MX-5 Miata NB1 1999-00 (BP-4W) → MoTeC M800 universal (auto)
MX-5 Miata NB1 1999-00 (BP-4W) — MoTeC — M800
Drawn by Michael Gnankou · Rev 0 · proposal · 2026-10-08
Before you start
| Status | proposal · not yet verified: nobody has reported building and running this harness |
|---|---|
| Open errors | none |
| Size of the job | 47 wires · 8 connectors · 6 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 | OEM-3-M | SP-14V-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W3 | SP-14V-1 | M800-A-26 | 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 | M800-A-10 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | SP-GND-1 | M800-A-11 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | OEM-3-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-I | M800-A-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | OEM-2-J | M800-B-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | OEM-2-H | M800-B-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | OEM-3-G | M800-A-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-3-H | M800-A-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-3-W | M800-A-19 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-3-X | M800-A-20 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-3-Y | M800-A-21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-3-Z | M800-A-22 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-1-I | M800-A-18 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-1-R | M800-A-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-1-S | M800-A-23 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-3-N | M800-A-24 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-1-U | M800-A-31 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-3-V | M800-A-32 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-3-O | M800-A-33 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-1-E | M800-A-34 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | OEM-1-O | M800-A-27 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-1-Q | M800-A-28 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-2-M | M800-A-29 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-2-N | M800-A-30 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-2-L | M800-A-14 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W35 | OEM-3-E | M800-A-15 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W36 | OEM-2-C | M800-A-16 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W37 | OEM-3-J | M800-A-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W38 | OEM-2-E | M800-B-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W39 | OEM-2-B | M800-B-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W40 | OEM-2-A | M800-A-25 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W41 | OEM-3-K | M800-B-20 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W42 | OEM-3-S | M800-B-21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W43 | OEM-2-D | M800-B-8 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W44 | OEM-1-F | M800-B-9 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W45 | OEM-1-G | M800-B-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W46 | OEM-1-P | M800-B-11 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W47 | OEM-1-V | M800-B-22 | 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-2 | M800-A-10 | open (OL) | 5 V sensor reference must not touch power ground | |
| 2 | M800-A-2 | M800-B-14 | open (OL) | 5 V sensor reference must not touch sensor ground | |
| 3 | M800-A-26 | M800-A-10 | open (OL) | +12 V supply must not touch power ground | |
| 4 | M800-A-26 | M800-B-14 | open (OL) | +12 V supply must not touch sensor ground | |
| 5 | M800-A-26 | M800-A-2 | open (OL) | +12 V supply must not touch 5 V sensor reference |
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-I | — | — | — |
| 3 | IGN1 | — | W16 | — | 0.5 | OEM-3-G | — | — | — |
| 4 | IGN2 | — | W17 | — | 0.5 | OEM-3-H | — | — | — |
| 5 | IGN3 | — | — | — | — | — | — | — | — |
| 6 | IGN4 | — | — | — | — | — | — | — | — |
| 7 | IGN5 | — | — | — | — | — | — | — | — |
| 8 | IGN6 | — | — | — | — | — | — | — | — |
| 9 | 5V Auxiliary Sensor Supply | — | — | — | — | — | — | — | — |
| 10 | GND Battery Negative | — | W7 | — | 0.85 | SP-GND-1 | — | — | — |
| 11 | GND Battery Negative | — | W8 | — | 0.85 | SP-GND-1 | — | — | — |
| 12 | 8V Engine Sensor Supply | — | — | — | — | — | — | — | — |
| 13 | 8V Auxiliary Sensor and CAN Supply | — | — | — | — | — | — | — | — |
| 14 | AV1 | — | W34 | — | 0.5 | OEM-2-L | — | — | — |
| 15 | Analog Voltage Input 2 | — | W35 | — | 0.5 | OEM-3-E | — | — | — |
| 16 | Analog Voltage Input 3 | — | W36 | — | 0.5 | OEM-2-C | — | — | — |
| 17 | Analog Voltage Input 4 | — | W37 | — | 0.5 | OEM-3-J | — | — | — |
| 18 | AUX1 | — | W22 | — | 0.5 | OEM-1-I | — | — | — |
| 19 | INJ1 | — | W18 | — | 0.5 | OEM-3-W | — | — | — |
| 20 | INJ2 | — | W19 | — | 0.5 | OEM-3-X | — | — | — |
| 21 | INJ3 | — | W20 | — | 0.5 | OEM-3-Y | — | — | — |
| 22 | INJ4 | — | W21 | — | 0.5 | OEM-3-Z | — | — | — |
| 23 | AUX3 | — | W24 | — | 0.5 | OEM-1-S | — | — | — |
| 24 | AUX4 | — | W25 | — | 0.5 | OEM-3-N | — | — | — |
| 25 | Analog Voltage Input 5 | — | W40 | — | 0.5 | OEM-2-A | — | — | — |
| 26 | VBAT Battery Positive | — | W3 | — | 0.85 | SP-14V-1 | — | — | — |
| 27 | INJ5 | — | W30 | — | 0.5 | OEM-1-O | — | — | — |
| 28 | INJ6 | — | W31 | — | 0.5 | OEM-1-Q | — | — | — |
| 29 | INJ7 | — | W32 | — | 0.5 | OEM-2-M | — | — | — |
| 30 | INJ8 | — | W33 | — | 0.5 | OEM-2-N | — | — | — |
| 31 | AUX5 | — | W26 | — | 0.5 | OEM-1-U | — | — | — |
| 32 | AUX6 | — | W27 | — | 0.5 | OEM-3-V | — | — | — |
| 33 | AUX7 | — | W28 | — | 0.5 | OEM-3-O | — | — | — |
| 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-J | — | — | — |
| 2 | Cam Sync Timing Input | — | W15 | — | 0.5 | OEM-2-H | — | — | — |
| 3 | Analog Temperature Input 1 | — | W38 | — | 0.5 | OEM-2-E | — | — | — |
| 4 | Analog Temperature Input 2 | — | W39 | — | 0.5 | OEM-2-B | — | — | — |
| 5 | Analog Temperature Input 3 | — | — | — | — | — | — | — | — |
| 6 | Analog Temperature Input 4 | — | — | — | — | — | — | — | — |
| 7 | Analog Temperature Input 5 | — | — | — | — | — | — | — | — |
| 8 | Digital Input 1 | — | W43 | — | 0.5 | OEM-2-D | — | — | — |
| 9 | Digital Input 2 | — | W44 | — | 0.5 | OEM-1-F | — | — | — |
| 10 | Digital Input 3 | — | W45 | — | 0.5 | OEM-1-G | — | — | — |
| 11 | Digital Input 4 | — | W46 | — | 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 | — | W41 | — | 0.5 | OEM-3-K | — | — | — |
| 21 | AV7 | — | W42 | — | 0.5 | OEM-3-S | — | — | — |
| 22 | AV8 | — | W47 | — | 0.5 | OEM-1-V | — | — | — |
| 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 | — | — | — |
| E | Malfunction indicator lamp (MIL) | — | W29 | — | 0.5 | M800-A-34 | — | — | — |
| F | Brake switch | — | W44 | — | 0.5 | M800-B-9 | — | — | — |
| G | Power steering pressure switch | — | W45 | — | 0.5 | M800-B-10 | — | — | — |
| I | Condenser fan relay | — | W22 | — | 0.5 | M800-A-18 | — | — | — |
| O | Alternator control | — | W30 | — | 0.5 | M800-A-27 | — | — | — |
| P | A/C request | — | W46 | — | 0.5 | M800-B-11 | — | — | — |
| Q | Charge lamp | — | W31 | — | 0.5 | M800-A-28 | — | — | — |
| R | Cooling fan relay | — | W23 | — | 0.5 | M800-A-1 | — | — | — |
| S | A/C clutch relay | — | W24 | — | 0.5 | M800-A-23 | — | — | — |
| U | Front O2 heater | — | W26 | — | 0.5 | M800-A-31 | — | — | — |
| V | Neutral switch | — | W47 | — | 0.5 | M800-B-22 | — | — | — |
OEM-2
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A | Fuel tank pressure | — | W40 | — | 0.5 | M800-A-25 | — | — | — |
| B | Intake air temperature (IAT) | — | W39 | — | 0.5 | M800-B-4 | — | — | — |
| C | Front O2 signal | — | W36 | — | 0.5 | M800-A-16 | — | — | — |
| D | Vehicle speed | — | W43 | — | 0.5 | M800-B-8 | — | — | — |
| E | Coolant temperature (ECT) | — | W38 | — | 0.5 | M800-B-3 | — | — | — |
| F | Knock sensor | — | — | — | — | — | — | — | — |
| H | Cam position (CMP) | — | W15 | — | 0.5 | M800-B-2 | — | — | — |
| I | +5V sensor supply | — | W13 | — | 0.5 | M800-A-2 | — | — | — |
| J | Crank position (CKP) | — | W14 | — | 0.5 | M800-B-1 | — | — | — |
| K | Tachometer output | — | — | — | — | — | — | — | — |
| L | Mass air flow (MAF) | — | W34 | — | 0.5 | M800-A-14 | — | — | — |
| M | EGR valve | — | W32 | — | 0.5 | M800-A-29 | — | — | — |
| N | EGR valve | — | W33 | — | 0.5 | M800-A-30 | — | — | — |
| 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) | — | W35 | — | 0.5 | M800-A-15 | — | — | — |
| F | Signal ground | — | W9 | — | 0.5 | SP-0V-1 | — | — | — |
| 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 | Clutch switch | — | — | — | — | — | — | — | — |
| J | Rear O2 signal | — | W37 | — | 0.5 | M800-A-17 | — | — | — |
| K | Fuel level | — | W41 | — | 0.5 | M800-B-20 | — | — | — |
| L | Evap purge solenoid | — | — | — | — | — | — | — | — |
| M | ISC valve +14V feed | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
| N | Fuel pump relay | — | W25 | — | 0.5 | M800-A-24 | — | — | — |
| O | ISC valve low side | — | W28 | — | 0.5 | M800-A-33 | — | — | — |
| Q | VICS solenoid (intake butterflies) | — | — | — | — | — | — | — | — |
| S | EGR boost sensor | — | W42 | — | 0.5 | M800-B-21 | — | — | — |
| T | EGR boost solenoid | — | — | — | — | — | — | — | — |
| U | Canister drain cut valve (CDCV) | — | — | — | — | — | — | — | — |
| V | Rear O2 heater | — | W27 | — | 0.5 | M800-A-32 | — | — | — |
| W | Injector 1 | — | W18 | — | 0.5 | M800-A-19 | — | — | — |
| X | Injector 2 | — | W19 | — | 0.5 | M800-A-20 | — | — | — |
| 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 | — | — | W9 | — | 0.5 | OEM-3-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 | OEM-3-M | — | — | — |
| 1 | — | — | W3 | — | 0.85 | M800-A-26 | — | — | — |
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 | M800-A-10 | — | — | — |
| 1 | — | — | W8 | — | 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 | — | — | — | single_source | |
| OEM-1-B | ECU power +14V (main relay) | power_in | M800-A-26 | VBAT Battery Positive | power_in | single_source | |
| OEM-1-E | Malfunction indicator lamp (MIL) | low_side_out | M800-A-34 | AUX8 | switch_out | single_source | |
| OEM-1-F | Brake switch | digital_in | M800-B-9 | Digital Input 2 | digital_in | single_source | |
| OEM-1-G | Power steering pressure switch | digital_in | M800-B-10 | Digital Input 3 | digital_in | single_source | |
| OEM-1-I | Condenser fan relay | low_side_out | M800-A-18 | AUX1 | switch_out | single_source | |
| OEM-1-O | Alternator control | low_side_out | M800-A-27 | INJ5 | injector_out | single_source | |
| OEM-1-P | A/C request | digital_in | M800-B-11 | Digital Input 4 | digital_in | single_source | |
| OEM-1-Q | Charge lamp | low_side_out | M800-A-28 | INJ6 | injector_out | single_source | |
| OEM-1-R | Cooling fan relay | low_side_out | M800-A-1 | AUX2 | switch_out | single_source | |
| OEM-1-S | A/C clutch relay | low_side_out | M800-A-23 | AUX3 | switch_out | single_source | |
| OEM-1-U | Front O2 heater | low_side_out | M800-A-31 | AUX5 | switch_out | single_source | |
| OEM-1-V | Neutral switch | digital_in | M800-B-22 | AV8 | analog_in | single_source | |
| OEM-2-A | Fuel tank pressure | analog_in | M800-A-25 | Analog Voltage Input 5 | analog_in | single_source | |
| OEM-2-B | Intake air temperature (IAT) | temp_in | M800-B-4 | Analog Temperature Input 2 | temp_in | single_source | |
| OEM-2-C | Front O2 signal | lambda_nb_in | M800-A-16 | Analog Voltage Input 3 | analog_in | single_source | |
| OEM-2-D | Vehicle speed | digital_in | M800-B-8 | Digital Input 1 | digital_in | single_source | |
| OEM-2-E | Coolant temperature (ECT) | temp_in | M800-B-3 | Analog Temperature Input 1 | temp_in | single_source | |
| OEM-2-F | Knock sensor | knock_in | — | — | — | single_source | |
| OEM-2-H | Cam position (CMP) | trigger_in | M800-B-2 | Cam Sync Timing Input | trigger_in | single_source | |
| OEM-2-I | +5V sensor supply | vref | M800-A-2 | 5V Engine Sensor Supply | vref | single_source | |
| OEM-2-J | Crank position (CKP) | trigger_in | M800-B-1 | Crank Reference Timing Input | trigger_in | single_source | |
| OEM-2-K | Tachometer output | tacho_out | — | — | — | single_source | |
| OEM-2-L | Mass air flow (MAF) | analog_in | M800-A-14 | AV1 | analog_in | single_source | |
| OEM-2-M | EGR valve | low_side_out | M800-A-29 | INJ7 | injector_out | single_source | |
| OEM-2-N | EGR valve | low_side_out | M800-A-30 | INJ8 | 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 | M800-A-10 + M800-A-11 | GND Battery Negative + GND Battery Negative | ground | single_source | |
| OEM-3-B | Power ground | ground | M800-A-10 + M800-A-11 | GND Battery Negative + GND Battery Negative | ground | single_source | |
| OEM-3-C | Power ground | ground | M800-A-10 + M800-A-11 | GND Battery Negative + GND Battery Negative | ground | single_source | |
| OEM-3-E | Throttle position (TPS) | analog_in | M800-A-15 | Analog Voltage Input 2 | analog_in | single_source | |
| OEM-3-F | Signal 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 | single_source | |
| OEM-3-G | Ignition 1 (coils 1+4, wasted spark) | ignition_out | M800-A-3 | IGN1 | ignition_out | single_source | |
| OEM-3-H | Ignition 2 (coils 2+3, wasted spark) | ignition_out | M800-A-4 | IGN2 | ignition_out | single_source | |
| OEM-3-I | Clutch switch | digital_in | — | — | — | single_source | |
| OEM-3-J | Rear O2 signal | lambda_nb_in | M800-A-17 | Analog Voltage Input 4 | analog_in | single_source | |
| OEM-3-K | Fuel level | analog_in | M800-B-20 | Analog Voltage Input 6 | analog_in | single_source | |
| OEM-3-L | Evap purge solenoid | low_side_out | — | — | — | single_source | |
| OEM-3-M | ISC valve +14V feed | power_in | M800-A-26 | VBAT Battery Positive | power_in | single_source | |
| OEM-3-N | Fuel pump relay | low_side_out | M800-A-24 | AUX4 | switch_out | single_source | |
| OEM-3-O | ISC valve low side | low_side_out | M800-A-33 | AUX7 | switch_out | single_source | |
| OEM-3-Q | VICS solenoid (intake butterflies) | low_side_out | — | — | — | single_source | |
| OEM-3-S | EGR boost sensor | analog_in | M800-B-21 | AV7 | analog_in | single_source | |
| OEM-3-T | EGR boost solenoid | low_side_out | — | — | — | single_source | |
| OEM-3-U | Canister drain cut valve (CDCV) | low_side_out | — | — | — | single_source | |
| OEM-3-V | Rear O2 heater | low_side_out | M800-A-32 | AUX6 | switch_out | single_source | |
| OEM-3-W | Injector 1 | injector_out | M800-A-19 | INJ1 | injector_out | single_source | |
| OEM-3-X | Injector 2 | injector_out | M800-A-20 | INJ2 | injector_out | single_source | |
| OEM-3-Y | Injector 3 | injector_out | M800-A-21 | INJ3 | injector_out | single_source | |
| OEM-3-Z | Injector 4 | injector_out | M800-A-22 | INJ4 | 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 | M800-A-26 | 0.85 | no route | VBAT Battery Positive | — | |
| 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 | M800-A-10 | 0.85 | no route | GND Battery Negative | — | |
| W8 | SP-GND-1 | M800-A-11 | 0.85 | no route | GND Battery Negative | — | |
| W9 | OEM-3-F | SP-0V-1 | 0.5 | no route | Signal 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-I | M800-A-2 | 0.5 | no route | +5V sensor supply | — | |
| W14 | OEM-2-J | M800-B-1 | 0.5 | no route | Crank position (CKP) | — | |
| W15 | OEM-2-H | M800-B-2 | 0.5 | no route | Cam position (CMP) | — | |
| W16 | OEM-3-G | M800-A-3 | 0.5 | no route | Ignition 1 (coils 1+4, wasted spark) | — | |
| W17 | OEM-3-H | M800-A-4 | 0.5 | no route | Ignition 2 (coils 2+3, wasted spark) | — | |
| W18 | OEM-3-W | M800-A-19 | 0.5 | no route | Injector 1 | — | |
| W19 | OEM-3-X | M800-A-20 | 0.5 | no route | Injector 2 | — | |
| W20 | OEM-3-Y | M800-A-21 | 0.5 | no route | Injector 3 | — | |
| W21 | OEM-3-Z | M800-A-22 | 0.5 | no route | Injector 4 | — | |
| W22 | OEM-1-I | M800-A-18 | 0.5 | no route | Condenser fan relay | — | |
| W23 | OEM-1-R | M800-A-1 | 0.5 | no route | Cooling fan relay | — | |
| W24 | OEM-1-S | M800-A-23 | 0.5 | no route | A/C clutch relay | — | |
| W25 | OEM-3-N | M800-A-24 | 0.5 | no route | Fuel pump relay | — | |
| W26 | OEM-1-U | M800-A-31 | 0.5 | no route | Front O2 heater | — | |
| W27 | OEM-3-V | M800-A-32 | 0.5 | no route | Rear O2 heater | — | |
| W28 | OEM-3-O | M800-A-33 | 0.5 | no route | ISC valve low side | — | |
| W29 | OEM-1-E | M800-A-34 | 0.5 | no route | Malfunction indicator lamp (MIL) | — | |
| W30 | OEM-1-O | M800-A-27 | 0.5 | no route | Alternator control | — | |
| W31 | OEM-1-Q | M800-A-28 | 0.5 | no route | Charge lamp | — | |
| W32 | OEM-2-M | M800-A-29 | 0.5 | no route | EGR valve | — | |
| W33 | OEM-2-N | M800-A-30 | 0.5 | no route | EGR valve | — | |
| W34 | OEM-2-L | M800-A-14 | 0.5 | no route | Mass air flow (MAF) | — | |
| W35 | OEM-3-E | M800-A-15 | 0.5 | no route | Throttle position (TPS) | — | |
| W36 | OEM-2-C | M800-A-16 | 0.5 | no route | Front O2 signal | — | |
| W37 | OEM-3-J | M800-A-17 | 0.5 | no route | Rear O2 signal | — | |
| W38 | OEM-2-E | M800-B-3 | 0.5 | no route | Coolant temperature (ECT) | — | |
| W39 | OEM-2-B | M800-B-4 | 0.5 | no route | Intake air temperature (IAT) | — | |
| W40 | OEM-2-A | M800-A-25 | 0.5 | no route | Fuel tank pressure | — | |
| W41 | OEM-3-K | M800-B-20 | 0.5 | no route | Fuel level | — | |
| W42 | OEM-3-S | M800-B-21 | 0.5 | no route | EGR boost sensor | — | |
| W43 | OEM-2-D | M800-B-8 | 0.5 | no route | Vehicle speed | — | |
| W44 | OEM-1-F | M800-B-9 | 0.5 | no route | Brake switch | — | |
| W45 | OEM-1-G | M800-B-10 | 0.5 | no route | Power steering pressure switch | — | |
| W46 | OEM-1-P | M800-B-11 | 0.5 | no route | A/C request | — | |
| W47 | OEM-1-V | M800-B-22 | 0.5 | no route | Neutral 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 |
| 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) | 41.000 | ea |
ECU setup sheet
| Role | Engine ref | Engine signal | Sensor | ECU point | ECU function | ECU class | Setup flag |
|---|---|---|---|---|---|---|---|
| No configured channels. | |||||||
Findings
Open (19)
| 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-I Condenser fan 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-1-S A/C clutch 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-3-N 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-3-O ISC valve low side (load 1.0 A) but its current rating is unknown. Check the ECU manual. |
| warn | NET_FAMILY | OEM-1-V ↔ M800-B-22 | OEM-1-V "Neutral switch" [digital_in] is wired to M800-B-22 "AV8" [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-I ↔ M800-A-18 | OEM-1-I "Condenser fan relay" [low_side_out] is wired to M800-A-18 "AUX1" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-1-O ↔ M800-A-27 | OEM-1-O "Alternator control" [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-1-Q ↔ M800-A-28 | OEM-1-Q "Charge lamp" [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 | 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-1-S ↔ M800-A-23 | OEM-1-S "A/C clutch relay" [low_side_out] is wired to M800-A-23 "AUX3" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-1-U ↔ M800-A-31 | OEM-1-U "Front O2 heater" [low_side_out] is wired to M800-A-31 "AUX5" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-2-M ↔ M800-A-29 | OEM-2-M "EGR valve" [low_side_out] is wired to M800-A-29 "INJ7" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-2-N ↔ M800-A-30 | OEM-2-N "EGR valve" [low_side_out] is wired to M800-A-30 "INJ8" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-3-N ↔ M800-A-24 | OEM-3-N "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-3-O ↔ M800-A-33 | OEM-3-O "ISC valve low side" [low_side_out] is wired to M800-A-33 "AUX7" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-3-V ↔ M800-A-32 | OEM-3-V "Rear O2 heater" [low_side_out] is wired to M800-A-32 "AUX6" [switch_out]. Configure this output as low side. |
| info | UNMAPPED | OEM | 9 optional OEM pins are not mapped: OEM-2-F Knock sensor; OEM-2-K Tachometer output; OEM-2-O EGR valve; OEM-2-P EGR valve; OEM-3-I Clutch switch; 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 2026-10-06. 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 F: Knock sensor: no free knock input on MoTeC M800 - OEM-2 O: EGR valve: no free low_side/ls_hs/injector/hbridge on MoTeC M800 - OEM-2 P: EGR valve: no free low_side/ls_hs/injector/hbridge on MoTeC M800 - OEM-3 L: Evap purge solenoid: no free low_side/ls_hs/injector/hbridge on MoTeC M800 - OEM-3 Q: VICS solenoid (intake butterflies): no free low_side/ls_hs/injector/hbridge on MoTeC M800 - OEM-3 T: EGR boost solenoid: no free low_side/ls_hs/injector/hbridge on MoTeC M800 - OEM-3 U: Canister drain cut valve (CDCV): no free low_side/ls_hs/injector/hbridge on MoTeC M800 - OEM-2 K: Tachometer output: no free tacho/frequency_out/low_side/ls_hs on MoTeC M800 - OEM-3 I: Clutch switch: no free switch_in/frequency_in/analog_0_5 on MoTeC M800
Sources
| Reliability | Kind | Title | URL | Archive | Captured | SHA-256 |
|---|---|---|---|---|---|---|
| 4 | vendor_doc | Link G4X MX5NB1X install manual (NB1 1999-00) | https://linkecu.com/documentation/MX5XNB1.pdf | archive | 2026-10-05 | 2e36c91270cc |
| 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 |