Trying convert a controller to PAS, need some help

Hello, I'm a lurker here for a while, but this is the first time I need help that I couldn't find using forum search, so I finally registered. I'm working on my second e-bike conversion.
I bought an e-bike conversion kit on Aliexpress, 500W geared hub motor with rim, 18A Bafang BBSX controller, DPC14 display, throttle, pedal torque sensor, two brake sensors and assorted cables. I want to make the bike road legal and so I bought a PAS sensor separately, planning on installing it instead of the throttle and torque sensor (I like that style of control).
It turns out the controller was meant for throttle control only. Instead of buying a new controller, I reprogrammed it to PAS using DH-sensor-12 pedal sensor type and connected the PAS signal to ZL1 pin in the controller (see pic attached). I don't have the PAS yet, but when I connect a 5 Hz square signal to ZL1 (PAS simulation), the controller won't start. Throttle control works normally. What am I missing here? I would be most grateful for any help!

I believe the correct email is Edward @Lyen.com to buy a pedal assist module that works like a throttle.
I remember about $20.00 / shipping.
Pm him to find out.

http://www.lyen.com/

Thank you for that info, but I'm saving that for plan B and I would build it myself in any case (Arduinos FTW ). What I really need is an advice from somebody who's more familiar with these controllers than I am, I'm sure I just need to connect the proper pins on the controller board. These controllers look to be all the same and I already programmed it accordingly, so it should already work - I need some insight into what could have gone wrong.

I believe a square wave simulation won't work. I've never verified it with a scope, but I believe the signal pattern is an assymetrical short-long pulse train, so the controller can tell the direction of crank rotation.

Check the 2nd response by the OP in this link. http://www.pedelecs.co.uk/forum/threads/pas-problem.20725/

@docw009: This is exactly the kind of info I needed Thank you, thank you, thank you!
Off to test it out

Update: No joy.
Now I actually took apart my previous e-bike to get access to the PAS sensor, connected the output to ZL1, ZL2 and various other inputs I could think of and it does not budge. Am at my wits end. Any other ideas anyone?

for future readers, solution here:
https://endless-sphere.com/forums/viewtopic.php?f=2&t=87116
or here:
https://endless-sphere.com/forums/viewtopic.php?f=2&t=104143