Harden Electric Blog Some of the challenges to your modern EV conversion – CANbus

Some of the challenges to your modern EV conversion – CANbus

So when we started this business, we originally wanted to be a bull at a gate, out the door, ready to go, let’s build an Australian car from the ground up, let’s revitalise the Australian Automotive Industry and bring back car manufacting.

Ok, that was probably a tad ambitious, even for us, with a number of roadblocks in our way, we were faced with the hassle of getting around a number of key failure points for any startup, mainly homologation and compliance. We quickly found, no one really wants to answer these questions and deal with you as a startup. So we needed to establish ourselves a little, so we looked a tad further afield of our original goal.


One of the biggest things we quickly realised in the EV space was that most conversions are done to older cars, cars that don’t have computers, or cars that gave rudimentary computers that can be removed with no detrimental effect to other systems.

The few examples of CANbus cars we could find such as This converted Audi are missing features, not everything works as it should, and it’s bit all over the place (still a cool conversion)

For those who don’t know what CANbus is, it’s essentially a computerised network of everything in the car talking to everything else, give are the days of a bunch of power wires running everywhere with simple dumb switches, it’s now all on a computer.

Headlights? CANbus. Taillights? CANbus. Wipers? CANbus. Electric Mirrors? CANbus. Fuel door? Metal cable.

But you get the idea, everything trunks through a computer, the computer knows all, sees all, and is sorry that it can’t do that.

So what we have done is started looking into a way to trick the ECU, so your car will be exactly the same as it was before, a small “piggyback” style module that will interface between the vehicles existing factory ECU, and the EV components that will be fitted in the conversion.

  • BMS will feed State of Charge to the ICU which will inform the ECU as if it was litres in a stock fuel tank, retaining your stock Fuel Gauge
  • Instead of Wh/km, the ICU will report a l/100km value to the ECU, allowing factory range calculations to be accurate (even if the l/100km is not “realistic”)
  • OBD will be retained, so you can still use your Bluetooth OBD Dongles and nearly any mechanic can connect to the car using off the shelf OBD tooling (SnapOn, Bosch, etc)
  • Sensors such as wheel speed, wheel slip, braking will be retained. This means that ABS and Traction control will function as intended, the main ECU knows no different
  • Things like injectors will be “spoofed”, essentially there will be a virtual engine simulation running inside the box, so the ECU is “controlling” a simulation. Welcome to the Matrix Neo….

Now there are still a lot of hurdles to overcome, a simple idea, a simple concept, but execution, well, that’s up to the tech guys to figure out from here.

We are also hoping to develop a software and tuning package so we can interface a number of controllers, so you select your ICE side, what each wire is going to, what each wire is doing, what outputs it needs, etc.

Then on the EV side, you select your controller, motor, tune settings, etc and the box does the rest, mating them both together seamlessly.

We are hoping that not only will this be a cheaper, more affordable way to do things, no custom wiring, splicing, programming, spoofing, etc going on, it will allow much more of the factory features to be retained on the motor, so your AC, Traction Control, ABS, etc. People don’t want to downgrade, and if you’re upgrading your motor, why would you downgrade your other features?

An electric vehicle conversions shouldn’t be about compromise, it should be about increasing your abilities, increasing your capabilities, and decreasing your burdens. So we say no to compromise, the way see if, as long as we can do it within the laws of physics, it can be done. That’s our goal.

4 thoughts on “Some of the challenges to your modern EV conversion – CANbus”

  1. It is a simple idea but the execution will be massively challenging depending on the donor vehicles in use. Both vehicles would need their CANbus completely reverse engineered. Start with the right cars and the CAN messages are already known (e.g Nissan Leaf and 350z) which would give you a big headstart. Also if OBD is of interest, the OVMS module can spoof it quite nicely.

    1. G’Day Hamish,
      We have not as of yet, we have been working on other things, however we are gathering data from as many sources as we can to try and get patterns of protocols established and start working on this.
      However we realised we were half-arsing two things, so take a break, step back, whole arse, one thing.
      Hopefully our current project should be finalised around the start of 2022 and we can move on to the next project.

  2. Hi, I am very interested in utilising the ‘black box’ concept for my proposed ice to EV conversion (2008 4wd/5speed Toyota Hilux). It appears that this vehicle does not have traction control, just ABS however I would need to confirm this.
    I would love to convert it and retain the 4wd (utilise existing gearbox/4wd), not sure if the clutch would still be required but if it simplifies the conversion then not a problem. There is a heap of space under the tray (it’s a dual cab with aluminium tray ute) as well as wherever ice stuff is removed. Please let me know if you have developed your product yet?

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