Error 06 on KT-controller

harrys

Pedelecer
Dec 1, 2016
169
22
69
Chicago, USA
PSWpower 20A sinewave model. I've had an occasional Error 06 when powering it up in the morning. Shaking the connector bundle on the controller, and wiggling the 9 pin Julet connector to the motor always cleared it.

Last night, I happened to look down and see the controller registering over 600 watts, but I was still puttering around at 12 mph. I toggled the buttons and it jumped back to to 100W again, but seconds later, Error 06 came up. I pedalled home w/o power.

The next morning, I powered up the controller. Still Error 06. I unplugged the motor and hooked up an umbilical cord to another KT box on another bike. Motor worked fine, so it had to be the controller. I took off the rear controller plate and yikes, a few drops of water came out. So I took off the top cover and rinsed the circuit board throroughly with 91% isopropyl alcohol. I didn't see any discolored solder lands, so I hoped for the best. It dried quickly in the hot sun, and the bike worked again. I'm hoping it keeps working.

Learned my lesson. I spent the rest of the day waterproofing the controller and its connectors. Even installed a rear fender to keep mud from spattering on it.

These controllers boxes are normally sealed pretty good, but I had the wire side pointing up, and I suppose a little moisture wicked in past the wires.
 

anotherkiwi

Esteemed Pedelecer
Jan 26, 2015
7,845
5,780
The European Union
I think I might have some water issues in my controller too except I get error 00. Now you can look for that error in the docs but it doesn't seem to exist... 06 being "Motor or controller has short circuit Abnormality"

I don't get nutty Watt numbers I get strange speed readings as in I am pottering about at over 40 km/h (more like 20 in reality).

After a while the LCD seems to "reboot" and all is back to normal but we have had some very muggy weather lately and I think there may be condensation in the wiring...
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
6,871
2,644
Basildon
You get 06 error when there's a problem on the motor cable, like the motor connector not pushed all the way in to the line. You also get it when the bullet connectors at the controller are not tight enough, and another cause is when the motor cable gets nicked where it comes out of the axle.

Those connection issues are very serious. You must never run your bike when they're intermittent. You must find the cause and fix them otherwise there's a high risk of burning out your controller and/or the motor. When I say burn out the controller, I mean blow the MOSFETs, which will then give you a permanent 06 code and requires the controller to be replaced.

The reason you got 600w and no power is because the faulty connection works like a brake in the motor. The two remaining phases can't turn the motor properly so it becomes extremely inefficient. A high watt reading when you're not getting high power out is a clear sign that there is an issue on the phase wires or their connections.

Water in the controller is very unusual, but you're going to get it if you mount the controller with the wires coming out upwards. I've never heard of anybody doing that before. If the water gets on the MOSFETs or the tracks that go to the switching transistors, they'll stop switching, which is the same fault and affect as a short or break on a phase wire.

it's much better to mount the controller in a bag - either one that goes behind the saddle or a triangular one that goes in the frame. You have to remember that the controller gets hot and it's not air-tight. the hot air will expand out, and when the controller cools down, it'll suck in any water that's sitting adjacent to where the air goes on with some force. I can imagine that the force of expansion is enough to overcome attempts to seal it.I always use the principle to let water out if it comes in, so leave the compartment unsealed at the bottom or drill a drain-hole.

All the controllers that I've seen drowned by water (around 5 in total) were from attempts to seal the compartment that they sit in.
 
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harrys

Pedelecer
Dec 1, 2016
169
22
69
Chicago, USA
Of course, you're correct, Vr. That bike was front drive, so the cables went naturally went up along the top downtube, plus I thought the controller was safe inside a box. Alas, water from the rear wheel splashed up behind the seat, and ran down the wires. Yep. That's why motor cables point down too.

With the wires pointing up, the shunt wire was at the bottom, and I bet moisture was short circuiting it to the case. Hence 600 watts, as I was riding along fine under pedal assist.

In four years of ebiking, I've never had a real failure, other than a loose connector. This year, I have had four show stoppers on four different ebikes. All due to water. We've had more rain than usual, and a couple of times we slogged thru some flooded pavement.

1) The above issue.

2) My wife's ebike had water thrown into the connectors, and her throttle went to max, but it's a low powered bike and the brake cutoffs work. I had to blow out the connector with an air pump.

3) The speed sensor inside a Bafang motor failed. I rode that bike on a winter day and didn't rinse off the salt from the roads. The sprockets were rusted by Spring, and I suspect corrosion in the motor too, as I hear scraping. Hope the Hall's don't go next.

4) A storebought ebike with controller inside a box under the pedals. I got caught in the rain and the bike didn't work the next day. When I opened the compartment, I saw the controller had been sitting in a pool of water and it seeped in thru the rear cover, which I had opened earlier to peek inside. I could see the gap I left in the gasket because I didn't tighten the screws firmly. Otherwise, it might have stayed dry.

Except for that speed sensor, everything is running again, but the two wetted controllers could go bad with time. Well, I have spares.