Help! EP8 no workee

[Teriatric]

Hiya folks.

Got my new bike on 28th October. Three rides later I have a major issue with the thing. I got a W10100 (speed not being sensed). So I did exactly what eTube app said, just a few minutes ago, same as an LBS would do I suppose. I fitted a new EW-SS301 sensor, checked the magnet, no change. I get assist as soon as I crank, but before a pedal rev is complete it cuts out, then I get another short kick, and so it goes on. In higher gears I get a rev or two. Speed shown on the display can be as high as 87mph/140kph while crusing gently with this cutting in and out going on (all at less than 12mph). Anyway, when I connected the eTube app to see if the fault had cleared before riding with the new sensor (it hadn't) it showed motor firmware update 4.1.8 available, so 15 minutes later that was installed (why so slow, is it a crappy Bluetooth implementation?). The Shimano Steps logo looks very much like Shimano StOps to me!

Does this sound fatal to you? The shop I bought it from is 200 miles away, any alternatives you boys can suggest for a diagnostic?

 

[MadTurnip]

Take a picture of the magnet and its senor and attach it.
The misread speed reading of 87mph/140kph suggests to me either the senor is misreading or the magnet is signaling a higher speed incorrectly. Since you've replaced the sensor that would lead me to believe the magnet is the problem.

I'd first verify that the magnets positioning is correct and it didn't get a bang off a rock or something. I find it hard to imagine the magnet causing it to report 140kmph that should lie with the sensor or the motor.

 

[Teriatric]

The new sensor in place, nowhere else it can go!

The magnet in its rightful place

Pliers hanging, magnet seems ok

 

[aarfeldt]

What`s the distance bewteen magnet and sensor ?

Can you move the magnet, so it´s centrered between the discs mount ?

 

[Teriatric]

Most of the EP8 error reports on this forum and elsewhere seem to indicate that an E10 error is the tragic type, whereas the W10 seems to be a simple matter of sensor alignment/replacement. So I'm just praying there's an easy fix, but maybe no-one else has had this problem.

 

[Teriatric]

What`s the distance bewteen magnet and sensor ?

it looks around 3 to 4mm. Range is supposed to be 3 to 17mm, got that from Shimano literature somewhere.

 

[MadTurnip]

Interesting, my Ep8 has it mounted on the spokes.
Can you feel the magnetic field of the magnet using a screw driver or something magnetic? Is for some crazy reason any of your disc rotor giving off a noticeable magnetic field?

When you replaced the sensor, did you reuse the old wire? A damaged cable would give this kind of issue.

 

[Mikerb]

the magnet position looks fixed so any adjustment ( front to back) would have to be done with the sensor. All the sensors I have seen have a line on them (a raised section) which indicates the proper alignment and it is usually quite near the cable end of the sensor assembly. That alignment often seems more critical than the distance of the magnet from the sensor which in your arrangement cannot be changed anyway.

 

[Teriatric]

@MadTurnip , @Mikerb sensor only fits in one position with two tiny screws. As for the magnet, here you go:

 

[Teriatric]

Interesting comment about possible magnetised rotor though! I have tried sticking another magnet, same size, on top of the standard one, no change.

 

[Mikerb]

Interesting comment about possible magnetised rotor though! I have tried sticking another magnet, same size, on top of the standard one, no change.

just noticed on your photo of the magnet that rather than being positioned midway between 2 of the 6 arms of the rotor it seems to be touching one of the arms. That could indeed turn a fair section of the rotor into a magnet

 

[Teriatric]

@Mikerb

just noticed on your photo of the magnet that rather than being positioned midway between 2 of the 6 arms of the rotor it seems to be touching one of the arms. That could indeed turn a fair section of the rotor into a magnet

So it does, I never gave that a thought! First thing in the morning I'll see if I can centre it, thank you for spotting that. I took it off to clean out the gunge I collected on a very dirty ride. If it fixes the thing I owe you one, although you are 4 or 5 hundred miles south of me for a Thank You pint

 

[flash]

On the photo of your rotor, what is that down the bottom next to the mount rivet? It kind of looks like a small magnet?? You haven't picked up a stray have you?

Gordon

 

[RustyIron]

Interesting comment about possible magnetised rotor though! I have tried sticking another magnet, same size, on top of the standard one, no change.

Your sensor is just a little switch. Proximity to the magnet turns it on. The light in your kitchen is not very different, except it's your finger that turns the switch on. Envision standing in your kitchen, clicking the light switch off and on. Clicky clicky clicky clicky clicky clicky. The little computer on your motor is counting how many clickies per second to determine your speed. It needs to see a minimum number of clickies to know that your moving. Too many clickies will make the computer think you're going over the restricted speed.

That last part should be a clue. The one thing for certain is your motor is shutting off. That could mean a bazillion things. But the other key observation is your reported speed is 87 mph. Your computer thinks you're going too fast, so it shuts down the assist. So what's the cause?

It's improbable you had two faulty pickups. The magnet is probably ok. If it makes you feel good, you can put a meter on the sensor that's unplugged, and watch the resistance go between zero and infinity as you rotate the wheel. Readings must not have fluctuation, only on or off. As someone mentioned, it could be a twitchy connection somewhere between the sensor and where it plugs into the motor. That's really all you can check. Do your meter check on the cable that connects to the motor, or wherever you can that is furthest from the pickup. Take it apart, wipe off the connectors, and reassemble. It's not unheard of to have a marginal chip, or more likely solder joint that is marginal. But that's all warranty stuff that's out of your hands.

Technicians hate intermittent problems. When a customer has a problem that he can't reproduce it in the shop, he makes an educated guess, rolls the dice, and hopes for the best. Your problem is 100% reproducible. That's the easy stuff to fix. If you need to return the bike, make sure you explain that the problem is "100% reproducible," and you can demonstrate the problem to him.

 

[Mikerb]

On the photo of your rotor, what is that down the bottom next to the mount rivet? It kind of looks like a small magnet?? You haven't picked up a stray have you?

Gordon

wow....I think you are right. I took a look at photos of the RT-EM600 rotor and all had the magnet in the same position as in the OPs picture (sorry OP to get your hopes up!!) ....but none had that small disc which as you said looks like a mini disc magnet.

 

[Teriatric]

just noticed on your photo of the magnet that rather than being positioned midway between 2 of the 6 arms of the rotor it seems to be touching one of the arms. That could indeed turn a fair section of the rotor into a magnet

On the photo of your rotor, what is that down the bottom next to the mount rivet? It kind of looks like a small magnet?? You haven't picked up a stray have you?

Gordon

Sure was! Did you know that your eyesight gets worse as you get older!

 

[Teriatric]

Your sensor is just a little switch. Proximity to the magnet turns it on. The light in your kitchen is not very different, except it's your finger that turns the switch on. Envision standing in your kitchen, clicking the light switch off and on. Clicky clicky clicky clicky clicky clicky. The little computer on your motor is counting how many clickies per second to determine your speed. It needs to see a minimum number of clickies to know that your moving. Too many clickies will make the computer think you're going over the restricted speed.

That last part should be a clue. The one thing for certain is your motor is shutting off. That could mean a bazillion things. But the other key observation is your reported speed is 87 mph. Your computer thinks you're going too fast, so it shuts down the assist. So what's the cause?

It's improbable you had two faulty pickups. The magnet is probably ok. If it makes you feel good, you can put a meter on the sensor that's unplugged, and watch the resistance go between zero and infinity as you rotate the wheel. Readings must not have fluctuation, only on or off. As someone mentioned, it could be a twitchy connection somewhere between the sensor and where it plugs into the motor. That's really all you can check. Do your meter check on the cable that connects to the motor, or wherever you can that is furthest from the pickup. Take it apart, wipe off the connectors, and reassemble. It's not unheard of to have a marginal chip, or more likely solder joint that is marginal. But that's all warranty stuff that's out of your hands.

Technicians hate intermittent problems. When a customer has a problem that he can't reproduce it in the shop, he makes an educated guess, rolls the dice, and hopes for the best. Your problem is 100% reproducible. That's the easy stuff to fix. If you need to return the bike, make sure you explain that the problem is "100% reproducible," and you can demonstrate the problem to him.

Thank you for your input, spot on. As it happens I was an electrical engineer for 30 years so really appreciate what you're saying. Story coming!

 

[Teriatric]

Thank you all so much for the help and lack of abuse! Here's what I told my buddies on FB this morning:


I'm still trying to figure out the answer boys. Someone online suggested a magnet problem, possibly in the wrong position (impossible as it turns out) or a magnetised disc rotor (easy to see how this would make it think it was doing 87mph at 5 on the stand! Anyway I sort of eliminated that possibility by visual inspection and cleaning. That may have cured it.
Next up Our Ian who suggested I should clean all the electrical connections. Well there was nowt to clean, they are still shiny brand new things. However, I did disconnect them all (2 at the display on the handlebars and 3 at the motor) and check that the connections were well seated.
The only other thing I did (harking back to work experiences when I was at BT) was to "shock" the system by dropping the battery out while the system was energised.
Then I jumped on it and VOILA!
Mystified but absolutely ecstatic, and covered in mud

 

[MadTurnip]

I'd probably chalk that up to a poor reseating of the cables, leading to a single pulse being recognized as more than one.
Glad you got it sorted.

Sure was! Did you know that your eyesight gets worse as you get older!

Sorry just to be clear, that is a second magnet?!?

Nice eyes, thats hilarious.

 

[Teriatric]

I'd probably chalk that up to a poor reseating of the cables, leading to a single pulse being recognized as more than one.
Glad you got it sorted.

Sorry just to be clear, that is a second magnet?!?

Nice eyes, thats hilarious.

Yes, one of my thoughts was that the rotor magnet may have lost some strength so I stuck another one on top of it but it didn't improve things. Must have knocked it off trying it out!

 

[RustyIron]

Mystified but absolutely ecstatic,

In my former profession, I worked on extremely complicated systems consisting of many hundreds of connections and devices. Anomalies could be very infrequent, so pinpointing a cause could be quite challenging. Sometimes there as just so little data that coming up with a logical troubleshooting solution was impossible.

In such a situation, one thing is for sure. If you do nothing, the anomaly would probably occur again. Checking connections in such situations isn't a bad idea. Sometimes you'll definitely find a faulty connection. Sometimes you might be improving a connection that might become twitchy at some time in the future. Other times, you'll find nothing definitive, but the problem will magically disappear. Those solutions might SEEM mystifying, but they're not. There was a bad connection somewhere, you made it better, and there's no sense in worrying about which of the hundreds was bad. Problem solved, time to go get coffee... or in your case, ride.

 

[LateRiser]

Thank you all so much for the help and lack of abuse! Here's what I told my buddies on FB this morning:


I'm still trying to figure out the answer boys. Someone online suggested a magnet problem, possibly in the wrong position (impossible as it turns out) or a magnetised disc rotor (easy to see how this would make it think it was doing 87mph at 5 on the stand! Anyway I sort of eliminated that possibility by visual inspection and cleaning. That may have cured it.
Next up Our Ian who suggested I should clean all the electrical connections. Well there was nowt to clean, they are still shiny brand new things. However, I did disconnect them all (2 at the display on the handlebars and 3 at the motor) and check that the connections were well seated.
The only other thing I did (harking back to work experiences when I was at BT) was to "shock" the system by dropping the battery out while the system was energised.
Then I jumped on it and VOILA!
Mystified but absolutely ecstatic, and covered in mud

Teriatric i'm having the same problem and have checked the connections twice- how hard was it to drop the battery? I'm waiting to make an appointment to put my motor on a diagnostic...: (. Glad u got it sorted i want to ride this thing again!

 

[Teriatric]

@LateRiser when you say "drop the battery" what do you mean exactly? It should just drop out of the frame after 1/4 turn with the allen key then a gentle press on the stainless steel tab stuck on its end that should become visible, or have I misunderstood? It's worth using battery grease (conductive stuff, not ordinary grease) on the battery termionals when you do get it out. Make sure to fill the little cavities around the connections. I may have caused my own particular fault by mucking around with the speed sensor, still not convinced exactly what went wrong. One piece of advice I'd give to any ebike owner is not to get the thing wet (motor, battery, controller, cable ends), either by submerging in streams or fords or pressure washing. I've even stopped using a normal hosepipe now. The sensor cables and thus their connectors are so small that I consider them to be pretty fragile and open to abuse even from a light dousing with water.

I'll duck now while the clever bods tell me I'm talking &^%*^%

 

[Chrisv]

I have developed a very similar problem, mine is the step 6100 motor. When I power up and start peddling the handlebar display goes up 30 mph (ish) and then drops back to normal speed, whilst riding any pressure on the pedals and does the same, motor is kicking in and out all the time, proper pain in the butt, magnet on the rear disc looks OK and the sensor cannot move as its screwed to the rear arm, I can get a new sensor for about £30 (Uk) but not sure its that. Do you have to drop the motor to change the sensor ??

Thanks Chris

 

[Teriatric]

No need for that buddy. Back wheel off to unscrew the sensor and top plastic motor cover off to access the connection at the motor. Be very gentle at that end, don't crush or stretch the thin wire.

 

[Chrisv]

Thanks for that, I have not noticed that the top cover comes off I will check tomorrow, spoke to the shimano service centre this afternoon and they said it might be the rear sensor but it might one of the internal sensors on the motor, as I am not getting any error error codes they said it needs plugging in to their shimano service software laptop, so not sure what to do spend the £30 and change the sensor or let them look at it. The annoying thing is its only two years old and done 1400 miles and the bike was a lot of money. The shop where I got it from pure electric has since stopped selling bikes and only sells electric scooters now and guess what are not interested in bike issues now, I used them because they were the only shop selling the BMC (swiss) model I wanted. BMC UK not helpful because I did not buy direct from them.

 

[Teriatric]

Sorry to hear you are being fobbed off. I dread any issues with mine. If the motor dies I'm banging a Bafang in. Have you tried the mysterious spinning the rear wheel backwards? Seems a common suggestion for software glitches on various forums. Try that first for daftness, you never know! I think I'd let them plug in. If it's fatal that might be your best route to a new motor.

 

[Chrisv]

well, had my bike on my bike stand this morning, spinning the back wheel lightly with my fingers indicates 26 mph on the handlebar read out so I thinking its the ewss301 sensor on the back wheel, spinning with my fingers eliminates pressure on the pedals. Taken the cover off and I can see the connectors for the sensor and handlebar read out, I suspect there must be a bit if the wire coiled up in the frame as the new sensors come 750mm wire on them

 

[blackwood]

Did you ever get this fixed? I am having to same issue, speed is jumping around al over the place and motor cuts out. I replaced the sensor with a new one and now get no speed reading. Scratching my head.

 

[RustyIron]

Did you ever get this fixed? I am having to same issue, speed is jumping around al over the place and motor cuts out. I replaced the sensor with a new one and now get no speed reading. Scratching my head.

Whenever you change out a part and the results are not as you would expect, it's a good Idea to reinstall the old part and confirm that nothing else has changed.

Proper troubleshooting practice aside, did you check the magnet? That's something to look at. If I'm not mistaken, the sensor is a simple reed switch. You can check it with an ohmmeter while it's on the bike. Watch the reed switch open and close as the magnet moves in proximity to the sensor. First check the connector on the sensor when it's disconnected. If all is good, check it again when it's hooked up to the motor. This should give you some insight as to what is working and what is not.