Help! Error code 8

Hollie Bretherton

Just Joined
Aug 25, 2025
3
0
Hi really struggling with ebike can't get rid of code. New sw900 controller and screen phase wires showing resistance hall sensors showing power and continuity flashes leds correctly when wheel is pushed backwards not flashing when pushed forwards runs on self learning wires but not on pedal or throttle. Loosing my mind does anyone have any suggestions on where to go next please
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
9,222
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Telford
Did the SW900 come with the controller. If it didn't, it's probably not compatible.

With most controllers, as a temporary measure, you should be able to run without any LCD. You bridge the red and the blue wires, which should give you normal throttle operation and level 1 power assist.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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Have you got the PAS and throttle connected correctly to the correct controller output.
Is the motor connector pushed all the way in.

Error 8 indicates as a throttle issue.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
21,626
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West Sx RH
Black, Red and White are throttle yes ?
Why cut off the connector ?
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
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West Sx RH
PAS is Black ,Red & Blue but cannot see it at all well amongst the birds nest.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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My guess is that PAS & throttle don't work because wire sequence is not correct.
In the pic throttle wires have been cut and suspect the final pin out is wrong. I see original Black Gnd theoretically connected to SIg Yellow pin and Sig White theoretically connected to Gnd Black pin.

Show us the pin out at the throttle SM3 connector.

Can't see PAS connector, so we also need to see the PAS pin out at the connector.
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
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#5 is a complete mess , disconnect the tester and get rid of out of the way.
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
9,222
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Hi yes came together and the screen works perfect sorry I meant the 3 led lights on hall sensor tester
If the wheel rotates when you operate the walk assist, there is nothing wrong with the controller, motor or battery. That leaves settings in the LCD, or connection issues (PAS and throttle) - possibly wrong connectors (swapped over).

The photo shows a connector with brown, yellow and black wires (colours for PAS) attached to the red white and black wires (throttle), and the brown is shown as shorted to black. You really need to sort out that mess.

Whenever testing a new system you should connect and test one thing at a time. Start with motor, controller and LCD connected. Test that the walk assist works. Next, connect the throttle and get it working, then the speed sensor, then the PAS, then the brakes, then anything else.
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
21,626
8,805
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West Sx RH
The throttle connector has been cut off and the wires twist to the SM3 tails, theoretically incorrectly !
 

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