Bosch 503 Error

[The Bear]

Any suggestions for this please?

Got the '503 ERROR' come up on my Purion display today. Bike was riding fine but then when freewheeling downhill I noticed the speedo said zero mph.
I stopped and turned the display off/on and same thing again. Set off riding and could feel that the motor wasn't on, then '503 ERROR' popped up again.

I've read its a sensor problem, but I've removed, cleaned and refitted it, and checked the magnet, but no success.

Any suggestions please?



2018 Cube Reaction Race 500 - Bosch motor - Purion display

 

[vfr400]

Try the connector under the left side cover, otherwise it's a trip to the Bosch shop.

 

[The Bear]

Try the connector under the left side cover, otherwise it's a trip to the Bosch shop.

Is it likely to be a loose connection under the cover?

 

[vfr400]

Is it likely to be a loose connection under the cover?

Well, it's not working. Can you suggest another reason?

 

[The Bear]

Dirt?
I haven't got a clue, which is why I asked the question.

 

[GLJoe]

Any suggestions for this please?
Bike was riding fine but then when freewheeling downhill I noticed the speedo said zero mph.

No speed displayed can sometimes happen when there is a comms problem with the main battery (or connector). Worth swapping/reseating that if you haven't already.

 

[The Bear]

No speed displayed can sometimes happen when there is a comms problem with the main battery (or connector). Worth swapping/reseating that if you haven't already.

Thanks, I have removed the battery and cleaned the connections. I'll have another look tomorrow and if I can't fix it I might have to take it to the local Bosch approved bike shop

 

[soundwave]

you need to remove the speed sensor cable from the motor and clean it and see if that fixes it you need to remove the crank arm from the left hand side to get to it and remove the motor cover.

 

[The Bear]

you need to remove the speed sensor cable from the motor and clean it and see if that fixes it you need to remove the crank arm from the left hand side to get to it and remove the motor cover.

I'll give that a try thanks. I've got a the tools from when I changed the front chain ring, so I shall see of this fixes the problem, thanks.

 

[soundwave]

if it still does not work then only other option is a new speed sensor.

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just make sure the cable is long enough.

 

[The Bear]

Just got the bike lifted up to have a look. Do I need to remove the skid plate before I can remove the left side cover?

As well as the two obvious bolts on the side of the cover...




Theres also two on the front (though one may be for the right cover), and the two for the skid plate..




Two underneath the skid plate...




And two at the rear (poor photo)...




Also, are they all the same size allen bolts as I don't want to be rounding any off?

Thanks.

 

[soundwave]

if the cover wont pull of with the bolts removed then id say you need to also remove the skid plate first.

 

[The Bear]

Took the bike to a local Bosch approved bike shop and they have fitted a new speed sensor cable, and its now back to working great. Frustratingly they performed a software update (I'd forgotten to tell them not to) but thankfully this update still works with my Badass 3.4 dongle, happy days.

 

[The Bear]

503 ERROR has returned today. Grrrrrrr!!

 

[soundwave]

do you still get the error when not using the dongle ?

 

[The Bear]

do you still get the error when not using the dongle ?

Haven't tried it without the dongle yet. I was riding home from work when the motor cut off and the error displayed. Had to walk home pushing the bike, as without the motor I couldn't get up the steep hill home.

I'll have a play with it later in the week when I have time to experiment, and check the magnet etc. Last time a new speed sensor cable fixed it.

Typical that it would fail just as I've spent £60 fitting a new 11 speed chain, front chainring and O ring !!!

 

[soundwave]

also try new bat in the dongle and display if not done so already but mine does not need to move much on the sensor to get a error.

 

[The Bear]

Hoping I've managed to fix this, if only temporarily?
Removed the Badass dongle, checked battery and it is still 100% power.
Readjusted the magnet and (without dongle fitted) went for a ride, still got the error code.
Removed the magnet, waved it past the sensor as fast as I could a few times so the Purion showed as high a speed as I could get, then refitted magnet. Turned Purion off/on and went for a ride, all seems good.
Will refit the dongle and see what happens.