MX-5 Miata NA8 1996-97 (BP-ZE, 1.8, OBD-II) → DTAFast T12 (auto)
MX-5 Miata NA8 1996-97 (BP-ZE, 1.8, OBD-II) — DTAFast — T12
⚠ NOT CHECKED. Don't build from this.
Drawn by Michael Gnankou · Rev 0 · draft · 2026-10-12
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 | 1: read the Findings page before cutting any wire |
| Size of the job | 51 wires · 9 connectors · 2 part lines |
| Tools | Crimp and extraction tools for each terminal family (see Connectors) · wire strippers · multimeter · heat gun + heat-shrink |
| Terminals | 3-1447221-4 |
| 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 | Colour | Cut | Label | Crimp A | Crimp B | Pin A | Pin B | Continuity |
|---|---|---|---|---|---|---|---|---|---|---|---|
| W1 | OEM-4-B | SP-14V-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W2 | SP-14V-1 | T12-C1-31 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W3 | OEM-4-I | T12-C3-26 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W4 | OEM-4-A | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W5 | OEM-4-C | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W6 | OEM-4-D | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W7 | OEM-4-K | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | SP-GND-1 | T12-C1-13 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | SP-GND-1 | T12-C1-14 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | OEM-3-O | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | OEM-4-H | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | SP-0V-1 | T12-C2-21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | SP-0V-1 | T12-C2-33 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | OEM-3-I | T12-C2-24 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | OEM-4-E | T12-C2-12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | OEM-4-G | T12-C2-22 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-4-F | T12-C2-29 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-4-N | T12-C1-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-4-R | T12-C1-18 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-4-U | T12-C1-9 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-4-V | T12-C1-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-4-W | T12-C1-34 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-4-X | T12-C1-25 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-3-B | T12-C2-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-3-F | T12-C2-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-3-G | T12-C2-7 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-1-A | T12-C1-5 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-1-B | T12-C1-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-1-G | T12-C1-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | OEM-1-U | T12-C3-22 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-3-M | T12-C3-9 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-1-E | T12-C3-23 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-4-J | T12-C3-24 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-4-O | T12-C3-25 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W35 | OEM-4-P | T12-C3-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W36 | OEM-4-Q | T12-C3-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W37 | OEM-4-T | T12-C3-28 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W38 | OEM-4-L | T12-C3-29 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W39 | OEM-3-H | T12-C2-5 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W40 | OEM-3-N | T12-C2-6 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W41 | OEM-3-C | T12-C2-18 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W42 | OEM-3-D | T12-C2-19 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W43 | OEM-3-K | T12-C2-25 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W44 | OEM-3-J | T12-C3-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W45 | OEM-1-M | T12-C2-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W46 | OEM-1-C | T12-C2-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W47 | OEM-1-K | T12-C2-8 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W48 | OEM-1-L | T12-C2-11 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W49 | OEM-1-Q | T12-C2-14 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W50 | OEM-3-L | T12-C2-15 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W51 | OEM-3-P | T12-C2-27 | 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 | Reading |
|---|---|---|---|---|---|
| 1 | T12-C2-24 | T12-C1-13 | open (OL) | 5 V sensor reference must not touch power ground | |
| 2 | T12-C2-24 | T12-C2-21 | open (OL) | 5 V sensor reference must not touch sensor ground | |
| 3 | T12-C1-13 | T12-C1-31 | open (OL) | power ground must not touch +12 V supply | |
| 4 | T12-C1-13 | T12-C3-26 | open (OL) | power ground must not touch +12 V supply | |
| 5 | T12-C2-21 | T12-C1-31 | open (OL) | sensor ground must not touch +12 V supply | |
| 6 | T12-C2-21 | T12-C3-26 | open (OL) | sensor ground must not touch +12 V supply | |
| 7 | T12-C2-24 | T12-C1-31 | open (OL) | 5 V sensor reference must not touch +12 V supply | |
| 8 | T12-C2-24 | T12-C3-26 | open (OL) | 5 V sensor reference must not touch +12 V supply |
If any reading doesn't match, stop and get help before powering up.
Revisions
| Rev | Label | By | Date |
|---|---|---|---|
| No revisions yet. | |||
Schematic
Connectors
OEM-1
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A | Cooling fan relay (low-side) | — | W27 | — | 0.5 | T12-C1-5 | — | — | — |
| B | A/C condenser fan relay | — | W28 | — | 0.5 | T12-C1-4 | — | — | — |
| C | Starter input (12V while cranking) | — | W46 | — | 0.5 | T12-C2-4 | — | — | — |
| E | Check engine light (MIL) | — | W32 | — | 0.5 | T12-C3-23 | — | — | — |
| G | A/C clutch relay | — | W29 | — | 0.5 | T12-C1-3 | — | — | — |
| K | A/C pressure switch (A/C request) | — | W47 | — | 0.5 | T12-C2-8 | — | — | — |
| L | Clutch switch | — | W48 | — | 0.5 | T12-C2-11 | — | — | — |
| M | Vehicle speed sensor (VSS) | — | W45 | — | 0.5 | T12-C2-2 | — | — | — |
| Q | Brake switch | — | W49 | — | 0.5 | T12-C2-14 | — | — | — |
| U | Fuel pump relay (low-side) | — | W30 | — | 0.5 | T12-C3-22 | — | — | — |
OEM-3
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| B | MAF sensor input | — | W24 | — | 0.5 | T12-C2-10 | — | — | — |
| C | Front O2 sensor input | — | W41 | — | 0.5 | T12-C2-18 | — | — | — |
| D | Rear O2 sensor input | — | W42 | — | 0.5 | T12-C2-19 | — | — | — |
| F | Throttle position (TPS) | — | W25 | — | 0.5 | T12-C2-1 | — | — | — |
| G | Engine coolant temp (CLT) | — | W26 | — | 0.5 | T12-C2-7 | — | — | — |
| H | EGR boost sensor | — | W39 | — | 0.5 | T12-C2-5 | — | — | — |
| I | +5V sensor reference | — | W14 | — | 0.5 | T12-C2-24 | — | — | — |
| J | EGR valve position sensor | — | W44 | — | 0.5 | T12-C3-17 | — | — | — |
| K | Intake air temp (IAT) | — | W43 | — | 0.5 | T12-C2-25 | — | — | — |
| L | Idle switch (closed throttle) | — | W50 | — | 0.5 | T12-C2-15 | — | — | — |
| M | Front O2 heater control | — | W31 | — | 0.5 | T12-C3-9 | — | — | — |
| N | EGR boost sensor (2nd channel) | — | W40 | — | 0.5 | T12-C2-6 | — | — | — |
| O | Sensor ground | — | W10 | — | 0.5 | SP-0V-1 | — | — | — |
| P | Power steering pressure switch | — | W51 | — | 0.5 | T12-C2-27 | — | — | — |
OEM-4
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A | Chassis ground | — | W4 | — | 0.85 | SP-GND-1 | — | — | — |
| B | ECU power +12V (main relay) | — | W1 | — | 0.85 | SP-14V-1 | — | — | — |
| C | Chassis ground | — | W5 | — | 0.85 | SP-GND-1 | — | — | — |
| D | Chassis ground | — | W6 | — | 0.85 | SP-GND-1 | — | — | — |
| E | Crank position (CKP) sensor | — | W15 | — | 0.5 | T12-C2-12 | — | — | — |
| F | CAS SGT (cam trigger) | — | W17 | — | 0.5 | T12-C2-29 | — | — | — |
| G | CAS SGC (cam sync) | — | W16 | — | 0.5 | T12-C2-22 | — | — | — |
| H | Crank pickup timing ground (CKP gnd) | — | W11 | — | 0.5 | SP-0V-1 | — | — | — |
| I | Permanent +12V (battery) | — | W3 | — | 0.85 | T12-C3-26 | — | — | — |
| J | PRC solenoid (FPR control) | — | W33 | — | 0.5 | T12-C3-24 | — | — | — |
| K | Chassis ground | — | W7 | — | 0.85 | SP-GND-1 | — | — | — |
| L | Tachometer output | — | W38 | — | 0.5 | T12-C3-29 | — | — | — |
| N | Ignition coil trigger (cyl 1&4) | — | W18 | — | 0.5 | T12-C1-10 | — | — | — |
| O | EGR vent solenoid | — | W34 | — | 0.5 | T12-C3-25 | — | — | — |
| P | EGR vacuum solenoid | — | W35 | — | 0.5 | T12-C3-10 | — | — | — |
| Q | Idle air control (IAC) valve | — | W36 | — | 0.5 | T12-C3-4 | — | — | — |
| R | Ignition coil trigger (cyl 2&3) | — | W19 | — | 0.5 | T12-C1-18 | — | — | — |
| T | EVAP purge solenoid | — | W37 | — | 0.5 | T12-C3-28 | — | — | — |
| U | Injector 1 (cyl 1) | — | W20 | — | 0.5 | T12-C1-9 | — | — | — |
| V | Injector 2 (cyl 2) | — | W21 | — | 0.5 | T12-C1-17 | — | — | — |
| W | Injector 3 (cyl 3) | — | W22 | — | 0.5 | T12-C1-34 | — | — | — |
| X | Injector 4 (cyl 4) | — | W23 | — | 0.5 | T12-C1-25 | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W10 | — | 0.5 | OEM-3-O | — | — | — |
| 1 | — | — | W11 | — | 0.5 | OEM-4-H | — | — | — |
| 1 | — | — | W12 | — | 0.5 | T12-C2-21 | — | — | — |
| 1 | — | — | W13 | — | 0.5 | T12-C2-33 | — | — | — |
SP-14V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W2 | — | 0.85 | T12-C1-31 | — | — | — |
| 1 | — | — | W1 | — | 0.85 | OEM-4-B | — | — | — |
SP-GND
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W4 | — | 0.85 | OEM-4-A | — | — | — |
| 1 | — | — | W5 | — | 0.85 | OEM-4-C | — | — | — |
| 1 | — | — | W6 | — | 0.85 | OEM-4-D | — | — | — |
| 1 | — | — | W7 | — | 0.85 | OEM-4-K | — | — | — |
| 1 | — | — | W8 | — | 0.85 | T12-C1-13 | — | — | — |
| 1 | — | — | W9 | — | 0.85 | T12-C1-14 | — | — | — |
T12-C1
Mating face
Wire side
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Coil 3 | — | — | — | — | — | — | — | — |
| 2 | Coil 11 | — | — | — | — | — | — | — | — |
| 3 | PWM 3 | — | W29 | — | 0.5 | OEM-1-G | — | — | — |
| 4 | PWM 2 | — | W28 | — | 0.5 | OEM-1-B | — | — | — |
| 5 | PWM 1 | — | W27 | — | 0.5 | OEM-1-A | — | — | — |
| 6 | Motor 1 + | — | — | — | — | — | — | — | — |
| 7 | Motor 1 - | — | — | — | — | — | — | — | — |
| 8 | Injector 11 | — | — | — | — | — | — | — | — |
| 9 | Injector 1 | — | W20 | — | 0.5 | OEM-4-U | — | — | — |
| 10 | Coil 1 | — | W18 | — | 0.5 | OEM-4-N | — | — | — |
| 11 | Coil 5 | — | — | — | — | — | — | — | — |
| 12 | Coil 7 | — | — | — | — | — | — | — | — |
| 13 | Power Ground 1 | — | W8 | — | 0.85 | SP-GND-1 | — | — | — |
| 14 | Power Ground 2 | — | W9 | — | 0.85 | SP-GND-1 | — | — | — |
| 15 | Injector 6 | — | — | — | — | — | — | — | — |
| 16 | Injector 5 | — | — | — | — | — | — | — | — |
| 17 | Injector 2 | — | W21 | — | 0.5 | OEM-4-V | — | — | — |
| 18 | Coil 2 | — | W19 | — | 0.5 | OEM-4-R | — | — | — |
| 19 | Coil 8 | — | — | — | — | — | — | — | — |
| 20 | Coil 9 | — | — | — | — | — | — | — | — |
| 21 | Injector 9 | — | — | — | — | — | — | — | — |
| 22 | Injector 10 | — | — | — | — | — | — | — | — |
| 23 | Injector 8 | — | — | — | — | — | — | — | — |
| 24 | Injector 7 | — | — | — | — | — | — | — | — |
| 25 | Injector 4 | — | W23 | — | 0.5 | OEM-4-X | — | — | — |
| 26 | Coil 4 | — | — | — | — | — | — | — | — |
| 27 | Coil 6 | — | — | — | — | — | — | — | — |
| 28 | Coil 10 | — | — | — | — | — | — | — | — |
| 29 | Motor 2 + | — | — | — | — | — | — | — | — |
| 30 | Motor 2 - | — | — | — | — | — | — | — | — |
| 31 | Ignition 12v In | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
| 32 | Injector 12 | — | — | — | — | — | — | — | — |
| 33 | Coil 12 | — | — | — | — | — | — | — | — |
| 34 | Injector 3 | — | W22 | — | 0.5 | OEM-4-W | — | — | — |
T12-C2
Mating face
Wire side
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Analogue 2 | — | W25 | — | 0.5 | OEM-3-F | — | — | — |
| 2 | Wheel 1 | — | W45 | — | 0.5 | OEM-1-M | — | — | — |
| 3 | Analogue 10 | — | — | — | — | — | — | — | — |
| 4 | Digital 1 | — | W46 | — | 0.5 | OEM-1-C | — | — | — |
| 5 | Analogue 3 | — | W39 | — | 0.5 | OEM-3-H | — | — | — |
| 6 | Analogue 4 | — | W40 | — | 0.5 | OEM-3-N | — | — | — |
| 7 | Thermistor 1 | — | W26 | — | 0.5 | OEM-3-G | — | — | — |
| 8 | Digital 2 | — | W47 | — | 0.5 | OEM-1-K | — | — | — |
| 9 | 5v Output | — | — | — | — | — | — | — | — |
| 10 | Analogue 1 | — | W24 | — | 0.5 | OEM-3-B | — | — | — |
| 11 | Digital 3 | — | W48 | — | 0.5 | OEM-1-L | — | — | — |
| 12 | Crank | — | W15 | — | 0.5 | OEM-4-E | — | — | — |
| 13 | Analogue 12 | — | — | — | — | — | — | — | — |
| 14 | Digital 4 | — | W49 | — | 0.5 | OEM-1-Q | — | — | — |
| 15 | Digital 5 | — | W50 | — | 0.5 | OEM-3-L | — | — | — |
| 16 | Analogue 11 | — | — | — | — | — | — | — | — |
| 17 | Thermistor 3 | — | — | — | — | — | — | — | — |
| 18 | Analogue 5 | — | W41 | — | 0.5 | OEM-3-C | — | — | — |
| 19 | Analogue 6 | — | W42 | — | 0.5 | OEM-3-D | — | — | — |
| 20 | Wheel 2 | — | — | — | — | — | — | — | — |
| 21 | Sensor Ground | — | W12 | — | 0.5 | SP-0V-1 | — | — | — |
| 22 | Cam 1 | — | W16 | — | 0.5 | OEM-4-G | — | — | — |
| 23 | Cam 3 | — | — | — | — | — | — | — | — |
| 24 | 5v Output | — | W14 | — | 0.5 | OEM-3-I | — | — | — |
| 25 | Thermistor 2 | — | W43 | — | 0.5 | OEM-3-K | — | — | — |
| 26 | CAN High | — | — | — | — | — | — | — | — |
| 27 | Digital 6 | — | W51 | — | 0.5 | OEM-3-P | — | — | — |
| 28 | CAN Low | — | — | — | — | — | — | — | — |
| 29 | Cam 2 | — | W17 | — | 0.5 | OEM-4-F | — | — | — |
| 30 | Cam 4 | — | — | — | — | — | — | — | — |
| 31 | Wheel 3 | — | — | — | — | — | — | — | — |
| 32 | Wheel 4 | — | — | — | — | — | — | — | — |
| 33 | Sensor Ground | — | W13 | — | 0.5 | SP-0V-1 | — | — | — |
| 34 | Analogue 9 | — | — | — | — | — | — | — | — |
T12-C3
Mating face
Wire side
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Lambda 2 Pump Current | — | — | — | — | — | — | — | — |
| 2 | Lambda 2 VGND | — | — | — | — | — | — | — | — |
| 3 | Lambda 2 Heater Negative | — | — | — | — | — | — | — | — |
| 4 | PWM 9 | — | W36 | — | 0.5 | OEM-4-Q | — | — | — |
| 5 | Lambda 2 Trim Resistor | — | — | — | — | — | — | — | — |
| 6 | Lambda 2 Nernst Voltage | — | — | — | — | — | — | — | — |
| 7 | Lambda 1 Pump Current | — | — | — | — | — | — | — | — |
| 8 | Lambda 1 VGND | — | — | — | — | — | — | — | — |
| 9 | Lambda 1 Heater Negative | — | W31 | — | 0.5 | OEM-3-M | — | — | — |
| 10 | PWM 8 | — | W35 | — | 0.5 | OEM-4-P | — | — | — |
| 11 | Lambda 1 Trim Resistor | — | — | — | — | — | — | — | — |
| 12 | Lambda 1 Nernst Voltage | — | — | — | — | — | — | — | — |
| 13 | Analogue 13 | — | — | — | — | — | — | — | — |
| 14 | Analogue 14 | — | — | — | — | — | — | — | — |
| 15 | Analogue 15 | — | — | — | — | — | — | — | — |
| 16 | Analogue 16 | — | — | — | — | — | — | — | — |
| 17 | Analogue 7 | — | W44 | — | 0.5 | OEM-3-J | — | — | — |
| 18 | Analogue 8 | — | — | — | — | — | — | — | — |
| 19 | Digital 7 | — | — | — | — | — | — | — | — |
| 20 | Digital 8 | — | — | — | — | — | — | — | — |
| 21 | Digital 9 | — | — | — | — | — | — | — | — |
| 22 | PWM 4 | — | W30 | — | 0.5 | OEM-1-U | — | — | — |
| 23 | PWM 5 | — | W32 | — | 0.5 | OEM-1-E | — | — | — |
| 24 | PWM 6 | — | W33 | — | 0.5 | OEM-4-J | — | — | — |
| 25 | PWM 7 | — | W34 | — | 0.5 | OEM-4-O | — | — | — |
| 26 | Permanent 12v | — | W3 | — | 0.85 | OEM-4-I | — | — | — |
| 27 | Permanent 12v | — | — | — | — | — | — | — | — |
| 28 | PWM 10 | — | W37 | — | 0.5 | OEM-4-T | — | — | — |
| 29 | PWM 11 | — | W38 | — | 0.5 | OEM-4-L | — | — | — |
| 30 | PWM 12 | — | — | — | — | — | — | — | — |
| 31 | Knock 1 | — | — | — | — | — | — | — | — |
| 32 | Knock 2 | — | — | — | — | — | — | — | — |
| 33 | CAN 2 High | — | — | — | — | — | — | — | — |
| 34 | CAN 2 Low | — | — | — | — | — | — | — | — |
Pin map
| OEM point | OEM function | OEM family | Target point | Target function | Target family | Wire colour | Evidence |
|---|---|---|---|---|---|---|---|
| OEM-1-A | Cooling fan relay (low-side) | low_side_out | T12-C1-5 | PWM 1 | low_side_out | corroborated | |
| OEM-1-B | A/C condenser fan relay | low_side_out | T12-C1-4 | PWM 2 | low_side_out | corroborated | |
| OEM-1-C | Starter input (12V while cranking) | digital_in | T12-C2-4 | Digital 1 | digital_in | corroborated | |
| OEM-1-E | Check engine light (MIL) | low_side_out | T12-C3-23 | PWM 5 | low_side_out | corroborated | |
| OEM-1-G | A/C clutch relay | low_side_out | T12-C1-3 | PWM 3 | low_side_out | corroborated | |
| OEM-1-K | A/C pressure switch (A/C request) | digital_in | T12-C2-8 | Digital 2 | digital_in | corroborated | |
| OEM-1-L | Clutch switch | digital_in | T12-C2-11 | Digital 3 | digital_in | corroborated | |
| OEM-1-M | Vehicle speed sensor (VSS) | digital_in | T12-C2-2 | Wheel 1 | digital_in | corroborated | |
| OEM-1-Q | Brake switch | digital_in | T12-C2-14 | Digital 4 | digital_in | corroborated | |
| OEM-1-U | Fuel pump relay (low-side) | low_side_out | T12-C3-22 | PWM 4 | low_side_out | corroborated | |
| OEM-3-B | MAF sensor input | analog_in | T12-C2-10 | Analogue 1 | analog_in | corroborated | |
| OEM-3-C | Front O2 sensor input | lambda_nb_in | T12-C2-18 | Analogue 5 | analog_in | corroborated | |
| OEM-3-D | Rear O2 sensor input | lambda_nb_in | T12-C2-19 | Analogue 6 | analog_in | corroborated | |
| OEM-3-F | Throttle position (TPS) | analog_in | T12-C2-1 | Analogue 2 | analog_in | corroborated | |
| OEM-3-G | Engine coolant temp (CLT) | temp_in | T12-C2-7 | Thermistor 1 | temp_in | corroborated | |
| OEM-3-H | EGR boost sensor | analog_in | T12-C2-5 | Analogue 3 | analog_in | corroborated | |
| OEM-3-I | +5V sensor reference | vref | T12-C2-24 | 5v Output | vref | corroborated | |
| OEM-3-J | EGR valve position sensor | analog_in | T12-C3-17 | Analogue 7 | analog_in | corroborated | |
| OEM-3-K | Intake air temp (IAT) | temp_in | T12-C2-25 | Thermistor 2 | temp_in | corroborated | |
| OEM-3-L | Idle switch (closed throttle) | digital_in | T12-C2-15 | Digital 5 | digital_in | corroborated | |
| OEM-3-M | Front O2 heater control | low_side_out | T12-C3-9 | Lambda 1 Heater Negative | low_side_out | corroborated | |
| OEM-3-N | EGR boost sensor (2nd channel) | analog_in | T12-C2-6 | Analogue 4 | analog_in | corroborated | |
| OEM-3-O | Sensor ground | sensor_ground | T12-C2-21 + T12-C2-33 | Sensor Ground + Sensor Ground | sensor_ground | corroborated | |
| OEM-3-P | Power steering pressure switch | digital_in | T12-C2-27 | Digital 6 | digital_in | corroborated | |
| OEM-4-A | Chassis ground | ground | T12-C1-13 + T12-C1-14 | Power Ground 1 + Power Ground 2 | ground | corroborated | |
| OEM-4-B | ECU power +12V (main relay) | power_in | T12-C1-31 | Ignition 12v In | power_in | corroborated | |
| OEM-4-C | Chassis ground | ground | T12-C1-13 + T12-C1-14 | Power Ground 1 + Power Ground 2 | ground | corroborated | |
| OEM-4-D | Chassis ground | ground | T12-C1-13 + T12-C1-14 | Power Ground 1 + Power Ground 2 | ground | corroborated | |
| OEM-4-E | Crank position (CKP) sensor | trigger_in | T12-C2-12 | Crank | trigger_in | corroborated | |
| OEM-4-F | CAS SGT (cam trigger) | trigger_in | T12-C2-29 | Cam 2 | trigger_in | corroborated | |
| OEM-4-G | CAS SGC (cam sync) | trigger_in | T12-C2-22 | Cam 1 | trigger_in | corroborated | |
| OEM-4-H | Crank pickup timing ground (CKP gnd) | sensor_ground | T12-C2-21 + T12-C2-33 | Sensor Ground + Sensor Ground | sensor_ground | corroborated | |
| OEM-4-I | Permanent +12V (battery) | power_in | T12-C3-26 | Permanent 12v | power_in | corroborated | |
| OEM-4-J | PRC solenoid (FPR control) | low_side_out | T12-C3-24 | PWM 6 | low_side_out | corroborated | |
| OEM-4-K | Chassis ground | ground | T12-C1-13 + T12-C1-14 | Power Ground 1 + Power Ground 2 | ground | corroborated | |
| OEM-4-L | Tachometer output | tacho_out | T12-C3-29 | PWM 11 | low_side_out | corroborated | |
| OEM-4-N | Ignition coil trigger (cyl 1&4) | ignition_out | T12-C1-10 | Coil 1 | ignition_out | corroborated | |
| OEM-4-O | EGR vent solenoid | low_side_out | T12-C3-25 | PWM 7 | low_side_out | corroborated | |
| OEM-4-P | EGR vacuum solenoid | low_side_out | T12-C3-10 | PWM 8 | low_side_out | corroborated | |
| OEM-4-Q | Idle air control (IAC) valve | low_side_out | T12-C3-4 | PWM 9 | low_side_out | corroborated | |
| OEM-4-R | Ignition coil trigger (cyl 2&3) | ignition_out | T12-C1-18 | Coil 2 | ignition_out | corroborated | |
| OEM-4-T | EVAP purge solenoid | low_side_out | T12-C3-28 | PWM 10 | low_side_out | corroborated | |
| OEM-4-U | Injector 1 (cyl 1) | injector_out | T12-C1-9 | Injector 1 | injector_out | corroborated | |
| OEM-4-V | Injector 2 (cyl 2) | injector_out | T12-C1-17 | Injector 2 | injector_out | corroborated | |
| OEM-4-W | Injector 3 (cyl 3) | injector_out | T12-C1-34 | Injector 3 | injector_out | corroborated | |
| OEM-4-X | Injector 4 (cyl 4) | injector_out | T12-C1-25 | Injector 4 | injector_out | corroborated |
Cut list
| Wire | From | To | Gauge (mm²) | Colour | Length | Signal | Ident |
|---|---|---|---|---|---|---|---|
| W1 | OEM-4-B | SP-14V-1 | 0.85 | no route | ECU power +12V (main relay) | — | |
| W2 | SP-14V-1 | T12-C1-31 | 0.85 | no route | Ignition 12v In | — | |
| W3 | OEM-4-I | T12-C3-26 | 0.85 | no route | Permanent +12V (battery) | — | |
| W4 | OEM-4-A | SP-GND-1 | 0.85 | no route | Chassis ground | — | |
| W5 | OEM-4-C | SP-GND-1 | 0.85 | no route | Chassis ground | — | |
| W6 | OEM-4-D | SP-GND-1 | 0.85 | no route | Chassis ground | — | |
| W7 | OEM-4-K | SP-GND-1 | 0.85 | no route | Chassis ground | — | |
| W8 | SP-GND-1 | T12-C1-13 | 0.85 | no route | Power Ground 1 | — | |
| W9 | SP-GND-1 | T12-C1-14 | 0.85 | no route | Power Ground 2 | — | |
| W10 | OEM-3-O | SP-0V-1 | 0.5 | no route | Sensor ground | — | |
| W11 | OEM-4-H | SP-0V-1 | 0.5 | no route | Crank pickup timing ground (CKP gnd) | — | |
| W12 | SP-0V-1 | T12-C2-21 | 0.5 | no route | Sensor Ground | — | |
| W13 | SP-0V-1 | T12-C2-33 | 0.5 | no route | Sensor Ground | — | |
| W14 | OEM-3-I | T12-C2-24 | 0.5 | no route | +5V sensor reference | — | |
| W15 | OEM-4-E | T12-C2-12 | 0.5 | no route | Crank position (CKP) sensor | — | |
| W16 | OEM-4-G | T12-C2-22 | 0.5 | no route | CAS SGC (cam sync) | — | |
| W17 | OEM-4-F | T12-C2-29 | 0.5 | no route | CAS SGT (cam trigger) | — | |
| W18 | OEM-4-N | T12-C1-10 | 0.5 | no route | Ignition coil trigger (cyl 1&4) | — | |
| W19 | OEM-4-R | T12-C1-18 | 0.5 | no route | Ignition coil trigger (cyl 2&3) | — | |
| W20 | OEM-4-U | T12-C1-9 | 0.5 | no route | Injector 1 (cyl 1) | — | |
| W21 | OEM-4-V | T12-C1-17 | 0.5 | no route | Injector 2 (cyl 2) | — | |
| W22 | OEM-4-W | T12-C1-34 | 0.5 | no route | Injector 3 (cyl 3) | — | |
| W23 | OEM-4-X | T12-C1-25 | 0.5 | no route | Injector 4 (cyl 4) | — | |
| W24 | OEM-3-B | T12-C2-10 | 0.5 | no route | MAF sensor input | — | |
| W25 | OEM-3-F | T12-C2-1 | 0.5 | no route | Throttle position (TPS) | — | |
| W26 | OEM-3-G | T12-C2-7 | 0.5 | no route | Engine coolant temp (CLT) | — | |
| W27 | OEM-1-A | T12-C1-5 | 0.5 | no route | Cooling fan relay (low-side) | — | |
| W28 | OEM-1-B | T12-C1-4 | 0.5 | no route | A/C condenser fan relay | — | |
| W29 | OEM-1-G | T12-C1-3 | 0.5 | no route | A/C clutch relay | — | |
| W30 | OEM-1-U | T12-C3-22 | 0.5 | no route | Fuel pump relay (low-side) | — | |
| W31 | OEM-3-M | T12-C3-9 | 0.5 | no route | Front O2 heater control | — | |
| W32 | OEM-1-E | T12-C3-23 | 0.5 | no route | Check engine light (MIL) | — | |
| W33 | OEM-4-J | T12-C3-24 | 0.5 | no route | PRC solenoid (FPR control) | — | |
| W34 | OEM-4-O | T12-C3-25 | 0.5 | no route | EGR vent solenoid | — | |
| W35 | OEM-4-P | T12-C3-10 | 0.5 | no route | EGR vacuum solenoid | — | |
| W36 | OEM-4-Q | T12-C3-4 | 0.5 | no route | Idle air control (IAC) valve | — | |
| W37 | OEM-4-T | T12-C3-28 | 0.5 | no route | EVAP purge solenoid | — | |
| W38 | OEM-4-L | T12-C3-29 | 0.5 | no route | Tachometer output | — | |
| W39 | OEM-3-H | T12-C2-5 | 0.5 | no route | EGR boost sensor | — | |
| W40 | OEM-3-N | T12-C2-6 | 0.5 | no route | EGR boost sensor (2nd channel) | — | |
| W41 | OEM-3-C | T12-C2-18 | 0.5 | no route | Front O2 sensor input | — | |
| W42 | OEM-3-D | T12-C2-19 | 0.5 | no route | Rear O2 sensor input | — | |
| W43 | OEM-3-K | T12-C2-25 | 0.5 | no route | Intake air temp (IAT) | — | |
| W44 | OEM-3-J | T12-C3-17 | 0.5 | no route | EGR valve position sensor | — | |
| W45 | OEM-1-M | T12-C2-2 | 0.5 | no route | Vehicle speed sensor (VSS) | — | |
| W46 | OEM-1-C | T12-C2-4 | 0.5 | no route | Starter input (12V while cranking) | — | |
| W47 | OEM-1-K | T12-C2-8 | 0.5 | no route | A/C pressure switch (A/C request) | — | |
| W48 | OEM-1-L | T12-C2-11 | 0.5 | no route | Clutch switch | — | |
| W49 | OEM-1-Q | T12-C2-14 | 0.5 | no route | Brake switch | — | |
| W50 | OEM-3-L | T12-C2-15 | 0.5 | no route | Idle switch (closed throttle) | — | |
| W51 | OEM-3-P | T12-C2-27 | 0.5 | no route | Power steering pressure switch | — |
Bill of materials
| Category | Part number | Manufacturer | Description | Qty | Unit |
|---|---|---|---|---|---|
| connector | 4-1437290-0 | TE | Superseal 1.0 34-way plug, Key 1 | 3.000 | ea |
| terminal | 3-1447221-4 | TE | Superseal 1.0 socket terminal, 20 AWG (0.5 sq mm) | 44.000 | ea |
ECU setup sheet
| Role | Engine ref | Engine signal | Sensor | ECU point | ECU function | ECU class | Setup flag |
|---|---|---|---|---|---|---|---|
| No configured channels. | |||||||
Findings
Open (2)
| Severity | Code | Subject | Message |
|---|---|---|---|
| error | PHYS_REQUIRED_OPEN | T12-C3-27 | T12-C3-27 "Permanent 12v" is required but not wired. |
| info | NET_FAMILY | OEM-4-L ↔ T12-C3-29 | OEM-4-L "Tachometer output" [tacho_out] is wired to T12-C3-29 "PWM 11" [low_side_out]. Tacho as a low-side output: check the tach needs a pull-up. |
Accepted (0)
| Code | Subject | Reason | By |
|---|
Notes
Fit check: unconfirmed. Confirm these before building: - Trigger pattern for Mazda BP-ZE not found in the ECU's docs (NA8 not named.) Auto-mapped by auto_map() from the library pin data on 2026-10-11. Review every wire against both manuals before building. Open items: - T12-C3 27: Permanent 12v: required by DTAFast T12 but no stock pin feeds it; wire by hand
Sources
| Reliability | Kind | Title | URL | Archive | Captured | SHA-256 |
|---|---|---|---|---|---|---|
| 4 | vendor_doc | AEM EMS 30-1720 Plug-and-Play adapter manual (1996-97 Miata) | https://static.summitracing.com/global/images/instructions/avm-30-1720.pdf | — | — | — |
| 4 | vendor_doc | DTAFast T12+ ECU wiring diagram (served for T12 and T12+) | https://cdn.shopify.com/s/files/1/0848/7508/4108/files/T12PLUS_Wiring-Diagram.pdf?v=1728572014 | — | — | — |
| 3 | community_copy | Mellens.net: 1996 Mazda Miata wiring diagrams (FSM-derived) | http://www.mellens.net/mazda/mazda_miata_extra_manual/1996_wiring.pdf | — | — | — |