FAULTY ELM 327 INTERFACES DE-MYSTIFIED (READ HERE)

Multiecuscan usage help and guides
SiC
Posts: 1
Joined: 06 Jul 2015, 15:36

Re: FAULTY ELM 327 INTERFACES DE-MYSTIFIED (READ HERE)

Post by SiC »

Anyone know where to get a real ELM327 Bluetooth V1.5's - rather than the 'new' chinese V2.1?

I've bought a whole load of different looking ones from eBay and Chinese retailers - the ones labeled as v1.5 seem to be all v2.1... :evil:

Don't really want to spend big bucks on a scantool.net lead and I really want bluetooth.

Cheers.
Alfaeddy
Posts: 1350
Joined: 19 Feb 2011, 17:43
Location: Germany , Aarbergen

Re: FAULTY ELM 327 INTERFACES DE-MYSTIFIED (READ HERE)

Post by Alfaeddy »

Hello

this one
and without the bridge Resistor

http://www.ebay.de/itm/151635712678?_tr ... EBIDX%3AIT

Greetings Eddy
Vic20
Posts: 3
Joined: 07 Jul 2015, 11:36

Re: FAULTY ELM 327 INTERFACES DE-MYSTIFIED (READ HERE)

Post by Vic20 »

Hi all,

My first post here as new to Multiecuscan but an electronics engineer by trade.


Been trying to figure out why this resistor across the CAN bus lines can possibly be a common issue with many of these devices.

It looks like Most of the problematic devices use the NXT TJA 1040T chip as the CAN transceiver.

http://www.nxp.com/documents/data_sheet/TJA1040.pdf Here's the datasheet for this device

I think the problem all along is that the datasheet has been initially misinterpreted / badly translated. If you look at page 8 you will see a circuit describing "Stabilization circuitry and application" This shows two 60 ohm resistors in conjunction with the 'SPLIT' pin of the chip. This is a suggested circuit to reduce Radio Frequency Interference problems. The designers of these ELM boards have made a short cut and used a single 120 ohm resistors and completely omitted the SPLIT part. WRONG!!

Why I think the interface still works with the resistor in place on some vehicles but not on others depends on the actual CAN voltages that the vehicles ECU's can cope with. The TJA 1040T, the datasheet tells us, can cope with a range of -27 to +40 Volts! The 120 ohm resistor will have the effect of suppressing any signals coming in and going outon the CAN bus. Some vehicles modules will be able to cope with this (I bet the resistor has the potential to get quite warm at times), others clearly don't.

This makes me think that the resistor could be quite safely 'taken out' by temporarily putting a DC voltage between pins 14 and 6 of the OBD plug on the device without even having to open it up! :D

I'd suggest 12v would give one eigth of a watt resistor 1.2 watts which should be more than enough to shorten its life to a couple of seconds. Anyone willing to give it a try :?:
Dortmunder
Posts: 2
Joined: 11 Jul 2015, 07:57

Re: FAULTY ELM 327 INTERFACES DE-MYSTIFIED (READ HERE)

Post by Dortmunder »

Hallo

Möchte gern auf mein Fiat Stilo BJ2002

den Wiederstand habe ich ausgelötet aber bekomm keine Daten

Bitte um Hilfe Help :-)

COMMAND: ATZ
RESPONSE: ELM327 v1.5
>

COMMAND: ATI
RESPONSE: ?
>

COMMAND: ATE0
RESPONSE: ?
>

COMMAND: ATL0
RESPONSE: ?
>

COMMAND: ATH0
RESPONSE: ?
>

COMMAND: ATSPC
RESPONSE: ?
>

COMMAND: ATS0
RESPONSE: ?
>

COMMAND: ATCAF0
RESPONSE: ?
>

COMMAND: ATCFC0
RESPONSE: ?
>

COMMAND: ATCRA 7B0
RESPONSE: ?
>

COMMAND: ATSH 7B0
RESPONSE: ?
>

COMMAND: ATAT1
RESPONSE: ?
>

COMMAND: ATST41
RESPONSE: ?
>

COMMAND: ATBI
RESPONSE: ?
>

WARNUNG: Dieses Interface ist nicht Kompatibel mit ELM 327 1.3! Keine Verbindung zu CAN Modulen möglich.


Image
Image
Image
paulik
Posts: 2
Joined: 11 Jul 2015, 20:16

Re: FAULTY ELM 327 INTERFACES DE-MYSTIFIED (READ HERE)

Post by paulik »

Hi there,
it is not in human abbilities to read all posts so I ask here.
i have Fiat Stilo 1.6 and I bought a cheap ELM327 bluetooth interface v1.5 (yea its fake because official ELM 1.5 is not exists).
But I tried it on Renault Thalia it worked, but on my Fiat it works strange. Multiecuscan claims that interface is not compatibile with 1.3+ but on SerialPortTerminal I have response OK, ELM327 1.5 and so on from adapter .(cmd ATI,...). I remove resistor between CANH and CANL and add components 100ohm and 560pF but still strange. In Torque android application I see proper value every each e.g. 5s for short time and then it shows unreliable numbers (-64.125 rpm, -41°C coolant temp.) I see that CAN chip interface is TJA1050 not MCP2551. What is the problem?
Foto http://s13.postimg.org/whp0pr2mf/20150711_194730.jpg
Image
Alfaeddy
Posts: 1350
Joined: 19 Feb 2011, 17:43
Location: Germany , Aarbergen

Re: FAULTY ELM 327 INTERFACES DE-MYSTIFIED (READ HERE)

Post by Alfaeddy »

Moin Dortmunder

Das Motor-, ABS-, Lenkungs ECU werden beim Stilo nicht über CAN Bus gelesen
Daher ist der Brückenwiderstand auch nicht dein Problem

Es ist so das dieses Interface gar nicht funktioniert es hat eine
geänderte Software auf dem PIC gebrannt und die kommt mit MES nicht zurecht.

Die im MES Test angezeigen v.1.5 und v2.1 laufen nicht mit MES

Zudem hast du extrem schlechte Bilder gemacht darauf kann ich nichts erkennen kann

Spielt aber nun keine Rolle mehr :?

Gruß Eddy
Alfaeddy
Posts: 1350
Joined: 19 Feb 2011, 17:43
Location: Germany , Aarbergen

Re: FAULTY ELM 327 INTERFACES DE-MYSTIFIED (READ HERE)

Post by Alfaeddy »

Hello Paulik

This is about Multiecuscan and Italian vehicles (technology)

Whether your interface in the Renault with any software works
Has nothing to do with the topic.

Your Stilo has the engine ECU ABS ECU, steering ECU not with CAN Bus
to read, so no resistor must be removed for this.

Greeting Eddy
Dortmunder
Posts: 2
Joined: 11 Jul 2015, 07:57

Re: FAULTY ELM 327 INTERFACES DE-MYSTIFIED (READ HERE)

Post by Dortmunder »

moin Alfaeddy

deine info ist mir ja bereits bekannt
abs motor und Lenkung komm ich mit einem kkl Interface dran wo die KkL Leitung für die verschiedenen bereiche auf die verschiedenen pins kommt

Ich wollte sber mit dem elm modul auf die anderen bereiche PDC Body Computer ect

gibt es da vielleicht noch ein anderes modul?
Alfaeddy
Posts: 1350
Joined: 19 Feb 2011, 17:43
Location: Germany , Aarbergen

Re: FAULTY ELM 327 INTERFACES DE-MYSTIFIED (READ HERE)

Post by Alfaeddy »

Dortmunder wrote:moin Alfaeddy

deine info ist mir ja bereits bekannt
abs motor und Lenkung komm ich mit einem kkl Interface dran wo die KkL Leitung für die verschiedenen bereiche auf die verschiedenen pins kommt

Ich wollte sber mit dem elm modul auf die anderen bereiche PDC Body Computer ect

gibt es da vielleicht noch ein anderes modul?


Moin

Ja gibt es ,

http://www.ebay.de/itm/151635712678?_tr ... EBIDX%3AIT

Bei diesem ist auch der Brückenwiderstand schon entfernt.

Wir haben wieder mal eine Zeit in der viele neue Versionen von ELMs auf den Markt kommen
mit geänderten (oder geclonten PICs) nur ist es leider so das diese Versionen nicht mit MES
laufen.

Ist wohl so ähnlich als vor einigen Jahren die v1.3 ELMs geändert wurden die haben auch nicht funktioniert.
Nur da war es "nur" ein Widerstand

Gruß Eddy
paulik
Posts: 2
Joined: 11 Jul 2015, 20:16

Re: FAULTY ELM 327 INTERFACES DE-MYSTIFIED (READ HERE)

Post by paulik »

Hi / Guten tag / Gruss Gott :)

I think that I have the same circuit as Dortmunder, but with other PCB layout.
I wrote that I have removed 120 Ohm resistor between CANH and CANL, and also I have added termination to each line 100R+560pF to GND .
So how to test if software is OK when I removed 100 ohm resistor, or what HW or SW modifications/settings can I do ? I have also KKL cable, but I need to access CAN / body computer and Air conditioning.
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