Can't Flash ECu When its Cold Out??
 

I have noticed something odd happening. I can't flash my ECU when its really cold out. For example it has been around 30-40 degrees recently and when I try to flash my ECU it does not respond to the INT codes. However, if I start the car up and let it warm up blasting the heat on the foot well area, after a few min of that, I can flash the car.

At first I didn't really think this was possible but after testing several times I have found that in fact it seems to be the cabin temp that stops the ECU from flashing.

Has anyone else experienced this?

I use a tactrix cable and ECU Flash 1.29

Lower the "Min Temp for Full Flash Control" value ...

I've never tried to flash in that type of weather, so i can't give any real input. it doesn't make much sense though ... does temp really affect electrical current?

No, but temp does affect battery output.. Much of the issues like this have to do with the voltage required to trigger the flash init.. Its even more pronounced if your also trying to power your laptop from the cigarette lighter.

I do have a mini battery, but I never have any trouble starting the car. It certainly does not crank the engine like it does in summer but it starts fine. I was not powering my laptop from the cig lighter.

So you think the issue is not the temp of the ECU but rather the temp of the engine compartment and the battery?

That makes sense Jack ...

Yep, low battery voltage is the #1 reason why you can't init the ECU to read or reflash. The evo9 ECU is VERY sensitive to voltage.. the 8 ecu doesn't seem to be as picky, but on a cold day it can happen, especially a mini battery.

I had issues flashing so now I only flash with the car running. Start car.... start flash.... car will shut off.... car will flash.... Works like a charm in every condition every car.

Thats a great idea, I am gonna try that. its really annoying right now to have to wait for the car to warm up first.

Jack - is their any danger to doing this?

I use a battery charger in winter or with repeated flashing, not ideal if away from power. I have a spare ECU in case one only partly programs and I would otherwise be stranded!

Colby says that the way the flash voltage is produced is a bit marginal on the IX as the chip seems to like a higher voltage. A redesign of the cables would sort it I gather.

Tactrix does have a new cable out

warming the car up first is a better idea. Triggering a reflash while its running likely won't hurt anything, but I personally wouldn't do it, or recommend doing it. by far the best option is to put a battery charger/booster on the battery if you can.

Lucas and I ran into this last winter. Here are the tricks for a refresher:

Start car long enough to get Evoscan to connect and initialise.
Turn car off and then flash.

Its something about the ECU needing to be a certain temp as well as the battery voltage being a certain level. Lucas had the unfortunate circumstance of getting halfway through a flash with a cold car that sat out in december failing to flash and then not starting. 30 minutes inside the shop with a heater in the car, a quick reflash, and it was all good. Warming the car up good beforehand will also do it but if you are in a rush the method I listed works.

You mean "Min Temp for Full Boost Control"?

That is for boost, not anything to do with the OP question. :)

It seems to be a IX thing.

I have had a few IX that need to be above 50deg in the cab to get a flash done.

When it 1st did it to me like Aaron said it scared the crap out me. To start I could not down load the flash. Well I got the car just warm enough to download and started loading up the new flash and 1/2 way through it stopped and the car would not start. I tried a few more times to upload the flash with no luck. Good 30min in the shop and it loaded up fine.

I think he was joking.