openecu.org

Another user has his car immobilised because he gets "no response to any known code" following a flash that reported OK but the car won't start. There was a change to the ROM combined with an upgrade to 1.29 on an old 1.3M cable. The recovery vehicle managed to read an OBD code with an immobiliser fault, but the immobiliser codes were matched in the ROM image. They tried a reprogram with a battery booster on too - still the same. Another user is going to visit him with a different laptop and cable.

I wanted to investigate the change to the ROM on my car, but I find with an old 1.3M cable that I either get no response to any known code, or that it got so far just reading the ROM:

http://john824.fotopic.net/p38025725.html

It is quite cold, battery voltage is 11.5V but my car starts easily and I've successfully flashed before using my newer Universal cable. Unfortunately at present my Universal cable is lent out, and the 1.3M I have is from another user who was having problems with this cable. Initially it worked, now the problem is as above. I don't have a battery charger handy.

Could there be a temperature or voltage issue with the earlier cables?

When I get my Universal cable back I will try again, and make sure I can do 100% successful reads and compares before trying a write to be sure.

Same problem on my recent 1.3 universal cable which has worked with the same car, same ECU, same laptop before.

I think it must be the cold weather making the battery voltage too low?

After a run in the car the battery voltage was healthier and I can read and compare OK a few times, then the battery voltage drops just below 12V and I start to get errors.

So the moral is at least for JDM/UK IX - if it is near to freezing check your battery voltage or a failed write could leave your car immobilised. Ideally take it for a run and get the battery charged and the underbonnet temperatures up a bit.

The immobilised car has also been fixed by charging it and flashing again.

That would explain why it is recommended to turn off all electricals (including interior light) and trickle charging.

I never flash my rom without a battery charger hooked up.. because anything under 12v and electrical equipment in the car will start to fail.
sitting in the car with the ignition on for 5 minutes can drain it to under 12v