MX-5 Miata Mazdaspeed 2004-05 (BP-ZET turbo, no VVT) → DTAFast P8 (auto)

MX-5 Miata Mazdaspeed 2004-05 (BP-ZET turbo, no VVT) — DTAFast — P8

⚠ NOT CHECKED. Don't build from this.

Drawn by Michael Gnankou · Rev 0 · draft · 2026-10-17

Before you start

Not confident with automotive wiring? Have a professional harness builder or tuner do it, or check your work before first power-up. A wiring mistake can damage the ECU, the engine or the car, or start a fire.

Status	draft · not yet verified: nobody has reported building and running this harness
Open errors	none
Size of the job	58 wires · 9 connectors · 0 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-2-P	SP-14V-1	0.85	☐	☐	☐	☐	☐	☐	☐
W2	OEM-4-AF	SP-14V-1	0.85	☐	☐	☐	☐	☐	☐	☐
W3	SP-14V-1	P8-C1-19	0.85	☐	☐	☐	☐	☐	☐	☐
W4	OEM-3-A	SP-GND-1	0.85	☐	☐	☐	☐	☐	☐	☐
W5	OEM-3-B	SP-GND-1	0.85	☐	☐	☐	☐	☐	☐	☐
W6	OEM-4-A	SP-GND-1	0.85	☐	☐	☐	☐	☐	☐	☐
W7	SP-GND-1	P8-C1-15	0.85	☐	☐	☐	☐	☐	☐	☐
W8	SP-GND-1	P8-C1-34	0.85	☐	☐	☐	☐	☐	☐	☐
W9	SP-GND-1	P8-C1-55	0.85	☐	☐	☐	☐	☐	☐	☐
W10	OEM-4-O	SP-0V-1	0.5	☐	☐	☐	☐	☐	☐	☐
W11	SP-0V-1	P8-C1-46	0.5	☐	☐	☐	☐	☐	☐	☐
W12	SP-0V-1	P8-C1-47	0.5	☐	☐	☐	☐	☐	☐	☐
W13	SP-0V-1	P8-C1-49	0.5	☐	☐	☐	☐	☐	☐	☐
W14	SP-0V-1	P8-C1-51	0.5	☐	☐	☐	☐	☐	☐	☐
W15	OEM-4-L	P8-C1-10	0.5	☐	☐	☐	☐	☐	☐	☐
W16	OEM-3-Y	P8-C1-8	0.5	☐	☐	☐	☐	☐	☐	☐
W17	OEM-3-V	P8-C1-27	0.5	☐	☐	☐	☐	☐	☐	☐
W18	OEM-3-F	P8-C1-1	0.5	☐	☐	☐	☐	☐	☐	☐
W19	OEM-3-I	P8-C1-38	0.5	☐	☐	☐	☐	☐	☐	☐
W20	OEM-2-A	P8-C1-37	0.5	☐	☐	☐	☐	☐	☐	☐
W21	OEM-2-D	P8-C1-18	0.5	☐	☐	☐	☐	☐	☐	☐
W22	OEM-2-G	P8-C1-54	0.5	☐	☐	☐	☐	☐	☐	☐
W23	OEM-2-J	P8-C1-36	0.5	☐	☐	☐	☐	☐	☐	☐
W24	OEM-4-X	P8-C1-25	0.5	☐	☐	☐	☐	☐	☐	☐
W25	OEM-4-V	P8-C1-48	0.5	☐	☐	☐	☐	☐	☐	☐
W26	OEM-4-P	P8-C1-26	0.5	☐	☐	☐	☐	☐	☐	☐
W27	OEM-2-B	P8-C1-41	0.5	☐	☐	☐	☐	☐	☐	☐
W28	OEM-2-C	P8-C1-5	0.5	☐	☐	☐	☐	☐	☐	☐
W29	OEM-2-K	P8-C1-43	0.5	☐	☐	☐	☐	☐	☐	☐
W30	OEM-2-M	P8-C1-42	0.5	☐	☐	☐	☐	☐	☐	☐
W31	OEM-3-H	P8-C1-21	0.5	☐	☐	☐	☐	☐	☐	☐
W32	OEM-2-O	P8-C1-23	0.5	☐	☐	☐	☐	☐	☐	☐
W33	OEM-4-D	RLY1-R-OUT	0.5	☐	☐	☐	☐	☐	☐	☐
W34	SP-14V-1	RLY1-R-IN	0.5	☐	☐	☐	☐	☐	☐	☐
W35	SP-14V-1	RLY1-R-COIL+	0.5	☐	☐	☐	☐	☐	☐	☐
W36	RLY1-R-COIL-	P8-C1-4	0.5	☐	☐	☐	☐	☐	☐	☐
W37	OEM-4-E	RLY2-R-OUT	0.5	☐	☐	☐	☐	☐	☐	☐
W38	SP-14V-1	RLY2-R-IN	0.5	☐	☐	☐	☐	☐	☐	☐
W39	SP-14V-1	RLY2-R-COIL+	0.5	☐	☐	☐	☐	☐	☐	☐
W40	RLY2-R-COIL-	P8-C1-6	0.5	☐	☐	☐	☐	☐	☐	☐
W41	OEM-3-J	P8-C1-17	0.5	☐	☐	☐	☐	☐	☐	☐
W42	OEM-3-P	P8-C1-35	0.5	☐	☐	☐	☐	☐	☐	☐
W43	OEM-2-Q	P8-C1-53	0.5	☐	☐	☐	☐	☐	☐	☐
W44	OEM-2-E	P8-C1-16	0.5	☐	☐	☐	☐	☐	☐	☐
W45	OEM-3-O	P8-C1-24	0.5	☐	☐	☐	☐	☐	☐	☐
W46	OEM-4-AE	P8-C1-30	0.5	☐	☐	☐	☐	☐	☐	☐
W47	OEM-4-AA	P8-C1-12	0.5	☐	☐	☐	☐	☐	☐	☐
W48	OEM-4-W	P8-C1-7	0.5	☐	☐	☐	☐	☐	☐	☐
W49	OEM-4-R	P8-C1-45	0.5	☐	☐	☐	☐	☐	☐	☐
W50	OEM-4-N	P8-C1-44	0.5	☐	☐	☐	☐	☐	☐	☐
W51	OEM-3-T	P8-C1-11	0.5	☐	☐	☐	☐	☐	☐	☐
W52	OEM-3-S	P8-C1-13	0.5	☐	☐	☐	☐	☐	☐	☐
W53	OEM-4-B	P8-C1-14	0.5	☐	☐	☐	☐	☐	☐	☐
W54	OEM-4-C	P8-C1-31	0.5	☐	☐	☐	☐	☐	☐	☐
W55	OEM-4-F	P8-C1-32	0.5	☐	☐	☐	☐	☐	☐	☐
W56	OEM-4-H	P8-C1-33	0.5	☐	☐	☐	☐	☐	☐	☐
W57	OEM-4-I	P8-C1-29	0.5	☐	☐	☐	☐	☐	☐	☐
W58	OEM-4-J	P8-C1-50	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	P8-C1-10	P8-C1-46	open (OL)	5 V sensor reference must not touch sensor ground
2	P8-C1-19	P8-C1-15	open (OL)	+12 V supply must not touch power ground
3	P8-C1-19	P8-C1-46	open (OL)	+12 V supply must not touch sensor ground
4	RLY1-R-OUT	P8-C1-46	open (OL)	+12 V supply must not touch sensor ground
5	RLY2-R-OUT	P8-C1-46	open (OL)	+12 V supply must not touch sensor ground
6	P8-C1-15	P8-C1-10	open (OL)	power ground must not touch 5 V sensor reference
7	P8-C1-15	RLY1-R-OUT	open (OL)	power ground must not touch +12 V supply
8	P8-C1-15	RLY2-R-OUT	open (OL)	power ground must not touch +12 V supply
9	P8-C1-19	P8-C1-10	open (OL)	+12 V supply must not touch 5 V sensor reference
10	RLY1-R-OUT	P8-C1-10	open (OL)	+12 V supply must not touch 5 V sensor reference
11	RLY2-R-OUT	P8-C1-10	open (OL)	+12 V supply must not touch 5 V sensor reference

If any reading doesn't match, stop and get help before powering up.

Revisions

Rev	Label	By	Date
No revisions yet.

Schematic

Connectors

OEM-2

Cavity	Function	Signal	Wire	Colour	Gauge (mm²)	Destination	Terminal	Seal	Plug
A	Injector 1	—	W20	—	0.5	P8-C1-37	—	—	—
B	Cooling fan relay	—	W27	—	0.5	P8-C1-41	—	—	—
C	Condenser fan relay	—	W28	—	0.5	P8-C1-5	—	—	—
D	Injector 2	—	W21	—	0.5	P8-C1-18	—	—	—
E	EGR valve	—	W44	—	0.5	P8-C1-16	—	—	—
F	EGR valve	—	—	—	—	—	—	—	—
G	Injector 3	—	W22	—	0.5	P8-C1-54	—	—	—
H	EGR valve	—	—	—	—	—	—	—	—
I	EGR valve	—	—	—	—	—	—	—	—
J	Injector 4	—	W23	—	0.5	P8-C1-36	—	—	—
K	A/C clutch relay	—	W29	—	0.5	P8-C1-43	—	—	—
L	NC	—	—	—	—	—	—	—	—
M	Fuel pump relay	—	W30	—	0.5	P8-C1-42	—	—	—
N	VTCS solenoid (intake butterflies)	—	—	—	—	—	—	—	—
O	Fuel pump relay (non-immobiliser)	—	W32	—	0.5	P8-C1-23	—	—	—
P	ISC valve +14V feed	—	W1	—	0.85	SP-14V-1	—	—	—
Q	ISC valve low side	—	W43	—	0.5	P8-C1-53	—	—	—
R	Malfunction indicator lamp (MIL)	—	—	—	—	—	—	—	—

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	Purge solenoid valve	—	—	—	—	—	—	—	—
D	EGR boost solenoid	—	—	—	—	—	—	—	—
E	NC	—	—	—	—	—	—	—	—
F	Ignition 1 (coils 1+4, wasted spark)	—	W18	—	0.5	P8-C1-1	—	—	—
G	NC	—	—	—	—	—	—	—	—
H	Main relay	—	W31	—	0.5	P8-C1-21	—	—	—
I	Ignition 2 (coils 2+3, wasted spark)	—	W19	—	0.5	P8-C1-38	—	—	—
J	Front O2 heater	—	W41	—	0.5	P8-C1-17	—	—	—
K	EVAP leak detection pump	—	—	—	—	—	—	—	—
L	NC	—	—	—	—	—	—	—	—
M	Alternator control	—	—	—	—	—	—	—	—
N	NC	—	—	—	—	—	—	—	—
O	Tachometer output	—	W45	—	0.5	P8-C1-24	—	—	—
P	Rear O2 heater	—	W42	—	0.5	P8-C1-35	—	—	—
Q	Data link connector (K-line)	—	—	—	—	—	—	—	—
R	NC	—	—	—	—	—	—	—	—
S	Immobiliser	—	W52	—	0.5	P8-C1-13	—	—	—
T	Vehicle speed	—	W51	—	0.5	P8-C1-11	—	—	—
U	Charge lamp	—	—	—	—	—	—	—	—
V	Cam position (CMP)	—	W17	—	0.5	P8-C1-27	—	—	—
W	NC	—	—	—	—	—	—	—	—
X	NC	—	—	—	—	—	—	—	—
Y	Crank position (CKP)	—	W16	—	0.5	P8-C1-8	—	—	—
Z	NC	—	—	—	—	—	—	—	—

OEM-4

Cavity	Function	Signal	Wire	Colour	Gauge (mm²)	Destination	Terminal	Seal	Plug
A	Power ground	—	W6	—	0.85	SP-GND-1	—	—	—
AA	Rear O2 signal	—	W47	—	0.5	P8-C1-12	—	—	—
AB	NC	—	—	—	—	—	—	—	—
AC	Data link connector (DLC TEN, turbo)	—	—	—	—	—	—	—	—
AD	Fuel level	—	—	—	—	—	—	—	—
AE	BARO/MAP sensor (turbo boost pressure)	—	W46	—	0.5	P8-C1-30	—	—	—
AF	ECU power +14V (main relay)	—	W2	—	0.85	SP-14V-1	—	—	—
AG	Constant +12V	—	—	—	—	—	—	—	—
AH	EVAP leak detection pump solenoid valve	—	—	—	—	—	—	—	—
B	Brake switch	—	W53	—	0.5	P8-C1-14	—	—	—
C	Power steering pressure switch	—	W54	—	0.5	P8-C1-31	—	—	—
D	Boost control solenoid (turbo)	—	W33	—	0.5	RLY1-R-OUT	—	—	—
E	Boost control solenoid (turbo)	—	W37	—	0.5	RLY2-R-OUT	—	—	—
F	A/C request	—	W55	—	0.5	P8-C1-32	—	—	—
G	NC	—	—	—	—	—	—	—	—
H	Neutral switch	—	W56	—	0.5	P8-C1-33	—	—	—
I	Clutch switch	—	W57	—	0.5	P8-C1-29	—	—	—
J	VTCS vacuum switch	—	W58	—	0.5	P8-C1-50	—	—	—
K	NC	—	—	—	—	—	—	—	—
L	+5V sensor supply	—	W15	—	0.5	P8-C1-10	—	—	—
M	Knock sensor	—	—	—	—	—	—	—	—
N	Intake air temperature (IAT)	—	W50	—	0.5	P8-C1-44	—	—	—
O	Signal ground	—	W10	—	0.5	SP-0V-1	—	—	—
P	Coolant temperature (ECT)	—	W26	—	0.5	P8-C1-26	—	—	—
Q	NC	—	—	—	—	—	—	—	—
R	Intake air temperature 2 (IAT2, turbo)	—	W49	—	0.5	P8-C1-45	—	—	—
S	Ignition switch (IG1) sense	—	—	—	—	—	—	—	—
T	Generator output voltage (terminal P)	—	—	—	—	—	—	—	—
U	NC	—	—	—	—	—	—	—	—
V	Throttle position (TPS)	—	W25	—	0.5	P8-C1-48	—	—	—
W	Front O2 signal	—	W48	—	0.5	P8-C1-7	—	—	—
X	Mass air flow (MAF)	—	W24	—	0.5	P8-C1-25	—	—	—
Y	NC	—	—	—	—	—	—	—	—
Z	TCM (automatic only)	—	—	—	—	—	—	—	—

P8-C1

Cavity	Function	Signal	Wire	Colour	Gauge (mm²)	Destination	Terminal	Seal	Plug
1	Coil 1	—	W18	—	0.5	OEM-3-F	—	—	—
10	5 Volts	—	W15	—	0.5	OEM-4-L	—	—	—
11	Undriven Wheel (must)	—	W51	—	0.5	OEM-3-T	—	—	—
12	Lambda Signal	—	W47	—	0.5	OEM-4-AA	—	—	—
13	Map2/ALS/Ana1 On/Off	—	W52	—	0.5	OEM-3-S	—	—	—
14	Traction Wet/Dry	—	W53	—	0.5	OEM-4-B	—	—	—
15	Power Ground	—	W7	—	0.85	SP-GND-1	—	—	—
16	Injector 8	—	W44	—	0.5	OEM-2-E	—	—	—
17	Injector 5	—	W41	—	0.5	OEM-3-J	—	—	—
18	Injector 2	—	W21	—	0.5	OEM-2-D	—	—	—
19	12 Volts	—	W3	—	0.85	SP-14V-1	—	—	—
2	Coil 4	—	—	—	—	—	—	—	—
20	Coil 3	—	—	—	—	—	—	—	—
21	Turbo Pressure Valve	—	W31	—	0.5	OEM-3-H	—	—	—
22	Coil 8/or Aux5	—	—	—	—	—	—	—	—
23	Turbo ALS Valve	—	W32	—	0.5	OEM-2-O	—	—	—
24	Tacho	—	W45	—	0.5	OEM-3-O	—	—	—
25	Analogue Input 1	—	W24	—	0.5	OEM-4-X	—	—	—
26	Water Temp	—	W26	—	0.5	OEM-4-P	—	—	—
27	Cam Sensor	—	W17	—	0.5	OEM-3-V	—	—	—
28	5 Volts	—	—	—	—	—	—	—	—
29	Left Driven Wheel	—	W57	—	0.5	OEM-4-I	—	—	—
3	Coil 6	—	—	—	—	—	—	—	—
30	Map	—	W46	—	0.5	OEM-4-AE	—	—	—
31	Launch Button	—	W54	—	0.5	OEM-4-C	—	—	—
32	Traction On/Off	—	W55	—	0.5	OEM-4-F	—	—	—
33	Shift Cut	—	W56	—	0.5	OEM-4-H	—	—	—
34	Power Ground	—	W8	—	0.85	SP-GND-1	—	—	—
35	Injector 6	—	W42	—	0.5	OEM-3-P	—	—	—
36	Injector 4	—	W23	—	0.5	OEM-2-J	—	—	—
37	Injector 1	—	W20	—	0.5	OEM-2-A	—	—	—
38	Coil 2	—	W19	—	0.5	OEM-3-I	—	—	—
39	Coil 5	—	—	—	—	—	—	—	—
4	Idle Valve	—	W36	—	0.5	RLY1-R-COIL-	—	—	—
40	Coil 7	—	—	—	—	—	—	—	—
41	Fuel Pump Relay	—	W27	—	0.5	OEM-2-B	—	—	—
42	Cam Phase Valve/Aux Out 4	—	W30	—	0.5	OEM-2-M	—	—	—
43	Aux Out 3	—	W29	—	0.5	OEM-2-K	—	—	—
44	Analogue Input 3	—	W50	—	0.5	OEM-4-N	—	—	—
45	Air Temp	—	W49	—	0.5	OEM-4-R	—	—	—
46	Signal Ground	—	W11	—	0.5	SP-0V-1	—	—	—
47	Signal Ground	—	W12	—	0.5	SP-0V-1	—	—	—
48	Throttle Wiper	—	W25	—	0.5	OEM-4-V	—	—	—
49	Lambda Earth	—	W13	—	0.5	SP-0V-1	—	—	—
5	Aux Out 2	—	W28	—	0.5	OEM-2-C	—	—	—
50	Undriven Wheel (optional)	—	W58	—	0.5	OEM-4-J	—	—	—
51	Signal Ground	—	W14	—	0.5	SP-0V-1	—	—	—
52	5 Volts	—	—	—	—	—	—	—	—
53	Injector 7	—	W43	—	0.5	OEM-2-Q	—	—	—
54	Injector 3	—	W22	—	0.5	OEM-2-G	—	—	—
55	Power Ground	—	W9	—	0.85	SP-GND-1	—	—	—
6	Shift Light	—	W40	—	0.5	RLY2-R-COIL-	—	—	—
7	Analogue Input 2 Or Log Switch	—	W48	—	0.5	OEM-4-W	—	—	—
8	Crank Sensor	—	W16	—	0.5	OEM-3-Y	—	—	—
9	Right Driven Wheel	—	—	—	—	—	—	—	—

RLY1-R

Cavity	Function	Signal	Wire	Colour	Gauge (mm²)	Destination	Terminal	Seal	Plug
COIL+	Relay coil positive (switched +12 V)	—	W35	—	0.5	SP-14V-1	—	—	—
COIL-	Relay coil negative (ECU low-side driver)	—	W36	—	0.5	P8-C1-4	—	—	—
IN	Relay contact input (switched +12 V)	—	W34	—	0.5	SP-14V-1	—	—	—
OUT	Relay contact output (switched +12 V to load)	—	W33	—	0.5	OEM-4-D	—	—	—

RLY2-R

Cavity	Function	Signal	Wire	Colour	Gauge (mm²)	Destination	Terminal	Seal	Plug
COIL+	Relay coil positive (switched +12 V)	—	W39	—	0.5	SP-14V-1	—	—	—
COIL-	Relay coil negative (ECU low-side driver)	—	W40	—	0.5	P8-C1-6	—	—	—
IN	Relay contact input (switched +12 V)	—	W38	—	0.5	SP-14V-1	—	—	—
OUT	Relay contact output (switched +12 V to load)	—	W37	—	0.5	OEM-4-E	—	—	—

SP-0V

Cavity	Function	Signal	Wire	Colour	Gauge (mm²)	Destination	Terminal	Seal	Plug
1	—	—	W10	—	0.5	OEM-4-O	—	—	—
1	—	—	W11	—	0.5	P8-C1-46	—	—	—
1	—	—	W12	—	0.5	P8-C1-47	—	—	—
1	—	—	W13	—	0.5	P8-C1-49	—	—	—
1	—	—	W14	—	0.5	P8-C1-51	—	—	—

SP-14V

Cavity	Function	Signal	Wire	Colour	Gauge (mm²)	Destination	Terminal	Seal	Plug
1	—	—	W1	—	0.85	OEM-2-P	—	—	—
1	—	—	W2	—	0.85	OEM-4-AF	—	—	—
1	—	—	W3	—	0.85	P8-C1-19	—	—	—
1	—	—	W34	—	0.5	RLY1-R-IN	—	—	—
1	—	—	W35	—	0.5	RLY1-R-COIL+	—	—	—
1	—	—	W38	—	0.5	RLY2-R-IN	—	—	—
1	—	—	W39	—	0.5	RLY2-R-COIL+	—	—	—

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-4-A	—	—	—
1	—	—	W7	—	0.85	P8-C1-15	—	—	—
1	—	—	W8	—	0.85	P8-C1-34	—	—	—
1	—	—	W9	—	0.85	P8-C1-55	—	—	—

Pin map

OEM point	OEM function	OEM family	Target point	Target function	Target family	Wire colour	Evidence
OEM-2-A	Injector 1	injector_out	P8-C1-37	Injector 1	injector_out		corroborated
OEM-2-B	Cooling fan relay	low_side_out	P8-C1-41	Fuel Pump Relay	low_side_out		corroborated
OEM-2-C	Condenser fan relay	low_side_out	P8-C1-5	Aux Out 2	low_side_out		corroborated
OEM-2-D	Injector 2	injector_out	P8-C1-18	Injector 2	injector_out		corroborated
OEM-2-E	EGR valve	low_side_out	P8-C1-16	Injector 8	injector_out		corroborated
OEM-2-F	EGR valve	low_side_out	—	—	—		corroborated
OEM-2-G	Injector 3	injector_out	P8-C1-54	Injector 3	injector_out		corroborated
OEM-2-H	EGR valve	low_side_out	—	—	—		corroborated
OEM-2-I	EGR valve	low_side_out	—	—	—		corroborated
OEM-2-J	Injector 4	injector_out	P8-C1-36	Injector 4	injector_out		corroborated
OEM-2-K	A/C clutch relay	low_side_out	P8-C1-43	Aux Out 3	low_side_out		corroborated
OEM-2-L	NC	—	—	—	—		single_source
OEM-2-M	Fuel pump relay	low_side_out	P8-C1-42	Cam Phase Valve/Aux Out 4	low_side_out		corroborated
OEM-2-N	VTCS solenoid (intake butterflies)	low_side_out	—	—	—		corroborated
OEM-2-O	Fuel pump relay (non-immobiliser)	low_side_out	P8-C1-23	Turbo ALS Valve	low_side_out		corroborated
OEM-2-P	ISC valve +14V feed	power_in	P8-C1-19 + RLY1-R-COIL+ + RLY1-R-IN + RLY2-R-COIL+ + RLY2-R-IN	12 Volts + Relay coil positive (switched +12 V) + Relay contact input (switched +12 V) + Relay coil positive (switched +12 V) + Relay contact input (switched +12 V)	power_in + power_out		corroborated
OEM-2-Q	ISC valve low side	low_side_out	P8-C1-53	Injector 7	injector_out		corroborated
OEM-2-R	Malfunction indicator lamp (MIL)	low_side_out	—	—	—		corroborated
OEM-3-A	Power ground	ground	P8-C1-15 + P8-C1-34 + P8-C1-55	Power Ground + Power Ground + Power Ground	ground		corroborated
OEM-3-B	Power ground	ground	P8-C1-15 + P8-C1-34 + P8-C1-55	Power Ground + Power Ground + Power Ground	ground		corroborated
OEM-3-C	Purge solenoid valve	low_side_out	—	—	—		corroborated
OEM-3-D	EGR boost solenoid	—	—	—	—		conflict
OEM-3-E	NC	—	—	—	—		single_source
OEM-3-F	Ignition 1 (coils 1+4, wasted spark)	ignition_out	P8-C1-1	Coil 1	ignition_out		corroborated
OEM-3-G	NC	—	—	—	—		single_source
OEM-3-H	Main relay	low_side_out	P8-C1-21	Turbo Pressure Valve	low_side_out		corroborated
OEM-3-I	Ignition 2 (coils 2+3, wasted spark)	ignition_out	P8-C1-38	Coil 2	ignition_out		corroborated
OEM-3-J	Front O2 heater	low_side_out	P8-C1-17	Injector 5	injector_out		corroborated
OEM-3-K	EVAP leak detection pump	low_side_out	—	—	—		corroborated
OEM-3-L	NC	—	—	—	—		single_source
OEM-3-M	Alternator control	low_side_out	—	—	—		corroborated
OEM-3-N	NC	—	—	—	—		single_source
OEM-3-O	Tachometer output	tacho_out	P8-C1-24	Tacho	tacho_out		corroborated
OEM-3-P	Rear O2 heater	low_side_out	P8-C1-35	Injector 6	injector_out		corroborated
OEM-3-Q	Data link connector (K-line)	serial	—	—	—		corroborated
OEM-3-R	NC	—	—	—	—		single_source
OEM-3-S	Immobiliser	digital_in	P8-C1-13	Map2/ALS/Ana1 On/Off	digital_in		corroborated
OEM-3-T	Vehicle speed	digital_in	P8-C1-11	Undriven Wheel (must)	digital_in		corroborated
OEM-3-U	Charge lamp	low_side_out	—	—	—		corroborated
OEM-3-V	Cam position (CMP)	trigger_in	P8-C1-27	Cam Sensor	trigger_in		corroborated
OEM-3-W	NC	—	—	—	—		single_source
OEM-3-X	NC	—	—	—	—		single_source
OEM-3-Y	Crank position (CKP)	trigger_in	P8-C1-8	Crank Sensor	trigger_in		corroborated
OEM-3-Z	NC	—	—	—	—		single_source
OEM-4-A	Power ground	ground	P8-C1-15 + P8-C1-34 + P8-C1-55	Power Ground + Power Ground + Power Ground	ground		corroborated
OEM-4-AA	Rear O2 signal	lambda_nb_in	P8-C1-12	Lambda Signal	lambda_nb_in		corroborated
OEM-4-AB	NC	—	—	—	—		single_source
OEM-4-AC	Data link connector (DLC TEN, turbo)	serial	—	—	—	BrY	single_source
OEM-4-AD	Fuel level	analog_in	—	—	—		corroborated
OEM-4-AE	BARO/MAP sensor (turbo boost pressure)	analog_in	P8-C1-30	Map	analog_in	LY	single_source
OEM-4-AF	ECU power +14V (main relay)	power_in	P8-C1-19 + RLY1-R-COIL+ + RLY1-R-IN + RLY2-R-COIL+ + RLY2-R-IN	12 Volts + Relay coil positive (switched +12 V) + Relay contact input (switched +12 V) + Relay coil positive (switched +12 V) + Relay contact input (switched +12 V)	power_in + power_out		corroborated
OEM-4-AG	Constant +12V	power_in	—	—	—		corroborated
OEM-4-AH	EVAP leak detection pump solenoid valve	low_side_out	—	—	—		corroborated
OEM-4-B	Brake switch	digital_in	P8-C1-14	Traction Wet/Dry	digital_in		corroborated
OEM-4-C	Power steering pressure switch	digital_in	P8-C1-31	Launch Button	digital_in		corroborated
OEM-4-D	Boost control solenoid (turbo)	high_side_out	RLY1-R-OUT	Relay contact output (switched +12 V to load)	power_out	Y	single_source
OEM-4-E	Boost control solenoid (turbo)	high_side_out	RLY2-R-OUT	Relay contact output (switched +12 V to load)	power_out	Y	single_source
OEM-4-F	A/C request	digital_in	P8-C1-32	Traction On/Off	digital_in		corroborated
OEM-4-G	NC	—	—	—	—		single_source
OEM-4-H	Neutral switch	digital_in	P8-C1-33	Shift Cut	digital_in		corroborated
OEM-4-I	Clutch switch	digital_in	P8-C1-29	Left Driven Wheel	digital_in		corroborated
OEM-4-J	VTCS vacuum switch	digital_in	P8-C1-50	Undriven Wheel (optional)	digital_in		corroborated
OEM-4-K	NC	—	—	—	—		single_source
OEM-4-L	+5V sensor supply	vref	P8-C1-10	5 Volts	vref		corroborated
OEM-4-M	Knock sensor	knock_in	—	—	—		corroborated
OEM-4-N	Intake air temperature (IAT)	temp_in	P8-C1-44	Analogue Input 3	analog_in		corroborated
OEM-4-O	Signal ground	sensor_ground	P8-C1-46 + P8-C1-47 + P8-C1-49 + P8-C1-51	Signal Ground + Signal Ground + Lambda Earth + Signal Ground	sensor_ground		corroborated
OEM-4-P	Coolant temperature (ECT)	temp_in	P8-C1-26	Water Temp	temp_in		corroborated
OEM-4-Q	NC	—	—	—	—		single_source
OEM-4-R	Intake air temperature 2 (IAT2, turbo)	temp_in	P8-C1-45	Air Temp	temp_in	VY	single_source
OEM-4-S	Ignition switch (IG1) sense	digital_in	—	—	—		corroborated
OEM-4-T	Generator output voltage (terminal P)	—	—	—	—		corroborated
OEM-4-U	NC	—	—	—	—		single_source
OEM-4-V	Throttle position (TPS)	analog_in	P8-C1-48	Throttle Wiper	analog_in		corroborated
OEM-4-W	Front O2 signal	lambda_nb_in	P8-C1-7	Analogue Input 2 Or Log Switch	analog_in		corroborated
OEM-4-X	Mass air flow (MAF)	analog_in	P8-C1-25	Analogue Input 1	analog_in		corroborated
OEM-4-Y	NC	—	—	—	—		single_source
OEM-4-Z	TCM (automatic only)	—	—	—	—		corroborated

Cut list

Wire	From	To	Gauge (mm²)	Length	Signal	Ident
W1	OEM-2-P	SP-14V-1	0.85	no route	ISC valve +14V feed	—
W2	OEM-4-AF	SP-14V-1	0.85	no route	ECU power +14V (main relay)	—
W3	SP-14V-1	P8-C1-19	0.85	no route	12 Volts	—
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-4-A	SP-GND-1	0.85	no route	Power ground	—
W7	SP-GND-1	P8-C1-15	0.85	no route	Power Ground	—
W8	SP-GND-1	P8-C1-34	0.85	no route	Power Ground	—
W9	SP-GND-1	P8-C1-55	0.85	no route	Power Ground	—
W10	OEM-4-O	SP-0V-1	0.5	no route	Signal ground	—
W11	SP-0V-1	P8-C1-46	0.5	no route	Signal Ground	—
W12	SP-0V-1	P8-C1-47	0.5	no route	Signal Ground	—
W13	SP-0V-1	P8-C1-49	0.5	no route	Lambda Earth	—
W14	SP-0V-1	P8-C1-51	0.5	no route	Signal Ground	—
W15	OEM-4-L	P8-C1-10	0.5	no route	+5V sensor supply	—
W16	OEM-3-Y	P8-C1-8	0.5	no route	Crank position (CKP)	—
W17	OEM-3-V	P8-C1-27	0.5	no route	Cam position (CMP)	—
W18	OEM-3-F	P8-C1-1	0.5	no route	Ignition 1 (coils 1+4, wasted spark)	—
W19	OEM-3-I	P8-C1-38	0.5	no route	Ignition 2 (coils 2+3, wasted spark)	—
W20	OEM-2-A	P8-C1-37	0.5	no route	Injector 1	—
W21	OEM-2-D	P8-C1-18	0.5	no route	Injector 2	—
W22	OEM-2-G	P8-C1-54	0.5	no route	Injector 3	—
W23	OEM-2-J	P8-C1-36	0.5	no route	Injector 4	—
W24	OEM-4-X	P8-C1-25	0.5	no route	Mass air flow (MAF)	—
W25	OEM-4-V	P8-C1-48	0.5	no route	Throttle position (TPS)	—
W26	OEM-4-P	P8-C1-26	0.5	no route	Coolant temperature (ECT)	—
W27	OEM-2-B	P8-C1-41	0.5	no route	Cooling fan relay	—
W28	OEM-2-C	P8-C1-5	0.5	no route	Condenser fan relay	—
W29	OEM-2-K	P8-C1-43	0.5	no route	A/C clutch relay	—
W30	OEM-2-M	P8-C1-42	0.5	no route	Fuel pump relay	—
W31	OEM-3-H	P8-C1-21	0.5	no route	Main relay	—
W32	OEM-2-O	P8-C1-23	0.5	no route	Fuel pump relay (non-immobiliser)	—
W33	OEM-4-D	RLY1-R-OUT	0.5	no route	Boost control solenoid (turbo)	—
W34	SP-14V-1	RLY1-R-IN	0.5	no route	Relay contact input (switched +12 V)	—
W35	SP-14V-1	RLY1-R-COIL+	0.5	no route	Relay coil positive (switched +12 V)	—
W36	RLY1-R-COIL-	P8-C1-4	0.5	no route	Relay coil negative (ECU low-side driver)	—
W37	OEM-4-E	RLY2-R-OUT	0.5	no route	Boost control solenoid (turbo)	—
W38	SP-14V-1	RLY2-R-IN	0.5	no route	Relay contact input (switched +12 V)	—
W39	SP-14V-1	RLY2-R-COIL+	0.5	no route	Relay coil positive (switched +12 V)	—
W40	RLY2-R-COIL-	P8-C1-6	0.5	no route	Relay coil negative (ECU low-side driver)	—
W41	OEM-3-J	P8-C1-17	0.5	no route	Front O2 heater	—
W42	OEM-3-P	P8-C1-35	0.5	no route	Rear O2 heater	—
W43	OEM-2-Q	P8-C1-53	0.5	no route	ISC valve low side	—
W44	OEM-2-E	P8-C1-16	0.5	no route	EGR valve	—
W45	OEM-3-O	P8-C1-24	0.5	no route	Tachometer output	—
W46	OEM-4-AE	P8-C1-30	0.5	no route	BARO/MAP sensor (turbo boost pressure)	—
W47	OEM-4-AA	P8-C1-12	0.5	no route	Rear O2 signal	—
W48	OEM-4-W	P8-C1-7	0.5	no route	Front O2 signal	—
W49	OEM-4-R	P8-C1-45	0.5	no route	Intake air temperature 2 (IAT2, turbo)	—
W50	OEM-4-N	P8-C1-44	0.5	no route	Intake air temperature (IAT)	—
W51	OEM-3-T	P8-C1-11	0.5	no route	Vehicle speed	—
W52	OEM-3-S	P8-C1-13	0.5	no route	Immobiliser	—
W53	OEM-4-B	P8-C1-14	0.5	no route	Brake switch	—
W54	OEM-4-C	P8-C1-31	0.5	no route	Power steering pressure switch	—
W55	OEM-4-F	P8-C1-32	0.5	no route	A/C request	—
W56	OEM-4-H	P8-C1-33	0.5	no route	Neutral switch	—
W57	OEM-4-I	P8-C1-29	0.5	no route	Clutch switch	—
W58	OEM-4-J	P8-C1-50	0.5	no route	VTCS vacuum switch	—

Bill of materials

Category	Part number	Manufacturer	Description	Qty	Unit

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	LOAD_UNKNOWN	P8-C1-21	P8-C1-21 "Turbo Pressure Valve" drives OEM-3-H Main relay (load 0.2 A) but its current rating is unknown. Check the ECU manual.
warn	LOAD_UNKNOWN	P8-C1-41	P8-C1-41 "Fuel Pump Relay" drives OEM-2-B Cooling fan relay (load 0.2 A) but its current rating is unknown. Check the ECU manual.
warn	LOAD_UNKNOWN	P8-C1-42	P8-C1-42 "Cam Phase Valve/Aux Out 4" drives OEM-2-M Fuel pump relay (load 0.2 A) but its current rating is unknown. Check the ECU manual.
warn	LOAD_UNKNOWN	P8-C1-43	P8-C1-43 "Aux Out 3" drives OEM-2-K A/C clutch relay (load 0.2 A) but its current rating is unknown. Check the ECU manual.
warn	LOAD_UNKNOWN	P8-C1-5	P8-C1-5 "Aux Out 2" drives OEM-2-C Condenser fan relay (load 0.2 A) but its current rating is unknown. Check the ECU manual.
warn	LOAD_UNKNOWN	P8-C1-53	P8-C1-53 "Injector 7" drives OEM-2-Q ISC valve low side (load 1.0 A) but its current rating is unknown. Check the ECU manual.
info	NET_FAMILY	OEM-2-E ↔ P8-C1-16	OEM-2-E "EGR valve" [low_side_out] is wired to P8-C1-16 "Injector 8" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency.
info	NET_FAMILY	OEM-2-Q ↔ P8-C1-53	OEM-2-Q "ISC valve low side" [low_side_out] is wired to P8-C1-53 "Injector 7" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency.
info	NET_FAMILY	OEM-3-J ↔ P8-C1-17	OEM-3-J "Front O2 heater" [low_side_out] is wired to P8-C1-17 "Injector 5" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency.
info	NET_FAMILY	OEM-3-P ↔ P8-C1-35	OEM-3-P "Rear O2 heater" [low_side_out] is wired to P8-C1-35 "Injector 6" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency.
info	NET_FAMILY	OEM-4-N ↔ P8-C1-44	OEM-4-N "Intake air temperature (IAT)" [temp_in] is wired to P8-C1-44 "Analogue Input 3" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one.
info	UNMAPPED	OEM	18 optional OEM pins are not mapped: OEM-2-F EGR valve; OEM-2-H EGR valve; OEM-2-I EGR valve; OEM-2-N VTCS solenoid (intake butterflies); OEM-2-R Malfunction indicator lamp (MIL); OEM-3-C Purge solenoid valve; OEM-3-D EGR boost solenoid; OEM-3-K EVAP leak detection pump; OEM-3-M Alternator control; OEM-3-Q Data link connector (K-line); OEM-3-U Charge lamp; OEM-4-AC Data link connector (DLC TEN, turbo); OEM-4-AD Fuel level; OEM-4-AH EVAP leak detection pump solenoid valve; OEM-4-M Knock sensor; OEM-4-S Ignition switch (IG1) sense; OEM-4-T Generator output voltage (terminal P); OEM-4-Z TCM (automatic only)

Accepted (1)

Code	Subject	Reason	By
REQUIRED_UNMAPPED	OEM-4-AG	Battery-constant (memory) feed of the stock ECU: the new ECU has no such input, so it is not needed.	mapping-proposal

Notes

Fit check: unconfirmed. Confirm these before building: - Knock input count not found Auto-mapped by auto_map() from the library pin data on 2026-10-17. Review every wire against both manuals before building. Not wired: - OEM-4 AG: Constant +12V: DTAFast P8 has no battery-constant input; not needed - OEM-4 M: Knock sensor: no free knock input on DTAFast P8 - OEM-4 S: Ignition switch (IG1) sense: key-on 12 V sense — optional in a swap (the main relay is energized from keyed 12 V, not from this pin); DTAFast P8 has no dedicated key-on input - OEM-2 F: EGR valve: no free low_side/relay_control/heater_low_side/ls_hs/injector on DTAFast P8 - OEM-2 H: EGR valve: no free low_side/relay_control/heater_low_side/ls_hs/injector on DTAFast P8 - OEM-2 I: EGR valve: no free low_side/relay_control/heater_low_side/ls_hs/injector on DTAFast P8 - OEM-2 N: VTCS solenoid (intake butterflies): no free low_side/relay_control/heater_low_side/ls_hs/injector on DTAFast P8 - OEM-2 R: Malfunction indicator lamp (MIL): no free low_side/relay_control/heater_low_side/ls_hs/injector on DTAFast P8 - OEM-3 C: Purge solenoid valve: no free low_side/relay_control/heater_low_side/ls_hs/injector on DTAFast P8 - OEM-3 K: EVAP leak detection pump: no free low_side/relay_control/heater_low_side/ls_hs/injector on DTAFast P8 - OEM-3 M: Alternator control: no free low_side/relay_control/heater_low_side/ls_hs/injector on DTAFast P8 - OEM-3 U: Charge lamp: no free low_side/relay_control/heater_low_side/ls_hs/injector on DTAFast P8 - OEM-4 AH: EVAP leak detection pump solenoid valve: no free low_side/relay_control/heater_low_side/ls_hs/injector on DTAFast P8 - OEM-4 AD: Fuel level: no free analog_0_5 on DTAFast P8 - OEM-3 Q: Data link connector (K-line): no free k_line on DTAFast P8 - OEM-4 AC: Data link connector (DLC TEN, turbo): no free k_line on DTAFast P8 - OEM-3 D: EGR boost solenoid: not classified in the library; wire by hand - OEM-4 T: Generator output voltage (terminal P): not classified in the library; wire by hand - OEM-4 Z: TCM (automatic only): not classified in the library; wire by hand

Sources

Reliability	Kind	Title	URL	Archive	Captured	SHA-256
4	oem_manual	2005 Mazda MX-5 Miata Engine Performance Control System (PCM terminal voltage reference, BP and BP WITH TC)	https://trull.org/alex/pubmirror/www.mellens.net/mazda/Mazda-Miata-2005/engine_control_system.pdf	—	—	—
4	vendor_doc	Adaptronic eSel039 Select Plugin ECU for Mazda MX5 / Miata NB8B/C (OEM ECU pinout)	https://www.miataturbo.net/attachments/ecus-tuning-54/04-msm-ecu-pinout-104032/nb8bc_oem_ecu_pinouts-224948d1602912806	—	—	—
4	vendor_doc	Bosch relay catalogue (mini ISO relays)	https://www.bosch-ibusiness.com/media/downloads/kataloge/relay/2025_10_bosch_relay_catalogue.pdf	archive	2026-10-05	20344cff1ef3
4	vendor_doc	DTAFast P8Pro wiring schematic	https://dtafast.co.uk/pages/ecu-wiring-diagrams	—	—	—
4	community_copy	Honda S2000 Service Manual 2000–2008, Fuel and Emissions Systems	https://www.s2000.wiki/view/images/7/7f/Service_Manual_2000-2008.pdf	archive	2026-10-05	a470cfc928e9
4	vendor_doc	Link G4X MX5NB2X install manual (NB2 2001-05)	https://linkecu.com/documentation/MX5XNB2.pdf	archive	2026-10-05	741efdd9f2c8
4	vendor_doc	Omron G8V-RH-1C7T-R-DC12 high-current micro 280 automotive relay datasheet	https://www.alldatasheet.com/datasheet-pdf/pdf/333797/OMRON/G8V-RH-1C7T-R-DC12.html	—	2026-10-05	764a0505a941