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

Posted: Sat Apr 08, 2017 5:57 pm
by Turbo3
Would you be willing to open up your new one to see if it has the old or new circuit board inside?

The old one uses separate wires to the display panel.

The new one uses a single flat cable.

(I have no idea why my email address is appended to the end of the quote. I did not put it there.)

chirpyboy wrote: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

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

Posted: Sat Apr 08, 2017 6:14 pm
by cliff
The 2012 service manual shows that when the VCM is disconnected that
measured resistance on the CANBUS side is 120 ohms(seeing the BCM),
but when disconnecting the ABS unit the resistance seen on the CANBUS
side is 60 ohms(seeing both VCM, and BCM). This would agree with terminations only on the 2 ends.
There are 11 controllers on the car-can side, so if each has a 120 ohm
resistor, then the resistance seen would be 11 ohms. This is much less
that 20 ohms, so that adding a parallel 20 ohms would have a small effect
on load (but of course would add a reflection).

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

Posted: Sat Apr 08, 2017 6:39 pm
by Turbo3
cliff wrote:The 2012 service manual shows that when the VCM is disconnected that
measured resistance on the CANBUS side is 120 ohms(seeing the BCM),
but when disconnecting the ABS unit the resistance seen on the CANBUS
side is 60 ohms(seeing both VCM, and BCM). This would agree with terminations only on the 2 ends.
There are 11 controllers on the car-can side, so if each has a 120 ohm
resistor, then the resistance seen would be 11 ohms. This is much less
that 20 ohms, so that adding a parallel 20 ohms would have a small effect
on load (but of course would add a reflection).

Yes, you are correct. I should have said every ending node.

Almost all OBDII adapters have a 120 ohm resistor. Exceptions I have found are ones by GoPoint, PLX, Vgate and the Consult 3+ which have no resistor.

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

Posted: Sat Apr 08, 2017 7:12 pm
by chirpyboy
Turbo3 wrote:Would you be willing to open up your new one to see if it has the old or new circuit board inside?

The old one uses separate wires to the display panel.

The new one uses a single flat cable.


Sure. Just checked and my new one has separate wires.

I had actually opened the bad one before returning it, because I heard something loose inside thinking that might be the problem (it was a tiny ball of solder). I remember it looked different and had a little flat ribbon cable.

Turbo3 wrote:(I have no idea why my email address is appended to the end of the quote. I did not put it there.)


This forum seems to do some hiding of Amazon links; somehow it sucked in your email? :?

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

Posted: Sat Apr 08, 2017 8:07 pm
by Turbo3
So it might be that all new manufacture with the new circuit board and the flat cable have the 20 ohm resistor.

This is pointing to a basic manufacturing error in the use of 20 instead of 120 perhaps on the assembly instructions or a miss read of the documentation used to load up the parts.

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

Posted: Sun Apr 09, 2017 9:04 am
by tbear2001
Bought this a few weeks ago based on LeafSpy recommendation, but it would never stay connected so I tried another brand BATX. I just checked and it has the 20ohm resistor and I opened it up and it has the flat ribbon cable. Returning today to Amazon as defective.

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

Posted: Sun Apr 09, 2017 4:25 pm
by Snlj
Confirmed! The replacement Konnwei KW902 scanner I purchased to replace my previous, malfunctioning unit only shows 20 ohms across the two pins you highlighted in your picture. Thank you for finding this out! I'll get this returned immediately.

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

Posted: Mon Apr 10, 2017 6:49 pm
by AdamFist
This thread was helpful and timely since I received my Konnwei KW902 yesterday. I'm returning it to Amazon. In the meantime, does anyone have a recommendation for an alternative ODB2 scanner that works?

Thanks,
Adam

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

Posted: Mon Apr 10, 2017 10:25 pm
by Turbo3
AdamFist wrote:This thread was helpful and timely since I received my Konnwei KW902 yesterday. I'm returning it to Amazon. In the meantime, does anyone have a recommendation for an alternative ODB2 scanner that works?

Thanks,
Adam

The currently available test version of LeafSpy Pro supports the newer Bluetooth 4.x LE as will the next official releases of all versions of LeafSpy which I hope to start rolling out within the week.

There are two supported Bluetooth 4.x LE OBDII adapters. The LELink and the PLX Kiwi 3 with the LELink from Amazon being the cheaper of the two. The LELink is what I use and works with the iOS version of LeafSpy and will work with the next release of the Android versions of LeafSpy.

Bluetooth 4.x LE being a low power adapter will result in less drain from your 12v battery when the Leaf is off. There is also no pairing required.

Anyone with the Android version of LeafSpy Pro can try the latest test version using this link.
https://play.google.com/apps/testing/com.Turbo3.Leaf_Spy_Pro

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

Posted: Mon Apr 10, 2017 10:41 pm
by Turbo3
AdamFist wrote:This thread was helpful and timely since I received my Konnwei KW902 yesterday. I'm returning it to Amazon. In the meantime, does anyone have a recommendation for an alternative ODB2 scanner that works?

Thanks,
Adam

I forgot to ask. Are you returning because it measured 20 ohms or just because it is a Konnwei KW902?

If you don't have an ohm meter you can tell if it is new manufacture by opening it up and seeing if it has a flat cable to the top display board. If it is new production it is probably bad. Measuring 20 ohms is of course the gold standard for defective.