MX-5 Miata NB1 1999-00 (BP-4W) → DTAFast P8 (auto)
MX-5 Miata NB1 1999-00 (BP-4W) — DTAFast — P8
Drawn by Michael Gnankou · Rev 0 · proposal · 2026-10-11
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.
Install modifications
Steps on the car itself, outside the harness. Every harness for this car inherits them.
- Re-route the pressure-sensor vacuum hose to the intake manifoldrequired
Re-route the pressure sensor's (Mazda "EGR boost sensor", pin 3S) vacuum hose directly to the intake manifold, bypassing the EGR boost solenoid. The stock ECU multiplexes baro + MAP through that solenoid: with it off the sensor reads atmosphere, with it energized it reads manifold (2000 FSM P0107/P0108). After re-routing the sensor reads MAP only, so the standalone needs its own barometric source — its onboard baro sensor if fitted, or a separate baro sensor on a spare analog input. (Alternative, not recommended: keep the hose stock and have the ECU energize the solenoid permanently via a low-side output switched with ignition; this costs an output.)
Why: With the solenoid off (its default) the sensor reads atmospheric pressure, not manifold pressure, so a standalone that uses this sensor as its MAP input would read the wrong value.
Where: EGR boost solenoid and the pressure sensor's vacuum hose (sensor signal 3S).
Source: 2000 Mazda MX-5 Miata factory service manual — engine self-diagnostics (DTC P0106/P0107/P0108)
| Status | proposal · not yet verified: nobody has reported building and running this harness |
|---|---|
| Open errors | none |
| Size of the job | 50 wires · 7 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 | Colour | 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 | 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-3-C | 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-3-F | 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-2-I | P8-C1-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | OEM-2-J | P8-C1-8 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-2-H | P8-C1-27 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-3-G | P8-C1-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-3-H | P8-C1-38 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-3-W | P8-C1-37 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-3-X | P8-C1-18 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-3-Y | P8-C1-54 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-3-Z | P8-C1-36 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-1-I | P8-C1-41 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-1-R | P8-C1-5 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-1-S | P8-C1-43 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-3-N | P8-C1-42 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-1-U | P8-C1-21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-3-V | P8-C1-23 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | OEM-3-O | P8-C1-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-1-E | P8-C1-6 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-1-O | P8-C1-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-1-Q | P8-C1-35 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-2-M | P8-C1-53 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W35 | OEM-2-N | P8-C1-16 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W36 | OEM-2-K | P8-C1-24 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W37 | OEM-2-L | P8-C1-25 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W38 | OEM-3-S | P8-C1-30 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W39 | OEM-3-E | P8-C1-48 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W40 | OEM-2-C | P8-C1-12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W41 | OEM-3-J | P8-C1-7 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W42 | OEM-2-E | P8-C1-26 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W43 | OEM-2-B | P8-C1-45 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W44 | OEM-2-A | P8-C1-44 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W45 | OEM-2-D | P8-C1-11 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W46 | OEM-1-F | P8-C1-13 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W47 | OEM-1-G | P8-C1-14 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W48 | OEM-1-P | P8-C1-31 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W49 | OEM-1-V | P8-C1-32 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W50 | OEM-3-I | P8-C1-33 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ |
Bench test (before first power-up)
Pre-power install steps (make these cuts/modifications on the car first, then verify the checks below): Re-route the pressure-sensor vacuum hose to the intake manifold.
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 | P8-C1-10 | P8-C1-15 | open (OL) | 5 V sensor reference must not touch power ground | |
| 2 | P8-C1-10 | P8-C1-46 | open (OL) | 5 V sensor reference must not touch sensor ground | |
| 3 | P8-C1-19 | P8-C1-15 | open (OL) | +12 V supply must not touch power ground | |
| 4 | P8-C1-19 | P8-C1-46 | open (OL) | +12 V supply must not touch sensor ground | |
| 5 | P8-C1-19 | 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-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) | — | W31 | — | 0.5 | P8-C1-6 | — | — | — |
| F | Brake switch | — | W46 | — | 0.5 | P8-C1-13 | — | — | — |
| G | Power steering pressure switch | — | W47 | — | 0.5 | P8-C1-14 | — | — | — |
| I | Condenser fan relay | — | W24 | — | 0.5 | P8-C1-41 | — | — | — |
| O | Alternator control | — | W32 | — | 0.5 | P8-C1-17 | — | — | — |
| P | A/C request | — | W48 | — | 0.5 | P8-C1-31 | — | — | — |
| Q | Charge lamp | — | W33 | — | 0.5 | P8-C1-35 | — | — | — |
| R | Cooling fan relay | — | W25 | — | 0.5 | P8-C1-5 | — | — | — |
| S | A/C clutch relay | — | W26 | — | 0.5 | P8-C1-43 | — | — | — |
| U | Front O2 heater | — | W28 | — | 0.5 | P8-C1-21 | — | — | — |
| V | Neutral switch | — | W49 | — | 0.5 | P8-C1-32 | — | — | — |
OEM-2
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A | Fuel tank pressure | — | W44 | — | 0.5 | P8-C1-44 | — | — | — |
| B | Intake air temperature (IAT) | — | W43 | — | 0.5 | P8-C1-45 | — | — | — |
| C | Front O2 signal | — | W40 | — | 0.5 | P8-C1-12 | — | — | — |
| D | Vehicle speed | — | W45 | — | 0.5 | P8-C1-11 | — | — | — |
| E | Coolant temperature (ECT) | — | W42 | — | 0.5 | P8-C1-26 | — | — | — |
| F | Knock sensor | — | — | — | — | — | — | — | — |
| H | Cam position (CMP) | — | W17 | — | 0.5 | P8-C1-27 | — | — | — |
| I | +5V sensor supply | — | W15 | — | 0.5 | P8-C1-10 | — | — | — |
| J | Crank position (CKP) | — | W16 | — | 0.5 | P8-C1-8 | — | — | — |
| K | Tachometer output | — | W36 | — | 0.5 | P8-C1-24 | — | — | — |
| L | Mass air flow (MAF) | — | W37 | — | 0.5 | P8-C1-25 | — | — | — |
| M | EGR valve | — | W34 | — | 0.5 | P8-C1-53 | — | — | — |
| N | EGR valve | — | W35 | — | 0.5 | P8-C1-16 | — | — | — |
| O | EGR valve | — | — | — | — | — | — | — | — |
| P | EGR valve | — | — | — | — | — | — | — | — |
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) | — | W39 | — | 0.5 | P8-C1-48 | — | — | — |
| F | Signal ground | — | W10 | — | 0.5 | SP-0V-1 | — | — | — |
| G | Ignition 1 (coils 1+4, wasted spark) | — | W18 | — | 0.5 | P8-C1-1 | — | — | — |
| H | Ignition 2 (coils 2+3, wasted spark) | — | W19 | — | 0.5 | P8-C1-38 | — | — | — |
| I | Clutch switch | — | W50 | — | 0.5 | P8-C1-33 | — | — | — |
| J | Rear O2 signal | — | W41 | — | 0.5 | P8-C1-7 | — | — | — |
| K | Fuel level | — | — | — | — | — | — | — | — |
| L | Evap purge solenoid | — | — | — | — | — | — | — | — |
| M | ISC valve +14V feed | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
| N | Fuel pump relay | — | W27 | — | 0.5 | P8-C1-42 | — | — | — |
| O | ISC valve low side | — | W30 | — | 0.5 | P8-C1-4 | — | — | — |
| Q | VICS solenoid (intake butterflies) | — | — | — | — | — | — | — | — |
| S | Pressure sensor (Mazda: EGR boost sensor) | — | W38 | — | 0.5 | P8-C1-30 | — | — | — |
| T | EGR boost solenoid | — | — | — | — | — | — | — | — |
| U | Canister drain cut valve (CDCV) | — | — | — | — | — | — | — | — |
| V | Rear O2 heater | — | W29 | — | 0.5 | P8-C1-23 | — | — | — |
| W | Injector 1 | — | W20 | — | 0.5 | P8-C1-37 | — | — | — |
| X | Injector 2 | — | W21 | — | 0.5 | P8-C1-18 | — | — | — |
| Y | Injector 3 | — | W22 | — | 0.5 | P8-C1-54 | — | — | — |
| Z | Injector 4 | — | W23 | — | 0.5 | P8-C1-36 | — | — | — |
P8-C1
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Coil 1 | — | W18 | — | 0.5 | OEM-3-G | — | — | — |
| 10 | 5 Volts | — | W15 | — | 0.5 | OEM-2-I | — | — | — |
| 11 | Undriven Wheel (must) | — | W45 | — | 0.5 | OEM-2-D | — | — | — |
| 12 | Lambda Signal | — | W40 | — | 0.5 | OEM-2-C | — | — | — |
| 13 | Map2/ALS/Ana1 On/Off | — | W46 | — | 0.5 | OEM-1-F | — | — | — |
| 14 | Traction Wet/Dry | — | W47 | — | 0.5 | OEM-1-G | — | — | — |
| 15 | Power Ground | — | W7 | — | 0.85 | SP-GND-1 | — | — | — |
| 16 | Injector 8 | — | W35 | — | 0.5 | OEM-2-N | — | — | — |
| 17 | Injector 5 | — | W32 | — | 0.5 | OEM-1-O | — | — | — |
| 18 | Injector 2 | — | W21 | — | 0.5 | OEM-3-X | — | — | — |
| 19 | 12 Volts | — | W3 | — | 0.85 | SP-14V-1 | — | — | — |
| 2 | Coil 4 | — | — | — | — | — | — | — | — |
| 20 | Coil 3 | — | — | — | — | — | — | — | — |
| 21 | Turbo Pressure Valve | — | W28 | — | 0.5 | OEM-1-U | — | — | — |
| 22 | Coil 8/or Aux5 | — | — | — | — | — | — | — | — |
| 23 | Turbo ALS Valve | — | W29 | — | 0.5 | OEM-3-V | — | — | — |
| 24 | Tacho | — | W36 | — | 0.5 | OEM-2-K | — | — | — |
| 25 | Analogue Input 1 | — | W37 | — | 0.5 | OEM-2-L | — | — | — |
| 26 | Water Temp | — | W42 | — | 0.5 | OEM-2-E | — | — | — |
| 27 | Cam Sensor | — | W17 | — | 0.5 | OEM-2-H | — | — | — |
| 28 | 5 Volts | — | — | — | — | — | — | — | — |
| 29 | Left Driven Wheel | — | — | — | — | — | — | — | — |
| 3 | Coil 6 | — | — | — | — | — | — | — | — |
| 30 | Map | — | W38 | — | 0.5 | OEM-3-S | — | — | — |
| 31 | Launch Button | — | W48 | — | 0.5 | OEM-1-P | — | — | — |
| 32 | Traction On/Off | — | W49 | — | 0.5 | OEM-1-V | — | — | — |
| 33 | Shift Cut | — | W50 | — | 0.5 | OEM-3-I | — | — | — |
| 34 | Power Ground | — | W8 | — | 0.85 | SP-GND-1 | — | — | — |
| 35 | Injector 6 | — | W33 | — | 0.5 | OEM-1-Q | — | — | — |
| 36 | Injector 4 | — | W23 | — | 0.5 | OEM-3-Z | — | — | — |
| 37 | Injector 1 | — | W20 | — | 0.5 | OEM-3-W | — | — | — |
| 38 | Coil 2 | — | W19 | — | 0.5 | OEM-3-H | — | — | — |
| 39 | Coil 5 | — | — | — | — | — | — | — | — |
| 4 | Idle Valve | — | W30 | — | 0.5 | OEM-3-O | — | — | — |
| 40 | Coil 7 | — | — | — | — | — | — | — | — |
| 41 | Fuel Pump Relay | — | W24 | — | 0.5 | OEM-1-I | — | — | — |
| 42 | Cam Phase Valve/Aux Out 4 | — | W27 | — | 0.5 | OEM-3-N | — | — | — |
| 43 | Aux Out 3 | — | W26 | — | 0.5 | OEM-1-S | — | — | — |
| 44 | Analogue Input 3 | — | W44 | — | 0.5 | OEM-2-A | — | — | — |
| 45 | Air Temp | — | W43 | — | 0.5 | OEM-2-B | — | — | — |
| 46 | Signal Ground | — | W11 | — | 0.5 | SP-0V-1 | — | — | — |
| 47 | Signal Ground | — | W12 | — | 0.5 | SP-0V-1 | — | — | — |
| 48 | Throttle Wiper | — | W39 | — | 0.5 | OEM-3-E | — | — | — |
| 49 | Lambda Earth | — | W13 | — | 0.5 | SP-0V-1 | — | — | — |
| 5 | Aux Out 2 | — | W25 | — | 0.5 | OEM-1-R | — | — | — |
| 50 | Undriven Wheel (optional) | — | — | — | — | — | — | — | — |
| 51 | Signal Ground | — | W14 | — | 0.5 | SP-0V-1 | — | — | — |
| 52 | 5 Volts | — | — | — | — | — | — | — | — |
| 53 | Injector 7 | — | W34 | — | 0.5 | OEM-2-M | — | — | — |
| 54 | Injector 3 | — | W22 | — | 0.5 | OEM-3-Y | — | — | — |
| 55 | Power Ground | — | W9 | — | 0.85 | SP-GND-1 | — | — | — |
| 6 | Shift Light | — | W31 | — | 0.5 | OEM-1-E | — | — | — |
| 7 | Analogue Input 2 Or Log Switch | — | W41 | — | 0.5 | OEM-3-J | — | — | — |
| 8 | Crank Sensor | — | W16 | — | 0.5 | OEM-2-J | — | — | — |
| 9 | Right Driven Wheel | — | — | — | — | — | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W10 | — | 0.5 | OEM-3-F | — | — | — |
| 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-1-B | — | — | — |
| 1 | — | — | W2 | — | 0.85 | OEM-3-M | — | — | — |
| 1 | — | — | W3 | — | 0.85 | P8-C1-19 | — | — | — |
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 | 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-1-A | Constant +12V | power_in | — | — | — | single_source | |
| OEM-1-B | ECU power +14V (main relay) | power_in | P8-C1-19 | 12 Volts | power_in | single_source | |
| OEM-1-E | Malfunction indicator lamp (MIL) | low_side_out | P8-C1-6 | Shift Light | low_side_out | single_source | |
| OEM-1-F | Brake switch | digital_in | P8-C1-13 | Map2/ALS/Ana1 On/Off | digital_in | single_source | |
| OEM-1-G | Power steering pressure switch | digital_in | P8-C1-14 | Traction Wet/Dry | digital_in | single_source | |
| OEM-1-I | Condenser fan relay | low_side_out | P8-C1-41 | Fuel Pump Relay | low_side_out | single_source | |
| OEM-1-O | Alternator control | low_side_out | P8-C1-17 | Injector 5 | injector_out | single_source | |
| OEM-1-P | A/C request | digital_in | P8-C1-31 | Launch Button | digital_in | single_source | |
| OEM-1-Q | Charge lamp | low_side_out | P8-C1-35 | Injector 6 | injector_out | single_source | |
| OEM-1-R | Cooling fan relay | low_side_out | P8-C1-5 | Aux Out 2 | low_side_out | single_source | |
| OEM-1-S | A/C clutch relay | low_side_out | P8-C1-43 | Aux Out 3 | low_side_out | single_source | |
| OEM-1-U | Front O2 heater | low_side_out | P8-C1-21 | Turbo Pressure Valve | low_side_out | single_source | |
| OEM-1-V | Neutral switch | digital_in | P8-C1-32 | Traction On/Off | digital_in | single_source | |
| OEM-2-A | Fuel tank pressure | analog_in | P8-C1-44 | Analogue Input 3 | analog_in | single_source | |
| OEM-2-B | Intake air temperature (IAT) | temp_in | P8-C1-45 | Air Temp | temp_in | single_source | |
| OEM-2-C | Front O2 signal | lambda_nb_in | P8-C1-12 | Lambda Signal | lambda_nb_in | single_source | |
| OEM-2-D | Vehicle speed | digital_in | P8-C1-11 | Undriven Wheel (must) | digital_in | single_source | |
| OEM-2-E | Coolant temperature (ECT) | temp_in | P8-C1-26 | Water Temp | temp_in | single_source | |
| OEM-2-F | Knock sensor | knock_in | — | — | — | single_source | |
| OEM-2-H | Cam position (CMP) | trigger_in | P8-C1-27 | Cam Sensor | trigger_in | single_source | |
| OEM-2-I | +5V sensor supply | vref | P8-C1-10 | 5 Volts | vref | single_source | |
| OEM-2-J | Crank position (CKP) | trigger_in | P8-C1-8 | Crank Sensor | trigger_in | single_source | |
| OEM-2-K | Tachometer output | tacho_out | P8-C1-24 | Tacho | tacho_out | single_source | |
| OEM-2-L | Mass air flow (MAF) | analog_in | P8-C1-25 | Analogue Input 1 | analog_in | single_source | |
| OEM-2-M | EGR valve | low_side_out | P8-C1-53 | Injector 7 | injector_out | single_source | |
| OEM-2-N | EGR valve | low_side_out | P8-C1-16 | Injector 8 | injector_out | single_source | |
| OEM-2-O | EGR valve | low_side_out | — | — | — | single_source | |
| OEM-2-P | EGR valve | low_side_out | — | — | — | single_source | |
| OEM-3-A | Power ground | ground | P8-C1-15 + P8-C1-34 + P8-C1-55 | Power Ground + Power Ground + Power Ground | ground | single_source | |
| OEM-3-B | Power ground | ground | P8-C1-15 + P8-C1-34 + P8-C1-55 | Power Ground + Power Ground + Power Ground | ground | single_source | |
| OEM-3-C | Power ground | ground | P8-C1-15 + P8-C1-34 + P8-C1-55 | Power Ground + Power Ground + Power Ground | ground | single_source | |
| OEM-3-E | Throttle position (TPS) | analog_in | P8-C1-48 | Throttle Wiper | analog_in | single_source | |
| OEM-3-F | 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 | single_source | |
| OEM-3-G | Ignition 1 (coils 1+4, wasted spark) | ignition_out | P8-C1-1 | Coil 1 | ignition_out | single_source | |
| OEM-3-H | Ignition 2 (coils 2+3, wasted spark) | ignition_out | P8-C1-38 | Coil 2 | ignition_out | single_source | |
| OEM-3-I | Clutch switch | digital_in | P8-C1-33 | Shift Cut | digital_in | single_source | |
| OEM-3-J | Rear O2 signal | lambda_nb_in | P8-C1-7 | Analogue Input 2 Or Log Switch | analog_in | single_source | |
| OEM-3-K | Fuel level | analog_in | — | — | — | single_source | |
| OEM-3-L | Evap purge solenoid | low_side_out | — | — | — | single_source | |
| OEM-3-M | ISC valve +14V feed | power_in | P8-C1-19 | 12 Volts | power_in | single_source | |
| OEM-3-N | Fuel pump relay | low_side_out | P8-C1-42 | Cam Phase Valve/Aux Out 4 | low_side_out | single_source | |
| OEM-3-O | ISC valve low side | low_side_out | P8-C1-4 | Idle Valve | low_side_out | single_source | |
| OEM-3-Q | VICS solenoid (intake butterflies) | low_side_out | — | — | — | single_source | |
| OEM-3-S | Pressure sensor (Mazda: EGR boost sensor) | analog_in | P8-C1-30 | Map | analog_in | single_source | |
| OEM-3-T | EGR boost solenoid | — | — | — | — | single_source | |
| OEM-3-U | Canister drain cut valve (CDCV) | low_side_out | — | — | — | single_source | |
| OEM-3-V | Rear O2 heater | low_side_out | P8-C1-23 | Turbo ALS Valve | low_side_out | single_source | |
| OEM-3-W | Injector 1 | injector_out | P8-C1-37 | Injector 1 | injector_out | single_source | |
| OEM-3-X | Injector 2 | injector_out | P8-C1-18 | Injector 2 | injector_out | single_source | |
| OEM-3-Y | Injector 3 | injector_out | P8-C1-54 | Injector 3 | injector_out | single_source | |
| OEM-3-Z | Injector 4 | injector_out | P8-C1-36 | Injector 4 | injector_out | 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 | OEM-3-M | SP-14V-1 | 0.85 | no route | ISC valve +14V feed | — | |
| 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-3-C | 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-3-F | 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-2-I | P8-C1-10 | 0.5 | no route | +5V sensor supply | — | |
| W16 | OEM-2-J | P8-C1-8 | 0.5 | no route | Crank position (CKP) | — | |
| W17 | OEM-2-H | P8-C1-27 | 0.5 | no route | Cam position (CMP) | — | |
| W18 | OEM-3-G | P8-C1-1 | 0.5 | no route | Ignition 1 (coils 1+4, wasted spark) | — | |
| W19 | OEM-3-H | P8-C1-38 | 0.5 | no route | Ignition 2 (coils 2+3, wasted spark) | — | |
| W20 | OEM-3-W | P8-C1-37 | 0.5 | no route | Injector 1 | — | |
| W21 | OEM-3-X | P8-C1-18 | 0.5 | no route | Injector 2 | — | |
| W22 | OEM-3-Y | P8-C1-54 | 0.5 | no route | Injector 3 | — | |
| W23 | OEM-3-Z | P8-C1-36 | 0.5 | no route | Injector 4 | — | |
| W24 | OEM-1-I | P8-C1-41 | 0.5 | no route | Condenser fan relay | — | |
| W25 | OEM-1-R | P8-C1-5 | 0.5 | no route | Cooling fan relay | — | |
| W26 | OEM-1-S | P8-C1-43 | 0.5 | no route | A/C clutch relay | — | |
| W27 | OEM-3-N | P8-C1-42 | 0.5 | no route | Fuel pump relay | — | |
| W28 | OEM-1-U | P8-C1-21 | 0.5 | no route | Front O2 heater | — | |
| W29 | OEM-3-V | P8-C1-23 | 0.5 | no route | Rear O2 heater | — | |
| W30 | OEM-3-O | P8-C1-4 | 0.5 | no route | ISC valve low side | — | |
| W31 | OEM-1-E | P8-C1-6 | 0.5 | no route | Malfunction indicator lamp (MIL) | — | |
| W32 | OEM-1-O | P8-C1-17 | 0.5 | no route | Alternator control | — | |
| W33 | OEM-1-Q | P8-C1-35 | 0.5 | no route | Charge lamp | — | |
| W34 | OEM-2-M | P8-C1-53 | 0.5 | no route | EGR valve | — | |
| W35 | OEM-2-N | P8-C1-16 | 0.5 | no route | EGR valve | — | |
| W36 | OEM-2-K | P8-C1-24 | 0.5 | no route | Tachometer output | — | |
| W37 | OEM-2-L | P8-C1-25 | 0.5 | no route | Mass air flow (MAF) | — | |
| W38 | OEM-3-S | P8-C1-30 | 0.5 | no route | Pressure sensor (Mazda: EGR boost sensor) | — | |
| W39 | OEM-3-E | P8-C1-48 | 0.5 | no route | Throttle position (TPS) | — | |
| W40 | OEM-2-C | P8-C1-12 | 0.5 | no route | Front O2 signal | — | |
| W41 | OEM-3-J | P8-C1-7 | 0.5 | no route | Rear O2 signal | — | |
| W42 | OEM-2-E | P8-C1-26 | 0.5 | no route | Coolant temperature (ECT) | — | |
| W43 | OEM-2-B | P8-C1-45 | 0.5 | no route | Intake air temperature (IAT) | — | |
| W44 | OEM-2-A | P8-C1-44 | 0.5 | no route | Fuel tank pressure | — | |
| W45 | OEM-2-D | P8-C1-11 | 0.5 | no route | Vehicle speed | — | |
| W46 | OEM-1-F | P8-C1-13 | 0.5 | no route | Brake switch | — | |
| W47 | OEM-1-G | P8-C1-14 | 0.5 | no route | Power steering pressure switch | — | |
| W48 | OEM-1-P | P8-C1-31 | 0.5 | no route | A/C request | — | |
| W49 | OEM-1-V | P8-C1-32 | 0.5 | no route | Neutral switch | — | |
| W50 | OEM-3-I | P8-C1-33 | 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 (10)
| Severity | Code | Subject | Message |
|---|---|---|---|
| warn | LOAD_UNKNOWN | P8-C1-4 | P8-C1-4 "Idle Valve" drives OEM-3-O ISC valve low side (load 1.0 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-1-I Condenser 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-3-N 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-1-S 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-1-R Cooling fan relay (load 0.2 A) but its current rating is unknown. Check the ECU manual. |
| info | NET_FAMILY | OEM-1-O ↔ P8-C1-17 | OEM-1-O "Alternator control" [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-1-Q ↔ P8-C1-35 | OEM-1-Q "Charge lamp" [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-2-M ↔ P8-C1-53 | OEM-2-M "EGR valve" [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-2-N ↔ P8-C1-16 | OEM-2-N "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 | UNMAPPED | OEM | 8 optional OEM pins are not mapped: OEM-2-F Knock sensor; OEM-2-O EGR valve; OEM-2-P EGR valve; OEM-3-K Fuel level; OEM-3-L Evap purge solenoid; OEM-3-Q VICS solenoid (intake butterflies); 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 2026-10-11. Review every wire against both manuals before building. Not wired: - OEM-1 A: Constant +12V: DTAFast P8 has no battery-constant input; not needed - OEM-2 F: Knock sensor: no free knock input on DTAFast P8 - OEM-2 O: EGR valve: no free low_side/ls_hs/injector/hbridge on DTAFast P8 - OEM-2 P: EGR valve: no free low_side/ls_hs/injector/hbridge on DTAFast P8 - OEM-3 L: Evap purge solenoid: no free low_side/ls_hs/injector/hbridge on DTAFast P8 - OEM-3 Q: VICS solenoid (intake butterflies): no free low_side/ls_hs/injector/hbridge on DTAFast P8 - OEM-3 U: Canister drain cut valve (CDCV): no free low_side/ls_hs/injector/hbridge on DTAFast P8 - OEM-3 K: Fuel level: no free analog_0_5 on DTAFast P8 - OEM-3 T: EGR boost solenoid: not classified in the library; wire by hand
Sources
| Reliability | Kind | Title | URL | Archive | Captured | SHA-256 |
|---|---|---|---|---|---|---|
| 4 | vendor_doc | DTAFast P8Pro wiring schematic | https://dtafast.co.uk/pages/ecu-wiring-diagrams | — | — | — |
| 4 | vendor_doc | Link G4X MX5NB1X install manual (NB1 1999-00) | https://linkecu.com/documentation/MX5XNB1.pdf | archive | 2026-10-05 | 2e36c91270cc |
| 2 | expert_report | Justin Barrera — Miata NA/NB wiring corrections | — | — | — | — |