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

ECU pinout 1.4i (AUA, BBY)

#	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

ECU pinout 1.6FSI

#	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