Turbo3
Gold Member
Posts: 1799
Joined: Mon Jul 19, 2010 8:34 pm
Delivery Date: 12 May 2011
Leaf Number: 002191
Location: San Jose, CA

Warning: Defective Konnwei KW-902 on the market

Fri Apr 07, 2017 4:07 pm

DO NOT PLUG A NEWLY BOUGHT KONNWEI KW-902 UNTIL YOU READ THIS.

I have recently been getting reports of strange things happening (I-Key error) when newly bought Konnwei KW-902 adapters are plugged into the Leaf.

I bought one this week and got it today from Amazon and had the same problem.

On opening it up I noticed they have changed the circuit board from the board in the old one I have been using.

The problem is that on at least some they have used the wrong resistor across the CAN bus. The spec is 120 ohms across pins 6 and 14.

They are using a 20 ohm resistor which is a near short of the CAN bus. If they are using automated equipment to build their boards then they most likely loaded the wrong reel of resistors. That means there are potentially many many of these out there.

Before plugging in a newly bought Konnwei KW-902 into your Leaf please have the resistance between pins 6 and 14 measured. If it is not 120 ohms return for a replacement until you get one with the correct resistor in it.

Shorting out the CAN bus is very serious. If you experience any strange behavior when using any OBDII adapter immediately stop using it and have the resistance checked. Never drive your Leaf under these conditions.

The CAN bus is used to control the vehicle it is not just a monitoring port. The communications on the CAN bus control the Leaf and shorting it out should never be allowed.

I have had one other user confirm 20 ohms on his defective Konnwei. Please send me a note if you also measure 20 ohms.
Two more confirmed to have 20 ohm resistors from AliExpress.

These are the two pins to check for 120 ohms.
Image

Here is what it looks like inside courtesy of a excellent picture from Mark Stevens. I have marked the bad resistor in RED. Removing this resistor will fix the problem.
Image
Last edited by Turbo3 on Wed Apr 12, 2017 1:40 pm, edited 7 times in total.

User avatar
mwalsh
Posts: 9465
Joined: Thu Apr 22, 2010 10:10 am
Delivery Date: 05 Jan 2011
Leaf Number: 0213
Location: Garden Grove, CA

Re: Warning: Defective Konnwei KW-902 on the market

Fri Apr 07, 2017 4:21 pm

Yikes!

Hope you posted this warning in a review on Amazon too?
2011 Blue Ocean SL with 70,000 miles.
2015 pack under warranty 12/30/15.
Tinted windows.
Michelin MXV4 tires.
L1 EVSE upgrade.
FIAMM horns.
Superbright LED lighting.
2013 sun visors.
LED shifter.
Heated seats.
GT-R map lamp lenses.
AV L2 EVSE.

alozzy
Posts: 600
Joined: Fri Jan 20, 2017 4:25 pm
Delivery Date: 18 Jan 2017
Location: Vancouver, BC
Contact: Website

Re: Warning: Defective Konnwei KW-902 on the market

Fri Apr 07, 2017 5:04 pm

Thanks for the warning! I've got the same device and it seems to be fine but I'll definitely check the resistance.

Probably explains these threads too:

viewtopic.php?f=30&t=23721&p=490436&hilit=warning#p490436

viewtopic.php?f=30&t=23767&p=490771&hilit=bluetooth#p490771
Vancouver, CA owner of a 2013 Ocean Blue SV + QC, purchased 01/2017 in WA
Zencar 12/20/24/30A L1/L2 portable EVSE
1-1/4" Curt #11396 hitch
After market, DIY LED DRLs
LeafSpy Pro + Konnwei KW902 ELM327 BT OBDII dongle
Loving my first BEV :D

cwerdna
Gold Member
Posts: 6963
Joined: Fri Jun 03, 2011 4:31 pm
Delivery Date: 28 Jul 2013
Location: SF Bay Area, CA

Re: Warning: Defective Konnwei KW-902 on the market

Sat Apr 08, 2017 12:19 am

Yowza!

Mods: If this isn't a sticky, can we make it one?

Also, if I don't get around to it, can someone add a warning to http://www.electricvehiclewiki.com/?tit ... th_Scanner to AVOID this dongle for the time being?

Anyone who bought one that is causing some major abnormal behavior on the car should post a review on the site they bought it from (e.g. Amazon). If they find the resistance is out of whack, they should also post a review. Some folks may only look at reviews from verified purchases.

Turbo3: Do the pinouts at http://connector.pinoutguide.com/16_pin ... 2_special/ look right? (I quickly found this via Google.)

'13 blue Leaf SV w/premium package (owned)
'13 blue Leaf SV w/QC + LED & premium packages (lease over, car returned)
'06 Prius

Turbo3
Gold Member
Posts: 1799
Joined: Mon Jul 19, 2010 8:34 pm
Delivery Date: 12 May 2011
Leaf Number: 002191
Location: San Jose, CA

Re: Warning: Defective Konnwei KW-902 on the market

Sat Apr 08, 2017 10:27 am

cwerdna wrote:Yowza!

Mods: If this isn't a sticky, can we make it one?

Also, if I don't get around to it, can someone add a warning to http://www.electricvehiclewiki.com/?tit ... th_Scanner to AVOID this dongle for the time being?

Anyone who bought one that is causing some major abnormal behavior on the car should post a review on the site they bought it from (e.g. Amazon). If they find the resistance is out of whack, they should also post a review. Some folks may only look at reviews from verified purchases.

Turbo3: Do the pinouts at http://connector.pinoutguide.com/16_pin ... 2_special/ look right? (I quickly found this via Google.)

The graphic is for the Leaf side. I have added a picture of the OBDII side showing where to measure to the first post.

Turbo3
Gold Member
Posts: 1799
Joined: Mon Jul 19, 2010 8:34 pm
Delivery Date: 12 May 2011
Leaf Number: 002191
Location: San Jose, CA

Re: Warning: Defective Konnwei KW-902 on the market

Sat Apr 08, 2017 10:59 am

mwalsh wrote:Yikes!

Hope you posted this warning in a review on Amazon too?

Not only did I post a review but also sent a note to the seller. The seller contacted me by email early this morning asking for additional information so they are taking this very seriously.

This seller had no way of knowing about this problem (only one positive review) but has responded immediately when notified of it. In my reply I highly recommended they stop selling it until they notify the manufacturer and get a new shipment of defect free adapters.

Of course this has to happen on the adapter I have been recommending :-(

sub3marathonman
Posts: 305
Joined: Wed Nov 03, 2010 11:57 am
Delivery Date: 31 Mar 2012
Location: Bartow, FL

Re: Warning: Defective Konnwei KW-902 on the market

Sat Apr 08, 2017 11:48 am

I'm wondering if there is any danger using a much older Konnwei KW-902. I got mine about 10/2015.

The strange thing is it worked fine for about a year. Then I started leaving it on all the time, because I worried about the On/Off switch going bad. It seemed like within a few months, it stopped working. So I waited a few more months, hoping it would work again. Then I ordered the OBDLink LX, which is supposed to be a high quality unit, at a much higher price. However, the higher price will be offset if it lasts a lot longer.

So, I got the new one, ready to plug it in, and decided, one last try for the Konnwei. And YES, it works again! :shock:

So for at least the time being I've left it plugged in, and on, until it goes out again.

But now I'm wondering, can even the older Konnwei adapter, or any adapter that fails, damage the OBDII network of the LEAF?

chirpyboy
Posts: 28
Joined: Wed Jan 11, 2017 4:30 pm
Delivery Date: 11 Jan 2017

Re: Warning: Defective Konnwei KW-902 on the market

Sat Apr 08, 2017 3:16 pm

Wow, I bought one off eBay recently and had this same problem (paired with phone but sent no valid data... eventual I-key error & T/M System Malfunction).
I returned it for a refund, and bought another off Amazon which works.

I wish I hadn't sent the bad one back already so I could check its resistance. The good one is 120ohm as expected.

ones I bought:
bad: http://www.ebay.com/itm/141978657396
ok: http://www.amazon.com/gp/product/B01LNJ77YI B01LNJ77YI

cliff
Posts: 104
Joined: Mon May 13, 2013 10:36 am
Delivery Date: 15 Sep 2012
Leaf Number: 022673
Location: Federal Way, WA

Re: Warning: Defective Konnwei KW-902 on the market

Sat Apr 08, 2017 4:34 pm

I thought the CANBUS was only terminated at the 2 ends?
Seems odd the diag port would also have a terminating resistor.
The 2012 service manual seems to show the VCM, and BCM as
the 2 units with active termination for the CAR-CANBUS.
I see my adapter also has the termination resistor in it.

Thinking about it, I guess during diags, it is considered better,
to reduce the reflection from the connecting wire, even though
the CANBUS load is increased.

Turbo3
Gold Member
Posts: 1799
Joined: Mon Jul 19, 2010 8:34 pm
Delivery Date: 12 May 2011
Leaf Number: 002191
Location: San Jose, CA

Re: Warning: Defective Konnwei KW-902 on the market

Sat Apr 08, 2017 5:45 pm

cliff wrote:I thought the CANBUS was only terminated at the 2 ends?
Seems odd the diag port would also have a terminating resistor.
The 2012 service manual seems to show the VCM, and BCM as
the 2 units with active termination for the CAR-CANBUS.
I see my adapter also has the termination resistor in it.

Thinking about it, I guess during diags, it is considered better,
to reduce the reflection from the connecting wire, even though
the CANBUS load is increased.

Every node on the CAN bus must have a 120 ohm resistor across the +/- CAN signals right next to the CAN transceiver pins. When you plug in the OBDII adapter you are adding another node which must have one across its CAN transceiver pins.

Return to “LEAF CANBus”