ECU to Laptop connection issues

[young_un1]

Hi there,
           I have been having some communication problems between my ecu and the laptop. I have checked that they are both using the same port but keep getting a "no response" message when testing the connection. Having read some other people's issues with the same problem it would appear that the usb to serial adapter is causing a bit of a headache across the board. I'm using version 1.0.69 of megatune. I'm assuming I probably just need to find a serial cable to fit straight into the serial port on the laptop to be sure that's what the problem is, yes?

Any other suggestions would be gratefully received?

Have a good weekend everyone,
                                           Al.

[rob@vems.co.uk]

Alan,

You should be using the MegaTune that comes with 1.1.18:
http://www.vems.co.uk/VEMSInstalls/VemsMT1.1.18Nissan.zip

If you have a serial port on the laptop then use that every time, you need a 'straight-through' RS232 cable - that is pin2->pin2, pin3->pin3 and pin5->pin5

[young_un1]

Hi there,
           Thanks for the help, although sadly it doesn't appear to have changed matters. I have now tried with a laptop that has a serial input but i still got the same message of no response. Hmmm....not really sure where to go from here. I'm assuming that there's no coding that is required at this early stage...in theory at least? I've also tried messing around with different port numbers to no avail...

[young_un1]

Have just been checking connections etc and there's continutity from the serial input to the vems unit so that rules out an ill functioning serial wire...

[s14nismo]

The way i got mine talking was; open the vems software, open the megatune folder then mtCfg, then there should be a file called "megatune.cfg" open it with notepad and the first line of text will tell you the com port it is using.
 I left this as it was then plugged in the usb/serial converter, opened the device manager on the pc, look in ports (COM &LPT), right click on "USB Serial port" open properties then port settings, click advanced, then change the COM port number to whatever the megatune file stated! (i ignored the warning about sharing ports etc.)

 It worked for me so might be worth a try.

[young_un1]

Sweet, I will give that a try tomorrow. I was disappointed with myself for falling at the first hurdle but hopefully your method may resolve my problem. Many thanks:)

[rob@vems.co.uk]

I'm not trying to be a prune here, but double check that 2&3 are not crossed or shorted.
And if you check Nismo's thread I've written a few words on how to use the Serial port program: Terminal to see if you have a good connection.

[young_un1]

The saga continues....

Ok, tried your method Nismo, as well as varying combos, and had no joy sadly.
Tried the terminal program too. It said connected and would transmit but wouldn't receive. i was typing "Man" as suggested by rob. I assume that's the test code as it were? I checked the settings at the top of the page and it was all as suggested in Nismo's thread. Hmm...
Had a gander inside the serial cable too - there's no apparent shorts and the earth wire is making a good connection. The Tx and Rx wires do go to the right pins on the serial and the econoseal connector.

As the tree said to the lumberjack....I'm stumped....

[young_un1]

Also meant to say that I got a random warning message that may shed some light on the situation: It only happened twice but it said:

Controller code version does not match signature in vemsv3.ini (see audit.log for where the above file was found)
Expected " vems v1.1 12x12 kpa = 2,2" (found in ini file)
Received "0x51" from controller table" Table corruption may occur. This is usually serious.
Terminate?"

I was worried to say the least....

[Bat]

Hi,
I've seen that one too
It's basically telling you it's the wrong MT for your ECU.
Have you changed the firmware in the ECU since you've had it?
Mine came with something like 1.0.53 in it, I had the same problems as you until I used an "old enough" MT
Cheers,
Gavin

[young_un1]

I haven't changed the firmware as I only began trying to connect it a couple of days ago but I've been using the version recommended by rob (1.0.89 off the top of my head). Can you remember what version it was that worked with yours please?

It's also stopped asking me which table I wish to select (12x12 etc) Is this a syptom of anything in particular?!

Cheers for the help:)

[Bat]

Hi,
Just checked mine was 1.0.53, it came direct from VEMS.
If yours came from Rob he may have upgraded it for you?
Try 53 won't hurt, I just kept trying different ones till I got it talking.
You do have to be using the correct com port though or you'll never get it talking.
You'll need to change the com port number in each version you try
Cheers,
Gavin

[young_un1]

Cheers mate, I will give that a try tomorrow. Hopefully it'll have stopped raining by then!

[rob@vems.co.uk]

The Nissan trigger only works with 1.1.18 firmware, the link in the previous posting gives you the zipped software.

Those messages do indicate that the VEMS and Laptop are communicating, as the signature from the VEMS is being read when asked for.

You will want to select 12x12 High Boost for your setup.

BTW 1.0.53 is in serious need of an upgrade to 1.0.73, they seem to shove on any old firmware for testing in Hungary.

[Bat]

BTW 1.0.53 is in serious need of an upgrade to 1.0.73, they seem to shove on any old firmware for testing in Hungary.

Hi,
That's what made it difficult to start with, I never expected to need a version that old! 
Running 1.0.73 now
Cheers,
Gavin