KT controller upgrade - throttle works but no PAS

[spleenharvester]

Hi all,

I have a new Falcon 2022 e-bike which has a Bafang G010, 36V battery and previously had generic chinese display/controller/PAS.

I upgraded the controller to a KT-15A and the display to a KT-LCD4. Everything works fine except PAS. No response forward or reverse. "PAS" does not appear on the display when pedalling.

I replaced the PAS with a KT-V12L. Still not working. I've checked with a multimeter and there is +5V being supplied to the PAS, roughly 0.8V between signal and ground when at rest.

I'm not sure what else to test. I presume either the LCD4 or the controller are DOA. Any ideas?

 

[Nealh]

Set C1 parameter to value 07.

 

[spleenharvester]

Cheers,

Thought that had fixed it at first - with the motor unplugged I did get the PAS indicator on the display. So I switched it off and plugged the motor in then tried it. Unfortunately it's now gone back to the original fault. I tried unplugging the motor again but still no PAS indicator.

Makes me wonder if the display has lost some information when I powered it off. I checked and C1 is still set to 07. Is there anything else that could affect it?

Only other thing to note is that a resistor on the controller board is getting really, really hot.

 

[spleenharvester]

Update, replaced the KT controller again, still throttle but no PAS. I am guessing the LCD4 must be faulty then? Any more ideas before I throw this KT garbage in the trash where it belongs? £100 and 3 weeks later, still no working bike...

 

[Nealh]

I use KT all the time with very minor issues (two in 8 years) , generally the system isn't garbage. One of my issues was the lcd4 which I liked for it's minimalist features, but also had minor issues with mine. I swapped it out and refitted one of my lcd3 displays and the issue went away.
Either KT have had a bad batch of lcd4 's or the processor can't handle the comms.

In eight years , the two issue I have had are;
1. Thermal cut out/shorting due to hot mosffets, remedied by using a 9 mosfet controller . Though temporary, extra heat sink and 5v fans did help .
2. More recently lcd4 tempermental, easily solved by reverting back to lcd3.

I tend to stick to three proven sellers of KT, rather then any tom,dick or harry .

 

[spleenharvester]

Thanks. I'm going to try and replace it with an LCD8 and see if it works. Unless I've got 2 faulty PAS sensors and 2 faulty controllers in a row I can't really see what else it can be.

 

[spleenharvester]

This morning I put together one of those jumpers to run the controller with no display. Aaaaand... with display bypassed still only throttle works. WTF is wrong with this thing? Is there a freak incompatibility with my motor or did I seriously get 2 parts in a row with an identical fault?

 

[Nealh]

Test the PAS wiring for any fault , make sure you are seeing approx. 4.4 - 5v on the 5v and then it switching off on the signal wire.
You will have to remind us again which PAS is in use.

I have only had one issue with PAS and that was a cheap non KT unit I bought off ebay many years ago and wasn't able to get the RED PAS sensor to work, so opted for a BZ10c PAS sensor and no issues.

I have only used LCD 1,2 3 & 4 displays all worked but the 4 being not so good with poor speed and odo reading. One dosen't need any fancy colour lcd , I try and always advise using the lcd3 as it has been bullet proof in all the years I have been using it.
lcd1 & 2 both work well but are a little basic, I like to have a volatge read out so the 3 suits the bill.

 

[Nealh]

Can you tell us the wire colour to wire colour of the PAS connection or are you using Julets ?

 

[spleenharvester]

Update, changed to a KT-V6 PAS and it worked straight away. Not sure why the two 12-magnet PAS weren't working as they were set properly on the LCD4, and the connection was exactly the same for all three.

 

[Nealh]

That's good to know it sorted your issue.
I have had a 12 pole disc not work well before, but a 10 pole worked fine . I now only use 10 poles all the time.

 

[spleenharvester]

Just following up on this a while later, as the KT-V6's sluggish response times were irritating me - replacement KT-V12L works fine, original must have been DOA