MX-5 Miata NA8 1994-95 (BP-ZE, 1.8, OBD-I) → MoTeC M800 universal (auto)
MX-5 Miata NA8 1994-95 (BP-ZE, 1.8, OBD-I) — MoTeC — M800
⚠ NOT CHECKED. Don't build from this.
Drawn by Michael Gnankou · Rev 0 · draft · 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.
| Status | draft · not yet verified: nobody has reported building and running this harness |
|---|---|
| Open errors | none |
| Size of the job | 42 wires · 7 connectors · 5 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 | M800-A-26 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W3 | OEM-2-A | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W4 | OEM-2-B | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W5 | SP-GND-1 | M800-A-10 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W6 | SP-GND-1 | M800-A-11 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W7 | OEM-2-C | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | OEM-2-D | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | OEM-2-F | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | SP-0V-1 | M800-B-14 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | SP-0V-1 | M800-B-15 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | SP-0V-1 | M800-B-16 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | OEM-2-K | M800-A-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | OEM-2-E | M800-B-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | OEM-2-G | M800-B-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | OEM-1-G | M800-A-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-1-H | M800-A-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-2-U | M800-A-19 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-2-V | M800-A-20 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-2-Y | M800-A-21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-2-Z | M800-A-22 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-1-J | M800-A-18 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-1-R | M800-A-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-2-S | M800-A-23 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-2-T | M800-A-24 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-1-L | M800-A-31 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-2-L | M800-A-32 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-2-W | M800-A-33 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-1-E | M800-A-34 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | OEM-2-R | M800-A-27 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-2-X | M800-A-28 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-2-O | M800-A-14 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-2-M | M800-A-15 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-2-N | M800-A-16 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W35 | OEM-2-Q | M800-B-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W36 | OEM-2-P | M800-B-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W37 | OEM-1-M | M800-B-8 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W38 | OEM-1-C | M800-B-9 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W39 | OEM-1-O | M800-B-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W40 | OEM-1-P | M800-B-11 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W41 | OEM-1-Q | M800-A-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W42 | OEM-1-V | M800-A-25 | 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 | M800-A-26 | M800-A-10 | open (OL) | +12 V supply must not touch power ground | |
| 2 | M800-A-26 | M800-B-14 | open (OL) | +12 V supply must not touch sensor ground | |
| 3 | M800-A-10 | M800-A-2 | open (OL) | power ground must not touch 5 V sensor reference | |
| 4 | M800-A-26 | M800-A-2 | open (OL) | +12 V supply must not touch 5 V sensor reference | |
| 5 | M800-B-14 | M800-A-2 | open (OL) | sensor ground 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
M800-A
Mating face
Wire side
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | AUX2 | — | W23 | — | 0.5 | OEM-1-R | — | — | — |
| 2 | 5V Engine Sensor Supply | — | W13 | — | 0.5 | OEM-2-K | — | — | — |
| 3 | IGN1 | — | W16 | — | 0.5 | OEM-1-G | — | — | — |
| 4 | IGN2 | — | W17 | — | 0.5 | OEM-1-H | — | — | — |
| 5 | IGN3 | — | — | — | — | — | — | — | — |
| 6 | IGN4 | — | — | — | — | — | — | — | — |
| 7 | IGN5 | — | — | — | — | — | — | — | — |
| 8 | IGN6 | — | — | — | — | — | — | — | — |
| 9 | 5V Auxiliary Sensor Supply | — | — | — | — | — | — | — | — |
| 10 | GND Battery Negative | — | W5 | — | 0.85 | SP-GND-1 | — | — | — |
| 11 | GND Battery Negative | — | W6 | — | 0.85 | SP-GND-1 | — | — | — |
| 12 | 8V Engine Sensor Supply | — | — | — | — | — | — | — | — |
| 13 | 8V Auxiliary Sensor and CAN Supply | — | — | — | — | — | — | — | — |
| 14 | AV1 | — | W32 | — | 0.5 | OEM-2-O | — | — | — |
| 15 | Analog Voltage Input 2 | — | W33 | — | 0.5 | OEM-2-M | — | — | — |
| 16 | Analog Voltage Input 3 | — | W34 | — | 0.5 | OEM-2-N | — | — | — |
| 17 | Analog Voltage Input 4 | — | W41 | — | 0.5 | OEM-1-Q | — | — | — |
| 18 | AUX1 | — | W22 | — | 0.5 | OEM-1-J | — | — | — |
| 19 | INJ1 | — | W18 | — | 0.5 | OEM-2-U | — | — | — |
| 20 | INJ2 | — | W19 | — | 0.5 | OEM-2-V | — | — | — |
| 21 | INJ3 | — | W20 | — | 0.5 | OEM-2-Y | — | — | — |
| 22 | INJ4 | — | W21 | — | 0.5 | OEM-2-Z | — | — | — |
| 23 | AUX3 | — | W24 | — | 0.5 | OEM-2-S | — | — | — |
| 24 | AUX4 | — | W25 | — | 0.5 | OEM-2-T | — | — | — |
| 25 | Analog Voltage Input 5 | — | W42 | — | 0.5 | OEM-1-V | — | — | — |
| 26 | VBAT Battery Positive | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
| 27 | INJ5 | — | W30 | — | 0.5 | OEM-2-R | — | — | — |
| 28 | INJ6 | — | W31 | — | 0.5 | OEM-2-X | — | — | — |
| 29 | INJ7 | — | — | — | — | — | — | — | — |
| 30 | INJ8 | — | — | — | — | — | — | — | — |
| 31 | AUX5 | — | W26 | — | 0.5 | OEM-1-L | — | — | — |
| 32 | AUX6 | — | W27 | — | 0.5 | OEM-2-L | — | — | — |
| 33 | AUX7 | — | W28 | — | 0.5 | OEM-2-W | — | — | — |
| 34 | AUX8 | — | W29 | — | 0.5 | OEM-1-E | — | — | — |
M800-B
Mating face
Wire side
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Crank Reference Timing Input | — | W14 | — | 0.5 | OEM-2-E | — | — | — |
| 2 | Cam Sync Timing Input | — | W15 | — | 0.5 | OEM-2-G | — | — | — |
| 3 | Analog Temperature Input 1 | — | W35 | — | 0.5 | OEM-2-Q | — | — | — |
| 4 | Analog Temperature Input 2 | — | W36 | — | 0.5 | OEM-2-P | — | — | — |
| 5 | Analog Temperature Input 3 | — | — | — | — | — | — | — | — |
| 6 | Analog Temperature Input 4 | — | — | — | — | — | — | — | — |
| 7 | Analog Temperature Input 5 | — | — | — | — | — | — | — | — |
| 8 | Digital Input 1 | — | W37 | — | 0.5 | OEM-1-M | — | — | — |
| 9 | Digital Input 2 | — | W38 | — | 0.5 | OEM-1-C | — | — | — |
| 10 | Digital Input 3 | — | W39 | — | 0.5 | OEM-1-O | — | — | — |
| 11 | Digital Input 4 | — | W40 | — | 0.5 | OEM-1-P | — | — | — |
| 12 | Lambda2 Sense Voltage | — | — | — | — | — | — | — | — |
| 13 | Lambda2 Pump Current | — | — | — | — | — | — | — | — |
| 14 | 0V Comms Reference | — | W10 | — | 0.5 | SP-0V-1 | — | — | — |
| 15 | 0V Auxiliary Sensor Supply | — | W11 | — | 0.5 | SP-0V-1 | — | — | — |
| 16 | 0V Engine Sensor Supply | — | W12 | — | 0.5 | SP-0V-1 | — | — | — |
| 17 | RS232 Transmit Data | — | — | — | — | — | — | — | — |
| 18 | RS232 Receive Data | — | — | — | — | — | — | — | — |
| 19 | Analog Temperature Input 6 | — | — | — | — | — | — | — | — |
| 20 | Analog Voltage Input 6 | — | — | — | — | — | — | — | — |
| 21 | AV7 | — | — | — | — | — | — | — | — |
| 22 | AV8 | — | — | — | — | — | — | — | — |
| 23 | CAN Bus High | — | — | — | — | — | — | — | — |
| 24 | CAN Bus Low | — | — | — | — | — | — | — | — |
| 25 | Lambda1 Sense Voltage | — | — | — | — | — | — | — | — |
| 26 | Lambda1 Pump Current | — | — | — | — | — | — | — | — |
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 | — | — | — |
| C | Start signal | — | W38 | — | 0.5 | M800-B-9 | — | — | — |
| D | Data link connector | — | — | — | — | — | — | — | — |
| E | Malfunction indicator lamp (MIL) | — | W29 | — | 0.5 | M800-A-34 | — | — | — |
| G | Ignition 1 (coils 1+4, wasted spark) | — | W16 | — | 0.5 | M800-A-3 | — | — | — |
| H | Ignition 2 (coils 2+3, wasted spark) | — | W17 | — | 0.5 | M800-A-4 | — | — | — |
| I | Powertrain control module (transmission) | — | — | — | — | — | — | — | — |
| J | A/C relay | — | W22 | — | 0.5 | M800-A-18 | — | — | — |
| L | Coolant fan relay | — | W26 | — | 0.5 | M800-A-31 | — | — | — |
| M | Vehicle speed | — | W37 | — | 0.5 | M800-B-8 | — | — | — |
| N | Powertrain control module (transmission) | — | — | — | — | — | — | — | — |
| O | Stop light switch | — | W39 | — | 0.5 | M800-B-10 | — | — | — |
| P | Power steering pressure switch | — | W40 | — | 0.5 | M800-B-11 | — | — | — |
| Q | A/C request | — | W41 | — | 0.5 | M800-A-17 | — | — | — |
| R | Cooling fan relay | — | W23 | — | 0.5 | M800-A-1 | — | — | — |
| S | Heater control unit | — | — | — | — | — | — | — | — |
| T | Unknown | — | — | — | — | — | — | — | — |
| U | Unknown | — | — | — | — | — | — | — | — |
| V | Neutral/clutch switch | — | W42 | — | 0.5 | M800-A-25 | — | — | — |
OEM-2
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A | Power ground | — | W3 | — | 0.85 | SP-GND-1 | — | — | — |
| B | Power ground | — | W4 | — | 0.85 | SP-GND-1 | — | — | — |
| C | Sensor ground (E2) | — | W7 | — | 0.5 | SP-0V-1 | — | — | — |
| D | Sensor ground (E2) | — | W8 | — | 0.5 | SP-0V-1 | — | — | — |
| E | Crank position (CAS NE) | — | W14 | — | 0.5 | M800-B-1 | — | — | — |
| F | MAF ground | — | W9 | — | 0.5 | SP-0V-1 | — | — | — |
| G | Cam position (CAS G) | — | W15 | — | 0.5 | M800-B-2 | — | — | — |
| H | Data link connector | — | — | — | — | — | — | — | — |
| I | Tachometer output | — | — | — | — | — | — | — | — |
| J | EGR function sensor | — | — | — | — | — | — | — | — |
| K | +5V sensor supply | — | W13 | — | 0.5 | M800-A-2 | — | — | — |
| L | Rear defroster relay | — | W27 | — | 0.5 | M800-A-32 | — | — | — |
| M | Throttle position (TPS) | — | W33 | — | 0.5 | M800-A-15 | — | — | — |
| N | O2 sensor | — | W34 | — | 0.5 | M800-A-16 | — | — | — |
| O | Mass air flow (MAF) | — | W32 | — | 0.5 | M800-A-14 | — | — | — |
| P | Intake air temperature (IAT) | — | W36 | — | 0.5 | M800-B-4 | — | — | — |
| Q | Coolant temperature (ECT) | — | W35 | — | 0.5 | M800-B-3 | — | — | — |
| R | PRC solenoid (fuel pressure regulator) | — | W30 | — | 0.5 | M800-A-27 | — | — | — |
| S | Condenser fan relay | — | W24 | — | 0.5 | M800-A-23 | — | — | — |
| T | Fuel pump relay | — | W25 | — | 0.5 | M800-A-24 | — | — | — |
| U | Injector 1 | — | W18 | — | 0.5 | M800-A-19 | — | — | — |
| V | Injector 2 | — | W19 | — | 0.5 | M800-A-20 | — | — | — |
| W | ISC solenoid | — | W28 | — | 0.5 | M800-A-33 | — | — | — |
| X | Evap purge solenoid | — | W31 | — | 0.5 | M800-A-28 | — | — | — |
| Y | Injector 3 | — | W20 | — | 0.5 | M800-A-21 | — | — | — |
| Z | Injector 4 | — | W21 | — | 0.5 | M800-A-22 | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W7 | — | 0.5 | OEM-2-C | — | — | — |
| 1 | — | — | W8 | — | 0.5 | OEM-2-D | — | — | — |
| 1 | — | — | W9 | — | 0.5 | OEM-2-F | — | — | — |
| 1 | — | — | W10 | — | 0.5 | M800-B-14 | — | — | — |
| 1 | — | — | W11 | — | 0.5 | M800-B-15 | — | — | — |
| 1 | — | — | W12 | — | 0.5 | M800-B-16 | — | — | — |
SP-14V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W1 | — | 0.85 | OEM-1-B | — | — | — |
| 1 | — | — | W2 | — | 0.85 | M800-A-26 | — | — | — |
SP-GND
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W3 | — | 0.85 | OEM-2-A | — | — | — |
| 1 | — | — | W4 | — | 0.85 | OEM-2-B | — | — | — |
| 1 | — | — | W5 | — | 0.85 | M800-A-10 | — | — | — |
| 1 | — | — | W6 | — | 0.85 | M800-A-11 | — | — | — |
Pin map
| OEM point | OEM function | OEM family | Target point | Target function | Target family | Wire colour | Evidence |
|---|---|---|---|---|---|---|---|
| OEM-1-A | Constant +12V | power_in | — | — | — | LR | single_source |
| OEM-1-B | ECU power +14V (main relay) | power_in | M800-A-26 | VBAT Battery Positive | power_in | WR | single_source |
| OEM-1-C | Start signal | digital_in | M800-B-9 | Digital Input 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 | M800-A-34 | AUX8 | switch_out | YB | single_source |
| OEM-1-G | Ignition 1 (coils 1+4, wasted spark) | ignition_out | M800-A-3 | IGN1 | ignition_out | BrY | single_source |
| OEM-1-H | Ignition 2 (coils 2+3, wasted spark) | ignition_out | M800-A-4 | IGN2 | ignition_out | Br | single_source |
| OEM-1-I | Powertrain control module (transmission) | — | — | — | — | LW | single_source |
| OEM-1-J | A/C relay | low_side_out | M800-A-18 | AUX1 | switch_out | single_source | |
| OEM-1-L | Coolant fan relay | low_side_out | M800-A-31 | AUX5 | switch_out | BG | single_source |
| OEM-1-M | Vehicle speed | digital_in | M800-B-8 | Digital Input 1 | digital_in | GR | single_source |
| OEM-1-N | Powertrain control module (transmission) | — | — | — | — | R | single_source |
| OEM-1-O | Stop light switch | digital_in | M800-B-10 | Digital Input 3 | digital_in | GB | single_source |
| OEM-1-P | Power steering pressure switch | digital_in | M800-B-11 | Digital Input 4 | digital_in | LY | single_source |
| OEM-1-Q | A/C request | digital_in | M800-A-17 | Analog Voltage Input 4 | analog_in | LgB | single_source |
| OEM-1-R | Cooling fan relay | low_side_out | M800-A-1 | AUX2 | switch_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 | M800-A-25 | Analog Voltage Input 5 | analog_in | BrW | single_source |
| OEM-2-A | Power ground | ground | M800-A-10 + M800-A-11 | GND Battery Negative + GND Battery Negative | ground | B | single_source |
| OEM-2-B | Power ground | ground | M800-A-10 + M800-A-11 | GND Battery Negative + GND Battery Negative | ground | B | single_source |
| OEM-2-C | Sensor ground (E2) | sensor_ground | M800-B-14 + M800-B-15 + M800-B-16 | 0V Comms Reference + 0V Auxiliary Sensor Supply + 0V Engine Sensor Supply | sensor_ground | BLg | corroborated |
| OEM-2-D | Sensor ground (E2) | sensor_ground | M800-B-14 + M800-B-15 + M800-B-16 | 0V Comms Reference + 0V Auxiliary Sensor Supply + 0V Engine Sensor Supply | sensor_ground | BL | corroborated |
| OEM-2-E | Crank position (CAS NE) | trigger_in | M800-B-1 | Crank Reference Timing Input | trigger_in | W | single_source |
| OEM-2-F | MAF ground | sensor_ground | M800-B-14 + M800-B-15 + M800-B-16 | 0V Comms Reference + 0V Auxiliary Sensor Supply + 0V Engine Sensor Supply | sensor_ground | BR | single_source |
| OEM-2-G | Cam position (CAS G) | trigger_in | M800-B-2 | Cam Sync Timing Input | trigger_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 | M800-A-2 | 5V Engine Sensor Supply | vref | LgW | single_source |
| OEM-2-L | Rear defroster relay | low_side_out | M800-A-32 | AUX6 | switch_out | LR | single_source |
| OEM-2-M | Throttle position (TPS) | analog_in | M800-A-15 | Analog Voltage Input 2 | analog_in | RB | single_source |
| OEM-2-N | O2 sensor | lambda_nb_in | M800-A-16 | Analog Voltage Input 3 | analog_in | RL | single_source |
| OEM-2-O | Mass air flow (MAF) | analog_in | M800-A-14 | AV1 | analog_in | R | single_source |
| OEM-2-P | Intake air temperature (IAT) | temp_in | M800-B-4 | Analog Temperature Input 2 | temp_in | RB | single_source |
| OEM-2-Q | Coolant temperature (ECT) | temp_in | M800-B-3 | Analog Temperature Input 1 | temp_in | LW | single_source |
| OEM-2-R | PRC solenoid (fuel pressure regulator) | low_side_out | M800-A-27 | INJ5 | injector_out | YG | single_source |
| OEM-2-S | Condenser fan relay | low_side_out | M800-A-23 | AUX3 | switch_out | LW | single_source |
| OEM-2-T | Fuel pump relay | low_side_out | M800-A-24 | AUX4 | switch_out | Lg | single_source |
| OEM-2-U | Injector 1 | injector_out | M800-A-19 | INJ1 | injector_out | Y | single_source |
| OEM-2-V | Injector 2 | injector_out | M800-A-20 | INJ2 | injector_out | YB | single_source |
| OEM-2-W | ISC solenoid | low_side_out | M800-A-33 | AUX7 | switch_out | LOr | single_source |
| OEM-2-X | Evap purge solenoid | low_side_out | M800-A-28 | INJ6 | injector_out | YR | single_source |
| OEM-2-Y | Injector 3 | injector_out | M800-A-21 | INJ3 | injector_out | GW | single_source |
| OEM-2-Z | Injector 4 | injector_out | M800-A-22 | INJ4 | 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 | M800-A-26 | 0.85 | no route | VBAT Battery Positive | — | |
| W3 | OEM-2-A | SP-GND-1 | 0.85 | no route | Power ground | — | |
| W4 | OEM-2-B | SP-GND-1 | 0.85 | no route | Power ground | — | |
| W5 | SP-GND-1 | M800-A-10 | 0.85 | no route | GND Battery Negative | — | |
| W6 | SP-GND-1 | M800-A-11 | 0.85 | no route | GND Battery Negative | — | |
| W7 | OEM-2-C | SP-0V-1 | 0.5 | no route | Sensor ground (E2) | — | |
| W8 | OEM-2-D | SP-0V-1 | 0.5 | no route | Sensor ground (E2) | — | |
| W9 | OEM-2-F | SP-0V-1 | 0.5 | no route | MAF ground | — | |
| W10 | SP-0V-1 | M800-B-14 | 0.5 | no route | 0V Comms Reference | — | |
| W11 | SP-0V-1 | M800-B-15 | 0.5 | no route | 0V Auxiliary Sensor Supply | — | |
| W12 | SP-0V-1 | M800-B-16 | 0.5 | no route | 0V Engine Sensor Supply | — | |
| W13 | OEM-2-K | M800-A-2 | 0.5 | no route | +5V sensor supply | — | |
| W14 | OEM-2-E | M800-B-1 | 0.5 | no route | Crank position (CAS NE) | — | |
| W15 | OEM-2-G | M800-B-2 | 0.5 | no route | Cam position (CAS G) | — | |
| W16 | OEM-1-G | M800-A-3 | 0.5 | no route | Ignition 1 (coils 1+4, wasted spark) | — | |
| W17 | OEM-1-H | M800-A-4 | 0.5 | no route | Ignition 2 (coils 2+3, wasted spark) | — | |
| W18 | OEM-2-U | M800-A-19 | 0.5 | no route | Injector 1 | — | |
| W19 | OEM-2-V | M800-A-20 | 0.5 | no route | Injector 2 | — | |
| W20 | OEM-2-Y | M800-A-21 | 0.5 | no route | Injector 3 | — | |
| W21 | OEM-2-Z | M800-A-22 | 0.5 | no route | Injector 4 | — | |
| W22 | OEM-1-J | M800-A-18 | 0.5 | no route | A/C relay | — | |
| W23 | OEM-1-R | M800-A-1 | 0.5 | no route | Cooling fan relay | — | |
| W24 | OEM-2-S | M800-A-23 | 0.5 | no route | Condenser fan relay | — | |
| W25 | OEM-2-T | M800-A-24 | 0.5 | no route | Fuel pump relay | — | |
| W26 | OEM-1-L | M800-A-31 | 0.5 | no route | Coolant fan relay | — | |
| W27 | OEM-2-L | M800-A-32 | 0.5 | no route | Rear defroster relay | — | |
| W28 | OEM-2-W | M800-A-33 | 0.5 | no route | ISC solenoid | — | |
| W29 | OEM-1-E | M800-A-34 | 0.5 | no route | Malfunction indicator lamp (MIL) | — | |
| W30 | OEM-2-R | M800-A-27 | 0.5 | no route | PRC solenoid (fuel pressure regulator) | — | |
| W31 | OEM-2-X | M800-A-28 | 0.5 | no route | Evap purge solenoid | — | |
| W32 | OEM-2-O | M800-A-14 | 0.5 | no route | Mass air flow (MAF) | — | |
| W33 | OEM-2-M | M800-A-15 | 0.5 | no route | Throttle position (TPS) | — | |
| W34 | OEM-2-N | M800-A-16 | 0.5 | no route | O2 sensor | — | |
| W35 | OEM-2-Q | M800-B-3 | 0.5 | no route | Coolant temperature (ECT) | — | |
| W36 | OEM-2-P | M800-B-4 | 0.5 | no route | Intake air temperature (IAT) | — | |
| W37 | OEM-1-M | M800-B-8 | 0.5 | no route | Vehicle speed | — | |
| W38 | OEM-1-C | M800-B-9 | 0.5 | no route | Start signal | — | |
| W39 | OEM-1-O | M800-B-10 | 0.5 | no route | Stop light switch | — | |
| W40 | OEM-1-P | M800-B-11 | 0.5 | no route | Power steering pressure switch | — | |
| W41 | OEM-1-Q | M800-A-17 | 0.5 | no route | A/C request | — | |
| W42 | OEM-1-V | M800-A-25 | 0.5 | no route | Neutral/clutch switch | — |
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 | 3-1437290-7 | TE | Superseal 1.0 26-way plug | 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) | 36.000 | ea |
ECU setup sheet
| Role | Engine ref | Engine signal | Sensor | ECU point | ECU function | ECU class | Setup flag |
|---|---|---|---|---|---|---|---|
| No configured channels. | |||||||
Findings
Open (18)
| Severity | Code | Subject | Message |
|---|---|---|---|
| warn | LOAD_UNKNOWN | M800-A-1 | M800-A-1 "AUX2" drives OEM-1-R Cooling fan relay (load 0.2 A) but its current rating is unknown. Check the ECU manual. |
| warn | LOAD_UNKNOWN | M800-A-18 | M800-A-18 "AUX1" drives OEM-1-J A/C relay (load 0.2 A) but its current rating is unknown. Check the ECU manual. |
| warn | LOAD_UNKNOWN | M800-A-23 | M800-A-23 "AUX3" drives OEM-2-S Condenser fan relay (load 0.2 A) but its current rating is unknown. Check the ECU manual. |
| warn | LOAD_UNKNOWN | M800-A-24 | M800-A-24 "AUX4" drives OEM-2-T Fuel pump relay (load 0.2 A) but its current rating is unknown. Check the ECU manual. |
| warn | LOAD_UNKNOWN | M800-A-33 | M800-A-33 "AUX7" drives OEM-2-W ISC solenoid (load 1.0 A) but its current rating is unknown. Check the ECU manual. |
| warn | NET_FAMILY | OEM-1-Q ↔ M800-A-17 | OEM-1-Q "A/C request" [digital_in] is wired to M800-A-17 "Analog Voltage Input 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-V ↔ M800-A-25 | OEM-1-V "Neutral/clutch switch" [digital_in] is wired to M800-A-25 "Analog Voltage Input 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. |
| info | NET_FAMILY | OEM-1-E ↔ M800-A-34 | OEM-1-E "Malfunction indicator lamp (MIL)" [low_side_out] is wired to M800-A-34 "AUX8" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-1-J ↔ M800-A-18 | OEM-1-J "A/C relay" [low_side_out] is wired to M800-A-18 "AUX1" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-1-L ↔ M800-A-31 | OEM-1-L "Coolant fan relay" [low_side_out] is wired to M800-A-31 "AUX5" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-1-R ↔ M800-A-1 | OEM-1-R "Cooling fan relay" [low_side_out] is wired to M800-A-1 "AUX2" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-2-L ↔ M800-A-32 | OEM-2-L "Rear defroster relay" [low_side_out] is wired to M800-A-32 "AUX6" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-2-R ↔ M800-A-27 | OEM-2-R "PRC solenoid (fuel pressure regulator)" [low_side_out] is wired to M800-A-27 "INJ5" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-2-S ↔ M800-A-23 | OEM-2-S "Condenser fan relay" [low_side_out] is wired to M800-A-23 "AUX3" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-2-T ↔ M800-A-24 | OEM-2-T "Fuel pump relay" [low_side_out] is wired to M800-A-24 "AUX4" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-2-W ↔ M800-A-33 | OEM-2-W "ISC solenoid" [low_side_out] is wired to M800-A-33 "AUX7" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-2-X ↔ M800-A-28 | OEM-2-X "Evap purge solenoid" [low_side_out] is wired to M800-A-28 "INJ6" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | UNMAPPED | OEM | 9 optional OEM pins are not mapped: OEM-1-D Data link connector; 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-2-H Data link connector; OEM-2-I Tachometer output; OEM-2-J EGR function sensor |
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
Fit check: unconfirmed. Confirm these before building: - Trigger pattern for Mazda BP-ZE not found in the ECU's docs (No documented M800 OEM preset.) 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: MoTeC M800 has no battery-constant input; not needed - OEM-2 I: Tachometer output: no free tacho/frequency_out/low_side/ls_hs on MoTeC M800 - OEM-1 D: Data link connector: no free k_line on MoTeC M800 - OEM-2 H: Data link connector: no free k_line on MoTeC M800 - 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 | Link G4X MX5X install manual (NA 1.6/1.8) | https://linkecu.com/documentation/MX5X.pdf | archive | 2026-10-05 | b7f730de9f6e |
| 4 | vendor_doc | MoTeC M400/M600/M800/M880 Manual — Appendix L: Pin list by Function | https://starracecars.com/wp-content/uploads/resources/M400_M600_M800_M880_Manual_A5.pdf | archive | 2026-10-05 | b69bb8ffb674 |
| 4 | vendor_doc | MoTeC M800 OEM WRX56 Installation | https://motec.com.au | archive | 2026-10-05 | 2ca4be92bb65 |
| 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 |