No PAS; Error message on walk assist

[steve2777]

I'm replacing my Hyper ebike 3 level controller, and have taken forum members' advice to go with KT products. I have installed a KT36/48ZWSRD controller and KT LCD-C display, as well as a thumb throttle. Display turns on and the settings and assist level adjustment work normally. The display shows when I activate the brakes and throttle, so presumably wired correctly. But when I pedal, there's no assist, and when I press walk assist, display shows "motor position sensor fault!" (I did replace the motor cable, as original was cut in a previous install; Is it possibly defective?) Bike already had operating PAS with 12 magnets, so no changes there. PAS to controller wiring is red>brown, yellow>black, blue>yellow. I'm at a loss as to the next step. Any help is appreciated.

 

[E-HP]

I'm replacing my Hyper ebike 3 level controller, and have taken forum members' advice to go with KT products. I have installed a KT36/48ZWSRD controller and KT LCD-C display, as well as a thumb throttle. Display turns on and the settings and assist level adjustment work normally. The display shows when I activate the brakes and throttle, so presumably wired correctly. But when I pedal, there's no assist, and when I press walk assist, display shows "motor position sensor fault!" (I did replace the motor cable, as original was cut in a previous install; Is it possibly defective?) Bike already had operating PAS with 12 magnets, so no changes there. PAS to controller wiring is red>brown, yellow>black, blue>yellow. I'm at a loss as to the next step. Any help is appreciated.

Can you provide a pic of the motor cable, and specifically any connectors. The error suggests that the hall sensor conductors may be in the wrong order or one of the sensors is faulty. The former is easier to correct.

 

[steve2777]

Photo enclosed. I should mention that I previously had a bad motor cable connector come apart on attempting to remove it from the controller, and the only way I could remove it was to Drexel off the lip of the controller's connector, and the arrow along with it. But I THOUGHT I had paid close attention to plugging it in at the same position. Also, before I removed the first cable, PAS didn't work then either, and the arrows were definitely aligned then. If it's possible the cable was rotated, can I determine the correct position from pin length and codes on the female end?

 

[E-HP]

Photo enclosed. I should mention that I previously had a bad motor cable connector come apart on attempting to remove it from the controller, and the only way I could remove it was to Drexel off the lip of the controller's connector, and the arrow along with it. But I THOUGHT I had paid close attention to plugging it in at the same position. Also, before I removed the first cable, PAS didn't work then either, and the arrows were definitely aligned then. If it's possible the cable was rotated, can I determine the correct position from pin length and codes on the female end?

Did your stock controller used the same cable?

 

[steve2777]

No. I bought this one because the second controller had different wiring, and I had to cut the original. I bought this one for the KT.

 

[E-HP]

No. I bought this one because the second controller had different wiring, and I had to cut the original. I bought this one for the KT.

Can you post a pic of the other controller's wiring (the wiring going to the motor)?

 

[steve2777]

Enclosed. What was in the 9 pin cable had to be routed to a 5 pin SM and 3 other wires. So I had to cut it. Turned out controller was probably defective, so I got a second cable. I test fitted the cut connector to the KT, then it came apart when I tried to remove it, and I had to Drexel the plug collar to get it out. I've also ordered another cable, arriving tomorrow, because I couldn't seem to fully seat cable 2 into the KT controller. (That's why I was test fitting cable 1's connector when it got stuck. Murphy's law in full force. also enclosed is what the dremeled controller end looks like. I've been looking at photos of the KT from the Amazon listing, and I'm pretty sure I inserted it correctly, but it would be nice to be certain.

 

[E-HP]

Are any of these pics the connector(s) coming out of the hub motor? Did the original controller plug into an extension cable that had JST connectors on the controller side, and a 9 pin motor connector on the other? Sorry, just trying to get better oriented.

 

[steve2777]

Here's the ORIGINAL controller. Standard 9 pin on both ends. The second controller made me have to cut a perfectly good cable, then it didn't work anyway.

 

[E-HP]

Ok, so post #7, pic 1, is the second controller (KT)with the bullet connectors cut off of the phase and battery wires, correct?

 

[steve2777]

Correct

 

[E-HP]

Thanks. Just confirming that in your first post, you said the display shows when the brake brake and throttle are activated, the throttle does spin the motor.
Also, do you have a multimeter, and are the motor conductors from the KT soldered when spliced to the harness cable?

 

[steve2777]

The throttle does not spin the motor. It only activates the throttle indicator on the display. Same with brakes: they show on the display. Nothing spins the motor. As to the motor conductors, do you want me to try to open the controller box? I'm not clear what you're asking.

 

[E-HP]

You will likely need to swap conductors, so if you soldered them when grafting them to the harness, you may need to unsolder them in order to do the swapping. Initially it will involve swapping at least two of the thick phase wires (e.g. green and blue, see the chart in the link below) to get a response from the motor (when there is no response, the motor is “stuck”, per the flow chart), so rather than unsoldering the halls now, you can wait to see if it moves first. If it moves, don’t continue to run it, unless it runs smoothly in the right direction to avoid damage.

The meter would be used to test the hall sensors to make sure they all work. If everything weren’t soldered up, I’d test them first. But since they are, doing a quick phase wire swap, assuming the halls are good, seems easier.

Testing BLDC motor's Phase Wiring - Hall Sensors and Wiring. - Electricbike.com Ebike Forum

Testing electrical components of a typical hub motor with a digital multi meter. First take a few minuets and look over the wiring going into the motor for cuts, scrapes, missing insulation and other wiring issues or poor connections that should be resolved first. Smell for...

electricbike.com

 

[steve2777]

Are you talking about what I did with the 2nd defective controller where I cut the 9 pin cable and separated out the phase wires and the 5 hall wires? This KT controller connects directly to the motor solely by the 9 pin cable, and that's the controller I'm trying to get to work. I have done no soldering on it.

 

[amberwolf]

If the motor was ever attempted to be operated or even powered on with the damaged cable, then depending on the specific damage, it could have shorted phase wires (battery voltage) to halls (low voltage), which can destroy them *and* the controller connected to the motor at the time, and any other 5v-powered device connected to the controllers' 5v line, depeding on which specific wires shorted to each other.

So the motor halls may not work. You can test them as E-HP notes above. If they don't work, you can replace them, or if your controller has a sensorless mode ("dual mode" controller) then you can switch to that and leave the halls disconnected.

Any controller that was connected to the dmaaged cable and powered up or used may also have damaged hall sensor inputs, or dead MCU, fried 5v supply, or blown FETs and possibly gate drivers.

 

[E-HP]

Are you talking about what I did with the 2nd defective controller where I cut the 9 pin cable and separated out the phase wires and the 5 hall wires? This KT controller connects directly to the motor solely by the 9 pin cable, and that's the controller I'm trying to get to work. I have done no soldering on it.

I missed that there was a middle controller. So none of the pics have the KT in them. Do you know what kind of motor you have? The 9 pin single cable was something implemented by Bafang, and miraculously became somewhat of a standard adopted by others, like KT.
Assuming the conductors are matched correctly, you may need to test the motor hall sensors, given the error. There are directions in the link.

 

[steve2777]

Thanks E-HP and Amberwolf for the advice. One thing's clear: I'm in way over my head, and have neither the tools nor the expertise to perform the testing, let alone the repairs discussed. I might with my limited knowledge have been ok if a defective controller followed by a defective cable end hadn't intervened (sort of like a 5 year old can drive to the store as long as no pedestrian crosses the street in front of them.) I'm afraid it's time for me to take the bike to a knowledgeable ebike repair shop and hope for the best!

 

[docw009]

You never touched the motor and its 9 pins are intact? You also have a new KT controller that is intact. You never chopped at it.

Plug in the display. No throttle, brakes or PAS lever. Connect only the 9 pin motor cable, Attach battery and power up the display. Press the walk assist button. If the motor and controller are working, it will spin. This is how I verify my motor wiring is OK when I work on it, If motor doesn't spin, that's big trouble.

Make sure the 9 pin connector is fully seated. That's another common problem, Which display did you get, as I'm not aware of an LCD-C. KT displays will flash a specific error message if they cannot see all three Hall sensors in the motor cable.

 

[steve2777]

Doc: THANKS! and perfect timing. The new cable just arrived, and I tried as you advised. The motor runs on walk assist. Connected brakes and throttle, and the throttle also runs the motor. Sounds like the defective cable was the culprit. HOWEVER, PAS still does not work on any assistance setting 1-5 when I rotate the pedals. As I mentioned. PAS was unchanged from the original operational bike, and I have enclosed a Pic of the PAS to controller connection, which I'm pretty sure is correct. (Also resistance tested each side of the connectors, and the pins are making contact). Where do I go from here? THANKS!

 

[E-HP]

Doc: THANKS! and perfect timing. The new cable just arrived, and I tried as you advised. The motor runs on walk assist. Connected brakes and throttle, and the throttle also runs the motor. Sounds like the defective cable was the culprit. HOWEVER, PAS still does not work on any assistance setting 1-5 when I rotate the pedals. As I mentioned. PAS was unchanged from the original operational bike, and I have enclosed a Pic of the PAS to controller connection, which I'm pretty sure is correct. (Also resistance tested each side of the connectors, and the pins are making contact). Where do I go from here? THANKS!

You may need to adjust C1 in your display settings. The PAS signal is picky on orientation, so if it's currently set to expect "forward" rotation, it may need to be set to one of the "reverse" rotation settings. (forward and reverse don't necessarily mean crank direction, but a PAS sensor mounted on the left or right side of the crank.

 

[steve2777]

Doc, That did it !!! I was hours away from taking the bike to the ebike hospital, but all I needed was an online consult with the "Doctor" ! Thanks to you and all the others for your help !!!