Toyota Prius Gen2 Board

Prius Board v1

The Toyota Prius Gen2 Board is an open source project to repurpose 2004-2009 Toyota Prius inverters for DIY EV use. It consists of a circuit board and programming that replaces the Prius' original ECU.

Prius Inverter

Prius Gen 2 Inverter Montage

Internal look at the Prius Gen2 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 tests indicate they can tolerate as much as 300kW
• Ease of repurposing. Emulating the original ECU seems reasonably feasible.

The Gen2 Prius (2004-2009 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 X(?) amps, and MG2 (drive motor) capable of handling Y(?) 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 Gen2 Inverter (Timestamp 1:15:30): https://www.youtube.com/watch?v=Y7Vm-C4MsW8&t=4531

Control Board

As designed by Damien Maguire, the open source hardware for the control board can be purchased as blank, unpopulated boards on his website: Prius Gen2 Logic Board on EVBMW's Webshop

How To Use

The Prius Gen2 Board is suitable to control any (please add: motor types here) motors.

Note: There is a mistake in the printing on the v1 circuitboard. The parts labelled T1, T2, and T3 - which are the small black transistors in the upper right of the board - are all drawn backwards to how they need to be inserted. These parts should be installed with the flat side of the component facing the opposite direction as the printing shows. The flat side should be to the right.

Schematics, Bill of Materials, and other documentation are available on Damien's Project Github (note: flesh out bill of materials here, or post changes to Damien to update his documentation directly?)

The control board utilizes the Blue Pill (link?) microcontroller, and takes advantage of the OpenInverter.org software (link?) for control.

Assembly notes? Blue Pill programming notes or just links to Blue Pill section?

Try to get all the wiring harness bits that plug into the inverter when you purchase it. Else, the 32-pin connector inside the inverter part number is: 1318747-1, and the pins to wire it are: 1123343-1

Terminal Block Connection list (rough, in-progress):

Pin Header Summary

Control Board Description:

Pin #	Designation	Description
TB1-1	12v-in	Primary 12v supply from ignition on
TB1-2	GND	Primary ground connection to 12v negative. All grounds are common
TB1-3	5v VCC	5V supply from board for use with throttle pot or hall pedal
TB1-4	Throttle In	0-5v variable voltage input from throttle pedal or pot
TB1-5	Regen In	0-5v variable voltage input. Can be used as second throttle channel or control regen from a brake pressure sensor
TB1-6	GND
TB1-7	Brake In	12v digital input from brake light switch.
TB1-8	Start In	12v digital input from "Start" position on a traditional ignition switch. Momentary action push button can be used.
TB1-9	For In	12v digital input commands motor to run in forward direction
TB1-10	Rev In	12v digital input commands motor to run in reverse direction
TB3-1	+12v VCC	12v output to inverter IGCT terminal
TB3-2	GND	Common ground
TB3-3	Phase U	Phase U output. Connect to Inverter MUU terminal for MG2 inverter drive or GUU for MG1 inverter drive
TB3-4	Phase Y	Phase V output. Connect to Inverter MVU terminal for MG2 inverter drive or GVU for MG1 inverter drive
TB3-5	Phase W	Phase W output. Connect to Inverter MWU terminal for MG2 inverter drive or GWU for MG1 inverter drive
TB3-6	Current U	Phase currents from inverter. Requires external divider circuit. Not required to run motor or inverter.
TB3-7	Current Y	Phase currents from inverter. Requires external divider circuit. Not required to run motor or inverter.
TB3-8	MG2 Enable	Connect to Inverter MSDN to run MG2 inverter or GSDN to run MG1 inverter
TB3-9	MG2 Fault	Connect to MFIV for MG2 or GFIV for MG1
TB3-10	DC Bus	Connect to inverter VH to measure DC link voltage
TB2-1	+5V VCC	5v output to encoder for induction motor
TB2-2	ENCA In	Encoder input A
TB2-3	ENCB In	Encoder input B
TB2-4	GND	Encoder ground
TB2-5	HS Temp	Heatsink temp sensor input
TB2-6	MOT Temp	Motor temp sensor input
TB4-1	GND	Common ground
TB4-2	Main Con	Main HV contactor control low side switch
TB4-3	Precharge	HV precharge contactor control low side switch
TB4-4	+12 V VCC	Spare 12v output
TB4-5	CAN L	Can bus low signal
TB4-6	CAN H	Can bus high signal

32-pin Prius Inverter Pinout: (Add photo of plug showing pin numbering? Where does numbering start?)

Pin #	Designation	Wire Color	Description
1	Example	Example	Example
2	Example	Example	Example
3	Example	Example	Example
4	Example	Example	Example
5	Example	Example	Example
6	Example	Example	Example
7	Example	Example	Example
8	Example	Example	Example
9	Example	Example	Example
10	Example	Example	Example
11	Example	Example	Example
12	Example	Example	Example
13	Example	Example	Example
14	Example	Example	Example
15	Example	Example	Example
16	Example	Example	Example
17	Example	Example	Example
18	Example	Example	Example
19	Example	Example	Example
20	Example	Example	Example
21	Example	Example	Example
22	Example	Example	Example
23	Example	Example	Example
24	Example	Example	Example
25	Example	Example	Example
26	Example	Example	Example
27	Example	Example	Example
28	Example	Example	Example
29	Example	Example	Example
30	Example	Example	Example
31	Example	Example	Example
32	Example	Example	Example