Carrera Vengeance e spec no pedal assist

[MegaBiteUK]

Hi,
I bought a carrera vengeance e spec used for my son. the display had error 00 and error 21. after checking, I noticed the wires had broken on the crank sensor. resoldered the wires, re attached the connectors and cleaned everything up. Errors all gone and seemed to work.
less than 2 miles no pedal assist and no errors. Bought a used sensor of ebay and installed but still no pedal assist and no errors. Display all seems to function, Walk mode works just no assist?

Thought about converting to a throttle but can only find instructions on a different wiring.

Anyway, anyone know how I can test this type of sensor. or know why no pedal assist? before I put it back up for sale

 

[saneagle]

Hi,
I bought a carrera vengeance e spec used for my son. the display had error 00 and error 21. after checking, I noticed the wires had broken on the crank sensor. resoldered the wires, re attached the connectors and cleaned everything up. Errors all gone and seemed to work.
less than 2 miles no pedal assist and no errors. Bought a used sensor of ebay and installed but still no pedal assist and no errors. Display all seems to function, Walk mode works just no assist?

Thought about converting to a throttle but can only find instructions on a different wiring.

Anyway, anyone know how I can test this type of sensor. or know why no pedal assist? before I put it back up for sale

I only checked the 4-wire type, which is pretty simple. The 4 wires are 5v, 0v, pulsing cadence signal, and 0-5v torque signal. There is some electronic device in the sensor that converts an optical signal into the two signal wires.

There are two castellated rims inside the chainwheel. One is fixed to the chainwheel and the other two the pedal, and they're held together with springs. There's a light beam that shines through the slots onto a sensor. The slots go round with the pedalling, so the frequency of light pulses gives the speed of pedalling. When you put force on the pedal, one rim moves a bit relative to the other against the spring, which gives the effect of shortening the gaps in the castellations, so the harder you pedal, the shorter the pulse durations. The electronics convert the length of the pulse into the 0-5v output for the controller to interpret as how hard you're pedalling.

There isn't really anything in there that can stop it from working unless you got dirt in the light sensor slots. A simple clean would fix that. If it's not that, it can only be a connection issue.