Audi A2 Conversion
On this page we describe the conversion of an Audi A2 1.4i petrol to electric propulsion. We will use the following components:
- Nissan Leaf 24 kWh battery pack with original BMS
- Toyota Prius Gen 2 (2004-2009) transaxle with matching inverter
- openinverter Prius Gen2 motor controller
- openinverter main board running stm32-car (VCU in ECU enclosure)
Pin mapping
We start out by mapping out useful pins of the original wire harness
ECU
The ECU has two connector slots, a smaller one with pins 82-121 and a larger one with pins 1-81. Here we map out pins useful to us
| # | orig function | our function | wire color |
|---|---|---|---|
| 1,2 | GND | br | |
| 3 | permanent 12V | ro | |
| 4 | ignition 12V | ro/sw | |
| 5 | Lambda (first) heater | gr | |
| 28 | From generator (maybe DF) | li/bl | |
| 33 | Throttle second pot +5V | gr/ge | |
| 34 | Throttle second pot (signal) | br/gn | |
| 35 | Throttle first pot (signal) | ge/bl | |
| 36 | Throttle first pot +5V | br/ro | |
| 38 | To cruise control switch * | ws | |
| 39 | Clutch pedal sensor * if installed | ro/ge | |
| 40 | To Climate control display | sw/ge | |
| 41 | To Climate control display | sw/gr | |
| 43 | To instrument cluster (function unknown) | gn/sw | |
| 51 | Lambda (first) signal | bl/ws | |
| 52 | Lambda (first) signal | ge | |
| 54 | To instrument cluster (function unknown) | bl/ws | |
| 55 | Brake light switch NC to +12V | ws/ro | |
| 56 | Brake light switch NO to +12V | ro/sw | |
| 57 | To cruise control switch * | bl/ro | |
| 58 | CAN L | or/br | |
| 60 | CAN H | or/sw | |
| 63 | Lambda (second) heater | li/ro | |
| 64 | Charcoal filter solenoid | bl/ge | |
| 65 | Fuel pump relay- control | ro/br | |
| 68 | Lambda (second) signal | bl/br | |
| 69 | Lambda (second) signal | ro/li | |
| 70 | Lambda (first) signal | bl | |
| 71 | Lambda (first) signal | sw | |
| 72 | Throttle second pot GND | gr | |
| 73 | Throttle first pot GND | ge/li | |
| 75 | To cruise control switch * | bl/sw | |
| 76 | To cruise control switch * | sw/ro | |
| 82 | Engine speed sensor | gr/br | |
| 83 | Throttle body sens power | ro/gn | |
| 84 | Throttle body sens 2 | gn/bl | |
| 85 | Intake manifold Temp/Pressure | gr | |
| 86 | Hall sender G40 signal | ro/sw | |
| 87 | Engine speed sensor | gn/sw | |
| 88 | Injector 3 | sw/li | |
| 89 | Injector 4 | li/sw | |
| 91 | Throttle body sens power | ro/bl | |
| 92 | Throttle body sens 1 | li/ro | |
| 93 | Coolant temp sensor | gr/ws | |
| 96 | Injector 1 | br/bl | |
| 97 | injector 2 | sw/gn | |
| 98 | +5V wiring to engine bay | gn/li | |
| 99 | Knock sensor | ws | |
| 100 | EGR pot | br/li | |
| 102 | Ignition coil bank 1 | gn/ws | |
| 103 | Ignition coil bank 2 | gn/ro | |
| 106 | Knock sensor | br | |
| 108 | GND for engine sensors | gr/ro | |
| 109 | Intake manifold Temp/Pressure | bl/gn | |
| 114 | EGR mot | li/ge | |
| 117 | Throttle body mot | gn | |
| 118 | Throttle body mot | br/sw |
| # | Org Function | Ours | Color |
|---|---|---|---|
| 1/2 | GND | br br | |
| 3/5 | permanent 12V | gn/ge gn/ge | |
| 6 | N290 Fuel metering valve | ro/bl | |
| 7 | Fuel pump relay control | ro/br | |
| 8/10 | CAN-H CAN-L | or/sw or/br | |
| 11/16/31
32/50 |
NOX controller | sw br/ws bl
ws/sw ge/ro | |
| 13/17/30 | Air mass meter | gr/ro gr/ws li/ws | |
| 23/46 | Climate cotroler | sw/gr sw/ge | |
| 26/45 | Radiator fan controller | sw/ge ge/gr | |
| 35 | EGT | ro/gn | |
| 36 | Brake vaccum sensor | bl/br | |
| 37 | Sensors GND | ge/bl | |
| 48/57 | Brake light switch NO/NC | ro/sw ws/ro | |
| 42 | +5V to sensors | ge/gn | |
| 62/64 | Current supply relay | ro gr/ro | |
| 65 | Generator DF | li/br | |
| 67 | Clutch pedal switch * if fitted | ro/ge | |
| 78 | N79 crankcase breather heater | br | |
| 88 | N316 Intake manifold flap valve | li/ge | |
| 89 | F265 Controlled cooling thermostat | ro/br | |
| 105 | N205 Inlet Camsh. timing valve | li/gn | |
| 113 | N276 Fuel pressure regulating valve | gn/bl | |
| 114/115
116/117 119/120 |
Injectors 1-4 | br/ge br/ws
br/gn br/ro br/bl br/sw | |