MX-5 Miata NA8 1994-95 (BP-ZE, 1.8, OBD-I) → DTAFast T2i (auto)
MX-5 Miata NA8 1994-95 (BP-ZE, 1.8, OBD-I) — DTAFast — T2i
⚠ 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 | 4: read the Findings page before cutting any wire |
| Size of the job | 32 wires · 6 connectors · 4 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-1-B | SP-14V-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W2 | SP-14V-1 | T2I-C1-31 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W3 | OEM-1-A | T2I-C1-21 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W4 | OEM-2-A | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W5 | OEM-2-B | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W6 | SP-GND-1 | T2I-C1-13 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W7 | SP-GND-1 | T2I-C1-14 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | OEM-2-C | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | OEM-2-D | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | OEM-2-F | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | SP-0V-1 | T2I-C1-28 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | SP-0V-1 | T2I-C1-29 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | OEM-2-K | T2I-C1-27 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | OEM-2-E | T2I-C1-19 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | OEM-2-G | T2I-C1-12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | OEM-1-G | T2I-C1-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-1-H | T2I-C1-6 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-2-O | T2I-C1-20 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-2-M | T2I-C1-22 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-2-Q | T2I-C1-24 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-1-J | T2I-C1-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-1-R | T2I-C1-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-2-S | T2I-C1-18 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-2-T | T2I-C1-26 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-1-L | T2I-C1-15 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-2-N | T2I-C1-23 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-2-P | T2I-C1-32 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-1-M | T2I-C1-11 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-1-C | T2I-C1-30 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | OEM-1-O | T2I-C1-25 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-1-P | T2I-C1-33 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-1-Q | T2I-C1-34 | 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 | T2I-C1-21 | T2I-C1-13 | open (OL) | +12 V supply must not touch power ground | |
| 2 | T2I-C1-21 | T2I-C1-28 | open (OL) | +12 V supply must not touch sensor ground | |
| 3 | T2I-C1-31 | T2I-C1-13 | open (OL) | +12 V supply must not touch power ground | |
| 4 | T2I-C1-31 | T2I-C1-28 | open (OL) | +12 V supply must not touch sensor ground | |
| 5 | T2I-C1-13 | T2I-C1-27 | open (OL) | power ground must not touch 5 V sensor reference | |
| 6 | T2I-C1-21 | T2I-C1-27 | open (OL) | +12 V supply must not touch 5 V sensor reference | |
| 7 | T2I-C1-28 | T2I-C1-27 | open (OL) | sensor ground must not touch 5 V sensor reference | |
| 8 | T2I-C1-31 | T2I-C1-27 | 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-1
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A | Constant +12V | — | W3 | — | 0.85 | T2I-C1-21 | — | — | — |
| B | ECU power +14V (main relay) | — | W1 | — | 0.85 | SP-14V-1 | — | — | — |
| C | Start signal | — | W29 | — | 0.5 | T2I-C1-30 | — | — | — |
| D | Data link connector | — | — | — | — | — | — | — | — |
| E | Malfunction indicator lamp (MIL) | — | — | — | — | — | — | — | — |
| G | Ignition 1 (coils 1+4, wasted spark) | — | W16 | — | 0.5 | T2I-C1-3 | — | — | — |
| H | Ignition 2 (coils 2+3, wasted spark) | — | W17 | — | 0.5 | T2I-C1-6 | — | — | — |
| I | Powertrain control module (transmission) | — | — | — | — | — | — | — | — |
| J | A/C relay | — | W21 | — | 0.5 | T2I-C1-1 | — | — | — |
| L | Coolant fan relay | — | W25 | — | 0.5 | T2I-C1-15 | — | — | — |
| M | Vehicle speed | — | W28 | — | 0.5 | T2I-C1-11 | — | — | — |
| N | Powertrain control module (transmission) | — | — | — | — | — | — | — | — |
| O | Stop light switch | — | W30 | — | 0.5 | T2I-C1-25 | — | — | — |
| P | Power steering pressure switch | — | W31 | — | 0.5 | T2I-C1-33 | — | — | — |
| Q | A/C request | — | W32 | — | 0.5 | T2I-C1-34 | — | — | — |
| R | Cooling fan relay | — | W22 | — | 0.5 | T2I-C1-10 | — | — | — |
| S | Heater control unit | — | — | — | — | — | — | — | — |
| T | Unknown | — | — | — | — | — | — | — | — |
| U | Unknown | — | — | — | — | — | — | — | — |
| V | Neutral/clutch switch | — | — | — | — | — | — | — | — |
OEM-2
| 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 | Sensor ground (E2) | — | W8 | — | 0.5 | SP-0V-1 | — | — | — |
| D | Sensor ground (E2) | — | W9 | — | 0.5 | SP-0V-1 | — | — | — |
| E | Crank position (CAS NE) | — | W14 | — | 0.5 | T2I-C1-19 | — | — | — |
| F | MAF ground | — | W10 | — | 0.5 | SP-0V-1 | — | — | — |
| G | Cam position (CAS G) | — | W15 | — | 0.5 | T2I-C1-12 | — | — | — |
| H | Data link connector | — | — | — | — | — | — | — | — |
| I | Tachometer output | — | — | — | — | — | — | — | — |
| J | EGR function sensor | — | — | — | — | — | — | — | — |
| K | +5V sensor supply | — | W13 | — | 0.5 | T2I-C1-27 | — | — | — |
| L | Rear defroster relay | — | — | — | — | — | — | — | — |
| M | Throttle position (TPS) | — | W19 | — | 0.5 | T2I-C1-22 | — | — | — |
| N | O2 sensor | — | W26 | — | 0.5 | T2I-C1-23 | — | — | — |
| O | Mass air flow (MAF) | — | W18 | — | 0.5 | T2I-C1-20 | — | — | — |
| P | Intake air temperature (IAT) | — | W27 | — | 0.5 | T2I-C1-32 | — | — | — |
| Q | Coolant temperature (ECT) | — | W20 | — | 0.5 | T2I-C1-24 | — | — | — |
| R | PRC solenoid (fuel pressure regulator) | — | — | — | — | — | — | — | — |
| S | Condenser fan relay | — | W23 | — | 0.5 | T2I-C1-18 | — | — | — |
| T | Fuel pump relay | — | W24 | — | 0.5 | T2I-C1-26 | — | — | — |
| U | Injector 1 | — | — | — | — | — | — | — | — |
| V | Injector 2 | — | — | — | — | — | — | — | — |
| W | ISC solenoid | — | — | — | — | — | — | — | — |
| X | Evap purge solenoid | — | — | — | — | — | — | — | — |
| Y | Injector 3 | — | — | — | — | — | — | — | — |
| Z | Injector 4 | — | — | — | — | — | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W8 | — | 0.5 | OEM-2-C | — | — | — |
| 1 | — | — | W9 | — | 0.5 | OEM-2-D | — | — | — |
| 1 | — | — | W10 | — | 0.5 | OEM-2-F | — | — | — |
| 1 | — | — | W11 | — | 0.5 | T2I-C1-28 | — | — | — |
| 1 | — | — | W12 | — | 0.5 | T2I-C1-29 | — | — | — |
SP-14V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W1 | — | 0.85 | OEM-1-B | — | — | — |
| 1 | — | — | W2 | — | 0.85 | T2I-C1-31 | — | — | — |
SP-GND
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W4 | — | 0.85 | OEM-2-A | — | — | — |
| 1 | — | — | W5 | — | 0.85 | OEM-2-B | — | — | — |
| 1 | — | — | W6 | — | 0.85 | T2I-C1-13 | — | — | — |
| 1 | — | — | W7 | — | 0.85 | T2I-C1-14 | — | — | — |
T2I-C1
Mating face
Wire side
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | PWM 1 | — | W21 | — | 0.5 | OEM-1-J | — | — | — |
| 2 | Lambda Nernst Voltage | — | — | — | — | — | — | — | — |
| 3 | Coil 1 | — | W16 | — | 0.5 | OEM-1-G | — | — | — |
| 4 | Lambda VGND | — | — | — | — | — | — | — | — |
| 5 | Lambda Pump Current | — | — | — | — | — | — | — | — |
| 6 | Coil 2 | — | W17 | — | 0.5 | OEM-1-H | — | — | — |
| 7 | Lambda Trim Resistor | — | — | — | — | — | — | — | — |
| 8 | — | — | — | — | — | — | — | — | — |
| 9 | — | — | — | — | — | — | — | — | — |
| 10 | PWM 2 | — | W22 | — | 0.5 | OEM-1-R | — | — | — |
| 11 | Digital 1 | — | W28 | — | 0.5 | OEM-1-M | — | — | — |
| 12 | Wheel 1 | — | W15 | — | 0.5 | OEM-2-G | — | — | — |
| 13 | Power Ground 1 | — | W6 | — | 0.85 | SP-GND-1 | — | — | — |
| 14 | Power Ground 2 | — | W7 | — | 0.85 | SP-GND-1 | — | — | — |
| 15 | Lambda Heater Negative | — | W25 | — | 0.5 | OEM-1-L | — | — | — |
| 16 | CAN High | — | — | — | — | — | — | — | — |
| 17 | CAN Low | — | — | — | — | — | — | — | — |
| 18 | PWM 3 | — | W23 | — | 0.5 | OEM-2-S | — | — | — |
| 19 | Crank | — | W14 | — | 0.5 | OEM-2-E | — | — | — |
| 20 | Analogue 1 | — | W18 | — | 0.5 | OEM-2-O | — | — | — |
| 21 | Permanent 12v | — | W3 | — | 0.85 | OEM-1-A | — | — | — |
| 22 | Analogue 2 | — | W19 | — | 0.5 | OEM-2-M | — | — | — |
| 23 | Analogue 3 | — | W26 | — | 0.5 | OEM-2-N | — | — | — |
| 24 | Thermistor 1 | — | W20 | — | 0.5 | OEM-2-Q | — | — | — |
| 25 | Analogue 4 | — | W30 | — | 0.5 | OEM-1-O | — | — | — |
| 26 | PWM 4 | — | W24 | — | 0.5 | OEM-2-T | — | — | — |
| 27 | 5v Output | — | W13 | — | 0.5 | OEM-2-K | — | — | — |
| 28 | Sensor Ground | — | W11 | — | 0.5 | SP-0V-1 | — | — | — |
| 29 | Sensor Ground | — | W12 | — | 0.5 | SP-0V-1 | — | — | — |
| 30 | Digital 2 | — | W29 | — | 0.5 | OEM-1-C | — | — | — |
| 31 | Ignition 12v In | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
| 32 | Thermistor 2 | — | W27 | — | 0.5 | OEM-2-P | — | — | — |
| 33 | Analogue 5 | — | W31 | — | 0.5 | OEM-1-P | — | — | — |
| 34 | Analogue 6 | — | W32 | — | 0.5 | OEM-1-Q | — | — | — |
Pin map
| OEM point | OEM function | OEM family | Target point | Target function | Target family | Wire colour | Evidence |
|---|---|---|---|---|---|---|---|
| OEM-1-A | Constant +12V | power_in | T2I-C1-21 | Permanent 12v | power_in | LR | single_source |
| OEM-1-B | ECU power +14V (main relay) | power_in | T2I-C1-31 | Ignition 12v In | power_in | WR | single_source |
| OEM-1-C | Start signal | digital_in | T2I-C1-30 | Digital 2 | digital_in | V | single_source |
| OEM-1-D | Data link connector | serial | — | — | — | WG | single_source |
| OEM-1-E | Malfunction indicator lamp (MIL) | low_side_out | — | — | — | YB | single_source |
| OEM-1-G | Ignition 1 (coils 1+4, wasted spark) | ignition_out | T2I-C1-3 | Coil 1 | ignition_out | BrY | single_source |
| OEM-1-H | Ignition 2 (coils 2+3, wasted spark) | ignition_out | T2I-C1-6 | Coil 2 | ignition_out | Br | single_source |
| OEM-1-I | Powertrain control module (transmission) | — | — | — | — | LW | single_source |
| OEM-1-J | A/C relay | low_side_out | T2I-C1-1 | PWM 1 | low_side_out | single_source | |
| OEM-1-L | Coolant fan relay | low_side_out | T2I-C1-15 | Lambda Heater Negative | low_side_out | BG | single_source |
| OEM-1-M | Vehicle speed | digital_in | T2I-C1-11 | Digital 1 | digital_in | GR | single_source |
| OEM-1-N | Powertrain control module (transmission) | — | — | — | — | R | single_source |
| OEM-1-O | Stop light switch | digital_in | T2I-C1-25 | Analogue 4 | analog_in | GB | single_source |
| OEM-1-P | Power steering pressure switch | digital_in | T2I-C1-33 | Analogue 5 | analog_in | LY | single_source |
| OEM-1-Q | A/C request | digital_in | T2I-C1-34 | Analogue 6 | analog_in | LgB | single_source |
| OEM-1-R | Cooling fan relay | low_side_out | T2I-C1-10 | PWM 2 | low_side_out | YB | single_source |
| OEM-1-S | Heater control unit | — | — | — | — | LOr | single_source |
| OEM-1-T | Unknown | — | — | — | — | YR | single_source |
| OEM-1-U | Unknown | — | — | — | — | RB | single_source |
| OEM-1-V | Neutral/clutch switch | digital_in | — | — | — | BrW | single_source |
| OEM-2-A | Power ground | ground | T2I-C1-13 + T2I-C1-14 | Power Ground 1 + Power Ground 2 | ground | B | single_source |
| OEM-2-B | Power ground | ground | T2I-C1-13 + T2I-C1-14 | Power Ground 1 + Power Ground 2 | ground | B | single_source |
| OEM-2-C | Sensor ground (E2) | sensor_ground | T2I-C1-28 + T2I-C1-29 | Sensor Ground + Sensor Ground | sensor_ground | BLg | corroborated |
| OEM-2-D | Sensor ground (E2) | sensor_ground | T2I-C1-28 + T2I-C1-29 | Sensor Ground + Sensor Ground | sensor_ground | BL | corroborated |
| OEM-2-E | Crank position (CAS NE) | trigger_in | T2I-C1-19 | Crank | trigger_in | W | single_source |
| OEM-2-F | MAF ground | sensor_ground | T2I-C1-28 + T2I-C1-29 | Sensor Ground + Sensor Ground | sensor_ground | BR | single_source |
| OEM-2-G | Cam position (CAS G) | trigger_in | T2I-C1-12 | Wheel 1 | digital_in | YL | single_source |
| OEM-2-H | Data link connector | serial | — | — | — | LgY | single_source |
| OEM-2-I | Tachometer output | tacho_out | — | — | — | BW | single_source |
| OEM-2-J | EGR function sensor | — | — | — | — | LgR | single_source |
| OEM-2-K | +5V sensor supply | vref | T2I-C1-27 | 5v Output | vref | LgW | single_source |
| OEM-2-L | Rear defroster relay | low_side_out | — | — | — | LR | single_source |
| OEM-2-M | Throttle position (TPS) | analog_in | T2I-C1-22 | Analogue 2 | analog_in | RB | single_source |
| OEM-2-N | O2 sensor | lambda_nb_in | T2I-C1-23 | Analogue 3 | analog_in | RL | single_source |
| OEM-2-O | Mass air flow (MAF) | analog_in | T2I-C1-20 | Analogue 1 | analog_in | R | single_source |
| OEM-2-P | Intake air temperature (IAT) | temp_in | T2I-C1-32 | Thermistor 2 | temp_in | RB | single_source |
| OEM-2-Q | Coolant temperature (ECT) | temp_in | T2I-C1-24 | Thermistor 1 | temp_in | LW | single_source |
| OEM-2-R | PRC solenoid (fuel pressure regulator) | low_side_out | — | — | — | YG | single_source |
| OEM-2-S | Condenser fan relay | low_side_out | T2I-C1-18 | PWM 3 | low_side_out | LW | single_source |
| OEM-2-T | Fuel pump relay | low_side_out | T2I-C1-26 | PWM 4 | low_side_out | Lg | single_source |
| OEM-2-U | Injector 1 | injector_out | — | — | — | Y | single_source |
| OEM-2-V | Injector 2 | injector_out | — | — | — | YB | single_source |
| OEM-2-W | ISC solenoid | low_side_out | — | — | — | LOr | single_source |
| OEM-2-X | Evap purge solenoid | low_side_out | — | — | — | YR | single_source |
| OEM-2-Y | Injector 3 | injector_out | — | — | — | GW | single_source |
| OEM-2-Z | Injector 4 | injector_out | — | — | — | G | single_source |
Cut list
| Wire | From | To | Gauge (mm²) | Colour | Length | Signal | Ident |
|---|---|---|---|---|---|---|---|
| W1 | OEM-1-B | SP-14V-1 | 0.85 | no route | ECU power +14V (main relay) | — | |
| W2 | SP-14V-1 | T2I-C1-31 | 0.85 | no route | Ignition 12v In | — | |
| W3 | OEM-1-A | T2I-C1-21 | 0.85 | no route | Constant +12V | — | |
| W4 | OEM-2-A | SP-GND-1 | 0.85 | no route | Power ground | — | |
| W5 | OEM-2-B | SP-GND-1 | 0.85 | no route | Power ground | — | |
| W6 | SP-GND-1 | T2I-C1-13 | 0.85 | no route | Power Ground 1 | — | |
| W7 | SP-GND-1 | T2I-C1-14 | 0.85 | no route | Power Ground 2 | — | |
| W8 | OEM-2-C | SP-0V-1 | 0.5 | no route | Sensor ground (E2) | — | |
| W9 | OEM-2-D | SP-0V-1 | 0.5 | no route | Sensor ground (E2) | — | |
| W10 | OEM-2-F | SP-0V-1 | 0.5 | no route | MAF ground | — | |
| W11 | SP-0V-1 | T2I-C1-28 | 0.5 | no route | Sensor Ground | — | |
| W12 | SP-0V-1 | T2I-C1-29 | 0.5 | no route | Sensor Ground | — | |
| W13 | OEM-2-K | T2I-C1-27 | 0.5 | no route | +5V sensor supply | — | |
| W14 | OEM-2-E | T2I-C1-19 | 0.5 | no route | Crank position (CAS NE) | — | |
| W15 | OEM-2-G | T2I-C1-12 | 0.5 | no route | Cam position (CAS G) | — | |
| W16 | OEM-1-G | T2I-C1-3 | 0.5 | no route | Ignition 1 (coils 1+4, wasted spark) | — | |
| W17 | OEM-1-H | T2I-C1-6 | 0.5 | no route | Ignition 2 (coils 2+3, wasted spark) | — | |
| W18 | OEM-2-O | T2I-C1-20 | 0.5 | no route | Mass air flow (MAF) | — | |
| W19 | OEM-2-M | T2I-C1-22 | 0.5 | no route | Throttle position (TPS) | — | |
| W20 | OEM-2-Q | T2I-C1-24 | 0.5 | no route | Coolant temperature (ECT) | — | |
| W21 | OEM-1-J | T2I-C1-1 | 0.5 | no route | A/C relay | — | |
| W22 | OEM-1-R | T2I-C1-10 | 0.5 | no route | Cooling fan relay | — | |
| W23 | OEM-2-S | T2I-C1-18 | 0.5 | no route | Condenser fan relay | — | |
| W24 | OEM-2-T | T2I-C1-26 | 0.5 | no route | Fuel pump relay | — | |
| W25 | OEM-1-L | T2I-C1-15 | 0.5 | no route | Coolant fan relay | — | |
| W26 | OEM-2-N | T2I-C1-23 | 0.5 | no route | O2 sensor | — | |
| W27 | OEM-2-P | T2I-C1-32 | 0.5 | no route | Intake air temperature (IAT) | — | |
| W28 | OEM-1-M | T2I-C1-11 | 0.5 | no route | Vehicle speed | — | |
| W29 | OEM-1-C | T2I-C1-30 | 0.5 | no route | Start signal | — | |
| W30 | OEM-1-O | T2I-C1-25 | 0.5 | no route | Stop light switch | — | |
| W31 | OEM-1-P | T2I-C1-33 | 0.5 | no route | Power steering pressure switch | — | |
| W32 | OEM-1-Q | T2I-C1-34 | 0.5 | no route | A/C request | — |
Bill of materials
| Category | Part number | Manufacturer | Description | Qty | Unit |
|---|---|---|---|---|---|
| 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 |
| connector | 4-1437290-0 | TE | Superseal 1.0 34-way plug, Key 1 | 1.000 | ea |
| terminal | 3-1447221-4 | TE | Superseal 1.0 socket terminal, 20 AWG (0.5 sq mm) | 26.000 | ea |
ECU setup sheet
| Role | Engine ref | Engine signal | Sensor | ECU point | ECU function | ECU class | Setup flag |
|---|---|---|---|---|---|---|---|
| No configured channels. | |||||||
Findings
Open (10)
| Severity | Code | Subject | Message |
|---|---|---|---|
| error | REQUIRED_UNMAPPED | OEM-2-U | Required OEM function "Injector 1" (injector_out) is not connected to the new ECU. |
| error | REQUIRED_UNMAPPED | OEM-2-V | Required OEM function "Injector 2" (injector_out) is not connected to the new ECU. |
| error | REQUIRED_UNMAPPED | OEM-2-Y | Required OEM function "Injector 3" (injector_out) is not connected to the new ECU. |
| error | REQUIRED_UNMAPPED | OEM-2-Z | Required OEM function "Injector 4" (injector_out) is not connected to the new ECU. |
| warn | DATASET_GAP | T2i C1 | 2 of 34 cavities on T2i C1 have no pin data (8,9). Anything there is invisible to these checks. |
| warn | NET_FAMILY | OEM-1-O ↔ T2I-C1-25 | OEM-1-O "Stop light switch" [digital_in] is wired to T2I-C1-25 "Analogue 4" [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-1-P ↔ T2I-C1-33 | OEM-1-P "Power steering pressure switch" [digital_in] is wired to T2I-C1-33 "Analogue 5" [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-1-Q ↔ T2I-C1-34 | OEM-1-Q "A/C request" [digital_in] is wired to T2I-C1-34 "Analogue 6" [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-2-G ↔ T2I-C1-12 | OEM-2-G "Cam position (CAS G)" [trigger_in] is wired to T2I-C1-12 "Wheel 1" [digital_in]. Hall-type cam/speed signals can use a digital input if it handles the frequency; VR signals cannot. |
| info | UNMAPPED | OEM | 15 optional OEM pins are not mapped: OEM-1-D Data link connector; OEM-1-E Malfunction indicator lamp (MIL); OEM-1-I Powertrain control module (transmission); OEM-1-N Powertrain control module (transmission); OEM-1-S Heater control unit; OEM-1-T Unknown; OEM-1-U Unknown; OEM-1-V Neutral/clutch switch; OEM-2-H Data link connector; OEM-2-I Tachometer output; OEM-2-J EGR function sensor; OEM-2-L Rear defroster relay; OEM-2-R PRC solenoid (fuel pressure regulator); OEM-2-W ISC solenoid; OEM-2-X Evap purge solenoid |
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.) - Only 2 ignition outputs for 4 cylinders: wasted spark (pair coils per firing order) Auto-mapped by auto_map() from the library pin data on 2026-10-11. Review every wire against both manuals before building. Open items: - OEM-2 U: Injector 1: no free injector output on DTAFast T2i - OEM-2 V: Injector 2: no free injector output on DTAFast T2i - OEM-2 Y: Injector 3: no free injector output on DTAFast T2i - OEM-2 Z: Injector 4: no free injector output on DTAFast T2i Not wired: - OEM-2 L: Rear defroster relay: no free relay_control/low_side/heater_low_side/ls_hs/injector on DTAFast T2i - OEM-2 W: ISC solenoid: no free low_side/relay_control/heater_low_side/ls_hs/injector rated ≥ 1.0 A on DTAFast T2i - OEM-1 E: Malfunction indicator lamp (MIL): no free low_side/relay_control/heater_low_side/ls_hs/injector on DTAFast T2i - OEM-2 R: PRC solenoid (fuel pressure regulator): no free low_side/relay_control/heater_low_side/ls_hs/injector on DTAFast T2i - OEM-2 X: Evap purge solenoid: no free low_side/relay_control/heater_low_side/ls_hs/injector on DTAFast T2i - OEM-2 I: Tachometer output: no free tacho/frequency_out/low_side/ls_hs on DTAFast T2i - OEM-1 V: Neutral/clutch switch: no free switch_in/frequency_in/analog_0_5 on DTAFast T2i - OEM-1 D: Data link connector: no free k_line on DTAFast T2i - OEM-2 H: Data link connector: no free k_line on DTAFast T2i - OEM-1 I: Powertrain control module (transmission): not classified in the library; wire by hand - OEM-1 N: Powertrain control module (transmission): not classified in the library; wire by hand - OEM-1 S: Heater control unit: not classified in the library; wire by hand - OEM-1 T: Unknown: not classified in the library; wire by hand - OEM-1 U: Unknown: not classified in the library; wire by hand - OEM-2 J: EGR function sensor: not classified in the library; wire by hand
Sources
| Reliability | Kind | Title | URL | Archive | Captured | SHA-256 |
|---|---|---|---|---|---|---|
| 4 | vendor_doc | DTAFast T2i ECU wiring diagram | https://cdn.shopify.com/s/files/1/0848/7508/4108/files/T2i_Wiring-Diagram.pdf?v=1728571341 | — | — | — |
| 4 | vendor_doc | Link G4X MX5X install manual (NA 1.6/1.8) | https://linkecu.com/documentation/MX5X.pdf | archive | 2026-10-05 | b7f730de9f6e |
| 2 | expert_report | Justin Barrera — Miata NA/NB wiring corrections | — | — | — | — |
| 2 | community_copy | rusefi wiki: 1994 Mazda Miata 1.8 (NA8) ECU pinout | https://github.com/rusefi/rusefi/wiki/Mazda-Miata-1994 | — | 2026-10-08 | 075801b907f4 |