CANBus Part 2 - CAN Bus and your Subaru Swap

CANBus Part 2 - CAN Bus and your Subaru Swap

Apr 15, '21
If you missed it, check out our Part 1 CANbus post that explains what CANbus means and which cars are CAN bus equipped. In this post we discuss how CANbus will effect your Subaru swap and ways to work with it.

Here's our owner Brian talking a bit about the realities of swapping with CANbus platforms.
Non CANbus Engine into a Non CANbus Car

These swaps are our specialty and are very simple to complete. There are some engines that are easier to swap but from a wiring perspective, we can tackle these easily. For those on a budget we recommend doing this swap over a CANbus equipped swap.


Non CANbus Engine into a CANbus Car

These swaps depend on the model of the car. One option is to gut the wiring harness and turn it into a race car and effectively eliminate the CANbus system. The other way to do it is to use a standalone ECU like Haltech that has the ability to communicate with the Subaru CANbus system up to 2014 as well as run the new engine. This will keep the CAN system happy on the car side and allow for more options on types of engines to run.


CANbus Engine into a Non CANbus Car

For this type of swap a standalone ECU can be utilized or depending on the model of engine the CANbus ECU can be replaced wit ha non CANbus equivalent. An example of this would be a 2010 WRX engine that could be run on a 2007 WRX ECU. Click here for a great resource for this.

Another option is something called a CANbus emulator. This is a module that would go onto the CAN line and recreate the ID's the ECU needs from the missing modules. We've have some prototype CANbus emulators working in a 15 WRX swapped 99 OBS (picture at top) and a few other cars including an 08 STi powered 02 WRX and a 3.6 6 cylinder in a 98 RS, but we're still working out some issues so we'll keep everyone posted on developments.

The other piece to consider when doing these swaps is the immobilizer system since the gauge cluster is part of the immobilizer circuit on CAN Bus equipped cars. We can wire the cluster up for this but the fitment isn't great and there are a lot of features you won't be able to use because the rest of the CANbus features of the original car are not communicating with the cluster. This is also something we plan to address with the CANbus emulator.

Keep up with progress on the OGRSTi, which is our GC swap with a 2018 STi engine on YouTube.


CANbus Engine into a CANbus Car

As of right now these swaps are purely a case by case basis because other than using a standalone ECU and treating the engine much like a non CANbus engine in a CANbus car (see section above), there really isn't a good option. The only viable option to run an OEM ECU at this point is to transfer the entire turbo car over (ideally a similar model year like 08 WRX donor into an 08 Impreza non turbo or 2006 Legacy GT into a 2006 Legacy non turbo) in parts and modify the harness where it meets the original non turbo chassis. As a byproduct of these issues, we currently do not recommend this swap. 

Note - We no longer build harnesses for standalone ECUs but there are plenty of companies that do.

CANbus Auto to Manual Swap

The automatic transmission system in general is fairly complex due to the number of components that intertwine to get the car to shift at the correct time. The complexity is increased on the CANbus platforms to point where it may be more complicated to make a change of the automatic transmission system than to do an engine swap. As a byproduct our recommendation is the same as the above scenario which is to find a similar version of your car in manual form and swap everything over. From a practical standpoint, it may be more cost and time effective to purchase the car in the form that you desire.

2009 to 2013 Forester XT Auto to Manual

We understand this is a common scenario because for this group of cars, a manual did not exist from Subaru. Unfortunately we do not have a solution to this problem. There are people we have seen take a WRX in parts since they are similar (but not the same) as a Forester and swap everything over as noted before. The problem we see is there are differences between the chassis features of a WRX and Forester like the rear hatch that would have to be addressed one way or another and just may not work so it would depend on how much someone cared about certain features to work if they were to go down this path. 

#CANBus #SubaruSwap