Shimano EP8 stops working while riding - no fault in log?

KristofH

New Member
Jun 7, 2022
6
2
Belgium
I have recently purchased a canyon grand canyon:ON 9 with the EP8 motor.
Done a couple of rides and everything went fine, a joy to ride the beast! I have +/- 300 km on the clock.

Although since my last couple of rides the display suddenly went black while driving. This happened after I already drove +/- 25 km without any problems. I was able to restart the engine. After some km's the screen went black again, I was again able to restart the computer.
I am driving the latest firmware, 4.1.8.
In the Etube application I cannot see anything in the fault log, it's empty. Also when the screen crashes and the engine gets turned off, no error code is being displayed.
I think it's very strange that I can ride for a long time without any problems and suddenly problems occur... A bad connection...? Engine poblem..?

I will get back to the dealer. Is there anyone having the same problems? Is there anything I can try to fix it?
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,361
8,587
Lincolnshire, UK
Check the push-in connections into the back of the display. If they are loose, they can exhibit your fault. The EP8 ones are better protected than they were on the e8000, but I guess it could still happen.

Also on a previous bike, I had a similar fault several hundred miles after a new battery was fitted. (It was a Focus with the fitted battery). One of the control cables had been pinched during installation. It worked mostly, but then it didn't...... A £7 cable cost a fair bit to replace.

Can't think of anything else.
 
Last edited:

Zimmerframe

MUPPET
Subscriber
Jun 12, 2019
13,770
20,452
Brittany, France
It doesn't sound like a failing motor.

As Steve says, check the connections. Then check the wires. The one to the display can sometimes get stretched or pinched which will cause the bike to randomly switch off. If you can, also check where they connect to the motor (on the none drive side).

The battery may also need adjusting/might be loose or the cable from the battery to the motor might be damaged - this would also give the same symptoms.
 

KristofH

New Member
Jun 7, 2022
6
2
Belgium
When the screen goes black, the engine stops working and doesn't assist anymore. I have to manually restart it, sometimes I have to wait some minutes before restarting is possible.
Sometimes the motor restarts automatically when the screen goes black (Shimano steps appears automatically and manual pushing the start button is not necessary).
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,361
8,587
Lincolnshire, UK
When the screen goes black, the engine stops working and doesn't assist anymore. I have to manually restart it, sometimes I have to wait some minutes before restarting is possible.
Sometimes the motor restarts automatically when the screen goes black (Shimano steps appears automatically and manual pushing the start button is not necessary).
That is what used to happen when I had a loose connection on the display. If I turned the bars, the cables moved slightly and made a connection.
When I had a pinched wire, nothing worked so I took it to a Focus dealer. He said that he would ring me when it was fixed and wheeled it into the workshop. I took a look around the shop before I left and while I was still there, he came out and told me it was fixed! He told me had connected it to his computer and did a refresh (or something). I said "great!" and grabbed the bars, turning them to leave the shop. The screen went black and would not restart. His face fell and he said "I'll ring you when it's fixed". :ROFLMAO:
 

KristofH

New Member
Jun 7, 2022
6
2
Belgium
Ok let's hope it's just such a small problem that can be fixed easily! :) I'll take it to the shop this week.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,361
8,587
Lincolnshire, UK
Ok let's hope it's just such a small problem that can be fixed easily! :) I'll take it to the shop this week.
Err it wasn't a small problem. The first issue was diagnosing it. He had a clue when I told him that a new battery had been fitted. The space inside a Focus frame is very tight and it is very easy to pinch a cable when removing or installing a battery. So, it's a motor out job, disconnection etc and removal of a battery that is not designed to be removed on a regular basis. Fit new wire then refit the battery trying hard not to pinch the same or a different wire. Thankfully it was a warranty job, although I had to pay £35 warranty charge because the dealer was not the one that I had bought the bike from. It was my choice; I could have made two 3-hour round trips instead.:unsure:
 

InRustWeTrust

E*POWAH Master
Mar 9, 2020
509
730
Sweden
Have you ridden when it has been very wet or washed the bike with a high pressure washer? .

in this case, you may need to unplug the engine cables and dry the connectors.
 

KristofH

New Member
Jun 7, 2022
6
2
Belgium
No I have not been riding the bike when it was very wet and certainly not washed the bike with high-pressure. I have sprayed it a little bit with low pressure while cleaning... ( 1 time..).
I have checked the battery yesterday and there were some water drops inside.. Not much but I'm asking myself the question of that's normal or an absolute "no go"...?I don't think that my problems are due to the little water drops at the battery.. I already had the problems when I had never driving the bike in the wet or sprayed the bike with water...

I have bought the bike at the canyon website and a canyon dealer installed it for me. Would the problem above fall under warranty or not? I certainly hope it is when it's a job that takes some effort..
 

InRustWeTrust

E*POWAH Master
Mar 9, 2020
509
730
Sweden
I would definitely say that it should go under warranty. Should contact Canyon and hear what they say, do not think there will be any problems as canyon is usually good when it comes to guarantees.
 

Wilonrs

Member
Jun 9, 2022
7
1
Krakow, Poland
I've got exactly the same symptoms. Problems happen after some 30+ minutes of constant ride, no errors in the system, random bike restart or I have to wait for few minuter for a bike to restart. Yesterday I left my bike at shimano service for a claim. Waiting for their verdict/solution.
 

KristofH

New Member
Jun 7, 2022
6
2
Belgium
I've got exactly the same symptoms. Problems happen after some 30+ minutes of constant ride, no errors in the system, random bike restart or I have to wait for few minuter for a bike to restart. Yesterday I left my bike at shimano service for a claim. Waiting for their verdict/solution.
If you have some news about the claim, could you give me some feedback? Thanx!
 

Aleksius

Member
Mar 6, 2021
5
3
Finland
I’d wager it’s your power button based on personal experience. It can get moisture inside from washing and riding and as you ride your bike and turn the handlebars, the cable inside the frame move ever so slightly and wiggle the cables going to the power button. You’ll get a momentariy short circuit and it’s either safety or literally the bike thinks that the rider pressed the button and wants to shut of the bike.
Like you said you can start the bike up again and might or might not get the same issue again.
Replacement power button is easy and cheap or free if warranty, to try if that solves it.
 

kendo

Member
Sep 2, 2019
123
81
Scotland
I have recently purchased a canyon grand canyon:ON 9 with the EP8 motor.
Done a couple of rides and everything went fine, a joy to ride the beast! I have +/- 300 km on the clock.

Although since my last couple of rides the display suddenly went black while driving. This happened after I already drove +/- 25 km without any problems. I was able to restart the engine. After some km's the screen went black again, I was again able to restart the computer.
I am driving the latest firmware, 4.1.8.
In the Etube application I cannot see anything in the fault log, it's empty. Also when the screen crashes and the engine gets turned off, no error code is being displayed.
I think it's very strange that I can ride for a long time without any problems and suddenly problems occur... A bad connection...? Engine poblem..?

I will get back to the dealer. Is there anyone having the same problems? Is there anything I can try to fix it?
Almost Certainly battery connections, make sure that the battery is not loose or moving in mountings which can be adjusted. Alternatively check your cables and make sure you haven't cut any or they have been worn by rubbing to cause them to fail, probably one of the most common faults brought to bike shop.
 

Mitchb

Member
Nov 13, 2021
56
41
San Diego
Same problem Ive been having with my Yamaha Moro. My problem is the battery connection; hit a big bump,battery moves and motor shuts down. I started spraying contact cleaner on the battery contacts and socket and could then go a ride and a half without issue, then it would shut down again and Id do the same and do another ride and a half.

Its at the dealer now and they asked me if I tried dielectric grease on the contacts, so you might try that. They're checking out the bike, I hope to hear back from them soon.
 

Mitchb

Member
Nov 13, 2021
56
41
San Diego
Same problem Ive been having with my Yamaha Moro. My problem is the battery connection; hit a big bump,battery moves and motor shuts down. I started spraying contact cleaner on the battery contacts and socket and could then go a ride and a half without issue, then it would shut down again and Id do the same and do another ride and a half.

Its at the dealer now and they asked me if I tried dielectric grease on the contacts, so you might try that. They're checking out the bike, I hope to hear back from them soon.
Got my bike back with Dielectric Grease "installed" and so far so good. Ive gone on three rides without a shutdown.
 

Wilonrs

Member
Jun 9, 2022
7
1
Krakow, Poland
Got today’s news. After some tests local service found out that cadende sensor doesn’t work properly. Motor will be sent to shimano for further investigatio and probably replacement.
 

Wilonrs

Member
Jun 9, 2022
7
1
Krakow, Poland
I got new motor from shimano. First they didn't want to do anything becouse there were no faults so I've recorder a film when my motor is turning off after 30+ minutes of constant riding - After sending link to shimano they have made more tests with my ep8 and finally found out problem in cadence sensor.
Hope this might help for someone with similar problems.
 

Camhowe

New Member
Mar 16, 2024
1
0
Queensland
Hey guys I’m new to this forum but joined after noticing a few people have had the same issue I have.
I have a Merida e140 with an ep8 motor and the motor cuts out and at the same time the screen goes blank then comes back on in the no power mode.
I’ve had the motor checked out by Shimano who said nothing is wrong with it.
So I swapped the battery with a mate who has the same bike.
Still the same.
Very frustrated now because I basically haven’t been able to ride my bike for 4 months.
I read above that the cadence sensor might be the issue.
Has anyone else had this problem and if so was there something else besides the cadence sensor that was the issue.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,361
8,587
Lincolnshire, UK
My sympathies @Camhowe . Here you are 4 months down the line and nobody in the bike industry that you should be able to rely on has been able to fix this problem. Shimano say it's not them. You appear to have ruled out the battery. That leaves the dealer! If you steadily replaced every single item on the bike, you might find the problem, but you should not have to resort to that. (There's a good chance that you may create some new faults too!)

I would take it to the dealer.
 

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