Pedal Assist not Working, throttle and display working fine

Ohio619

New Member
Region
USA
I have a Motiv Spark ebike with both throttle and PAS. Both quit working a few days ago, but display was working so I knew the battery and battery connection were ok, so I took apart the controller box and found some heavy corrosion. I cleaned all of them and then put it back together and alsocleaned around where the cadence sensor is located. Now my throttle is working fine but still no Pedal Assist...so my question is how do I know if I didn't break or loose some part of the PAS system and what else can I try to get it working again??

Thanks In advance for any help!!
 

harryS

Well-Known Member
When you say "clean", what did you do about individual connectors Take apart and re-connect? What type were they, waterproof (Julet on left) or open terminal (JST on right)? Corrosion can really get to JST type.
Julet.jpg JST.jpg

Have you identified the PAS sensor? There are generally two styles. One is integrated and the other is a discrete magnet ring and a separate sensor. With the first style. sometimes the magnet and sensor get pushed apart, but the second type is self aligned.

type1b.jpg type2.jpg
If you haven't done so, trace the cable from the pedals back to your controller and check the connector integrity.

If that doesn't do it, then you have to do electrical detective work. YOu would need to own a voltmeter and know how to use it. It's probably a dirty connector though.
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
Often the PAS sensor has a tiny red LED that lights up when the bike is turned on. If that's on, it's a good sign!
 

mogulskier

Active Member
I've had the same problem but on a different bike. That is, throttle ok, but PAS not working. The connections were snug and clean so I was worried the controller was bad.

Turned out to be a faulty PAS sensor. I have the self aligned one that HarryS has pictured.
 

Ohio619

New Member
Region
USA
Ok so my question I have after doing some detective work with my multimeter is: when I took the controller apart and cleaned it, the throttle is now working and PAS isn't, can just part of the controller go bad, or just one connection or would it have to be the PAS sensor?