Drive by Cable to Drive by Wire Conversion for Subaru

Drive by Cable to Drive by Wire Conversion for Subaru

Apr 15, '21

This blog post describes the basics of how to update cable throttle (drive by cable) to an electronic throttle (drive by wire) in a Subaru. Not sure if your car is cable throttle or electronic throttle? Check here. Unfortunately we can't give a full wiring write-up for this conversion since there are so many variations but we can list the step-by-step basics of what will need to be updated in the car.

If you use an OEM ECU you must also swap the engine to match

This conversion can only happen if the new engine platform is a drive by wire because the ECU must match the engine. When we do the harness merge we will sort out just about everything in regards to the cable throttle to drive by wire setup. You'll just bolt on the bracket and plug it in. This blog post goes into more details about how to pick the correct parts for your project



If you are using a standalone ECU you can swap parts without the restrictions of the stock ECU since it is customizable however you want.

It basically comes down to updating three components:

1. Updating the throttle body

2. Connecting the new throttle body to your ECU

3. Updating the gas pedal


Updating the Throttle Body in a Subaru

The cable for the throttle is attached to the throttle body which is attached to the engine. To update the throttle body in a Subaru is rather simple, it is attached to the new engine being installed. The other piece of this conversion is removing the cable for the throttle from the car which runs from the old throttle body to the old pedal. To do this, simply unbolt the cable by removing the clip that's attached to the pedal and the engine. Then pull the throttle cable out of the engine bay and into the car through the firewall grommet.


Connecting the New DBW Throttle to the ECU

If you've done a merge with iWire than you can skip this step and just plug the harness back into the ECU and the new pedal. If you went a DIY route, then wire up the DBW Relay to the ECU. We can't give specific pin information here because it changes so much between different car models and years. Find a diagram that is specific to your car's model and year for this information. Below are links to common DBW plugs needed for this conversion.


Updating the DBW Gas Pedal

To update your pedal you will remove the two bolts that currently hold it in place and then just pull it out. Then mount our iWire DBW Pedal Adapter Plate into place. (You'll want this bracket because the mounting points for the cable throttle pedal are different than the DBW pedal). Next just bolt the new DBW pedal onto the mounting plate and you're good to go. If you're more of a visual person we have posted our install video below.

Tags: DBW