SI-Drive or Subaru Intelligent Drive is a button that changes engine computer mapping and the transmission computer mapping if the car is equipped with an automatic transmission. The engine computer will change the throttle response and target boost to maintain fuel efficiency. There are three different settings.
Sport - This is the default position for the system every time the car is turned off and back on again. The engine settings will be in the middle of the
Intelligent - When selected, intelligent will be put in the most fuel-efficient setting, which causes slow throttle response and reduces the target boost.
Sport Sharp - Move the switch to Sport Sharp for maximum boost and the quickest throttle response.
How does it work?
The SI-Drive switch is a basic resistance-based momentary switch. When the mode is selected, the analog signal is sent to the cluster and is slightly different for each setting. For the 2008-2014 models, the cluster picks up this analog signal and transmits it to the body module via the low-speed CAN network. The body module picks up this input and resends the message to the ECU via the high-speed CAN network since the ECU does not communicate on the low-speed network. Based on this message, the ECU will switch between the three maps (Sport, Sport Sharp, and Intelligent).
The same basic scenario applies to the 2015 and newer modules, where the momentary switch sends the analog signal to the cluster, and the cluster transmits it to the rest of the car. Since the cluster is on the high-speed CAN network, the rest of the modules, including the ECU, can see it without the intermediary of the body module.
For those looking to remove the original cluster for a digital dash, several issues can happen due to this change. SI-Drive would be lost because the analog to CAN conversion process through the cluster is removed. At this time, we do not have a solution for this problem. Theoretically, if you use a standalone ECU, additional analog inputs could be used directly from the switch to get the map-switching feature to work.
Please click this link for more about what it takes to switch to a digital dash.
WRX Models Without SI-Drive
Although it's plausible that if the SI-Drive switch was wired into an STi cluster and the STI ECU was swapped over, then it could be a possible addition. We haven't seen anyone successfully do this at this time due to the complexities of the CANbus system found in the models with SI-Drive as an option.
For more about CANbus, please click here.
DCCD Switches with the SI-Drive Controller
If you have a 2008+ WRX with a DCCD transmission swap. You can utilize the SI-Drive switch panel type even if the SI-Drive knob doesn't function. Please take a look at the DCCDPro with iWire Plug-and-Play kit.
We also carry replacement connectors to the panel, which might be helpful depending on your project.