Pedal assist problems

[RiverRun]

Good Morning,
My grandfather has a Hyper E-Mountain bike. Of course it is on the cheaper end of the E-bike spectrum, but he can't afford much more. The 6km walking mode works perfectly on it. However, the pedal assist mode does not work at all. The battery and controller lights come on, butt he assist never kicks in when pedaling. I have made sure the cadence sensor is very close to the magnets, as told to do since the 6km mode worked. I looked at all wires that I can see to ensure they wires are not loose, and are plugged into wiring harnesses. Some of the wires that run through the frame are harder to see. However, I still cannot figure out the problem. I have called the company for him, since the bike is useless for him, and he needs the pedal assist mode to use the bike (weaker legs.) However, the bike is out of warranty. Attached are pics. What should be my next step for troubleshooting? Thanks for any input.

 

[AHicks]

Have you checked the condition of the wire to the cadence sensor? It's connector to the controller?

Do you have a digital volt meter to see if one of the cadence sensor wires measures about 5v?

When using the walk assist, is the speedo working?

 

[harryS]

Most pedal assist senors (PAS) are three wires, +5V power, ground, signal. The signal will flip between ground and 5 volts every time a magnet crosses the sensor, I would find where the PAS connects with the controller and put my voltmeter on the signal line to see it behaves properly,

Good thinking with Walk mode. That shows there's nothing wrong with wiring between motor and controller. The brake levers cut off the motor, and my experienece is that they would inhibit walk mode too, but you might unplug them anyway to make sure they're not killing power. (Sometimes a loose lever/cable will tell the controller the brakes are on.)

If you're good with wiring, it's about 50 bucks to replace the controller, I'd add a throttle to the bike too,

 

[ebikerod]

The previous observations are correct, the three cables are: 5 volts, ground, Signal. Between ground and signal, there must be voltage variations between approximately 0 and 4 volts, this each time the magnets pass. In amazon they sell some motor, controller and throttle testers, you just have to find how to change the input connections a bit, since they do not match most of the time.