KTM speed/motor fault

[KTM Hippo]

Hi, my KTM Macina has recently developed an intermittent fault. The indicated speed will suddenly just drop to zero and I'll have no assistance from the motor, a fact which amuses my normal bike owning girlfriend greatly. It will kick back in soon after but the fault is getting steadily worse...happening more often and staying on 0mph for longer, even though I'm moving. I've noticed it happens more when I go over a bump so possibly a loose connection somewhere. The magnet is in the correct place and the terminals on the display are clean. (Although the display switched off completely yesterday at one point!) There are no errors shown on the display.

The motor is a Bosch Performance Line CX.

Thanks in advance for any help!

 

[KTM Hippo]

This has got my local electric bike shop, and BOSCH baffled. Without an error code and such an intermittent fault it's understandably difficult to diagnose. I have the bike back now so will try and figure out when and for what reason that it's happening.

 

[Deleted member 4366]

If you go out in the rain, have a look inside the display receiver. There's secondary contacts in there and water can get in when they don't fit the seal properly.

Photo in this thread:
http://www.pedelecs.co.uk/forum/threads/the-dog-ate-my-homework.28476/

 

[KTM Hippo]

Thanks for that. I got caught out in the mother of all monsoons on Exmoor last year...it cost me an iPhone, and to be honest, I think the problem stems from there

 

[Deleted member 4366]

Not shown in those photos is the pcb, which is stuck in the little cover that you remove. It has some pads that contact those gold springs and the other end of the gold springs contact the pads that you can see on the outside. Maybe something is compromised. All will be revealed when you remove those two little covers. It's probably best to turn the receiver upside down before disassembling so that the springs don't fall out.

 

[Gary c]

KTM Hippo, have you got to the bottom of it? I've recently bought a used 2017 mtb with the bosch cx unit and after two weeks use its started doing exactly as you've described. Mine has the purion display though so doesn't have the contacts on the back of the display to check. The display has also now started going off all together!