carerra subway e going on its own

[E-bobby]

Hi all. New member here, I have purchased a carerra subway e bike second hand, it has had light use and is still like new. i have ridden it a few times to work and back and one occasion it was raining, since then, when i turn it on it gives a jolt to the motor, causing the bike to move forward slightly for a split second, which it wasnt doing before, also, sometimes, it will want to keep going on its own, without touching the pedals, also if i lean to the left and circle round it rides on its own, intermittantly. I have removed the torque sensor and it is clean with no damage or loose wiring inside, as are the cogs, also the wiring at the steering is all still new, no damage or wear. When i rode it immediately after putting the sensor back in place, it gave error 22, since then it has not given error 22 yet the initial problems remain. Can anybody help on what to do next? I literally spent all my money on it and cant afford to take it to a shop unfortunately.

 

[Nealh]

Taking it to a LBS will unfortunately not get you anywhere as to fault finding or curing th issue.
Moisture ingress somewhere causing an intimittent short . Typically the display is the obvious place where moisture gets in, shorting is caused by tracking between contacts .

 

[saneagle]

The controller needs a pulsing signal from the rotation sensor AND a voltage from the torque sensor for the motor to give power. I can't see how it could get both signals accidentally. That means it can only be the walk assist that's activating the motor, so either something is touching the button or it has water where it shouldn't oughta, like in the display (fixed) display contacts (removeable)

 

[AndyBike]

I wouldnt think being in the rain once would cause any problems whatsoever, and in fact being in the rain day after day shouldn't cause any issues either, or its unfit for purpose.

I ride in the rain a lot, as I expect most here, so whatever the problem is,k its unlikely to have been caused by your rainy day out.
In fact, when I visit family its not unusual for the bike to sit out in the rain for a number of hours.

 

[matthewslack]

You could try unplugging every connector and leaving it in a heated space for a week, to allow as far as possible any moisture to get out.

 

[E-bobby]

Hi guys, thanks for the replys, we have checked it all over and its bone dry, i am pretty sure its not water related, however, its giving error 22 everytime it reaches 15mph now, and the bike trys to ride away on its own when switched on, evern when not on the bike, its quite dangerous, literally only had it 2 days and ridden it about a couple of miles overall and its developed this fault, which has worsened to it being unuseable now.

 

[Nealh]

Do you have a working throttle ?

 

[E-bobby]

Do you have a working throttle ?

there is no handlebar throttle, its just off the pedals but yes, it does kick in when requested, also when not requested!

 

[guerney]

Perhaps your bike was originally designed to have a throttle, and it's being activated by a short caused by water ingress? You could put your display and controller into a ziplock bag with a couple of kg of this for a week, to properly dry it out? I don't know if bike sized airtight ziplock bags are available.

Pardon our interruption...

My display has a DIY rain hat.

 

[E-bobby]

Perhaps your bike was originally designed to have a throttle, and it's being activated by a short caused by water ingress? You could put your display and controller into a ziplock bag with a couple of kg of this for a week, to properly dry it out? I don't know if bike sized airtight ziplock bags are available.

Pardon our interruption...

My display has a DIY rain hat.

View attachment 55156

thanks for the advice

 

[Bonzo Banana]

I don't know how old the model is but you could try bluffing it in Halfords that you bought it new and haven't got your receipt to hand to see what advice they can give. I remember having a conversation with Halfords regarding these Suntour HESC ebikes and they often have to swop parts with another similar ebike until they discover which part is faulty.

I went into a different Halfords to which I bought my Carrera Subway 8 when I had a puncture and they sorted my puncture for me free of charge. It was clear the bike was very new though and in warranty, only 2 or 3 months old.

However if your Carrera is well out of guarantee and an older model this won't work. Still worth trying Halfords for advice though. Some of the bike mechanics are very competent and friendly (others not so much). You don't have to pay them anything for their advice if they give it.

One thing that isn't clear is if your Carrera Subway ebike is a shop bought configured ebike originally from Halfords or a ebike conversion. A conversion would be a lot easier to sort out by swopping out components. However you did say as new so perhaps the original seller still has the receipt if bought at Halfords.