03 USDM WRX reflash issue

Has anyone figured out the issue for the 02-03 USDM wrx flash mode problem? My tactrix cable works fine and the green connectors are connected and the flash block is in. Sometimes it works just fine, but sometimes I cannot get it to go into flash mode at all! I get a flashing CEL and fans cycling. Any ideas?

Tausha,

Make sure you have sufficient battery voltage, and voltage to your ECU.

Confirm ground connections are also proper.

If that's all good, then check input voltage to the flash block.

If it's not sufficient, which is often an issue on those old ECUs, you can externally supply proper voltage to enter flash mode. 2-3 volts instead of 12 is something I've seen many times.

When you are ready to read or flash ensure the ignition is set to off position, click the read or flash button in ECUEdit and a dialog will pop up with an OK button, click the button with one hand and turn the ignition to ON with the other so that the ignition is turned to on as soon as that button is clicked. That should be your standard process when reading or writing and you shouldn't running into the unable to communicate/read/write error.