Bosch motor/display cutting out.

soundwave

Esteemed Pedelecer
May 23, 2015
16,127
6,314
I'm writing because I've had an identical sequence of problems to those reported in previous posts. My bike is a cube touring hybrid. The problems included Intuvia not starting and bumps in the road causing cut-outs sometimes multiple times a ride. This thread has been hugely useful and I hope that I've now solved my problem. I loosened the bolts on the Intuvia mount and could see under the unit. There you'll find a small number of very tiny screws that connect the Intuvia to the rest of the system. I found that all of mine were a quarter to a half turn from tight. I tightened them up and then retightened the mount (while making sure it wasn't too tight). Since then (100 miles), I have had no problem. This may not be the case for everyone, but it may be worth checking it out.
that display has a internal batt soldered to the pcb and they start to stop working when 3-4 years old as wont hold a charge anymore.

 

mnaeh

Finding my (electric) wheels
Jul 15, 2019
13
2
You can see the pattern if you look at the photo in the Amazon order screenshot I previously attached. Two silver and two gold/brass of the four on the right side.

BTW this issue was so frustrating I would have paid 4 times as much for the replacement mount—riding is finally enjoyable again…..
I know this is an old thread but I still haven's found a solution. I wanted to replace the mount but COVID-19 situation made it dificult for me to obtain one. Now new riding seson is here and I'm once more able to order the given part, I was just wandering did you reuse the existing cable (which connects Intuvia mount to the motor) or did you also change the cable?

I'm asking because changing just the mount and keeping the cable seems infinitely easier and doesn't require additional tools (such as crank puller).
 

mnaeh

Finding my (electric) wheels
Jul 15, 2019
13
2
***SOLVED... kinda***

You can find Bosch 2020 Dealer Manual here.

On page 201 there's info regarding new mount for Intuvia (see picture). When a company decides to change the production of a component "to improve contact quality" you can be certain it's simply because the old design didn't work well... for some people :) This got my hopes high.

47277

The guy at the service shop first opened the motor cover and plugged in new mount along with new cable directly to motor and nothing improved. Then he replaced Intuvia mount without replacing the cables (as recommended in the manual) and... nothing improved :( The bike still wouldn't turn on most of the times using button on the display. I can't tell if this fixed mid-ride cut-offs because these happen rarely and almost without any pattern.

I rode for half an hour on a VERY bumpy terrain outside the shop and everything seemed fine, no cut-offs, but bike still wouldn't power on every time using power button on the display. Maybe cut-offs were related to the mount, yet they are so random that it was hard to tell.

Then he gave me another (used) Powerpack 500 battery to try out. Yes, he was an extremely nice guy and determined to find the culprit. And suddenly... everything worked perfectly :) The bike turned on every time using display button, no matter how much we tried to "abuse" it. I left my battery at the shop and we agreed that I try this one for a few days.

During one-hour ride home (~17km) everything was fine.

The bike turns on every time, whether I use battery or display button. I'm truying my best to torture-test it and it works flawlessly.

Cut-offs are still to be tested more. Maybe, just maybe, these two problems are unrelated, but I highly doubt it. For now my unfortunate solution seems to be faulty battery.
 

GLJoe

Esteemed Pedelecer
May 21, 2017
852
407
UK
***SOLVED... kinda***

On page 201 there's info regarding new mount for Intuvia
...
For now my unfortunate solution seems to be faulty battery.
Just want to reinforce this as we do get this fault popping up every now and again but people still keep banging on about the mount and seem to ignore the potential faulty battery issue.

IT CAN BE EITHER PROBLEM.

Sometimes, removing and reinserting the Intuvia display a few times will do the job of cleaning slightly corroded contacts, and the bike will be ok again. Or try to manually clean the contacts. But whatever - its often a bad contact issue (and sometimes this can be on the battery connection side, not just the display mount, but the latter seems more common)

But sometimes, the display not coming up with any speed means its a comms problem with the battery, and sometimes, its the battery itself that's knackered.

I've had both types of issue. Fortunately, I had more than one Bosch bike in the family so I could swap bits to find the problem.

Note - when it was a battery issue, it started as an intermittent problem, but then progressed to the battery being totally unable to talk to the rest of the bike, despite it being charged, the LEDs showing all ok etc. But it wouldn't power any of the Bosch bikes, yet the 'faulty' bike worked flawlessly with a different battery. The dealer replaced the battery under warranty and the bike has been fine ever since.
 

mnaeh

Finding my (electric) wheels
Jul 15, 2019
13
2
***SOLVED (definitely). It was... drumroll... INTUVIA MOUNT***

I'happy to report that I'm part of the #teamnocutoffs ;)

While I completely agree that any of the components can be the potential culprit, for me the guilty one was definitely Intuvia mount. It's just that my "testing methodology" was flawed. If you have the opportunity to change and test different components (mount, display, battery, cables…) go for it, but if you don't, I can tell you from my experience and everything I was able to dig out on the web, go with the mount. It's the cheapest solution for the best chance you can get.

Having no more mid-ride cut-offs is more awesome than you imagine. Like having a new bike.
 

Deno

Pedelecer
Jan 24, 2018
91
47
43
Dublin
I had very similar issues with a gen2 CX. Bike would power off mid-cycle. I solved it by replacing the wiring loom between the battery mount and the motor. Problem went away. I think that the contacts in the battery mount were worn and it was loosing connection as a result.
 

sjpt

Esteemed Pedelecer
Jun 8, 2018
3,668
2,673
Winchester
We've had both problems on our old Motus (2016, ?gen 2 motor?).

The Intuvia mount one has been resolved by careful cleaning and being very careful to push home properly when engaging.

The battery is a rear rack one. The rails it sits on make it very easy to have the battery engaged and locked, but not properly seated. This is obviously bad for the immediate connections while it is mounted wrong, and could cause longer term issues with the connections as well even after remounting properly. It is easy enough to mount the battery correctly once you know the issue; even then it took a few goes to work out a reliable battery mounting strategy.

Both these problems are down to bad (German) design, not to do with poor manufacture (?Chinese?, not sure what bits were made where).
 

Barrio Barranco

Esteemed Pedelecer
Nov 24, 2018
281
99
55
Interesting thread as my Gen3 CX has started doing this after almost 4 1/2 years of flawless service(One Performancelinebearings rebuild). I've cleaned and silicone greased the terminals/connections from the Purion and from the speed sensor into the motor. I'd already cleaned both batteries and the terminal on the frame and greased them. The day it started it happened pretty frequently but after the maintenance today just once in 62km. Like others bumps seem to trigger it worse. And it's only had the same battery in it. SO I maybe need to put in the other battery and try that, and examine the terminals for any damage, maybe lightly sand/scuff them.
I have the (hardly used) Intuvia the bike came with I could put that back on for a while? I've costed up the parts though and could get a new Purion, frame to motor battery cable and a new speed sensor for probably £140 all in so rather than F about stabbing in the dark pulling the motor in and out (new gaskets each time too) if it's not the battery I'd rather do that... It really screws up any notion of big days out here in the Cairngorms having an unreliable bike, which is what I've used it for in the last few years being back on the road bike for 6-800km a month. Only thing I'd need to do is work out what lengths each of the battery/sensor cables are... It's an expense I can do without but in the grand scheme of things given the bikes age maybe I should give it a refresh??
Any thoughts??