Subaru ECU Re-Flash

I am currently doing Subaru ECU Re-Flash using 'open source' for Subaru vehicles (OBD2 equipped WRX and STI,year 2000 and above).The Re-Flash will be done using Tactrix Open-Port 2.0 as shown below. A brief introduction to ecu reflash is written below, i only write some basics just to give an insight on this process.

What is a ECU Reflash?

ECU reflash is a way of tuning our stock factory ecu using a dedicated software to read and re-write (this process called reflash) certain parameters and maps inside the ECU. ECU reflash is the most cost effective way of tuning our ECU as there is no need to pay for expensive standalone ECU and installation charges. There downtime on your car, just connect the device to your OBD2 port and start tuning.

Which Subaru model can be Reflashed?

Basically all Subaru with HC16 or SH2 processor can be reflashed.

What is the ECU Flash software?

ECU Flash is a software used to read and write 'maps' to your factory ecu. It also allows user to edit parameters and maps as a process of tuning. The parameters and maps read from the ecu is called ROM image or simply,ROM.

Ecuflash software

Shown here is the fuel and ignition timing map,this map can be adjusted just like any other stand alone ecu. Beside this,there are a lot of other parameters and maps can be accessed for tuning such as AVCS (valve timing),MAF scaling,injectors,idle,compensations etc.

The advantages of tuning the factory ecu is we will not sacrifice drivability and tuning is quick as most parameters is already set from factory, factory ecu also have safety features that the manufacturer have develop to safe guard our engine such as knock control and limp home mode if sensors fail. Our Subaru factory ECU is very intelligent and can adapt with new changes quickly and learns the changes over time.

What are the tools needed?

Basically, for open-source reflash, we need a Tactrix Open-Port cable,a reflash connector and the EcuFlash software. One more software can be used to make changes and the most popular for Subaru Open-Source tuning is Romraider. Other tuning tools is Wideband O2 sensor and a dynamometer (where accessible).

What is Romraider?

Romraider is a software developed to tune our subaru ROM after being read using the EcuFlash software. It will allow user to change the parameters and maps and also to log the ecu data while driving the vehicle. ECU data logging is  very very important in tuning our vehicle. Through ecu logging, we can verify whether the tune that have been made is good or safe to our engine. We also can check our engine health through logging and check for problems by viewing various data.

On the next installment i will talk about some parameters inside the Subaru ecu.