Bosch motor won't power up

[fooferdoggie]

I would be 100% sure that the speed magnet on the spoke or brake rotor is properly aligned with the sensor if the speedometer on the display appears intermittently. Visit the Bosch Ebike website and download the PDF of the manual to see an image how to align the magnet to the speed sensor as positioning this correctly is very important.

that gives you the 503 error code. I have gotten it a few times when I forgot to put the magnet back on the new wheel and just today when the magnet was at 90 degrees.

 

[webcurl]

Thanks.
I will give that a try.

So the display unit (on handlebars) show's the battery level!?
If it does then i believe the battery is directly connected to the drive unit (main cpu) and the display is connected to the drive unit and therefore the display unit =seems= fine and communications (and those parts of the drive unit associated to performing this) =seems= fine.
Controller on handlebars do anything? Any error(s)/codes on the display unit (handlebars)?
You mentioned you had the display unit showing speed correctly and drive power for a minute, this must mean that comms to the speed sensor also seems ok.
When you had power for those minute periods:- Can it determine the torque you input via the cranks & dynamically adjust the motor output based upon that?
If so then the torque sensor (crucial part within the drive unit) seems ok.
Beyond that i guess motor drive electronics or motor itself overheating or showing other problem which the electronics can detect maybe.

 

[William - Bosch Team]

Based on the information you've shared, @Andrew Edwards, this sounds like it may be a faulty battery cable. A few possible symptoms of a faulty battery cable are:
- no connection to DU or DU/battery shown in Bosch Diagnostic Tool
- Speed read-out on screen is blank (not even 0.0)
- Intermittent support/asssitance cut-out. Severity/frequency varies based on how bad the battery cable issue is.