Help! Suntour HESC ATS Carrera Crossfire E - E21 Error (again)

JohnSear

Finding my (electric) wheels
Jun 17, 2019
13
6
The classic 'Torque Sensor electrical problem'

I've recently had the Torque sensor replaced at Halfords (for the 2nd time in 9 months) and while this has cured the consistent E21 errors I was getting I'm still getting intermittent ones.

Given lock-down I'm using my E-bike to get my goverment mandated daily exericse. I'm typically doing an hour or so a day but on every trip I'm finding similar problems.

Sometimes it's a clear E21 error - other times the motor just doesn't seem responsive. I find I have to pedal harder than usual to get the assist to kick in. It _is_ doing something - if anything I'm getting more assistance going up hills less on the flat. On the flat it's barely usable on the eco mode. So I've got the assist mode to maximum.

Sometimes I can disconnect the battery and LCD for a minute and it seems to help. Didn't seem to help today - and I've come back hot & sweaty after my ride - which I wouldn't usually do :(

Is it worth taking the crankset to pieces? I've seen pictures on here with springs inside - but didn't really understand it. I'm guessing halfords only replaces the sensor. Is there anything that could be going wrong there?

I'm rapidly thinking that I need to replace all the electrical components - just keeping the hub motor and battery. Is there a guide from people who have done this? I've seen plenty of discussion on the forums - but it would be nice to have a step-by-step guide or at least more feedback from someone who has done this.

It's a real shame because when the ATS system works well it's amazing!

Any suggestions greating appreciated.
 

JohnSear

Finding my (electric) wheels
Jun 17, 2019
13
6
Ok, so I spoke too soon. The intermittent error is now a permanent one again. I guess the behaviour I'm seeing is what happens before it fails.

That's 3x torque failures in less than 9 months. Surely this points to another problem? The bike is clean & only driven on roads so it's not like it's getting covered in mud.

Anyway I'm off to take it to pieces & see if I can spot anything loose.
 

Amoto65

Esteemed Pedelecer
Jul 2, 2017
807
502
61
Cheshire
The only way of solving this problem is demand a refund if it is still under warranty, this model is renowned for its cut out faults, I know from experience as I took mine back and got a full refund, great motor when it works but totally unreliable.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,126
8,226
60
West Sx RH
E21 is TS wiring fault and the most likely cause is a broken or intermittent wire fault at the TS end. Pay attention particularly to the wiring where it enters the TS unit esp last 10cm if it bends or has any kink in the wire route.

In all the Suntour system is just trying to be to clever for it's own good.
 
Last edited:
  • Like
Reactions: JohnSear

JohnSear

Finding my (electric) wheels
Jun 17, 2019
13
6
The only way of solving this problem is demand a refund if it is still under warranty, this model is renowned for its cut out faults, I know from experience as I took mine back and got a full refund, great motor when it works but totally unreliable.
No such luck with the warranty :( I feel like I've read every thread on here about it and like you say it's fantastic when it works but so unreliable. Might have to start saving for another one - or having a go with the controller replacement!
 

JohnSear

Finding my (electric) wheels
Jun 17, 2019
13
6
E21 is TS wiring fault and the most likely cause is a broken or intermittent wire fault at the TS end. Pay attention particularly to the wiring where it enters the TS unit esp last 10cm if it bends or has any kink in the wire route.

In all the Suntour system is just trying to be to clever for it's own good.
Thanks for your advice and completely agree on Suntour being too clever for their own good :)

I took it all to pieces and had a good explore - thinking this might be my first step in figuring out what all the wires do in preparation for a replacement controller, pas & lcd. It all looked pretty decent in there and the TS sensor is brand new - well Halfords told it was brand new at least ;)

There's a small amount of damage to the TS connector (see picture) - although it seemed to be snug. I did think about soldering it together - but I think I'll try and source the plastic connector first. I connected it all back up - gave the wires a good inspection and then lots of flexing but couldn't get E21 to reappear. Unless of course I disconnect the TS sensor completely.

I've put some strong duct tape around it for now and it seems to be happier. I'm hoping it's just that loose connection - Watch this space!
 

Attachments

JohnSear

Finding my (electric) wheels
Jun 17, 2019
13
6
I've just gone through some photos I took of the controller last year when I first got it and that damage to the TS connector was there before I dismantled it. I'm guessing I didn't understand what it did at that time and didn't think too much of it. To be fair it's a bit of a rats nest when you first look at it!

Maybe it's just a combination of that and all the speed bumps / pot holes around causing it to work loose. Fingers crossed.
 

wheeliepete

Esteemed Pedelecer
Feb 28, 2016
2,047
755
60
Devon
Looks like the damaged connector is on the controller side which would help to explain why replacing the TS only acts as a temp. fix. There is an old thread on here from anon4 who changed the controller on his Carrera a while back, use the search feature.
 
Last edited:

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,126
8,226
60
West Sx RH
E21 is a specific error code for the TS and is an electrical conection issue of some sort, whether the connector or wiring it itself.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,126
8,226
60
West Sx RH
Thanks for your advice and completely agree on Suntour being too clever for their own good :)

I took it all to pieces and had a good explore - thinking this might be my first step in figuring out what all the wires do in preparation for a replacement controller, pas & lcd. It all looked pretty decent in there and the TS sensor is brand new - well Halfords told it was brand new at least ;)

There's a small amount of damage to the TS connector (see picture) - although it seemed to be snug. I did think about soldering it together - but I think I'll try and source the plastic connector first. I connected it all back up - gave the wires a good inspection and then lots of flexing but couldn't get E21 to reappear. Unless of course I disconnect the TS sensor completely.

I've put some strong duct tape around it for now and it seems to be happier. I'm hoping it's just that loose connection - Watch this space!
Maybe try also a thin cable tie longitudinally to keep the connector together or replace the 4 pin connector altogether.


 

JohnSear

Finding my (electric) wheels
Jun 17, 2019
13
6
Maybe try also a thin cable tie longitudinally to keep the connector together or replace the 4 pin connector altogether.
Thanks - I was wondering what the name of those connectors was. I'll order some of those and replace it just to be on the safe side :) Will give it a bumpy test drive tomorrow and see how it goes!
 

JohnSear

Finding my (electric) wheels
Jun 17, 2019
13
6
Looks like the repair is shaping up well - managed almost 100miles over reasonably bumpy terrain and it looks much happier. Zero cutouts / E21 appearances so far :) Touch wood!

I've done a fair bit of research on replacing the controller, LCD and PAS sensor since that seemed like the only option for a while. I think I will keep a lookout for a 2nd hand bike which I can do the upgrades on - leaving my working crossfire-e untouched!

Thanks again for everyone's advice / words of encouragement :)
 

Mic88

Just Joined
Nov 6, 2021
1
0
Se pare că reparația se conturează bine - gestionat aproape 100 de mile pe teren destul de accidentat și pare mult mai fericit. Zero decupaje / Apariții E21 până acum :) Atingeți lemn!

Am făcut destul de multe cercetări cu privire la înlocuirea controlerului, LCD-ului și a senzorului PAS, deoarece asta mi s-a părut singura opțiune pentru o vreme. Cred că voi urmări o bicicletă de la mâna a doua pe care să-l pot face upgrade-ul - lăsând neatins fire-e-ul meu de lucru!

Mulțumesc încă o dată pentru sfaturile / cuvintele de încurajare ale tuturor :)
[/CITAT] Hello ! how did you solve with e21?
 

Advertisers