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

[KristofH]

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]

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.

 

[KristofH]

Thanx! Is there any chance that the ep8 is failing? Are these regular symtoms or not at all?

 

[Zimmerframe]

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.

 

[InRustWeTrust]

When the screen goes black, does the engine still work? or the engine stops assisting when it does

 

[KristofH]

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]

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".

 

[KristofH]

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]

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.

 

[InRustWeTrust]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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.

 

[uberamd]

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.

Did you (or anyone beyond the one person who got a new motor) find a fix to this?

My Spectral with EP801 and only 300 miles on it started doing this a couple days ago. My friend who got his Spectral with EP801 just a month or so before I did has also run into this with his. I’ve got the 900wh battery, he the 720wh.

Could this be firmware related? Mine cut out on a flat road in eco. No bumps. No anything. 7 cycles on the battery, 300ish miles on the bike. Purchased in November 2023.

Used the Shimano cable + the e-Tube Professional windows application and it found nothing in the logs. No errors.

 

[hctagalong]

I'm the friend with the same problem. Had my LBS (a Shimano authorized dealer) dig into it. They didn't find anything after checking for pinched wires, bad connections, etc. No related code(s) being thrown; there was one error about the firmware so they refreshed that (to version 4.3.0). Went for a ride and.....over the course of a 2hr outing the EP801 powered down ~8 times. Like before, no codes, the error log is clean.

I've looked at my ride data from e-Tube Ride and there are no long drops from cadence or speed, just the normal ebb and flow of a ride. At each power down, press-and-hold the button and started again. My observation is that each ride this has happened it's been ~1hr into it with the battery drain around 40 - 50%. I primarily ride in Trail which I've slightly modified from default (dialed back max torque for example). The power down moment has not [yet] occurred when the motor was under any significant stress. Riding style? My primary trail is XC-focused. I'm not an exceptionally strong rider w/kg-wise and ride with average speeds at that trial around 12mph. Meaning, I can't imagine that I'm stressing that motor much to cause some type of thermal event nor is there a code being thrown that would indicate that condition.

I guess the bike is going back to the LBS. Problem is, without any sort of error code or correlation to some trigger, not sure what they'll be able to do besides start replacing stuff. Pretty frustrating. I had zero problems with it last year and am not riding in any discernible different way from last year.

 

[steve_sordy]

Do control pinched wires show as any sort of fault?

It is what my fault was; nothing was shown on my screen. I don't dive into the gubbins via a laptop (like many on this site) and I never asked the LBS people.

 

[hctagalong]

@steve_sordy Good question.My LBS said that they visually inspected the wire runs and didn't find anything. As for fault codes, I don't receive any; not on the display and not from the drive unit. They plugged it in to eTube Pro and claimed to have run some diagnostics with all systems passing. What they found was some error (I did not get details) related to the firmware which prompted them to reinstall it. I'll be running it back to the shop later today as I've exhausted all the things that I know of to inspect and test.

 

[hctagalong]

An update on this: My bike had its second comfortable stay at my LBS for a number of days (8+) where a whole lot of nothing was done (I won't call out the LBS specifically nor say that the delay was all on them). Only thing that was done was to pull a report for Shimano. I acquired an alternate battery and once the trails opened up locally I shoved in the different battery and set out for ride. After a 30 mile outing with 90% of the battery consumed, zero cutouts (same trail, similar outdoor temp to other rides, same pilot). Another ride on that same 'new' battery; again no cutouts (battery consumption of 40%-ish, but different/easier trail).

Haven't been out again since but a different battery potentially may be the answer. I plan to ride the new battery again in the next few days and then switch back to the old and see what's-what. If it's as simple as a battery problem, I'll be thrilled.

 

[hctagalong]

Well....bummer. New battery is not the answer. Another ride (using the alternate battery) and unfortunately additional power cut-outs. Again, no faults in the drive unit logs. And, like the other events, it doesn't occur until later in a ride (60%+ of the battery consumed). Only guess I have left is that it's a thermal-related problem.

At this point I have nothing left to try except keep working the warranty process (which has its own challenges that I'm learning about).

 

[Spiff]

If problem happens with two different batteries and LBS has checked the cables and speed sensor magnet and found them OK, then looks like it is time for a new motor.

If you want to ride your ebike, don´t let your LBS delay the process, try contacting Shimano Service in Facebook, post your issue in USA forums like MTBR. Good luck!!!

 

[Enduromalagaemtbholidays]

Well....bummer. New battery is not the answer. Another ride (using the alternate battery) and unfortunately additional power cut-outs. Again, no faults in the drive unit logs. And, like the other events, it doesn't occur until later in a ride (60%+ of the battery consumed). Only guess I have left is that it's a thermal-related problem.

At this point I have nothing left to try except keep working the warranty process (which has its own challenges that I'm learning about).

Well how’s it going lads any joy in recent weeks? I run a guiding business and now have 2 in the fleet with this problem