The Project Pad

The other night, Nick (AMDisthebest) helped me get started tuning my car on VEMS. It ran ok on the base tune on the box after we changed the injector scaling. However, the car would have an erratic trigger error at about 2000 RPM. I am assuming this is because I am using a 7A flywheel. Nick recommended that I first try to update the firmware on the ECU to see if that helps with the trigger error. Today I did as he suggested and everything went wrong. The car would not start with the new firmware and even worse is that VEMStune can no longer detect the ECU at all. I need to revert back to the old firmware and configuration, but I have no way of doing so. I have tried EVERYTHING I can think of to get the VEMStune to detect the ECU and it just will not work.

I am seeing this when I open up VEMStune:


gifs upload

I have run out of ideas and frankly I am very upset with the situation. I currently have an unusable ECU in my car. Please help!

Have you tried calling Marc or posting on the VEMS forum? This isn't the kind of issue you're going to find help for here unless Marc sees it.

This is the kind of thing that you will run into occasionally with a standalone ecu which is constantly in development.

Vemstune opens fine but trying to context screws up, correct? None of the communication settings have changed? I know it's basic but I have to ask. You can fiddle with everything in the communications tab. What about moving your cable to a different USB port?

A few times while trying to communicate with my ecu, I would need to go back into device manager to re-enable the com-usb adapter in its device properties. This occurs randomly upon removal of the adapter from the usb ports. I still don't know why it disables it on its own. I doubt this is your issue but it's worth a brief look as well as different usb ports. hth

There's a few things on vems side..., first if you're on usb and don't have a ftdi usb adapter, get one, older type usb adapter is crap, well drivers for certain random comm disconnections being normal, (max232?) and will get you in a mess among other things.

To reflash firmware, try getting the ecu in bootloader mode, there's a few how to's if you google the vems pages, try forcing it via vemstune.

If that fails then you need to go with reflashing the chip with new firmware and bootloader via avrdude or something similar, you'll have fuses to set and such (been there for unknown reasons in my case, worked, was left on shelf few months, connected to engine harness, dead). Might be easier and cheaper to send it to Marc if you don't have the skills or equip.

There's also the encrypted bootloader that takes like a month to get from vems if you wanna try the latest firmwares, not sure why it took that long in my case but was happily surprised when i got it.

I run on 1.2.11, seems pretty steady cept for needing 2 revolutions to start engine.

If your issue is that the firmware is corrupted there is an easy recovery from this. you just need to get the ecu into bootloader mode. to do this, you can use a "loopback" method on the serial connector. Take a piece of wire or a paper clip and physically connect pin 2 on the vems serial connector to pin 3 (this is with the power on the ecu off and the serial connector disconnected from your laptop. you are looping-back the ecu side). power it up. wait 10 second. remove the paper clip and plug your laptop into the serial connector (leave the power to the ecu on). if you try to connect with vemstune it should now say something along the lines of "detected boot mode". it will ask you if you want to "stay" or "leave". select stay. then upload firmware as normal via vemstune.

hope that helps.

if you get completely stuck you can send the ecu in to my shop and I'll take care of it for you, but there is no reason you shouldn't be able to fix it with the loopback mode.