How to Flash a Car Computer

Flashing your car's computer, or ECU, will open up many performance gains that are often restricted at the factory for various reasons. Manufacturer's often under-run car engines to help increase their lifespan and fuel economy. If you want to add some more power under your hood, an ECU flash is a quick and inexpensive way to increase the output of your engine.

Step 1 Download and install EcuFlash from OpenECU (see Resources). This freeware program works with most cars and provides access to information stored in the car's computer, including the ability to flash a new image onto the computer. Install this program on a laptop computer if possible so you may take it to your car.

Step 2 Connect your computer to the car's OBD-II port with an OpenPort cable. Be sure to obtain the OpenPort cable designed for your make of car. This cable allows your laptop to connect via USB to your car's computer.

Step 3 Open EcuFlash and click on the folder icon at the top of the screen. Choose the new computer image you wish to flash to your car's ECU.

Step 4
Click the "Write to ECU" button in EcuFlash. When prompted, turn on your car's ignition to the accessory position (do not run the engine) and click "OK." The new ECU image will be uploaded to the computer in your car.

Turn off the car's ignition after the flash is complete and you are prompted to do so. Click "OK" to confirm.

Tip: You can do much more than just flash your car's computer with EcuFlash. It is also useful to run diagnostics and tweak the current computer settings.

Warning: Flashing your car's ECU will terminate your warranty. Do so with caution.

Items you will need: Computer with Ecu, Flash software, OpenPort cable