When putting a 5 or 6 speed DCCD equipped transmission into a car that did not come with DCCD from the factory (example a 2007 STi transmission into a 04 WRX), the best solution for getting the DCCD working is with an aftermarket controller. We’ve had customers try to transfer everything from a factory STi into a WRX or RS to try to maintain the factory DCCD but it’s just not worth it due to the complexities of the OEM DCCD system.
To get the OEM DCCD to work in a vehicle that didn't come with DCCD, it would require wiring up the matching ABS unit for the OEM DCCD controller being used, steering angle sensor, G sensors, and yaw rate sensors because the OEM DCCD needs all of these inputs functioning properly to work. For Subaru models with CANbus (IE 08+ WRX), the OEM DCCD wouldn’t even be an option because the addition of the VDC system. The VDC system can't be modified/changed without causing a domino effect of other issues since there are a number of differences between DCCD and non DCCD models.
Instead of doing all of the work of trying to wire up the OEM system, iWire recommends getting an aftermarket DCCD controller like the DCCDPro. The DCCDPro replicates Subaru's ability to adjust the center differential on the fly based on similar inputs as the OEM unit, but without the hassle of wiring in all of the factory components. Plus, with iWire's plug and play model it’s extremely simple to install.
CANbus (CAN) and Your DCCD Transmission Swap
Models that are CAN equipped do not have issues with the DCCD transmission swap assuming that the car came from the factory with a manual transmission (auto to manual conversions are another can of worms) and are using an aftermarket controller to adjust the center diff.
The effect of the CAN system only relates to vehicle speed with a transmission swap. With CAN equipped cars the speed information comes directly from the ABS module via the CAN wiring, so whether the speed sensor is built into the transmission or not doesn't matter.
The only time having a speed sensor in the transmission is a concern is when installing a newer transmission that came from a CAN equipped vehicle like a 2010 STi into a 2002 WRX. In this case the transmission does not have the speed sensor or speed gear built into the transmission which means adding in a VSSPro with iWire Plug and Play Kit. The VSSPro replicates the speed signal by utilizing the wheel speed input from the ABS tone ring, converting the signal type, and sending it into the original speed sensor signal wire to communicate with the ECU and cluster. Learn more about Vehicle Speed Sensors in your swap here.
Still have questions about DCCD in your transmission swap? Contact us!