Bosch CX not working - Help me diagnose please

[NeverL8]

Hi everyone, new here. I just bought a used 2019 Fuji Blackhill with Bosch Performance CX (I believe Gen 3?). The Purion screen shows no error and turns on and off with ability to scrolls through. I am able to put it in walk mode and it walks the bike for about 3 seconds then stop so power is going to the motor. The screen show the speed of the bike when it ridden so it reads the magnet on rear wheel fine. When any mode are selected, nothing happens, no power assist from the motor at all.

What can I do diagnose this issue? Thanks in advance.

 

[fooferdoggie]

Hi everyone, new here. I just bought a used 2019 Fuji Blackhill with Bosch Performance CX (I believe Gen 3?). The Purion screen shows no error and turns on and off with ability to scrolls through. I am able to put it in walk mode and it walks the bike for about 3 seconds then stop so power is going to the motor. The screen show the speed of the bike when it ridden so it reads the magnet on rear wheel fine. When any mode are selected, nothing happens, no power assist from the motor at all.

What can I do diagnose this issue? Thanks in advance.

it sounds like the battery I would take it to a dealer and have them check it all over. I take its used? there is nothing you can fix though. does the battery show a full charge on its lights? usually you would get a error message if it was the wheel magnet. but that would not stop walk assist as I have forgotten the magnet and used walk assist to get back up the hill and put the magnet back on.

 

[NeverL8]

Yes, a used bike, only 700ish miles on the odometer. Battery is at full charge. Is there a voltage test I can do or anything myself? I like to do hands on work whenever possible. thank for the assist fooferdoggie.

 

[fooferdoggie]

Yes, a used bike, only 700ish miles on the odometer. Battery is at full charge. Is there a voltage test I can do or anything myself? I like to do hands on work whenever possible. thank for the assist fooferdoggie.

700 miles on a bike thats been in service for 3 years may mean the battery may have been sitting around a long time. no you cant check the battery it will not show the correct voltage because the battery needs a signal from the motor or the charger to actually start putting out power. there is pretty much nothing you can do it needs to be checked by a dealer who can run diagnostics. I bet it could use updates too.

 

[NeverL8]

Thanks for the advice. I'll run it to a LBS. If its just battery, I would not mind replacing it if that fixes the problem. I'll write back with an update.

 

[fooferdoggie]

Thanks for the advice. I'll run it to a LBS. If its just battery, I would not mind replacing it if that fixes the problem. I'll write back with an update.

thats the o9nly bad part of Bosch is there is no much you can really do. but its also what makes Bosch so reliable. without error codes it seems like the battery but that's a guess.

 

[wildtrak]

Hi everyone, new here. I just bought a used 2019 Fuji Blackhill with Bosch Performance CX (I believe Gen 3?). The Purion screen shows no error and turns on and off with ability to scrolls through. I am able to put it in walk mode and it walks the bike for about 3 seconds then stop so power is going to the motor. The screen show the speed of the bike when it ridden so it reads the magnet on rear wheel fine. When any mode are selected, nothing happens, no power assist from the motor at all.

What can I do diagnose this issue? Thanks in advance.

That is an interesting one. It should give you a 510 or 532 error if it was the torque sensor.
Turning off walk assistance after 3 seconds and no assistance when riding might be a battery issue or just lose battery contact (which can get you a 6xx error or leave you with no error, but is less likely after less than 1000 miles).
Does it show 5 bars on the display and 5 LEDs on the battery? Does that go down when using walk assist?

 

[NeverL8]

It was actually something extremely simple and I was a total dummy for not doing so first. Just had to press the reset button for 10 seconds and all is well.

Thank you all for your input in trying to help.

Now, onto another issue.......

My purion screen is badly scratches from turning the bike upside down (from previous owner). I ordered the black surround shell thinking it included the new screen but it doesn't. Can't seem to find a part number for that. Anyone knows?

 

[fooferdoggie]

It was actually something extremely simple and I was a total dummy for not doing so first. Just had to press the reset button for 10 seconds and all is well.

Thank you all for your input in trying to help.

Now, onto another issue.......

My purion screen is badly scratches from turning the bike upside down (from previous owner). I ordered the black surround shell thinking it included the new screen but it doesn't. Can't seem to find a part number for that. Anyone knows?

I forgot about the battery reset sorry about that. I don't think you can replace the screen. too bad I just gave one away. but it's a pain to to replace it. myself I would get something like this https://www.amazon.com/NOVUS-PK1-2-...sprefix=plastic+screen+scratch,aps,185&sr=8-5
you may need sandpaper to get the deepest ones out.

 

[NeverL8]

I did use blue masking tape to try to sand out like 1/4 in to see if it helped. The scratches are pretty deep so I may have to live with it unless I either upgrade or find another used one with a good screen.

 

[fooferdoggie]

I did use blue masking tape to try to sand out like 1/4 in to see if it helped. The scratches are pretty deep so I may have to live with it unless I either upgrade or find another used one with a good screen.

they have to drop the motor to rerun the wires unless you want to splice it. then you might as well upgrade to a nyon.

 

[wildtrak]

they have to drop the motor to rerun the wires unless you want to splice it. then you might as well upgrade to a nyon.

You can pull the pins out with a needle to get the plug off. Then you don't need to drop the motor.

 

[rich c]

Do you have a 400 battery pack? If you do, you boot up the display like always. When the speedometer and PAS level doesn't come on, reach down and press the battery reset for 15 seconds. The display should now be booted up correctly and everything should be fine.

 

[NeverL8]

I've read other threads and my go the Kiox route if I can find an used one for a good price (because I'm a cheap bast###, lol)

As for rich c question, mine is a 500 pack and my frame actually have a small hole cutout which the reset switch for the battery underneath it perfectly aligns for a reset without taking it off the bike.

 

[ananords]

I had the exact same problem, and found out in the end it was because I had my bike upside down during service of the bike. Apparently it has a safety feature where it won't run if it is not the correct way.

 

[wildtrak]

because I had my bike upside down during service of the bike.

Exactly. If you have your bike upside down, the walk assist will not work (Gen3 and newer)