Fgtech v51 3led can-line not work please help

[giuseppe1374]

Hi guys, I was wondering if anyone is willing to help me, I purchased fgtech "v51" from gocardiag but unfortunately the can-line not work, can you help me?
198296198297

[camil]

You see the 4 resistors marked 000 on the right of the U12, measure them. Problem can be U12 itself too.

[giuseppe1374]

the extent to which you should have? you should also replace U12?

[gezame]

Hi guys, I was wondering if anyone is willing to help me, I purchased fgtech "v51" from gocardiag but unfortunately the can-line not work, can you help me?
198296198297
Hi
I think you K-line, do not going to work well.
Br.

[giuseppe1374]

Hi
I think you K-line, do not going to work well.
Br.
k-line work well I think I replaced the resistor circled in red, but on the whole my problem and can-line
198317

[serdarmsc]

You can try to change U12 (MCP2551)

[giuseppe1374]

I checked the resistance and they are good, I replaced mcp2551i fgtech but still does not work the can line. possible solution?

[ahadi]

I have same problem . i add can filter , it worked but very slow(30 minutes for edc16u1) by can .

any help to make it faster .

thanks

[veloseeped]

I checked the resistance and they are good, I replaced mcp2551i fgtech but still does not work the can line. possible solution?

Before do something try first to work on some another ECU type also using CAN-interface.
Maybe your problem isn't in box hardware but in software protocol realization using for IAW ECU connection.

[giuseppe1374]

I have tried other ECU but I have the same problem, the problem is hardware
I tried 5 different ECU in all can-line, fiat, vw, audi, problem is always the same, no identification, nothing.

[veloseeped]

I have tried other ECU but I have the same problem, the problem is hardware
I tried 5 different ECU in all can-line, fiat, vw, audi, problem is always the same, no identification, nothing.

Than there is nothing you can change or resolder in home conditions.
CAN interface consist of:
Main MCU with firmware -> MCP2551-> 4 x 0 Om resistors -> connector -> external cable.
Red marked elements are still checked.
To change CPU you must have firmware for it - imho it is impossible to optain for free or reasonable price.
As you see left to check your cable only.

PS: And check for broken or short circuit lines on PCB.

[giuseppe1374]

is there a way to know if it mcu problem?

[giuseppe1374]

no one wants to help me?

[camil]

no one wants to help me?

What?

I think we all helped you. Pointed you in direction of where the fault can be, 0 ohm resistors (that can be replaced by can filter as suggested by ahadi), MCP2551 (U12), and finally, once veloseeped have described you the complete interface that holds can communication, the only things that can be faulty are MCU (strange but possible, then trash your unit) and your cable. So don't tell no one wants to help you.

[giuseppe1374]

thanks mate for your clarification! I asked for help and I received, but on the whole I still need help, it is true veloseeped has clarified the situation much, but I'm not convinced that the problem is micro for the simple reason that k-line and bdm-line works perfect if the micro is damaged then it must not run anything, or am I wrong? MCU fgtech are programmed in series so I think it's impossible programming flaw, I wonder why I wanted to say further help, please no controversy.

[mishu_b]

dear

could be broken only the I/Os used for CAN protocol if the rest is ok.
So - could be uC damaged only for CAN and for the rest it works fine - ones again if all other elements on the CAN path are OK.

[camil]

Can be also bad soldering on mcu io pins that manage can communication. Not rare find bad solder joints in chinesse equipment.