MX-5 Miata NA8 1996-97 (BP-ZE, 1.8, OBD-II) → Motorsport Electronics ME442 (auto)
MX-5 Miata NA8 1996-97 (BP-ZE, 1.8, OBD-II) — Motorsport Electronics — ME442
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.
| Status | proposal · not yet verified: nobody has reported building and running this harness |
|---|---|
| Open errors | none |
| Size of the job | 52 wires · 7 connectors · 0 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-4-B | SP-14V-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W2 | SP-14V-1 | ME442-C1-15 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W3 | SP-14V-1 | ME442-C1-64 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W4 | OEM-4-A | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W5 | OEM-4-C | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W6 | OEM-4-D | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W7 | OEM-4-K | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | SP-GND-1 | ME442-C1-10 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | SP-GND-1 | ME442-C1-61 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | SP-GND-1 | ME442-C1-89 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | SP-GND-1 | ME442-C1-90 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | OEM-3-O | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | OEM-4-H | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | SP-0V-1 | ME442-C1-52 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | SP-0V-1 | ME442-C1-84 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | OEM-3-I | ME442-C1-45 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-4-E | ME442-C1-80 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-4-G | ME442-C1-22 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-4-F | ME442-C1-23 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-4-N | ME442-C1-32 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-4-R | ME442-C1-31 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-4-U | ME442-C1-63 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-4-V | ME442-C1-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-4-W | ME442-C1-33 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-4-X | ME442-C1-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-3-B | ME442-C1-26 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-3-F | ME442-C1-56 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-3-G | ME442-C1-86 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-1-A | ME442-C1-73 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | OEM-1-B | ME442-C1-12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-1-G | ME442-C1-74 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-1-U | ME442-C1-44 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-3-M | ME442-C1-16 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-1-E | ME442-C1-69 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W35 | OEM-4-J | ME442-C1-39 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W36 | OEM-4-O | ME442-C1-37 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W37 | OEM-4-P | ME442-C1-42 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W38 | OEM-4-Q | ME442-C1-72 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W39 | OEM-4-T | ME442-C1-43 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W40 | OEM-4-L | ME442-C1-79 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W41 | OEM-3-H | ME442-C1-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W42 | OEM-3-N | ME442-C1-18 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W43 | OEM-3-C | ME442-C1-87 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W44 | OEM-3-D | ME442-C1-78 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W45 | OEM-3-K | ME442-C1-57 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W46 | OEM-3-J | ME442-C1-48 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W47 | OEM-1-M | ME442-C1-6 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W48 | OEM-1-C | ME442-C1-7 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W49 | OEM-1-K | ME442-C1-8 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W50 | OEM-1-L | ME442-C1-5 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W51 | OEM-1-Q | ME442-C1-62 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W52 | OEM-3-L | ME442-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 | ME442-C1-45 | ME442-C1-10 | open (OL) | 5 V sensor reference must not touch power ground | |
| 2 | ME442-C1-45 | ME442-C1-52 | open (OL) | 5 V sensor reference must not touch sensor ground | |
| 3 | ME442-C1-10 | ME442-C1-15 | open (OL) | power ground must not touch +12 V supply | |
| 4 | ME442-C1-45 | ME442-C1-15 | open (OL) | 5 V sensor reference must not touch +12 V supply | |
| 5 | ME442-C1-52 | ME442-C1-15 | open (OL) | sensor ground must not touch +12 V supply |
If any reading doesn't match, stop and get help before powering up.
Revisions
| Rev | Label | By | Date |
|---|---|---|---|
| No revisions yet. | |||
Schematic
Connectors
ME442-C1
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | COIL 4 | — | — | — | — | — | — | — | — |
| 10 | GROUND CHASSIS | — | W8 | — | 0.85 | SP-GND-1 | — | — | — |
| 11 | EGT 1 | — | — | — | — | — | — | — | — |
| 12 | LOW SIDE 2 | — | W30 | — | 0.5 | OEM-1-B | — | — | — |
| 13 | LOW SIDE RELAY 15 | — | — | — | — | — | — | — | — |
| 14 | LSU +12V | — | — | — | — | — | — | — | — |
| 15 | IGN +12V | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
| 16 | LSU HEATER -VE | — | W33 | — | 0.5 | OEM-3-M | — | — | — |
| 17 | ANA VOLT 3 | — | W41 | — | 0.5 | OEM-3-H | — | — | — |
| 18 | ANA VOLT 4 | — | W42 | — | 0.5 | OEM-3-N | — | — | — |
| 19 | LSU UN | — | — | — | — | — | — | — | — |
| 2 | COIL 3 | — | — | — | — | — | — | — | — |
| 20 | LSU VM | — | — | — | — | — | — | — | — |
| 21 | CAN 1 HIGH | — | — | — | — | — | — | — | — |
| 22 | CAM A VR+ | — | W18 | — | 0.5 | OEM-4-G | — | — | — |
| 23 | CAM A VR- | — | W19 | — | 0.5 | OEM-4-F | — | — | — |
| 24 | SERIAL 1 GROUND | — | — | — | — | — | — | — | — |
| 25 | SERIAL 1 TX | — | — | — | — | — | — | — | — |
| 26 | ANA VOLT 1 | — | W26 | — | 0.5 | OEM-3-B | — | — | — |
| 27 | INJECTOR 8 | — | — | — | — | — | — | — | — |
| 28 | INJECTOR 5 | — | — | — | — | — | — | — | — |
| 29 | COIL 7 | — | — | — | — | — | — | — | — |
| 3 | INJECTOR 4 | — | W25 | — | 0.5 | OEM-4-X | — | — | — |
| 30 | COIL 8 | — | — | — | — | — | — | — | — |
| 31 | COIL 2 | — | W21 | — | 0.5 | OEM-4-R | — | — | — |
| 32 | COIL 1 | — | W20 | — | 0.5 | OEM-4-N | — | — | — |
| 33 | INJECTOR 3 | — | W24 | — | 0.5 | OEM-4-W | — | — | — |
| 34 | DIG_IN 6 | — | W52 | — | 0.5 | OEM-3-L | — | — | — |
| 35 | USB D+ | — | — | — | — | — | — | — | — |
| 36 | USB D- | — | — | — | — | — | — | — | — |
| 37 | LOW SIDE RELAY 11 | — | W36 | — | 0.5 | OEM-4-O | — | — | — |
| 38 | USB VBUS | — | — | — | — | — | — | — | — |
| 39 | LOW SIDE 6 | — | W35 | — | 0.5 | OEM-4-J | — | — | — |
| 4 | INJECTOR 2 | — | W23 | — | 0.5 | OEM-4-V | — | — | — |
| 40 | LOW SIDE RELAY 17 | — | — | — | — | — | — | — | — |
| 41 | USB GROUND | — | — | — | — | — | — | — | — |
| 42 | LOW SIDE RELAY 12 | — | W37 | — | 0.5 | OEM-4-P | — | — | — |
| 43 | LOW SIDE RELAY 14 | — | W39 | — | 0.5 | OEM-4-T | — | — | — |
| 44 | LOW SIDE 4 | — | W32 | — | 0.5 | OEM-1-U | — | — | — |
| 45 | 5V REF | — | W16 | — | 0.5 | OEM-3-I | — | — | — |
| 46 | 5V REF | — | — | — | — | — | — | — | — |
| 47 | ANA TEMP 4 | — | — | — | — | — | — | — | — |
| 48 | ANA VOLT 7 | — | W46 | — | 0.5 | OEM-3-J | — | — | — |
| 49 | LSU IA | — | — | — | — | — | — | — | — |
| 5 | DIG_IN 4 | — | W50 | — | 0.5 | OEM-1-L | — | — | — |
| 50 | LSU IP | — | — | — | — | — | — | — | — |
| 51 | CAN 1 LOW | — | — | — | — | — | — | — | — |
| 52 | SENSORS GROUND | — | W14 | — | 0.5 | SP-0V-1 | — | — | — |
| 53 | KNOCK 1 SIGNAL | — | — | — | — | — | — | — | — |
| 54 | KNOCK 2 SIGNAL | — | — | — | — | — | — | — | — |
| 55 | SERIAL 1 RX | — | — | — | — | — | — | — | — |
| 56 | ANA VOLT 2 | — | W27 | — | 0.5 | OEM-3-F | — | — | — |
| 57 | ANA TEMP 2 | — | W45 | — | 0.5 | OEM-3-K | — | — | — |
| 58 | INJECTOR 6 | — | — | — | — | — | — | — | — |
| 59 | COIL 5 | — | — | — | — | — | — | — | — |
| 6 | DIG_IN 1 | — | W47 | — | 0.5 | OEM-1-M | — | — | — |
| 60 | COIL 6 | — | — | — | — | — | — | — | — |
| 61 | GROUND | — | W9 | — | 0.85 | SP-GND-1 | — | — | — |
| 62 | DIG_IN 5 | — | W51 | — | 0.5 | OEM-1-Q | — | — | — |
| 63 | INJECTOR 1 | — | W22 | — | 0.5 | OEM-4-U | — | — | — |
| 64 | VBAT | — | W3 | — | 0.85 | SP-14V-1 | — | — | — |
| 65 | H-BRIDGE A OUT 1 | — | — | — | — | — | — | — | — |
| 66 | H-BRIDGE A OUT 2 | — | — | — | — | — | — | — | — |
| 67 | Stepper 1 / A1 | — | — | — | — | — | — | — | — |
| 68 | Stepper 2 / A2 | — | — | — | — | — | — | — | — |
| 69 | LOW SIDE 5 | — | W34 | — | 0.5 | OEM-1-E | — | — | — |
| 7 | DIG_IN 2 | — | W48 | — | 0.5 | OEM-1-C | — | — | — |
| 70 | Stepper 3 / B1 | — | — | — | — | — | — | — | — |
| 71 | Stepper 4 / B2 | — | — | — | — | — | — | — | — |
| 72 | LOW SIDE RELAY 13 | — | W38 | — | 0.5 | OEM-4-Q | — | — | — |
| 73 | LOW SIDE 1 | — | W29 | — | 0.5 | OEM-1-A | — | — | — |
| 74 | LOW SIDE 3 | — | W31 | — | 0.5 | OEM-1-G | — | — | — |
| 75 | LOW SIDE RELAY 16 | — | — | — | — | — | — | — | — |
| 76 | 5V REF | — | — | — | — | — | — | — | — |
| 77 | ANA TEMP 3 | — | — | — | — | — | — | — | — |
| 78 | ANA VOLT 6 | — | W44 | — | 0.5 | OEM-3-D | — | — | — |
| 79 | TACHOMETER | — | W40 | — | 0.5 | OEM-4-L | — | — | — |
| 8 | DIG_IN 3 | — | W49 | — | 0.5 | OEM-1-K | — | — | — |
| 80 | CRANK VR+ | — | W17 | — | 0.5 | OEM-4-E | — | — | — |
| 81 | CRANK VR- | — | — | — | — | — | — | — | — |
| 82 | CAM B VR+ | — | — | — | — | — | — | — | — |
| 83 | CAM B VR- | — | — | — | — | — | — | — | — |
| 84 | Sensor Ground | — | W15 | — | 0.5 | SP-0V-1 | — | — | — |
| 86 | ANA TEMP 1 | — | W28 | — | 0.5 | OEM-3-G | — | — | — |
| 87 | ANA VOLT 5 | — | W43 | — | 0.5 | OEM-3-C | — | — | — |
| 88 | INJECTOR 7 | — | — | — | — | — | — | — | — |
| 89 | GROUND | — | W10 | — | 0.85 | SP-GND-1 | — | — | — |
| 9 | LOW SIDE RELAY 18 | — | — | — | — | — | — | — | — |
| 90 | GROUND | — | W11 | — | 0.85 | SP-GND-1 | — | — | — |
OEM-1
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A | Cooling fan relay (low-side) | — | W29 | — | 0.5 | ME442-C1-73 | — | — | — |
| B | A/C condenser fan relay | — | W30 | — | 0.5 | ME442-C1-12 | — | — | — |
| C | Starter input (12V while cranking) | — | W48 | — | 0.5 | ME442-C1-7 | — | — | — |
| E | Check engine light (MIL) | — | W34 | — | 0.5 | ME442-C1-69 | — | — | — |
| G | A/C clutch relay | — | W31 | — | 0.5 | ME442-C1-74 | — | — | — |
| K | A/C pressure switch (A/C request) | — | W49 | — | 0.5 | ME442-C1-8 | — | — | — |
| L | Clutch switch | — | W50 | — | 0.5 | ME442-C1-5 | — | — | — |
| M | Vehicle speed sensor (VSS) | — | W47 | — | 0.5 | ME442-C1-6 | — | — | — |
| Q | Brake switch | — | W51 | — | 0.5 | ME442-C1-62 | — | — | — |
| U | Fuel pump relay (low-side) | — | W32 | — | 0.5 | ME442-C1-44 | — | — | — |
OEM-3
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| B | MAF sensor input | — | W26 | — | 0.5 | ME442-C1-26 | — | — | — |
| C | Front O2 sensor input | — | W43 | — | 0.5 | ME442-C1-87 | — | — | — |
| D | Rear O2 sensor input | — | W44 | — | 0.5 | ME442-C1-78 | — | — | — |
| F | Throttle position (TPS) | — | W27 | — | 0.5 | ME442-C1-56 | — | — | — |
| G | Engine coolant temp (CLT) | — | W28 | — | 0.5 | ME442-C1-86 | — | — | — |
| H | EGR boost sensor | — | W41 | — | 0.5 | ME442-C1-17 | — | — | — |
| I | +5V sensor reference | — | W16 | — | 0.5 | ME442-C1-45 | — | — | — |
| J | EGR valve position sensor | — | W46 | — | 0.5 | ME442-C1-48 | — | — | — |
| K | Intake air temp (IAT) | — | W45 | — | 0.5 | ME442-C1-57 | — | — | — |
| L | Idle switch (closed throttle) | — | W52 | — | 0.5 | ME442-C1-34 | — | — | — |
| M | Front O2 heater control | — | W33 | — | 0.5 | ME442-C1-16 | — | — | — |
| N | EGR boost sensor (2nd channel) | — | W42 | — | 0.5 | ME442-C1-18 | — | — | — |
| O | Sensor ground | — | W12 | — | 0.5 | SP-0V-1 | — | — | — |
| P | Power steering pressure switch | — | — | — | — | — | — | — | — |
OEM-4
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A | Chassis ground | — | W4 | — | 0.85 | SP-GND-1 | — | — | — |
| B | ECU power +12V (main relay) | — | W1 | — | 0.85 | SP-14V-1 | — | — | — |
| C | Chassis ground | — | W5 | — | 0.85 | SP-GND-1 | — | — | — |
| D | Chassis ground | — | W6 | — | 0.85 | SP-GND-1 | — | — | — |
| E | Crank position (CKP) sensor | — | W17 | — | 0.5 | ME442-C1-80 | — | — | — |
| F | CAS SGT (cam trigger) | — | W19 | — | 0.5 | ME442-C1-23 | — | — | — |
| G | CAS SGC (cam sync) | — | W18 | — | 0.5 | ME442-C1-22 | — | — | — |
| H | Crank pickup timing ground (CKP gnd) | — | W13 | — | 0.5 | SP-0V-1 | — | — | — |
| I | Permanent +12V (battery) | — | — | — | — | — | — | — | — |
| J | PRC solenoid (FPR control) | — | W35 | — | 0.5 | ME442-C1-39 | — | — | — |
| K | Chassis ground | — | W7 | — | 0.85 | SP-GND-1 | — | — | — |
| L | Tachometer output | — | W40 | — | 0.5 | ME442-C1-79 | — | — | — |
| N | Ignition coil trigger (cyl 1&4) | — | W20 | — | 0.5 | ME442-C1-32 | — | — | — |
| O | EGR vent solenoid | — | W36 | — | 0.5 | ME442-C1-37 | — | — | — |
| P | EGR vacuum solenoid | — | W37 | — | 0.5 | ME442-C1-42 | — | — | — |
| Q | Idle air control (IAC) valve | — | W38 | — | 0.5 | ME442-C1-72 | — | — | — |
| R | Ignition coil trigger (cyl 2&3) | — | W21 | — | 0.5 | ME442-C1-31 | — | — | — |
| T | EVAP purge solenoid | — | W39 | — | 0.5 | ME442-C1-43 | — | — | — |
| U | Injector 1 (cyl 1) | — | W22 | — | 0.5 | ME442-C1-63 | — | — | — |
| V | Injector 2 (cyl 2) | — | W23 | — | 0.5 | ME442-C1-4 | — | — | — |
| W | Injector 3 (cyl 3) | — | W24 | — | 0.5 | ME442-C1-33 | — | — | — |
| X | Injector 4 (cyl 4) | — | W25 | — | 0.5 | ME442-C1-3 | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W12 | — | 0.5 | OEM-3-O | — | — | — |
| 1 | — | — | W13 | — | 0.5 | OEM-4-H | — | — | — |
| 1 | — | — | W14 | — | 0.5 | ME442-C1-52 | — | — | — |
| 1 | — | — | W15 | — | 0.5 | ME442-C1-84 | — | — | — |
SP-14V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W1 | — | 0.85 | OEM-4-B | — | — | — |
| 1 | — | — | W2 | — | 0.85 | ME442-C1-15 | — | — | — |
| 1 | — | — | W3 | — | 0.85 | ME442-C1-64 | — | — | — |
SP-GND
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W4 | — | 0.85 | OEM-4-A | — | — | — |
| 1 | — | — | W5 | — | 0.85 | OEM-4-C | — | — | — |
| 1 | — | — | W6 | — | 0.85 | OEM-4-D | — | — | — |
| 1 | — | — | W7 | — | 0.85 | OEM-4-K | — | — | — |
| 1 | — | — | W8 | — | 0.85 | ME442-C1-10 | — | — | — |
| 1 | — | — | W9 | — | 0.85 | ME442-C1-61 | — | — | — |
| 1 | — | — | W10 | — | 0.85 | ME442-C1-89 | — | — | — |
| 1 | — | — | W11 | — | 0.85 | ME442-C1-90 | — | — | — |
Pin map
| OEM point | OEM function | OEM family | Target point | Target function | Target family | Wire colour | Evidence |
|---|---|---|---|---|---|---|---|
| OEM-1-A | Cooling fan relay (low-side) | low_side_out | ME442-C1-73 | LOW SIDE 1 | low_side_out | corroborated | |
| OEM-1-B | A/C condenser fan relay | low_side_out | ME442-C1-12 | LOW SIDE 2 | low_side_out | corroborated | |
| OEM-1-C | Starter input (12V while cranking) | digital_in | ME442-C1-7 | DIG_IN 2 | digital_in | corroborated | |
| OEM-1-E | Check engine light (MIL) | low_side_out | ME442-C1-69 | LOW SIDE 5 | low_side_out | corroborated | |
| OEM-1-G | A/C clutch relay | low_side_out | ME442-C1-74 | LOW SIDE 3 | low_side_out | corroborated | |
| OEM-1-K | A/C pressure switch (A/C request) | digital_in | ME442-C1-8 | DIG_IN 3 | digital_in | corroborated | |
| OEM-1-L | Clutch switch | digital_in | ME442-C1-5 | DIG_IN 4 | digital_in | corroborated | |
| OEM-1-M | Vehicle speed sensor (VSS) | digital_in | ME442-C1-6 | DIG_IN 1 | digital_in | corroborated | |
| OEM-1-Q | Brake switch | digital_in | ME442-C1-62 | DIG_IN 5 | digital_in | corroborated | |
| OEM-1-U | Fuel pump relay (low-side) | low_side_out | ME442-C1-44 | LOW SIDE 4 | low_side_out | corroborated | |
| OEM-3-B | MAF sensor input | analog_in | ME442-C1-26 | ANA VOLT 1 | analog_in | corroborated | |
| OEM-3-C | Front O2 sensor input | lambda_nb_in | ME442-C1-87 | ANA VOLT 5 | analog_in | corroborated | |
| OEM-3-D | Rear O2 sensor input | lambda_nb_in | ME442-C1-78 | ANA VOLT 6 | analog_in | corroborated | |
| OEM-3-F | Throttle position (TPS) | analog_in | ME442-C1-56 | ANA VOLT 2 | analog_in | corroborated | |
| OEM-3-G | Engine coolant temp (CLT) | temp_in | ME442-C1-86 | ANA TEMP 1 | temp_in | corroborated | |
| OEM-3-H | EGR boost sensor | analog_in | ME442-C1-17 | ANA VOLT 3 | analog_in | corroborated | |
| OEM-3-I | +5V sensor reference | vref | ME442-C1-45 | 5V REF | vref | corroborated | |
| OEM-3-J | EGR valve position sensor | analog_in | ME442-C1-48 | ANA VOLT 7 | analog_in | corroborated | |
| OEM-3-K | Intake air temp (IAT) | temp_in | ME442-C1-57 | ANA TEMP 2 | temp_in | corroborated | |
| OEM-3-L | Idle switch (closed throttle) | digital_in | ME442-C1-34 | DIG_IN 6 | digital_in | corroborated | |
| OEM-3-M | Front O2 heater control | low_side_out | ME442-C1-16 | LSU HEATER -VE | low_side_out | corroborated | |
| OEM-3-N | EGR boost sensor (2nd channel) | analog_in | ME442-C1-18 | ANA VOLT 4 | analog_in | corroborated | |
| OEM-3-O | Sensor ground | sensor_ground | ME442-C1-52 + ME442-C1-84 | SENSORS GROUND + Sensor Ground | sensor_ground | corroborated | |
| OEM-3-P | Power steering pressure switch | digital_in | — | — | — | corroborated | |
| OEM-4-A | Chassis ground | ground | ME442-C1-10 + ME442-C1-61 + ME442-C1-89 + ME442-C1-90 | GROUND CHASSIS + GROUND + GROUND + GROUND | ground | corroborated | |
| OEM-4-B | ECU power +12V (main relay) | power_in | ME442-C1-15 + ME442-C1-64 | IGN +12V + VBAT | power_in | corroborated | |
| OEM-4-C | Chassis ground | ground | ME442-C1-10 + ME442-C1-61 + ME442-C1-89 + ME442-C1-90 | GROUND CHASSIS + GROUND + GROUND + GROUND | ground | corroborated | |
| OEM-4-D | Chassis ground | ground | ME442-C1-10 + ME442-C1-61 + ME442-C1-89 + ME442-C1-90 | GROUND CHASSIS + GROUND + GROUND + GROUND | ground | corroborated | |
| OEM-4-E | Crank position (CKP) sensor | trigger_in | ME442-C1-80 | CRANK VR+ | trigger_in | corroborated | |
| OEM-4-F | CAS SGT (cam trigger) | trigger_in | ME442-C1-23 | CAM A VR- | trigger_in | corroborated | |
| OEM-4-G | CAS SGC (cam sync) | trigger_in | ME442-C1-22 | CAM A VR+ | trigger_in | corroborated | |
| OEM-4-H | Crank pickup timing ground (CKP gnd) | sensor_ground | ME442-C1-52 + ME442-C1-84 | SENSORS GROUND + Sensor Ground | sensor_ground | corroborated | |
| OEM-4-I | Permanent +12V (battery) | power_in | — | — | — | corroborated | |
| OEM-4-J | PRC solenoid (FPR control) | low_side_out | ME442-C1-39 | LOW SIDE 6 | low_side_out | corroborated | |
| OEM-4-K | Chassis ground | ground | ME442-C1-10 + ME442-C1-61 + ME442-C1-89 + ME442-C1-90 | GROUND CHASSIS + GROUND + GROUND + GROUND | ground | corroborated | |
| OEM-4-L | Tachometer output | tacho_out | ME442-C1-79 | TACHOMETER | tacho_out | corroborated | |
| OEM-4-N | Ignition coil trigger (cyl 1&4) | ignition_out | ME442-C1-32 | COIL 1 | ignition_out | corroborated | |
| OEM-4-O | EGR vent solenoid | low_side_out | ME442-C1-37 | LOW SIDE RELAY 11 | low_side_out | corroborated | |
| OEM-4-P | EGR vacuum solenoid | low_side_out | ME442-C1-42 | LOW SIDE RELAY 12 | low_side_out | corroborated | |
| OEM-4-Q | Idle air control (IAC) valve | low_side_out | ME442-C1-72 | LOW SIDE RELAY 13 | low_side_out | corroborated | |
| OEM-4-R | Ignition coil trigger (cyl 2&3) | ignition_out | ME442-C1-31 | COIL 2 | ignition_out | corroborated | |
| OEM-4-T | EVAP purge solenoid | low_side_out | ME442-C1-43 | LOW SIDE RELAY 14 | low_side_out | corroborated | |
| OEM-4-U | Injector 1 (cyl 1) | injector_out | ME442-C1-63 | INJECTOR 1 | injector_out | corroborated | |
| OEM-4-V | Injector 2 (cyl 2) | injector_out | ME442-C1-4 | INJECTOR 2 | injector_out | corroborated | |
| OEM-4-W | Injector 3 (cyl 3) | injector_out | ME442-C1-33 | INJECTOR 3 | injector_out | corroborated | |
| OEM-4-X | Injector 4 (cyl 4) | injector_out | ME442-C1-3 | INJECTOR 4 | injector_out | corroborated |
Cut list
| Wire | From | To | Gauge (mm²) | Colour | Length | Signal | Ident |
|---|---|---|---|---|---|---|---|
| W1 | OEM-4-B | SP-14V-1 | 0.85 | no route | ECU power +12V (main relay) | — | |
| W2 | SP-14V-1 | ME442-C1-15 | 0.85 | no route | IGN +12V | — | |
| W3 | SP-14V-1 | ME442-C1-64 | 0.85 | no route | VBAT | — | |
| W4 | OEM-4-A | SP-GND-1 | 0.85 | no route | Chassis ground | — | |
| W5 | OEM-4-C | SP-GND-1 | 0.85 | no route | Chassis ground | — | |
| W6 | OEM-4-D | SP-GND-1 | 0.85 | no route | Chassis ground | — | |
| W7 | OEM-4-K | SP-GND-1 | 0.85 | no route | Chassis ground | — | |
| W8 | SP-GND-1 | ME442-C1-10 | 0.85 | no route | GROUND CHASSIS | — | |
| W9 | SP-GND-1 | ME442-C1-61 | 0.85 | no route | GROUND | — | |
| W10 | SP-GND-1 | ME442-C1-89 | 0.85 | no route | GROUND | — | |
| W11 | SP-GND-1 | ME442-C1-90 | 0.85 | no route | GROUND | — | |
| W12 | OEM-3-O | SP-0V-1 | 0.5 | no route | Sensor ground | — | |
| W13 | OEM-4-H | SP-0V-1 | 0.5 | no route | Crank pickup timing ground (CKP gnd) | — | |
| W14 | SP-0V-1 | ME442-C1-52 | 0.5 | no route | SENSORS GROUND | — | |
| W15 | SP-0V-1 | ME442-C1-84 | 0.5 | no route | Sensor Ground | — | |
| W16 | OEM-3-I | ME442-C1-45 | 0.5 | no route | +5V sensor reference | — | |
| W17 | OEM-4-E | ME442-C1-80 | 0.5 | no route | Crank position (CKP) sensor | — | |
| W18 | OEM-4-G | ME442-C1-22 | 0.5 | no route | CAS SGC (cam sync) | — | |
| W19 | OEM-4-F | ME442-C1-23 | 0.5 | no route | CAS SGT (cam trigger) | — | |
| W20 | OEM-4-N | ME442-C1-32 | 0.5 | no route | Ignition coil trigger (cyl 1&4) | — | |
| W21 | OEM-4-R | ME442-C1-31 | 0.5 | no route | Ignition coil trigger (cyl 2&3) | — | |
| W22 | OEM-4-U | ME442-C1-63 | 0.5 | no route | Injector 1 (cyl 1) | — | |
| W23 | OEM-4-V | ME442-C1-4 | 0.5 | no route | Injector 2 (cyl 2) | — | |
| W24 | OEM-4-W | ME442-C1-33 | 0.5 | no route | Injector 3 (cyl 3) | — | |
| W25 | OEM-4-X | ME442-C1-3 | 0.5 | no route | Injector 4 (cyl 4) | — | |
| W26 | OEM-3-B | ME442-C1-26 | 0.5 | no route | MAF sensor input | — | |
| W27 | OEM-3-F | ME442-C1-56 | 0.5 | no route | Throttle position (TPS) | — | |
| W28 | OEM-3-G | ME442-C1-86 | 0.5 | no route | Engine coolant temp (CLT) | — | |
| W29 | OEM-1-A | ME442-C1-73 | 0.5 | no route | Cooling fan relay (low-side) | — | |
| W30 | OEM-1-B | ME442-C1-12 | 0.5 | no route | A/C condenser fan relay | — | |
| W31 | OEM-1-G | ME442-C1-74 | 0.5 | no route | A/C clutch relay | — | |
| W32 | OEM-1-U | ME442-C1-44 | 0.5 | no route | Fuel pump relay (low-side) | — | |
| W33 | OEM-3-M | ME442-C1-16 | 0.5 | no route | Front O2 heater control | — | |
| W34 | OEM-1-E | ME442-C1-69 | 0.5 | no route | Check engine light (MIL) | — | |
| W35 | OEM-4-J | ME442-C1-39 | 0.5 | no route | PRC solenoid (FPR control) | — | |
| W36 | OEM-4-O | ME442-C1-37 | 0.5 | no route | EGR vent solenoid | — | |
| W37 | OEM-4-P | ME442-C1-42 | 0.5 | no route | EGR vacuum solenoid | — | |
| W38 | OEM-4-Q | ME442-C1-72 | 0.5 | no route | Idle air control (IAC) valve | — | |
| W39 | OEM-4-T | ME442-C1-43 | 0.5 | no route | EVAP purge solenoid | — | |
| W40 | OEM-4-L | ME442-C1-79 | 0.5 | no route | Tachometer output | — | |
| W41 | OEM-3-H | ME442-C1-17 | 0.5 | no route | EGR boost sensor | — | |
| W42 | OEM-3-N | ME442-C1-18 | 0.5 | no route | EGR boost sensor (2nd channel) | — | |
| W43 | OEM-3-C | ME442-C1-87 | 0.5 | no route | Front O2 sensor input | — | |
| W44 | OEM-3-D | ME442-C1-78 | 0.5 | no route | Rear O2 sensor input | — | |
| W45 | OEM-3-K | ME442-C1-57 | 0.5 | no route | Intake air temp (IAT) | — | |
| W46 | OEM-3-J | ME442-C1-48 | 0.5 | no route | EGR valve position sensor | — | |
| W47 | OEM-1-M | ME442-C1-6 | 0.5 | no route | Vehicle speed sensor (VSS) | — | |
| W48 | OEM-1-C | ME442-C1-7 | 0.5 | no route | Starter input (12V while cranking) | — | |
| W49 | OEM-1-K | ME442-C1-8 | 0.5 | no route | A/C pressure switch (A/C request) | — | |
| W50 | OEM-1-L | ME442-C1-5 | 0.5 | no route | Clutch switch | — | |
| W51 | OEM-1-Q | ME442-C1-62 | 0.5 | no route | Brake switch | — | |
| W52 | OEM-3-L | ME442-C1-34 | 0.5 | no route | Idle switch (closed throttle) | — |
Bill of materials
| Category | Part number | Manufacturer | Description | Qty | Unit |
|---|
ECU setup sheet
| Role | Engine ref | Engine signal | Sensor | ECU point | ECU function | ECU class | Setup flag |
|---|---|---|---|---|---|---|---|
| No configured channels. | |||||||
Findings
Open (1)
| Severity | Code | Subject | Message |
|---|---|---|---|
| info | UNMAPPED | OEM | 1 optional OEM pins are not mapped: OEM-3-P Power steering pressure switch |
Accepted (1)
| Code | Subject | Reason | By |
|---|---|---|---|
| REQUIRED_UNMAPPED | OEM-4-I | 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-4 I: Permanent +12V (battery): Motorsport Electronics ME442 has no battery-constant input; not needed - OEM-3 P: Power steering pressure switch: no free switch_in/frequency_in/analog_0_5 on Motorsport Electronics ME442
Sources
| Reliability | Kind | Title | URL | Archive | Captured | SHA-256 |
|---|---|---|---|---|---|---|
| 4 | vendor_doc | AEM EMS 30-1720 Plug-and-Play adapter manual (1996-97 Miata) | https://static.summitracing.com/global/images/instructions/avm-30-1720.pdf | — | — | — |
| 4 | vendor_doc | Motorsport Electronics GEN2 ME221/ME360/ME442 wire-in pinout | https://motorsport-electronics.co.uk/onlinehelp/html/ME442ME360ME221GEN2Wire-InPinout.html | — | — | — |
| 3 | community_copy | Mellens.net: 1996 Mazda Miata wiring diagrams (FSM-derived) | http://www.mellens.net/mazda/mazda_miata_extra_manual/1996_wiring.pdf | — | — | — |