FAULTY ELM 327 INTERFACES DE-MYSTIFIED (READ HERE)

[blkid]

Cxem, do you tested the can lines? They work? Because i have some suspicion on the resistance R27 between the 2 lines. In theory it should not be present, but there should be only R24-C18 and R25-C19.

[cxem]

CAN-Line, I can't check.
R27-120om; R24-100om; R25-100om.

[Waltomatic]

As expected, pins 4 and 5 are shorted. There is no impedance between pin 2 and 10 and between them and the negative (2-4,10-4), even with a full scale of 200MOhm, therefore, even if there is a wire connected, this does not lead to anything. I do not know what else to do besides return

I can check tonight the values of my Silicon Labs, which usually use in Mareas (Bosch Motronic ME3.1 and Aisin AT), Palios (Marelli IAW series) and GM Celta 2008 (Delphi Multech). It might help you.

[blkid]

CAN-Line, I can't check.
R27-120om; R24-100om; R25-100om.

R24 and R25 (in series with C18 and C19) are the standard for elm327 circuit for CAN but, ever on the elm327 schema, the R27 of our scanner there must not be (between the other is just 120 ohms!). You can see these on the elm327 diagram that i posted above.


There is always the question that is lost time. If the alfa 159 ECU communicates through J1850 is just a waste of time, since this scanner does not phisically implement this standard. At most, if the CAN line become functional (removing R27), it could connect to the auxiliary ecu (BCM, ecc).

[Waltomatic]

Why, I am not expert in the protocols, but as Yani (Supported Vehicles) ALL 159 models communicate by ELM AND KKL, therefore should not use the J1850 ...

[blkid]

Ok, on this link is reported that fiat bravo 1.9jtd 16v 150HP ECU use KWP FAST protocol:
http://pinoutsguide.com/CarElectronics/ ... nout.shtml

The KWP FAST protocol is on the K-Line, pin 7: http://www.obdtester.com/obd2_protocols

If you see in the first link, no fiat ecu use J1850 but all on K-line and newer on can. Fiat bravo and alfa 159 uses the same ecu Bosch EDC16C39 CF4/EOBD.

I still doubt of those additional components on the k-line which I reported in the post above. On the real ELM327 those components are not present. We should try making the change in the photo attached for K-line and remove R27 on the CAN Line.
I still can not try because i'm waiting for a possible refund.

[Waltomatic]

Exactly, you do not need nothing but pins 4-5, 7, 15 and 16 (as in my pict of VAG). So I think that would not be necessary to remove any resistor. I begin to believe possible interface defect. Anyway I can test the resistance in mine and report later.

[cxem]

Google:-CAN bus 120 Ohm resistor

BK3132Q/pin51 - signal is rotated 180

[blkid]

Sorry cxem but i'm not very expert in electronics. I just compared the real elm327 reference schema with our clone scanner schema and reported the differences. Now i don't know what they cloned, but if the plc is equivalent and the software is cloned from elm327 probably also the hw must be the same. In the reference elm327 the proper CAN termination is to use 100 Ohm resistor on each of the 2 lines connected to ground through a 560 pF capacitor, without any bridge resistor (the R27 120 ohm). Same goes for the k-line and the components that I think are too. But if the terminations of lines are all good, the problem is a flawed software, probably very bad cloned and the only thing i can do is throw it in the garbage if i not obtain a refund!

[Waltomatic]

Exactly, you do not need nothing but pins 4-5, 7, 15 and 16 (as in my pict of VAG). So I think that would not be necessary to remove any resistor. I begin to believe possible interface defect. Anyway I can test the resistance in mine and report later.

Well, there you go...

2-4 = 31 kohms
2-10 = 435 k
4-10 = nothing
2-6 = 1.1 M
2-7 = 100 k
2-14 = 1.1 M
2-15 = 100 k
2-16 = 87 k
4-6 = 1.05 M
4-7 = 67 k
4-14 = 1.05 M
4-15 = 69 k
4-16 = 55 k


* Checked and rechecked