Toyota Prius Gen3 Board

Prius Gen3 Control Board v2

The Toyota Prius Gen3 Board is an open source project to repurpose 2010-2015 Toyota Prius inverters for DIY EV use. It consists of a circuit board and programming that replaces the original logic board in the inverter and allows independent control of it without communicating with a Prius ECU.

Note that there is also a Toyota Prius Gen2 Board for the 2004-2009 model years.

Prius Inverter

The Toyota Prius is a hybrid vehicle. Their inverters are suitable and attractive for DIY EVs because of:

• Large part availability. Priuses have been made in large numbers for 20 years.
• High affordability. Prius inverters are available for around $150 from scrapyards everywhere.
• Durability. Toyota engineers appear to have made the inverters foolproof, many inputs and outputs gracefully handle fault conditions.
• Respectable performance. Rated for 50kW output, but tested to handle 600v, and 500+A on MG2. (MG1 unknown, Gen2 had 70% of MG2 on MG1).
• Ease of repurposing. Emulating the original ECU seems reasonably feasible.

The Gen3 Prius (2010-2015 model years) has a variety of useful components inside the inverter package:

• 2 high power inverters, for the 2 motors MG1 (starter) capable of handling 250 amps, and MG2 (drive motor) capable of handling 350 amps.
• A DC-DC converter to provide 12v power supply to the automotive systems and accessories.
• A boost module to boost the 200v battery pack up to 500v, which looks to be able to function as a battery charger (wish list for future development)
• See this video for a thorough disassembly and explanation of the Gen3 Inverter (Timestamp ???? ): https://www.youtube.com/watch?v=Y7Vm-C4MsW8

Control Board

The current version as of Jan 20, 2020 is v2.

As designed by Damien Maguire, the open source hardware for the control board can be purchased as both partially populated and fully populated and tested boards on his website:

Prius Gen3 Partial

Prius Gen3 Prius Gen3 Full & Tested

The control board is a physical replacement for the OEM Prius Gen3 inverter logic board inside the inverter. Remove the old one and replace it with the new one.

Development History

V1 - This board was sold tested but also as a bare logic board requiring purchase of your own components and SMD placement and soldering skills. https://www.evbmw.com/index.php/evbmw-webshop/toyota-bare-boards/prius-gen-3-inverter-bare-logic-board

V2 - A new board source was found to be both high quality and low cost. The boards were redesigned around the inventory of parts available from this supplier. In particular the high cost of populated and soldered boards (10x the price) from the source used to make the v1 boards is so significantly lower on the v2 that there are likely no savings by building and soldering the board yourself. The circuit now has hardware to support repurposing the MG1 inverter as a battery charger, though as of Jan 20, 2020, software is still in development.

Vendors

- ?? List of known vendors with support?

Support

Community support is available on the Prius Gen 3 Inverter Logic Board Support Thread

You are not entitled to support, purchase from a vendor who offers support if you want it guaranteed. Treat the community with respect.

Inverter Model Numbers

Inverter No	Car model(s)	Logic Board No	Power Board No	Compatible 50 pin connector	PCB size	Confirmed works with board	Link
G9200-47141	Auris 2012, RHD
G9200-47140	Prius 2010	F1759-47041 01
G9200-47180							Photo diyelectriccar.com
G9200-47190	Auris	F1759-52010 04		?			Forum Thread openinverter.com
G9200-52010	Yaris	F1759-52010 04	F1789-52010		154x143mm		https://openinverter.org/forum/viewtopic.php?f=14&t=257&p=5828#p5828
G9200-52032	Yaris 2015	F1759-52010 04	F1789-52010	YES	Long 143mm		Forum Thread openinverter.com Forum Thread openinverter.com
G9201-52011	Yaris			YES			Forum Thread openinverter.com
G9201-52012	Prius C	F1759-52010	F1789-52010	YES (presumably)			Forum Thread openinverter.com

Assembly Instructions (V1C)

This guide is for the assembly of version V1C of the Gen 3 board available here: https://www.evbmw.com/index.php/evbmw-webshop/toyota-built-and-tested-boards/prius-gen-3-inverter-built-tested

This is based on the assembly videos by Damien Maguire.

Part 1: https://www.youtube.com/watch?v=QE-zym8iIgM&t=2643s

Part 2: https://www.youtube.com/watch?v=Nu5_OBOPk4s&t=1787s

Soldering

I started with the breakout board. Soldering the Ampseal connector the the board, the board instructs which side to fit it.

Assembly Notes

The Prius Gen3 Board is suitable to control any (please add: motor types here) motors.

Note: Early versions of the board have a few mistakes.

There are some parts that have to be changed and populated to get the partly build board working.

You need for the board 3 resistors 1kOhm, 1 resistor 1,2kOhm, 2 LED red and 1 elcap 35V 330µF.

• First you have to desoldering the diodes D1, D2 and D3 to change the polarity and resolder them.
• R52 is missing, 1kOhm resistor.
• Change R89 from 1,5kOhm to 1,2kOhm to correct tmphs, it is 20°C to high.
• C26 has to change for an elcap with higher voltage, so use 330µF 35V.
• Change R38 from 330Ohm to 1kOhm so that LED1 is not so bright.
• LED2 and LED3 are missing, for LED2 change R39 from 330Ohm to 1kOhm.

With the new Firmware v4.85R customized by Damien you don't need to change the hardware as explained in the past, see at his post https://openinverter.org/forum/viewtopic.php?f=14&t=488&start=60#p11328

For mounting in the original case you have to remove some plastic from the carrier of the current sensors below the battery input for the PriusG3_V1b board.

For the Yaris inverter you have to remove additionally some of the mounting points below the board.

If you want to reuse the connectors from the original board, for the Yaris the connector from the MG2 current sensor plug and the HV interlock plug is different to the Prius, so you have to get extra connectors or you can only use one connector for the current sensor and no connector for HV interlock, which is usually sufficient. It is not a fun to desolder the connectors,especially the 50 pol connector, and if you have not some experience in soldering it is better to get them new.

Some of the points are as well for the other prius boards noteworthy.

Source Documentation:

Damien's Prius Gen3 v2 Github

Bill of Materials (from above)

The control board takes advantage of the OpenInverter.org software for control.