What is iDCCD?

Oct 8, '26

In this blog post we talk about iDCCD - iWire's Driver Controlled Center Differential (DCCD) Controller that is designed for transmission swaps and as an upgrade to the factory STi DCCD.

If you're curious what DCCD is and if your car or transmission has it, click here.

What is iDCCD?

iDCCD is an aftermarket controller created by iWire to allow drivers to control the DCCD in STi 6 speed transmissions. iDCCD works for non STi chassis receiving a DCCD transmission and for STi cars that already came with DCCD from the factory that are looking for an upgrade.

How Does iDCCD Work?

iDCCD receives vehicle information like vehicle speed, throttle position, brake input, etc and uses it to determine how much center differential lock to command. In automatic mode iDCCD handles all of the calculations, you guessed it, automatically. In manual mode the driver can select their settings using OEM STi controls or the iWire App.

iDCCD works for most Subarus of all ages but on supported CAN bus vehicles, it can access information such as wheel speed, throttle position, steering angle, and brake pressure through the vehicle’s communication network. CAN bus allows electronic modules in the car to share information.

This connection gives the controller information about how the car is being driven without requiring a separate wire to every individual sensor. The available inputs depend on the chassis and installation.

Why Would You Want iDCCD?

You Want More Adjustment Than Your Factory Controller Offers

For an STI that already has functioning factory DCCD, iDCCD is an upgrade. The reason to consider it is greater configuration flexibility, including adjustable maps, live data read outs, and app access. iDCCD is useful if you want to tailor the controller’s behavior to a particular driving style or vehicle setup.

You’re Installing a DCCD-Equipped Transmission

A transmission swap includes both mechanical and electrical work. Installing a DCCD-equipped STI transmission does not, by itself, give a WRX or Forester electronic control of its center differential.

iDCCD provides that control with a package designed for the supported chassis. This makes it a practical consideration when planning the electrical side of a swap. Check the transmission first: not every Subaru six-speed has DCCD, and iDCCD cannot add DCCD hardware to a transmission that does not have it.

We don't recommend using the OEM STi controller in a non STi chassis due to the complexities of installing it and getting it to work properly. More about that here.

You Want Controls That Fit Your Build

Depending on the installation, iDCCD can work with:

The iWire Connect app for configuration and control.
OEM Subaru controls for a familiar, factory-style interior.
Custom switches for a custom dashboard or track-focused build.

You can use physical controls for everyday adjustments and the app for deeper setup. Once configured, the app does not need to remain open for iDCCD to operate. Custom switches require appropriate wiring. Learn more about iDCCD Switch Options Here.

You Want DCCD Information in Your Dashboard

iDCCD offers several ways to view system operation, including the app, compatible STI gauge clusters, and compatible digital dashboards.

For a supported 2008+ STI cluster installation, CAN bus communication allows iDCCD to provide the information needed for the cluster’s DCCD display. That is useful for a build where factory dashboard integration matters. However, installing an STI cluster in a non-STI chassis can require additional wiring. Controller installation and cluster conversion are separate parts of the project. Learn more about iDCCD Display Options Here.

You Want an Updateable Controller

iDCCD supports firmware updates through the app, allowing released software improvements to be applied after installation.

That gives the platform room to develop. When comparing features, check what is available for your specific setup today and which capabilities are still planned.