Toyota Prius Gen2 Board
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
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 | (Do I supply this or is this created by the HV Battery connecting to the inverter, which then creates 12v from its DC-DC converter?) |
| TB1-2 | GND | (All GNDs in common? Chassis GND or HV battery Neg?) |
| TB1-3 | 5v VCC | (Looks like this is created by this board, from the 12v in. Does it wire to the inverter?) |
| TB1-4 | Throttle In | (Added by me with a pedal? If so what's expected? Also connected to inverter or not?) |
| TB1-5 | Regen In | (Ditto with throttle same questions) |
| TB1-6 | GND | |
| TB1-7 | Brake In | (Ditto with throttle) |
| TB1-8 | Start In | (Ditto with throttle) |
| TB1-9 | For In | (Forward input? Just a signal? Ditto with throttle) |
| TB1-10 | Rev In | (Reverse input? Ditto with throttle) |
| TB3-1 | +12v VCC | (Appears to be 12v after the protection diode, versus 12v input. Connected to inverter too?) |
| TB3-2 | GND | |
| TB3-3 | Phase U |
(PWM signals for that phase that create the waveform that the inverter then boosts to motor-size voltages and currents?) |
| TB3-4 | Phase Y | |
| TB3-5 | Phase W | |
| TB3-6 | Current U | |
| TB3-7 | Current Y | |
| TB3-8 | MG2 Enable | |
| TB3-9 | MG2 Fault | |
| TB3-10 | DC Bus | |
| TB2-1 | +5V VCC | (Again just from this board's regulator, redundant wire to TB1-3?) |
| TB2-2 | ENCA In | (Encoder inputs?) |
| TB3-3 | ENCB In | |
| TB3-4 | GND | |
| TB3-5 | HS Temp | |
| TB3-6 | MOT Temp | |
| TB4-1 | GND | |
| TB4-2 | Main Con | |
| TB4-3 | Precharge | |
| TB4-4 | +12 V VCC | (Redundant to TB2-1?) |
| TB4-5 | CAN L | |
| TB4-6 | CAN H |
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 |