MX-5 Miata NB1 1999-00 (BP-4W) → rusEFI Proteus (auto)

MX-5 Miata NB1 1999-00 (BP-4W) — rusEFI — Proteus

Drawn by Michael Gnankou · Rev 0 · proposal · 2026-10-08

Before you start

Status	proposal · not yet verified: nobody has reported building and running this harness
Open errors	none
Size of the job	65 wires · 9 connectors · 3 part lines
Tools	Crimp and extraction tools for each terminal family (see Connectors) · wire strippers · multimeter · heat gun + heat-shrink
Order of work	1. Check every part against the parts list. 2. Cut and label every wire (labels: Export → Wire labels). 3. Crimp and pin connector by connector, ticking the build checklist. 4. Run the bench test with nothing plugged in and the battery disconnected. 5. Only then connect the ECU and power up.

Build checklist

Tick each box as you go. Continuity: meter from end to end, expect under 1 Ω.

Wire	From	To	Gauge	Cut	Label	Crimp A	Crimp B	Pin A	Pin B	Continuity
W1	OEM-1-B	SP-14V-1	0.85	☐	☐	☐	☐	☐	☐	☐
W2	OEM-3-M	SP-14V-1	0.85	☐	☐	☐	☐	☐	☐	☐
W3	SP-14V-1	PROTEUS-Black23-23	0.85	☐	☐	☐	☐	☐	☐	☐
W4	OEM-3-A	SP-GND-1	0.85	☐	☐	☐	☐	☐	☐	☐
W5	OEM-3-B	SP-GND-1	0.85	☐	☐	☐	☐	☐	☐	☐
W6	OEM-3-C	SP-GND-1	0.85	☐	☐	☐	☐	☐	☐	☐
W7	SP-GND-1	PROTEUS-Black23-14	0.85	☐	☐	☐	☐	☐	☐	☐
W8	SP-GND-1	PROTEUS-Black23-19	0.85	☐	☐	☐	☐	☐	☐	☐
W9	SP-GND-1	PROTEUS-Black23-20	0.85	☐	☐	☐	☐	☐	☐	☐
W10	SP-GND-1	PROTEUS-Black35-17	0.85	☐	☐	☐	☐	☐	☐	☐
W11	SP-GND-1	PROTEUS-Black35-18	0.85	☐	☐	☐	☐	☐	☐	☐
W12	SP-GND-1	PROTEUS-Black35-24	0.85	☐	☐	☐	☐	☐	☐	☐
W13	OEM-3-F	SP-0V-1	0.5	☐	☐	☐	☐	☐	☐	☐
W14	SP-0V-1	PROTEUS-White35-1	0.5	☐	☐	☐	☐	☐	☐	☐
W15	SP-0V-1	PROTEUS-White35-2	0.5	☐	☐	☐	☐	☐	☐	☐
W16	SP-0V-1	PROTEUS-White35-23	0.5	☐	☐	☐	☐	☐	☐	☐
W17	SP-0V-1	PROTEUS-White35-29	0.5	☐	☐	☐	☐	☐	☐	☐
W18	SP-0V-1	PROTEUS-White35-3	0.5	☐	☐	☐	☐	☐	☐	☐
W19	SP-0V-1	PROTEUS-White35-4	0.5	☐	☐	☐	☐	☐	☐	☐
W20	SP-0V-1	PROTEUS-White35-5	0.5	☐	☐	☐	☐	☐	☐	☐
W21	SP-0V-1	PROTEUS-White35-6	0.5	☐	☐	☐	☐	☐	☐	☐
W22	SP-0V-1	PROTEUS-White35-7	0.5	☐	☐	☐	☐	☐	☐	☐
W23	SP-0V-1	PROTEUS-White35-8	0.5	☐	☐	☐	☐	☐	☐	☐
W24	OEM-2-I	PROTEUS-White35-10	0.5	☐	☐	☐	☐	☐	☐	☐
W25	OEM-2-J	PROTEUS-Black23-5	0.5	☐	☐	☐	☐	☐	☐	☐
W26	SP-0V-1	PROTEUS-Black23-13	0.5	☐	☐	☐	☐	☐	☐	☐
W27	OEM-2-H	PROTEUS-Black23-1	0.5	☐	☐	☐	☐	☐	☐	☐
W28	OEM-2-F	PROTEUS-White35-34	0.5	☐	☐	☐	☐	☐	☐	☐
W29	OEM-3-G	PROTEUS-Black35-35	0.5	☐	☐	☐	☐	☐	☐	☐
W30	OEM-3-H	PROTEUS-Black35-34	0.5	☐	☐	☐	☐	☐	☐	☐
W31	OEM-3-W	PROTEUS-Black35-3	0.5	☐	☐	☐	☐	☐	☐	☐
W32	OEM-3-X	PROTEUS-Black35-15	0.5	☐	☐	☐	☐	☐	☐	☐
W33	OEM-3-Y	PROTEUS-Black35-4	0.5	☐	☐	☐	☐	☐	☐	☐
W34	OEM-3-Z	PROTEUS-Black35-16	0.5	☐	☐	☐	☐	☐	☐	☐
W35	OEM-1-I	PROTEUS-Black35-20	0.5	☐	☐	☐	☐	☐	☐	☐
W36	OEM-1-R	PROTEUS-Black35-9	0.5	☐	☐	☐	☐	☐	☐	☐
W37	OEM-1-S	PROTEUS-Black35-21	0.5	☐	☐	☐	☐	☐	☐	☐
W38	OEM-3-N	PROTEUS-Black35-10	0.5	☐	☐	☐	☐	☐	☐	☐
W39	OEM-1-U	PROTEUS-Black35-11	0.5	☐	☐	☐	☐	☐	☐	☐
W40	OEM-3-V	PROTEUS-Black35-12	0.5	☐	☐	☐	☐	☐	☐	☐
W41	OEM-3-O	PROTEUS-Black35-23	0.5	☐	☐	☐	☐	☐	☐	☐
W42	OEM-1-E	PROTEUS-Black35-5	0.5	☐	☐	☐	☐	☐	☐	☐
W43	OEM-1-O	PROTEUS-Black35-6	0.5	☐	☐	☐	☐	☐	☐	☐
W44	OEM-1-Q	PROTEUS-Black35-7	0.5	☐	☐	☐	☐	☐	☐	☐
W45	OEM-2-M	PROTEUS-Black35-19	0.5	☐	☐	☐	☐	☐	☐	☐
W46	OEM-2-N	PROTEUS-Black35-8	0.5	☐	☐	☐	☐	☐	☐	☐
W47	OEM-2-O	PROTEUS-Black23-6	0.5	☐	☐	☐	☐	☐	☐	☐
W48	OEM-2-P	PROTEUS-Black23-7	0.5	☐	☐	☐	☐	☐	☐	☐
W49	OEM-3-L	PROTEUS-Black23-15	0.5	☐	☐	☐	☐	☐	☐	☐
W50	OEM-3-Q	PROTEUS-Black23-8	0.5	☐	☐	☐	☐	☐	☐	☐
W51	OEM-2-L	PROTEUS-White35-13	0.5	☐	☐	☐	☐	☐	☐	☐
W52	OEM-3-E	PROTEUS-White35-24	0.5	☐	☐	☐	☐	☐	☐	☐
W53	OEM-2-C	PROTEUS-White35-14	0.5	☐	☐	☐	☐	☐	☐	☐
W54	OEM-3-J	PROTEUS-White35-25	0.5	☐	☐	☐	☐	☐	☐	☐
W55	OEM-2-E	PROTEUS-White35-20	0.5	☐	☐	☐	☐	☐	☐	☐
W56	OEM-2-B	PROTEUS-White35-30	0.5	☐	☐	☐	☐	☐	☐	☐
W57	OEM-2-A	PROTEUS-White35-15	0.5	☐	☐	☐	☐	☐	☐	☐
W58	OEM-3-K	PROTEUS-White35-26	0.5	☐	☐	☐	☐	☐	☐	☐
W59	OEM-3-S	PROTEUS-White35-16	0.5	☐	☐	☐	☐	☐	☐	☐
W60	OEM-2-D	PROTEUS-Black23-2	0.5	☐	☐	☐	☐	☐	☐	☐
W61	OEM-1-F	PROTEUS-Black23-10	0.5	☐	☐	☐	☐	☐	☐	☐
W62	OEM-1-G	PROTEUS-Black23-3	0.5	☐	☐	☐	☐	☐	☐	☐
W63	OEM-1-P	PROTEUS-Black23-9	0.5	☐	☐	☐	☐	☐	☐	☐
W64	OEM-1-V	PROTEUS-Black23-11	0.5	☐	☐	☐	☐	☐	☐	☐
W65	OEM-3-I	PROTEUS-White35-27	0.5	☐	☐	☐	☐	☐	☐	☐

Bench test (before first power-up)

Battery disconnected, ECU and every sensor unplugged. Meter on resistance. Each pair below must read open (OL): a reading means a pinched wire, a stray strand or a mis-pinned cavity. Then check continuity of every wire (last column of the build checklist).

#	Probe A	Probe B	Expect	Why
1	PROTEUS-Black23-23	PROTEUS-Black23-13	open (OL)	+12 V supply must not touch sensor ground
2	PROTEUS-Black23-23	PROTEUS-Black23-14	open (OL)	+12 V supply must not touch power ground
3	PROTEUS-White35-10	PROTEUS-Black23-13	open (OL)	5 V sensor reference must not touch sensor ground
4	PROTEUS-White35-10	PROTEUS-Black23-14	open (OL)	5 V sensor reference must not touch power ground
5	PROTEUS-Black23-23	PROTEUS-White35-10	open (OL)	+12 V supply must not touch 5 V sensor reference

Revisions

Rev	Label	By	Date
No revisions yet.

Schematic

Connectors

OEM-1

Cavity	Function	Signal	Wire	Colour	Gauge (mm²)	Destination	Terminal	Seal	Plug
A	Constant +12V	—	—	—	—	—	—	—	—
B	ECU power +14V (main relay)	—	W1	—	0.85	SP-14V-1	—	—	—
E	Malfunction indicator lamp (MIL)	—	W42	—	0.5	PROTEUS-Black35-5	—	—	—
F	Brake switch	—	W61	—	0.5	PROTEUS-Black23-10	—	—	—
G	Power steering pressure switch	—	W62	—	0.5	PROTEUS-Black23-3	—	—	—
I	Condenser fan relay	—	W35	—	0.5	PROTEUS-Black35-20	—	—	—
O	Alternator control	—	W43	—	0.5	PROTEUS-Black35-6	—	—	—
P	A/C request	—	W63	—	0.5	PROTEUS-Black23-9	—	—	—
Q	Charge lamp	—	W44	—	0.5	PROTEUS-Black35-7	—	—	—
R	Cooling fan relay	—	W36	—	0.5	PROTEUS-Black35-9	—	—	—
S	A/C clutch relay	—	W37	—	0.5	PROTEUS-Black35-21	—	—	—
U	Front O2 heater	—	W39	—	0.5	PROTEUS-Black35-11	—	—	—
V	Neutral switch	—	W64	—	0.5	PROTEUS-Black23-11	—	—	—

OEM-2

Cavity	Function	Signal	Wire	Colour	Gauge (mm²)	Destination	Terminal	Seal	Plug
A	Fuel tank pressure	—	W57	—	0.5	PROTEUS-White35-15	—	—	—
B	Intake air temperature (IAT)	—	W56	—	0.5	PROTEUS-White35-30	—	—	—
C	Front O2 signal	—	W53	—	0.5	PROTEUS-White35-14	—	—	—
D	Vehicle speed	—	W60	—	0.5	PROTEUS-Black23-2	—	—	—
E	Coolant temperature (ECT)	—	W55	—	0.5	PROTEUS-White35-20	—	—	—
F	Knock sensor	—	W28	—	0.5	PROTEUS-White35-34	—	—	—
H	Cam position (CMP)	—	W27	—	0.5	PROTEUS-Black23-1	—	—	—
I	+5V sensor supply	—	W24	—	0.5	PROTEUS-White35-10	—	—	—
J	Crank position (CKP)	—	W25	—	0.5	PROTEUS-Black23-5	—	—	—
K	Tachometer output	—	—	—	—	—	—	—	—
L	Mass air flow (MAF)	—	W51	—	0.5	PROTEUS-White35-13	—	—	—
M	EGR valve	—	W45	—	0.5	PROTEUS-Black35-19	—	—	—
N	EGR valve	—	W46	—	0.5	PROTEUS-Black35-8	—	—	—
O	EGR valve	—	W47	—	0.5	PROTEUS-Black23-6	—	—	—
P	EGR valve	—	W48	—	0.5	PROTEUS-Black23-7	—	—	—

OEM-3

Cavity	Function	Signal	Wire	Colour	Gauge (mm²)	Destination	Terminal	Seal	Plug
A	Power ground	—	W4	—	0.85	SP-GND-1	—	—	—
B	Power ground	—	W5	—	0.85	SP-GND-1	—	—	—
C	Power ground	—	W6	—	0.85	SP-GND-1	—	—	—
E	Throttle position (TPS)	—	W52	—	0.5	PROTEUS-White35-24	—	—	—
F	Signal ground	—	W13	—	0.5	SP-0V-1	—	—	—
G	Ignition 1 (coils 1+4, wasted spark)	—	W29	—	0.5	PROTEUS-Black35-35	—	—	—
H	Ignition 2 (coils 2+3, wasted spark)	—	W30	—	0.5	PROTEUS-Black35-34	—	—	—
I	Clutch switch	—	W65	—	0.5	PROTEUS-White35-27	—	—	—
J	Rear O2 signal	—	W54	—	0.5	PROTEUS-White35-25	—	—	—
K	Fuel level	—	W58	—	0.5	PROTEUS-White35-26	—	—	—
L	Evap purge solenoid	—	W49	—	0.5	PROTEUS-Black23-15	—	—	—
M	ISC valve +14V feed	—	W2	—	0.85	SP-14V-1	—	—	—
N	Fuel pump relay	—	W38	—	0.5	PROTEUS-Black35-10	—	—	—
O	ISC valve low side	—	W41	—	0.5	PROTEUS-Black35-23	—	—	—
Q	VICS solenoid (intake butterflies)	—	W50	—	0.5	PROTEUS-Black23-8	—	—	—
S	EGR boost sensor	—	W59	—	0.5	PROTEUS-White35-16	—	—	—
T	EGR boost solenoid	—	—	—	—	—	—	—	—
U	Canister drain cut valve (CDCV)	—	—	—	—	—	—	—	—
V	Rear O2 heater	—	W40	—	0.5	PROTEUS-Black35-12	—	—	—
W	Injector 1	—	W31	—	0.5	PROTEUS-Black35-3	—	—	—
X	Injector 2	—	W32	—	0.5	PROTEUS-Black35-15	—	—	—
Y	Injector 3	—	W33	—	0.5	PROTEUS-Black35-4	—	—	—
Z	Injector 4	—	W34	—	0.5	PROTEUS-Black35-16	—	—	—

PROTEUS-Black23

Cavity	Function	Signal	Wire	Colour	Gauge (mm²)	Destination	Terminal	Seal	Plug
1	Digital 2	—	W27	—	0.5	OEM-2-H	—	—	—
10	Digital 1	—	W61	—	0.5	OEM-1-F	—	—	—
11	Digital 6	—	W64	—	0.5	OEM-1-V	—	—	—
12	VR 2 negative	—	—	—	—	—	—	—	—
13	VR 1 negative	—	W26	—	0.5	SP-0V-1	—	—	—
14	Power ground	—	W7	—	0.85	SP-GND-1	—	—	—
15	ETB 2 positive	—	W49	—	0.5	OEM-3-L	—	—	—
16	CAN 1 Low	—	—	—	—	—	—	—	—
17	CAN 1 High	—	—	—	—	—	—	—	—
18	Ignition switch in	—	—	—	—	—	—	—	—
19	Power ground	—	W8	—	0.85	SP-GND-1	—	—	—
2	Digital 3	—	W60	—	0.5	OEM-2-D	—	—	—
20	Power ground	—	W9	—	0.85	SP-GND-1	—	—	—
21	CAN 2 Low	—	—	—	—	—	—	—	—
22	CAN 2 High	—	—	—	—	—	—	—	—
23	Main relay feed	—	W3	—	0.85	SP-14V-1	—	—	—
3	Digital 4	—	W62	—	0.5	OEM-1-G	—	—	—
4	VR 2 positive	—	—	—	—	—	—	—	—
5	VR 1 positive	—	W25	—	0.5	OEM-2-J	—	—	—
6	ETB 1 negative	—	W47	—	0.5	OEM-2-O	—	—	—
7	ETB 1 positive	—	W48	—	0.5	OEM-2-P	—	—	—
8	ETB 2 negative	—	W50	—	0.5	OEM-3-Q	—	—	—
9	Digital 5	—	W63	—	0.5	OEM-1-P	—	—	—

PROTEUS-Black35

Cavity	Function	Signal	Wire	Colour	Gauge (mm²)	Destination	Terminal	Seal	Plug
1	Highside 2	—	—	—	—	—	—	—	—
10	Lowside 13	—	W38	—	0.5	OEM-3-N	—	—	—
11	Lowside 14	—	W39	—	0.5	OEM-1-U	—	—	—
12	Lowside 15	—	W40	—	0.5	OEM-3-V	—	—	—
13	Highside 3	—	—	—	—	—	—	—	—
14	Highside 4	—	—	—	—	—	—	—	—
15	Injector 2	—	W32	—	0.5	OEM-3-X	—	—	—
16	Injector 4	—	W34	—	0.5	OEM-3-Z	—	—	—
17	Power ground	—	W10	—	0.85	SP-GND-1	—	—	—
18	Power ground	—	W11	—	0.85	SP-GND-1	—	—	—
19	Injector 8	—	W45	—	0.5	OEM-2-M	—	—	—
2	Highside 1	—	—	—	—	—	—	—	—
20	Lowside 10	—	W35	—	0.5	OEM-1-I	—	—	—
21	Lowside 12	—	W37	—	0.5	OEM-1-S	—	—	—
22	Ignition 3	—	—	—	—	—	—	—	—
23	Lowside 16	—	W41	—	0.5	OEM-3-O	—	—	—
24	Power ground	—	W12	—	0.85	SP-GND-1	—	—	—
25	Ignition 12	—	—	—	—	—	—	—	—
26	Ignition 11	—	—	—	—	—	—	—	—
27	Ignition 10	—	—	—	—	—	—	—	—
28	Ignition 9	—	—	—	—	—	—	—	—
29	Ignition 8	—	—	—	—	—	—	—	—
3	Injector 1	—	W31	—	0.5	OEM-3-W	—	—	—
30	Ignition 7	—	—	—	—	—	—	—	—
31	Ignition 6	—	—	—	—	—	—	—	—
32	Ignition 5	—	—	—	—	—	—	—	—
33	Ignition 4	—	—	—	—	—	—	—	—
34	Ignition 2	—	W30	—	0.5	OEM-3-H	—	—	—
35	Ignition 1	—	W29	—	0.5	OEM-3-G	—	—	—
4	Injector 3	—	W33	—	0.5	OEM-3-Y	—	—	—
5	Injector 5	—	W42	—	0.5	OEM-1-E	—	—	—
6	Injector 6	—	W43	—	0.5	OEM-1-O	—	—	—
7	Injector 7	—	W44	—	0.5	OEM-1-Q	—	—	—
8	Injector 9	—	W46	—	0.5	OEM-2-N	—	—	—
9	Lowside 11	—	W36	—	0.5	OEM-1-R	—	—	—

PROTEUS-White35

Cavity	Function	Signal	Wire	Colour	Gauge (mm²)	Destination	Terminal	Seal	Plug
1	Sensor ground	—	W14	—	0.5	SP-0V-1	—	—	—
10	5V supply #2	—	W24	—	0.5	OEM-2-I	—	—	—
11	12V sensor supply	—	—	—	—	—	—	—	—
12	12V sensor supply	—	—	—	—	—	—	—	—
13	Analog Volt 1	—	W51	—	0.5	OEM-2-L	—	—	—
14	Analog Volt 3	—	W53	—	0.5	OEM-2-C	—	—	—
15	Analog Volt 5	—	W57	—	0.5	OEM-2-A	—	—	—
16	Analog Volt 7	—	W59	—	0.5	OEM-3-S	—	—	—
17	Analog Volt 9	—	—	—	—	—	—	—	—
18	Analog Volt 11	—	—	—	—	—	—	—	—
19	Thermistor 1	—	—	—	—	—	—	—	—
2	Sensor ground	—	W15	—	0.5	SP-0V-1	—	—	—
20	Coolant temp (CLT)	—	W55	—	0.5	OEM-2-E	—	—	—
21	5V supply #1	—	—	—	—	—	—	—	—
22	5V supply #2	—	—	—	—	—	—	—	—
23	Sensor ground	—	W16	—	0.5	SP-0V-1	—	—	—
24	Analog Volt 2	—	W52	—	0.5	OEM-3-E	—	—	—
25	Analog Volt 4	—	W54	—	0.5	OEM-3-J	—	—	—
26	Analog Volt 6	—	W58	—	0.5	OEM-3-K	—	—	—
27	Analog Volt 8	—	W65	—	0.5	OEM-3-I	—	—	—
28	Analog Volt 10	—	—	—	—	—	—	—	—
29	Sensor ground	—	W17	—	0.5	SP-0V-1	—	—	—
3	Sensor ground	—	W18	—	0.5	SP-0V-1	—	—	—
30	Intake air temp (IAT)	—	W56	—	0.5	OEM-2-B	—	—	—
31	Thermistor 4	—	—	—	—	—	—	—	—
32	5V supply #1	—	—	—	—	—	—	—	—
33	5V supply #2	—	—	—	—	—	—	—	—
34	Knock 1	—	W28	—	0.5	OEM-2-F	—	—	—
35	Knock 2	—	—	—	—	—	—	—	—
4	Sensor ground	—	W19	—	0.5	SP-0V-1	—	—	—
5	Sensor ground	—	W20	—	0.5	SP-0V-1	—	—	—
6	Sensor ground	—	W21	—	0.5	SP-0V-1	—	—	—
7	Sensor ground	—	W22	—	0.5	SP-0V-1	—	—	—
8	Sensor ground	—	W23	—	0.5	SP-0V-1	—	—	—
9	5V supply #1	—	—	—	—	—	—	—	—

SP-0V

Cavity	Function	Signal	Wire	Colour	Gauge (mm²)	Destination	Terminal	Seal	Plug
1	—	—	W13	—	0.5	OEM-3-F	—	—	—
1	—	—	W14	—	0.5	PROTEUS-White35-1	—	—	—
1	—	—	W15	—	0.5	PROTEUS-White35-2	—	—	—
1	—	—	W16	—	0.5	PROTEUS-White35-23	—	—	—
1	—	—	W17	—	0.5	PROTEUS-White35-29	—	—	—
1	—	—	W18	—	0.5	PROTEUS-White35-3	—	—	—
1	—	—	W19	—	0.5	PROTEUS-White35-4	—	—	—
1	—	—	W20	—	0.5	PROTEUS-White35-5	—	—	—
1	—	—	W21	—	0.5	PROTEUS-White35-6	—	—	—
1	—	—	W22	—	0.5	PROTEUS-White35-7	—	—	—
1	—	—	W23	—	0.5	PROTEUS-White35-8	—	—	—
1	—	—	W26	—	0.5	PROTEUS-Black23-13	—	—	—

SP-14V

Cavity	Function	Signal	Wire	Colour	Gauge (mm²)	Destination	Terminal	Seal	Plug
1	—	—	W1	—	0.85	OEM-1-B	—	—	—
1	—	—	W2	—	0.85	OEM-3-M	—	—	—
1	—	—	W3	—	0.85	PROTEUS-Black23-23	—	—	—

SP-GND

Cavity	Function	Signal	Wire	Colour	Gauge (mm²)	Destination	Terminal	Seal	Plug
1	—	—	W4	—	0.85	OEM-3-A	—	—	—
1	—	—	W5	—	0.85	OEM-3-B	—	—	—
1	—	—	W6	—	0.85	OEM-3-C	—	—	—
1	—	—	W7	—	0.85	PROTEUS-Black23-14	—	—	—
1	—	—	W8	—	0.85	PROTEUS-Black23-19	—	—	—
1	—	—	W9	—	0.85	PROTEUS-Black23-20	—	—	—
1	—	—	W10	—	0.85	PROTEUS-Black35-17	—	—	—
1	—	—	W11	—	0.85	PROTEUS-Black35-18	—	—	—
1	—	—	W12	—	0.85	PROTEUS-Black35-24	—	—	—

Pin map

OEM point	OEM function	OEM family	Target point	Target function	Target family	Evidence
OEM-1-A	Constant +12V	power_in	—	—	—	single_source
OEM-1-B	ECU power +14V (main relay)	power_in	PROTEUS-Black23-23	Main relay feed	power_in	single_source
OEM-1-E	Malfunction indicator lamp (MIL)	low_side_out	PROTEUS-Black35-5	Injector 5	injector_out	single_source
OEM-1-F	Brake switch	digital_in	PROTEUS-Black23-10	Digital 1	digital_in	single_source
OEM-1-G	Power steering pressure switch	digital_in	PROTEUS-Black23-3	Digital 4	digital_in	single_source
OEM-1-I	Condenser fan relay	low_side_out	PROTEUS-Black35-20	Lowside 10	low_side_out	single_source
OEM-1-O	Alternator control	low_side_out	PROTEUS-Black35-6	Injector 6	injector_out	single_source
OEM-1-P	A/C request	digital_in	PROTEUS-Black23-9	Digital 5	digital_in	single_source
OEM-1-Q	Charge lamp	low_side_out	PROTEUS-Black35-7	Injector 7	injector_out	single_source
OEM-1-R	Cooling fan relay	low_side_out	PROTEUS-Black35-9	Lowside 11	low_side_out	single_source
OEM-1-S	A/C clutch relay	low_side_out	PROTEUS-Black35-21	Lowside 12	low_side_out	single_source
OEM-1-U	Front O2 heater	low_side_out	PROTEUS-Black35-11	Lowside 14	low_side_out	single_source
OEM-1-V	Neutral switch	digital_in	PROTEUS-Black23-11	Digital 6	digital_in	single_source
OEM-2-A	Fuel tank pressure	analog_in	PROTEUS-White35-15	Analog Volt 5	analog_in	single_source
OEM-2-B	Intake air temperature (IAT)	temp_in	PROTEUS-White35-30	Intake air temp (IAT)	temp_in	single_source
OEM-2-C	Front O2 signal	lambda_nb_in	PROTEUS-White35-14	Analog Volt 3	analog_in	single_source
OEM-2-D	Vehicle speed	digital_in	PROTEUS-Black23-2	Digital 3	digital_in	single_source
OEM-2-E	Coolant temperature (ECT)	temp_in	PROTEUS-White35-20	Coolant temp (CLT)	temp_in	single_source
OEM-2-F	Knock sensor	knock_in	PROTEUS-White35-34	Knock 1	knock_in	single_source
OEM-2-H	Cam position (CMP)	trigger_in	PROTEUS-Black23-1	Digital 2	trigger_in	single_source
OEM-2-I	+5V sensor supply	vref	PROTEUS-White35-10	5V supply #2	vref	single_source
OEM-2-J	Crank position (CKP)	trigger_in	PROTEUS-Black23-5	VR 1 positive	trigger_in	single_source
OEM-2-K	Tachometer output	tacho_out	—	—	—	single_source
OEM-2-L	Mass air flow (MAF)	analog_in	PROTEUS-White35-13	Analog Volt 1	analog_in	single_source
OEM-2-M	EGR valve	low_side_out	PROTEUS-Black35-19	Injector 8	injector_out	single_source
OEM-2-N	EGR valve	low_side_out	PROTEUS-Black35-8	Injector 9	injector_out	single_source
OEM-2-O	EGR valve	low_side_out	PROTEUS-Black23-6	ETB 1 negative	hbridge_out	single_source
OEM-2-P	EGR valve	low_side_out	PROTEUS-Black23-7	ETB 1 positive	hbridge_out	single_source
OEM-3-A	Power ground	ground	PROTEUS-Black23-14 + PROTEUS-Black23-19 + PROTEUS-Black23-20 + PROTEUS-Black35-17 + PROTEUS-Black35-18 + PROTEUS-Black35-24	Power ground + Power ground + Power ground + Power ground + Power ground + Power ground	ground	single_source
OEM-3-B	Power ground	ground	PROTEUS-Black23-14 + PROTEUS-Black23-19 + PROTEUS-Black23-20 + PROTEUS-Black35-17 + PROTEUS-Black35-18 + PROTEUS-Black35-24	Power ground + Power ground + Power ground + Power ground + Power ground + Power ground	ground	single_source
OEM-3-C	Power ground	ground	PROTEUS-Black23-14 + PROTEUS-Black23-19 + PROTEUS-Black23-20 + PROTEUS-Black35-17 + PROTEUS-Black35-18 + PROTEUS-Black35-24	Power ground + Power ground + Power ground + Power ground + Power ground + Power ground	ground	single_source
OEM-3-E	Throttle position (TPS)	analog_in	PROTEUS-White35-24	Analog Volt 2	analog_in	single_source
OEM-3-F	Signal ground	sensor_ground	PROTEUS-Black23-13 + PROTEUS-White35-1 + PROTEUS-White35-2 + PROTEUS-White35-23 + PROTEUS-White35-29 + PROTEUS-White35-3 + PROTEUS-White35-4 + PROTEUS-White35-5 + PROTEUS-White35-6 + PROTEUS-White35-7 + PROTEUS-White35-8	VR 1 negative + Sensor ground + Sensor ground + Sensor ground + Sensor ground + Sensor ground + Sensor ground + Sensor ground + Sensor ground + Sensor ground + Sensor ground	sensor_ground + trigger_in	single_source
OEM-3-G	Ignition 1 (coils 1+4, wasted spark)	ignition_out	PROTEUS-Black35-35	Ignition 1	ignition_out	single_source
OEM-3-H	Ignition 2 (coils 2+3, wasted spark)	ignition_out	PROTEUS-Black35-34	Ignition 2	ignition_out	single_source
OEM-3-I	Clutch switch	digital_in	PROTEUS-White35-27	Analog Volt 8	analog_in	single_source
OEM-3-J	Rear O2 signal	lambda_nb_in	PROTEUS-White35-25	Analog Volt 4	analog_in	single_source
OEM-3-K	Fuel level	analog_in	PROTEUS-White35-26	Analog Volt 6	analog_in	single_source
OEM-3-L	Evap purge solenoid	low_side_out	PROTEUS-Black23-15	ETB 2 positive	hbridge_out	single_source
OEM-3-M	ISC valve +14V feed	power_in	PROTEUS-Black23-23	Main relay feed	power_in	single_source
OEM-3-N	Fuel pump relay	low_side_out	PROTEUS-Black35-10	Lowside 13	low_side_out	single_source
OEM-3-O	ISC valve low side	low_side_out	PROTEUS-Black35-23	Lowside 16	low_side_out	single_source
OEM-3-Q	VICS solenoid (intake butterflies)	low_side_out	PROTEUS-Black23-8	ETB 2 negative	hbridge_out	single_source
OEM-3-S	EGR boost sensor	analog_in	PROTEUS-White35-16	Analog Volt 7	analog_in	single_source
OEM-3-T	EGR boost solenoid	low_side_out	—	—	—	single_source
OEM-3-U	Canister drain cut valve (CDCV)	low_side_out	—	—	—	single_source
OEM-3-V	Rear O2 heater	low_side_out	PROTEUS-Black35-12	Lowside 15	low_side_out	single_source
OEM-3-W	Injector 1	injector_out	PROTEUS-Black35-3	Injector 1	injector_out	single_source
OEM-3-X	Injector 2	injector_out	PROTEUS-Black35-15	Injector 2	injector_out	single_source
OEM-3-Y	Injector 3	injector_out	PROTEUS-Black35-4	Injector 3	injector_out	single_source
OEM-3-Z	Injector 4	injector_out	PROTEUS-Black35-16	Injector 4	injector_out	single_source

Cut list

Wire	From	To	Gauge (mm²)	Length	Signal	Ident
W1	OEM-1-B	SP-14V-1	0.85	no route	ECU power +14V (main relay)	—
W2	OEM-3-M	SP-14V-1	0.85	no route	ISC valve +14V feed	—
W3	SP-14V-1	PROTEUS-Black23-23	0.85	no route	Main relay feed	—
W4	OEM-3-A	SP-GND-1	0.85	no route	Power ground	—
W5	OEM-3-B	SP-GND-1	0.85	no route	Power ground	—
W6	OEM-3-C	SP-GND-1	0.85	no route	Power ground	—
W7	SP-GND-1	PROTEUS-Black23-14	0.85	no route	Power ground	—
W8	SP-GND-1	PROTEUS-Black23-19	0.85	no route	Power ground	—
W9	SP-GND-1	PROTEUS-Black23-20	0.85	no route	Power ground	—
W10	SP-GND-1	PROTEUS-Black35-17	0.85	no route	Power ground	—
W11	SP-GND-1	PROTEUS-Black35-18	0.85	no route	Power ground	—
W12	SP-GND-1	PROTEUS-Black35-24	0.85	no route	Power ground	—
W13	OEM-3-F	SP-0V-1	0.5	no route	Signal ground	—
W14	SP-0V-1	PROTEUS-White35-1	0.5	no route	Sensor ground	—
W15	SP-0V-1	PROTEUS-White35-2	0.5	no route	Sensor ground	—
W16	SP-0V-1	PROTEUS-White35-23	0.5	no route	Sensor ground	—
W17	SP-0V-1	PROTEUS-White35-29	0.5	no route	Sensor ground	—
W18	SP-0V-1	PROTEUS-White35-3	0.5	no route	Sensor ground	—
W19	SP-0V-1	PROTEUS-White35-4	0.5	no route	Sensor ground	—
W20	SP-0V-1	PROTEUS-White35-5	0.5	no route	Sensor ground	—
W21	SP-0V-1	PROTEUS-White35-6	0.5	no route	Sensor ground	—
W22	SP-0V-1	PROTEUS-White35-7	0.5	no route	Sensor ground	—
W23	SP-0V-1	PROTEUS-White35-8	0.5	no route	Sensor ground	—
W24	OEM-2-I	PROTEUS-White35-10	0.5	no route	+5V sensor supply	—
W25	OEM-2-J	PROTEUS-Black23-5	0.5	no route	Crank position (CKP)	—
W26	SP-0V-1	PROTEUS-Black23-13	0.5	no route	VR 1 negative	—
W27	OEM-2-H	PROTEUS-Black23-1	0.5	no route	Cam position (CMP)	—
W28	OEM-2-F	PROTEUS-White35-34	0.5	no route	Knock sensor	—
W29	OEM-3-G	PROTEUS-Black35-35	0.5	no route	Ignition 1 (coils 1+4, wasted spark)	—
W30	OEM-3-H	PROTEUS-Black35-34	0.5	no route	Ignition 2 (coils 2+3, wasted spark)	—
W31	OEM-3-W	PROTEUS-Black35-3	0.5	no route	Injector 1	—
W32	OEM-3-X	PROTEUS-Black35-15	0.5	no route	Injector 2	—
W33	OEM-3-Y	PROTEUS-Black35-4	0.5	no route	Injector 3	—
W34	OEM-3-Z	PROTEUS-Black35-16	0.5	no route	Injector 4	—
W35	OEM-1-I	PROTEUS-Black35-20	0.5	no route	Condenser fan relay	—
W36	OEM-1-R	PROTEUS-Black35-9	0.5	no route	Cooling fan relay	—
W37	OEM-1-S	PROTEUS-Black35-21	0.5	no route	A/C clutch relay	—
W38	OEM-3-N	PROTEUS-Black35-10	0.5	no route	Fuel pump relay	—
W39	OEM-1-U	PROTEUS-Black35-11	0.5	no route	Front O2 heater	—
W40	OEM-3-V	PROTEUS-Black35-12	0.5	no route	Rear O2 heater	—
W41	OEM-3-O	PROTEUS-Black35-23	0.5	no route	ISC valve low side	—
W42	OEM-1-E	PROTEUS-Black35-5	0.5	no route	Malfunction indicator lamp (MIL)	—
W43	OEM-1-O	PROTEUS-Black35-6	0.5	no route	Alternator control	—
W44	OEM-1-Q	PROTEUS-Black35-7	0.5	no route	Charge lamp	—
W45	OEM-2-M	PROTEUS-Black35-19	0.5	no route	EGR valve	—
W46	OEM-2-N	PROTEUS-Black35-8	0.5	no route	EGR valve	—
W47	OEM-2-O	PROTEUS-Black23-6	0.5	no route	EGR valve	—
W48	OEM-2-P	PROTEUS-Black23-7	0.5	no route	EGR valve	—
W49	OEM-3-L	PROTEUS-Black23-15	0.5	no route	Evap purge solenoid	—
W50	OEM-3-Q	PROTEUS-Black23-8	0.5	no route	VICS solenoid (intake butterflies)	—
W51	OEM-2-L	PROTEUS-White35-13	0.5	no route	Mass air flow (MAF)	—
W52	OEM-3-E	PROTEUS-White35-24	0.5	no route	Throttle position (TPS)	—
W53	OEM-2-C	PROTEUS-White35-14	0.5	no route	Front O2 signal	—
W54	OEM-3-J	PROTEUS-White35-25	0.5	no route	Rear O2 signal	—
W55	OEM-2-E	PROTEUS-White35-20	0.5	no route	Coolant temperature (ECT)	—
W56	OEM-2-B	PROTEUS-White35-30	0.5	no route	Intake air temperature (IAT)	—
W57	OEM-2-A	PROTEUS-White35-15	0.5	no route	Fuel tank pressure	—
W58	OEM-3-K	PROTEUS-White35-26	0.5	no route	Fuel level	—
W59	OEM-3-S	PROTEUS-White35-16	0.5	no route	EGR boost sensor	—
W60	OEM-2-D	PROTEUS-Black23-2	0.5	no route	Vehicle speed	—
W61	OEM-1-F	PROTEUS-Black23-10	0.5	no route	Brake switch	—
W62	OEM-1-G	PROTEUS-Black23-3	0.5	no route	Power steering pressure switch	—
W63	OEM-1-P	PROTEUS-Black23-9	0.5	no route	A/C request	—
W64	OEM-1-V	PROTEUS-Black23-11	0.5	no route	Neutral switch	—
W65	OEM-3-I	PROTEUS-White35-27	0.5	no route	Clutch switch	—

Bill of materials

Category	Part number	Manufacturer	Description	Qty	Unit
connector	174514-6	TE	AMP Multilock .040/.070 hybrid 16-pin female harness plug (Miata NB1 ECU)	1.000	ea
connector	174515-6	TE	AMP Multilock .040/.070 hybrid 22-pin female harness plug (Miata NA/NB ECU)	1.000	ea
connector	174516-6	TE	AMP Multilock .040/.070 hybrid 26-pin female harness plug (Miata NA/NB ECU)	1.000	ea

ECU setup sheet

Role	Engine ref	Engine signal	Sensor	ECU point	ECU function	ECU class	Setup flag
No configured channels.

Findings

Open (12)

Severity	Code	Subject	Message
warn	NET_FAMILY	OEM-2-O ↔ PROTEUS-Black23-6	OEM-2-O "EGR valve" [low_side_out] is wired to PROTEUS-Black23-6 "ETB 1 negative" [hbridge_out]. A half-bridge can act as a low-side switch only if configured that way.
warn	NET_FAMILY	OEM-2-P ↔ PROTEUS-Black23-7	OEM-2-P "EGR valve" [low_side_out] is wired to PROTEUS-Black23-7 "ETB 1 positive" [hbridge_out]. A half-bridge can act as a low-side switch only if configured that way.
warn	NET_FAMILY	OEM-3-I ↔ PROTEUS-White35-27	OEM-3-I "Clutch switch" [digital_in] is wired to PROTEUS-White35-27 "Analog Volt 8" [analog_in]. Analog and digital on one net. A switch on an analog input works with a pull-up and a threshold; an analog sensor on a digital input loses its value.
warn	NET_FAMILY	OEM-3-L ↔ PROTEUS-Black23-15	OEM-3-L "Evap purge solenoid" [low_side_out] is wired to PROTEUS-Black23-15 "ETB 2 positive" [hbridge_out]. A half-bridge can act as a low-side switch only if configured that way.
warn	NET_FAMILY	OEM-3-Q ↔ PROTEUS-Black23-8	OEM-3-Q "VICS solenoid (intake butterflies)" [low_side_out] is wired to PROTEUS-Black23-8 "ETB 2 negative" [hbridge_out]. A half-bridge can act as a low-side switch only if configured that way.
info	NET_FAMILY	OEM-1-E ↔ PROTEUS-Black35-5	OEM-1-E "Malfunction indicator lamp (MIL)" [low_side_out] is wired to PROTEUS-Black35-5 "Injector 5" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency.
info	NET_FAMILY	OEM-1-O ↔ PROTEUS-Black35-6	OEM-1-O "Alternator control" [low_side_out] is wired to PROTEUS-Black35-6 "Injector 6" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency.
info	NET_FAMILY	OEM-1-Q ↔ PROTEUS-Black35-7	OEM-1-Q "Charge lamp" [low_side_out] is wired to PROTEUS-Black35-7 "Injector 7" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency.
info	NET_FAMILY	OEM-2-M ↔ PROTEUS-Black35-19	OEM-2-M "EGR valve" [low_side_out] is wired to PROTEUS-Black35-19 "Injector 8" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency.
info	NET_FAMILY	OEM-2-N ↔ PROTEUS-Black35-8	OEM-2-N "EGR valve" [low_side_out] is wired to PROTEUS-Black35-8 "Injector 9" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency.
info	NET_FAMILY	PROTEUS-White35-1 ↔ PROTEUS-Black23-13	PROTEUS-White35-1 "Sensor ground" [sensor_ground] is wired to PROTEUS-Black23-13 "VR 1 negative" [trigger_in]. Trigger return tied to sensor/trigger ground: correct for single-ended trigger inputs.
info	UNMAPPED	OEM	3 optional OEM pins are not mapped: OEM-2-K Tachometer output; OEM-3-T EGR boost solenoid; OEM-3-U Canister drain cut valve (CDCV)

Accepted (1)

Code	Subject	Reason	By
REQUIRED_UNMAPPED	OEM-1-A	Battery-constant (memory) feed of the stock ECU: the new ECU has no such input, so it is not needed.	mapping-proposal

Notes

Auto-mapped by auto_map() from the library pin data on 2026-10-06. Review every wire against both manuals before building. Not wired: - OEM-1 A: Constant +12V: rusEFI Proteus has no battery-constant input; not needed - OEM-3 T: EGR boost solenoid: no free low_side/ls_hs/injector/hbridge on rusEFI Proteus - OEM-3 U: Canister drain cut valve (CDCV): no free low_side/ls_hs/injector/hbridge on rusEFI Proteus - OEM-2 K: Tachometer output: no free tacho/frequency_out/low_side/ls_hs on rusEFI Proteus - PROTEUS-Black23 18: Ignition switch in: not fed (the stock ECU has no ignition-sense pin); feed it from a switched-ignition source

Sources

Reliability	Kind	Title	URL	Archive	Captured	SHA-256
4	vendor_doc	Link G4X MX5NB1X install manual (NB1 1999-00)	https://linkecu.com/documentation/MX5XNB1.pdf	archive	2026-10-05	2e36c91270cc
4	vendor_doc	rusEFI Proteus — board connector definitions (Black35 / White35 / Black23)	https://github.com/rusefi/rusefi/tree/master/firmware/config/boards/proteus/connectors	archive	2026-10-05	738a2ea934c0