor or Controller Temperature protection. Do you know if this motor/controller will overheat or is there inbuilt temperature protection? I intend on going up some very big hills!
The controller has a built in temperature sensor and will cut all power to the motor if it gets too hot.

Max Forward Speed, default setting is 380rpm, the software does not let me upload any changes to this setting?
You should be able to enter a lower value if you need to reduce the maximum speed, but it will not accept a higher value than 380rpm.

Regen was a little abrupt, and I was able to adjust it by reducing EBS Phase current from 70 to 60A. Default regen returns up to 1200W to the battery when braking. I'm unsure if this rate of charge is sensible in the long run for my 8p14s battery made of 18650 cells.
You can lower the EBS phase current (regen current) if you want to lower the power being sent to your battery, but this will obviously reduce the braking effect of the regen.
1200W @ 58.8V is just over 20A. If your 18650 cells are 2.6Ah or above this is still only charging the individual cells at a maximum of 1C, which should be fine.

I reduced "Decel Level 1 (rpm)" from 65 to 20 but I could not say for sure if this changed anything. Do you know what this setting does?
The Decel Level 1 (rpm) setting is incorrectly labelled and is very misleading, as it actually relates to the maximum reverse speed in rpm.  ::)
Check out this post for further information on the program settings.
If you don't have a reverse switch, you won't need to worry about this setting.  ;)

Regards,

Alan
 

Offline Cloudy

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Thanks Alan for your help. It is  :D running great now