MX-5 Miata NB1 1999-00 (BP-4W) → MaxxECU MaxxECU SPORT REV9+ (auto)
MX-5 Miata NB1 1999-00 (BP-4W) — MaxxECU — MaxxECU SPORT
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 | 41 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 | MAXXECUSPORT-C1-M4 | 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 | MAXXECUSPORT-C1-L4 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | OEM-3-F | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | SP-0V-1 | MAXXECUSPORT-C1-H1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | SP-0V-1 | MAXXECUSPORT-C1-H2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | OEM-2-I | MAXXECUSPORT-C1-G1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | OEM-2-J | MAXXECUSPORT-C1-H3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | OEM-2-H | MAXXECUSPORT-C1-H4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | OEM-3-G | MAXXECUSPORT-C1-A2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | OEM-3-H | MAXXECUSPORT-C1-A3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | OEM-3-W | MAXXECUSPORT-C1-K1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-3-X | MAXXECUSPORT-C1-K2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-3-Y | MAXXECUSPORT-C1-M1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-3-Z | MAXXECUSPORT-C1-M2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-1-I | MAXXECUSPORT-C1-B4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-1-R | MAXXECUSPORT-C1-C4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-1-S | MAXXECUSPORT-C1-D4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-3-N | MAXXECUSPORT-C1-A1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-1-U | MAXXECUSPORT-C1-D1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-3-V | MAXXECUSPORT-C1-B1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-3-O | MAXXECUSPORT-C1-A4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-1-E | MAXXECUSPORT-C1-M3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-1-O | MAXXECUSPORT-C1-L3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-1-Q | MAXXECUSPORT-C1-L1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | OEM-2-M | MAXXECUSPORT-C1-L2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-2-L | MAXXECUSPORT-C1-J3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-3-E | MAXXECUSPORT-C1-G2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-2-C | MAXXECUSPORT-C1-J4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-3-J | MAXXECUSPORT-C1-C1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W35 | OEM-2-E | MAXXECUSPORT-C1-J1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W36 | OEM-2-B | MAXXECUSPORT-C1-J2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W37 | OEM-2-A | MAXXECUSPORT-C1-D2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W38 | OEM-3-K | MAXXECUSPORT-C1-D3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W39 | OEM-3-S | MAXXECUSPORT-C1-E4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W40 | OEM-2-D | MAXXECUSPORT-C1-K3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W41 | OEM-1-F | MAXXECUSPORT-C1-K4 | 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 | MAXXECUSPORT-C1-G1 | MAXXECUSPORT-C1-H1 | open (OL) | 5 V sensor reference must not touch sensor ground | |
| 2 | MAXXECUSPORT-C1-G1 | MAXXECUSPORT-C1-L4 | open (OL) | 5 V sensor reference must not touch power ground | |
| 3 | MAXXECUSPORT-C1-M4 | MAXXECUSPORT-C1-H1 | open (OL) | +12 V supply must not touch sensor ground | |
| 4 | MAXXECUSPORT-C1-M4 | MAXXECUSPORT-C1-L4 | open (OL) | +12 V supply must not touch power ground | |
| 5 | MAXXECUSPORT-C1-M4 | MAXXECUSPORT-C1-G1 | open (OL) | +12 V supply must not touch 5 V sensor reference |
Revisions
| Rev | Label | By | Date |
|---|---|---|---|
| No revisions yet. | |||
Schematic
Connectors
MAXXECUSPORT-C1
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A1 | GPO 4 | — | W23 | — | 0.5 | OEM-3-N | — | — | — |
| A2 | IGN 1 | — | W14 | — | 0.5 | OEM-3-G | — | — | — |
| A3 | IGN 2 | — | W15 | — | 0.5 | OEM-3-H | — | — | — |
| A4 | GPO 8/TACHO | — | W26 | — | 0.5 | OEM-3-O | — | — | — |
| B1 | GPO 5 | — | W25 | — | 0.5 | OEM-3-V | — | — | — |
| B2 | IGN 3 | — | — | — | — | — | — | — | — |
| B3 | IGN 4 | — | — | — | — | — | — | — | — |
| B4 | GPO 1 | — | W20 | — | 0.5 | OEM-1-I | — | — | — |
| C1 | AIN 5 (0-5V) | — | W34 | — | 0.5 | OEM-3-J | — | — | — |
| C2 | IGN 5 | — | — | — | — | — | — | — | — |
| C3 | IGN 6 | — | — | — | — | — | — | — | — |
| C4 | GPO 2 | — | W21 | — | 0.5 | OEM-1-R | — | — | — |
| D1 | WBO2 Heater- | — | W24 | — | 0.5 | OEM-1-U | — | — | — |
| D2 | AIN 6 (0-5V) | — | W37 | — | 0.5 | OEM-2-A | — | — | — |
| D3 | AIN 7 (0-5V) | — | W38 | — | 0.5 | OEM-3-K | — | — | — |
| D4 | GPO 3 | — | W22 | — | 0.5 | OEM-1-S | — | — | — |
| E1 | CAN H | — | — | — | — | — | — | — | — |
| E2 | CAN L | — | — | — | — | — | — | — | — |
| E3 | GND Shield | — | — | — | — | — | — | — | — |
| E4 | AIN 8 (0-5V) | — | W39 | — | 0.5 | OEM-3-S | — | — | — |
| F1 | CLT | — | — | — | — | — | — | — | — |
| F2 | IAT | — | — | — | — | — | — | — | — |
| F3 | WBO2 VREF | — | — | — | — | — | — | — | — |
| F4 | WBO2 VS | — | — | — | — | — | — | — | — |
| G1 | +5V sensor supply | — | W11 | — | 0.5 | OEM-2-I | — | — | — |
| G2 | TPS/AIN | — | W32 | — | 0.5 | OEM-3-E | — | — | — |
| G3 | WBO2 IP | — | — | — | — | — | — | — | — |
| G4 | WBO2 RCAL | — | — | — | — | — | — | — | — |
| H1 | Sensor GND | — | W9 | — | 0.5 | SP-0V-1 | — | — | — |
| H2 | Trigger GND | — | W10 | — | 0.5 | SP-0V-1 | — | — | — |
| H3 | TRIGGER | — | W12 | — | 0.5 | OEM-2-J | — | — | — |
| H4 | HOME | — | W13 | — | 0.5 | OEM-2-H | — | — | — |
| J1 | AIN 1 (temperature) | — | W35 | — | 0.5 | OEM-2-E | — | — | — |
| J2 | AIN 2 (Temperature) | — | W36 | — | 0.5 | OEM-2-B | — | — | — |
| J3 | AIN 3 (0-5V) | — | W31 | — | 0.5 | OEM-2-L | — | — | — |
| J4 | AIN 4 (0-5V) | — | W33 | — | 0.5 | OEM-2-C | — | — | — |
| K1 | INJ 1 | — | W16 | — | 0.5 | OEM-3-W | — | — | — |
| K2 | INJ 2 | — | W17 | — | 0.5 | OEM-3-X | — | — | — |
| K3 | DIN 1 | — | W40 | — | 0.5 | OEM-2-D | — | — | — |
| K4 | DIN 2 | — | W41 | — | 0.5 | OEM-1-F | — | — | — |
| L1 | GPO 11/Motor 1- | — | W29 | — | 0.5 | OEM-1-Q | — | — | — |
| L2 | GPO 12/MOTOR 1+ | — | W30 | — | 0.5 | OEM-2-M | — | — | — |
| L3 | INJ 6 | — | W28 | — | 0.5 | OEM-1-O | — | — | — |
| L4 | Engine GND | — | W7 | — | 0.85 | SP-GND-1 | — | — | — |
| M1 | INJ 3 | — | W18 | — | 0.5 | OEM-3-Y | — | — | — |
| M2 | INJ 4 | — | W19 | — | 0.5 | OEM-3-Z | — | — | — |
| M3 | INJ 5 | — | W27 | — | 0.5 | OEM-1-E | — | — | — |
| M4 | +12V ECU power supply | — | W3 | — | 0.85 | SP-14V-1 | — | — | — |
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) | — | W27 | — | 0.5 | MAXXECUSPORT-C1-M3 | — | — | — |
| F | Brake switch | — | W41 | — | 0.5 | MAXXECUSPORT-C1-K4 | — | — | — |
| G | Power steering pressure switch | — | — | — | — | — | — | — | — |
| I | Condenser fan relay | — | W20 | — | 0.5 | MAXXECUSPORT-C1-B4 | — | — | — |
| O | Alternator control | — | W28 | — | 0.5 | MAXXECUSPORT-C1-L3 | — | — | — |
| P | A/C request | — | — | — | — | — | — | — | — |
| Q | Charge lamp | — | W29 | — | 0.5 | MAXXECUSPORT-C1-L1 | — | — | — |
| R | Cooling fan relay | — | W21 | — | 0.5 | MAXXECUSPORT-C1-C4 | — | — | — |
| S | A/C clutch relay | — | W22 | — | 0.5 | MAXXECUSPORT-C1-D4 | — | — | — |
| U | Front O2 heater | — | W24 | — | 0.5 | MAXXECUSPORT-C1-D1 | — | — | — |
| V | Neutral switch | — | — | — | — | — | — | — | — |
OEM-2
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A | Fuel tank pressure | — | W37 | — | 0.5 | MAXXECUSPORT-C1-D2 | — | — | — |
| B | Intake air temperature (IAT) | — | W36 | — | 0.5 | MAXXECUSPORT-C1-J2 | — | — | — |
| C | Front O2 signal | — | W33 | — | 0.5 | MAXXECUSPORT-C1-J4 | — | — | — |
| D | Vehicle speed | — | W40 | — | 0.5 | MAXXECUSPORT-C1-K3 | — | — | — |
| E | Coolant temperature (ECT) | — | W35 | — | 0.5 | MAXXECUSPORT-C1-J1 | — | — | — |
| F | Knock sensor | — | — | — | — | — | — | — | — |
| H | Cam position (CMP) | — | W13 | — | 0.5 | MAXXECUSPORT-C1-H4 | — | — | — |
| I | +5V sensor supply | — | W11 | — | 0.5 | MAXXECUSPORT-C1-G1 | — | — | — |
| J | Crank position (CKP) | — | W12 | — | 0.5 | MAXXECUSPORT-C1-H3 | — | — | — |
| K | Tachometer output | — | — | — | — | — | — | — | — |
| L | Mass air flow (MAF) | — | W31 | — | 0.5 | MAXXECUSPORT-C1-J3 | — | — | — |
| M | EGR valve | — | W30 | — | 0.5 | MAXXECUSPORT-C1-L2 | — | — | — |
| N | EGR valve | — | — | — | — | — | — | — | — |
| 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) | — | W32 | — | 0.5 | MAXXECUSPORT-C1-G2 | — | — | — |
| F | Signal ground | — | W8 | — | 0.5 | SP-0V-1 | — | — | — |
| G | Ignition 1 (coils 1+4, wasted spark) | — | W14 | — | 0.5 | MAXXECUSPORT-C1-A2 | — | — | — |
| H | Ignition 2 (coils 2+3, wasted spark) | — | W15 | — | 0.5 | MAXXECUSPORT-C1-A3 | — | — | — |
| I | Clutch switch | — | — | — | — | — | — | — | — |
| J | Rear O2 signal | — | W34 | — | 0.5 | MAXXECUSPORT-C1-C1 | — | — | — |
| K | Fuel level | — | W38 | — | 0.5 | MAXXECUSPORT-C1-D3 | — | — | — |
| L | Evap purge solenoid | — | — | — | — | — | — | — | — |
| M | ISC valve +14V feed | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
| N | Fuel pump relay | — | W23 | — | 0.5 | MAXXECUSPORT-C1-A1 | — | — | — |
| O | ISC valve low side | — | W26 | — | 0.5 | MAXXECUSPORT-C1-A4 | — | — | — |
| Q | VICS solenoid (intake butterflies) | — | — | — | — | — | — | — | — |
| S | EGR boost sensor | — | W39 | — | 0.5 | MAXXECUSPORT-C1-E4 | — | — | — |
| T | EGR boost solenoid | — | — | — | — | — | — | — | — |
| U | Canister drain cut valve (CDCV) | — | — | — | — | — | — | — | — |
| V | Rear O2 heater | — | W25 | — | 0.5 | MAXXECUSPORT-C1-B1 | — | — | — |
| W | Injector 1 | — | W16 | — | 0.5 | MAXXECUSPORT-C1-K1 | — | — | — |
| X | Injector 2 | — | W17 | — | 0.5 | MAXXECUSPORT-C1-K2 | — | — | — |
| Y | Injector 3 | — | W18 | — | 0.5 | MAXXECUSPORT-C1-M1 | — | — | — |
| Z | Injector 4 | — | W19 | — | 0.5 | MAXXECUSPORT-C1-M2 | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W8 | — | 0.5 | OEM-3-F | — | — | — |
| 1 | — | — | W9 | — | 0.5 | MAXXECUSPORT-C1-H1 | — | — | — |
| 1 | — | — | W10 | — | 0.5 | MAXXECUSPORT-C1-H2 | — | — | — |
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 | MAXXECUSPORT-C1-M4 | — | — | — |
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 | MAXXECUSPORT-C1-L4 | — | — | — |
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 | MAXXECUSPORT-C1-M4 | +12V ECU power supply | power_in | single_source | |
| OEM-1-E | Malfunction indicator lamp (MIL) | low_side_out | MAXXECUSPORT-C1-M3 | INJ 5 | injector_out | single_source | |
| OEM-1-F | Brake switch | digital_in | MAXXECUSPORT-C1-K4 | DIN 2 | digital_in | single_source | |
| OEM-1-G | Power steering pressure switch | digital_in | — | — | — | single_source | |
| OEM-1-I | Condenser fan relay | low_side_out | MAXXECUSPORT-C1-B4 | GPO 1 | low_side_out | single_source | |
| OEM-1-O | Alternator control | low_side_out | MAXXECUSPORT-C1-L3 | INJ 6 | injector_out | single_source | |
| OEM-1-P | A/C request | digital_in | — | — | — | single_source | |
| OEM-1-Q | Charge lamp | low_side_out | MAXXECUSPORT-C1-L1 | GPO 11/Motor 1- | hbridge_out | single_source | |
| OEM-1-R | Cooling fan relay | low_side_out | MAXXECUSPORT-C1-C4 | GPO 2 | low_side_out | single_source | |
| OEM-1-S | A/C clutch relay | low_side_out | MAXXECUSPORT-C1-D4 | GPO 3 | low_side_out | single_source | |
| OEM-1-U | Front O2 heater | low_side_out | MAXXECUSPORT-C1-D1 | WBO2 Heater- | low_side_out | single_source | |
| OEM-1-V | Neutral switch | digital_in | — | — | — | single_source | |
| OEM-2-A | Fuel tank pressure | analog_in | MAXXECUSPORT-C1-D2 | AIN 6 (0-5V) | analog_in | single_source | |
| OEM-2-B | Intake air temperature (IAT) | temp_in | MAXXECUSPORT-C1-J2 | AIN 2 (Temperature) | temp_in | single_source | |
| OEM-2-C | Front O2 signal | lambda_nb_in | MAXXECUSPORT-C1-J4 | AIN 4 (0-5V) | analog_in | single_source | |
| OEM-2-D | Vehicle speed | digital_in | MAXXECUSPORT-C1-K3 | DIN 1 | digital_in | single_source | |
| OEM-2-E | Coolant temperature (ECT) | temp_in | MAXXECUSPORT-C1-J1 | AIN 1 (temperature) | temp_in | single_source | |
| OEM-2-F | Knock sensor | knock_in | — | — | — | single_source | |
| OEM-2-H | Cam position (CMP) | trigger_in | MAXXECUSPORT-C1-H4 | HOME | trigger_in | single_source | |
| OEM-2-I | +5V sensor supply | vref | MAXXECUSPORT-C1-G1 | +5V sensor supply | vref | single_source | |
| OEM-2-J | Crank position (CKP) | trigger_in | MAXXECUSPORT-C1-H3 | TRIGGER | trigger_in | single_source | |
| OEM-2-K | Tachometer output | tacho_out | — | — | — | single_source | |
| OEM-2-L | Mass air flow (MAF) | analog_in | MAXXECUSPORT-C1-J3 | AIN 3 (0-5V) | analog_in | single_source | |
| OEM-2-M | EGR valve | low_side_out | MAXXECUSPORT-C1-L2 | GPO 12/MOTOR 1+ | hbridge_out | single_source | |
| OEM-2-N | EGR valve | low_side_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 | MAXXECUSPORT-C1-L4 | Engine GND | ground | single_source | |
| OEM-3-B | Power ground | ground | MAXXECUSPORT-C1-L4 | Engine GND | ground | single_source | |
| OEM-3-C | Power ground | ground | MAXXECUSPORT-C1-L4 | Engine GND | ground | single_source | |
| OEM-3-E | Throttle position (TPS) | analog_in | MAXXECUSPORT-C1-G2 | TPS/AIN | analog_in | single_source | |
| OEM-3-F | Signal ground | sensor_ground | MAXXECUSPORT-C1-H1 + MAXXECUSPORT-C1-H2 | Sensor GND + Trigger GND | sensor_ground | single_source | |
| OEM-3-G | Ignition 1 (coils 1+4, wasted spark) | ignition_out | MAXXECUSPORT-C1-A2 | IGN 1 | ignition_out | single_source | |
| OEM-3-H | Ignition 2 (coils 2+3, wasted spark) | ignition_out | MAXXECUSPORT-C1-A3 | IGN 2 | ignition_out | single_source | |
| OEM-3-I | Clutch switch | digital_in | — | — | — | single_source | |
| OEM-3-J | Rear O2 signal | lambda_nb_in | MAXXECUSPORT-C1-C1 | AIN 5 (0-5V) | analog_in | single_source | |
| OEM-3-K | Fuel level | analog_in | MAXXECUSPORT-C1-D3 | AIN 7 (0-5V) | analog_in | single_source | |
| OEM-3-L | Evap purge solenoid | low_side_out | — | — | — | single_source | |
| OEM-3-M | ISC valve +14V feed | power_in | MAXXECUSPORT-C1-M4 | +12V ECU power supply | power_in | single_source | |
| OEM-3-N | Fuel pump relay | low_side_out | MAXXECUSPORT-C1-A1 | GPO 4 | low_side_out | single_source | |
| OEM-3-O | ISC valve low side | low_side_out | MAXXECUSPORT-C1-A4 | GPO 8/TACHO | low_side_out | single_source | |
| OEM-3-Q | VICS solenoid (intake butterflies) | low_side_out | — | — | — | single_source | |
| OEM-3-S | EGR boost sensor | analog_in | MAXXECUSPORT-C1-E4 | AIN 8 (0-5V) | 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 | MAXXECUSPORT-C1-B1 | GPO 5 | low_side_out | single_source | |
| OEM-3-W | Injector 1 | injector_out | MAXXECUSPORT-C1-K1 | INJ 1 | injector_out | single_source | |
| OEM-3-X | Injector 2 | injector_out | MAXXECUSPORT-C1-K2 | INJ 2 | injector_out | single_source | |
| OEM-3-Y | Injector 3 | injector_out | MAXXECUSPORT-C1-M1 | INJ 3 | injector_out | single_source | |
| OEM-3-Z | Injector 4 | injector_out | MAXXECUSPORT-C1-M2 | INJ 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 | MAXXECUSPORT-C1-M4 | 0.85 | no route | +12V ECU power supply | — | |
| 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 | MAXXECUSPORT-C1-L4 | 0.85 | no route | Engine GND | — | |
| W8 | OEM-3-F | SP-0V-1 | 0.5 | no route | Signal ground | — | |
| W9 | SP-0V-1 | MAXXECUSPORT-C1-H1 | 0.5 | no route | Sensor GND | — | |
| W10 | SP-0V-1 | MAXXECUSPORT-C1-H2 | 0.5 | no route | Trigger GND | — | |
| W11 | OEM-2-I | MAXXECUSPORT-C1-G1 | 0.5 | no route | +5V sensor supply | — | |
| W12 | OEM-2-J | MAXXECUSPORT-C1-H3 | 0.5 | no route | Crank position (CKP) | — | |
| W13 | OEM-2-H | MAXXECUSPORT-C1-H4 | 0.5 | no route | Cam position (CMP) | — | |
| W14 | OEM-3-G | MAXXECUSPORT-C1-A2 | 0.5 | no route | Ignition 1 (coils 1+4, wasted spark) | — | |
| W15 | OEM-3-H | MAXXECUSPORT-C1-A3 | 0.5 | no route | Ignition 2 (coils 2+3, wasted spark) | — | |
| W16 | OEM-3-W | MAXXECUSPORT-C1-K1 | 0.5 | no route | Injector 1 | — | |
| W17 | OEM-3-X | MAXXECUSPORT-C1-K2 | 0.5 | no route | Injector 2 | — | |
| W18 | OEM-3-Y | MAXXECUSPORT-C1-M1 | 0.5 | no route | Injector 3 | — | |
| W19 | OEM-3-Z | MAXXECUSPORT-C1-M2 | 0.5 | no route | Injector 4 | — | |
| W20 | OEM-1-I | MAXXECUSPORT-C1-B4 | 0.5 | no route | Condenser fan relay | — | |
| W21 | OEM-1-R | MAXXECUSPORT-C1-C4 | 0.5 | no route | Cooling fan relay | — | |
| W22 | OEM-1-S | MAXXECUSPORT-C1-D4 | 0.5 | no route | A/C clutch relay | — | |
| W23 | OEM-3-N | MAXXECUSPORT-C1-A1 | 0.5 | no route | Fuel pump relay | — | |
| W24 | OEM-1-U | MAXXECUSPORT-C1-D1 | 0.5 | no route | Front O2 heater | — | |
| W25 | OEM-3-V | MAXXECUSPORT-C1-B1 | 0.5 | no route | Rear O2 heater | — | |
| W26 | OEM-3-O | MAXXECUSPORT-C1-A4 | 0.5 | no route | ISC valve low side | — | |
| W27 | OEM-1-E | MAXXECUSPORT-C1-M3 | 0.5 | no route | Malfunction indicator lamp (MIL) | — | |
| W28 | OEM-1-O | MAXXECUSPORT-C1-L3 | 0.5 | no route | Alternator control | — | |
| W29 | OEM-1-Q | MAXXECUSPORT-C1-L1 | 0.5 | no route | Charge lamp | — | |
| W30 | OEM-2-M | MAXXECUSPORT-C1-L2 | 0.5 | no route | EGR valve | — | |
| W31 | OEM-2-L | MAXXECUSPORT-C1-J3 | 0.5 | no route | Mass air flow (MAF) | — | |
| W32 | OEM-3-E | MAXXECUSPORT-C1-G2 | 0.5 | no route | Throttle position (TPS) | — | |
| W33 | OEM-2-C | MAXXECUSPORT-C1-J4 | 0.5 | no route | Front O2 signal | — | |
| W34 | OEM-3-J | MAXXECUSPORT-C1-C1 | 0.5 | no route | Rear O2 signal | — | |
| W35 | OEM-2-E | MAXXECUSPORT-C1-J1 | 0.5 | no route | Coolant temperature (ECT) | — | |
| W36 | OEM-2-B | MAXXECUSPORT-C1-J2 | 0.5 | no route | Intake air temperature (IAT) | — | |
| W37 | OEM-2-A | MAXXECUSPORT-C1-D2 | 0.5 | no route | Fuel tank pressure | — | |
| W38 | OEM-3-K | MAXXECUSPORT-C1-D3 | 0.5 | no route | Fuel level | — | |
| W39 | OEM-3-S | MAXXECUSPORT-C1-E4 | 0.5 | no route | EGR boost sensor | — | |
| W40 | OEM-2-D | MAXXECUSPORT-C1-K3 | 0.5 | no route | Vehicle speed | — | |
| W41 | OEM-1-F | MAXXECUSPORT-C1-K4 | 0.5 | no route | Brake 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 | MAXXECUSPORT-C1-A1 | MAXXECUSPORT-C1-A1 "GPO 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 | MAXXECUSPORT-C1-A4 | MAXXECUSPORT-C1-A4 "GPO 8/TACHO" 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 | MAXXECUSPORT-C1-B4 | MAXXECUSPORT-C1-B4 "GPO 1" drives OEM-1-I Condenser fan relay (load 0.2 A) but its current rating is unknown. Check the ECU manual. |
| warn | LOAD_UNKNOWN | MAXXECUSPORT-C1-C4 | MAXXECUSPORT-C1-C4 "GPO 2" drives OEM-1-R Cooling fan relay (load 0.2 A) but its current rating is unknown. Check the ECU manual. |
| warn | LOAD_UNKNOWN | MAXXECUSPORT-C1-D4 | MAXXECUSPORT-C1-D4 "GPO 3" drives OEM-1-S A/C clutch relay (load 0.2 A) but its current rating is unknown. Check the ECU manual. |
| warn | NET_FAMILY | OEM-1-Q ↔ MAXXECUSPORT-C1-L1 | OEM-1-Q "Charge lamp" [low_side_out] is wired to MAXXECUSPORT-C1-L1 "GPO 11/Motor 1-" [hbridge_out]. A half-bridge can act as a low-side switch only if configured that way. |
| warn | NET_FAMILY | OEM-2-M ↔ MAXXECUSPORT-C1-L2 | OEM-2-M "EGR valve" [low_side_out] is wired to MAXXECUSPORT-C1-L2 "GPO 12/MOTOR 1+" [hbridge_out]. A half-bridge can act as a low-side switch only if configured that way. |
| info | NET_FAMILY | OEM-1-E ↔ MAXXECUSPORT-C1-M3 | OEM-1-E "Malfunction indicator lamp (MIL)" [low_side_out] is wired to MAXXECUSPORT-C1-M3 "INJ 5" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-1-O ↔ MAXXECUSPORT-C1-L3 | OEM-1-O "Alternator control" [low_side_out] is wired to MAXXECUSPORT-C1-L3 "INJ 6" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | UNMAPPED | OEM | 13 optional OEM pins are not mapped: OEM-1-G Power steering pressure switch; OEM-1-P A/C request; OEM-1-V Neutral switch; OEM-2-F Knock sensor; OEM-2-K Tachometer output; OEM-2-N EGR valve; 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: MaxxECU MaxxECU SPORT has no battery-constant input; not needed - OEM-2 F: Knock sensor: no free knock input on MaxxECU MaxxECU SPORT - OEM-2 N: EGR valve: no free low_side/ls_hs/injector/hbridge on MaxxECU MaxxECU SPORT - OEM-2 O: EGR valve: no free low_side/ls_hs/injector/hbridge on MaxxECU MaxxECU SPORT - OEM-2 P: EGR valve: no free low_side/ls_hs/injector/hbridge on MaxxECU MaxxECU SPORT - OEM-3 L: Evap purge solenoid: no free low_side/ls_hs/injector/hbridge on MaxxECU MaxxECU SPORT - OEM-3 Q: VICS solenoid (intake butterflies): no free low_side/ls_hs/injector/hbridge on MaxxECU MaxxECU SPORT - OEM-3 T: EGR boost solenoid: no free low_side/ls_hs/injector/hbridge on MaxxECU MaxxECU SPORT - OEM-3 U: Canister drain cut valve (CDCV): no free low_side/ls_hs/injector/hbridge on MaxxECU MaxxECU SPORT - OEM-2 K: Tachometer output: no free tacho/frequency_out/low_side/ls_hs on MaxxECU MaxxECU SPORT - OEM-1 G: Power steering pressure switch: no free switch_in/frequency_in/analog_0_5 on MaxxECU MaxxECU SPORT - OEM-1 P: A/C request: no free switch_in/frequency_in/analog_0_5 on MaxxECU MaxxECU SPORT - OEM-1 V: Neutral switch: no free switch_in/frequency_in/analog_0_5 on MaxxECU MaxxECU SPORT - OEM-3 I: Clutch switch: no free switch_in/frequency_in/analog_0_5 on MaxxECU MaxxECU SPORT
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 | MaxxECU GEN1 pinout (MINI / STREET / SPORT / V1 / RACE / PRO) | http://www.maxxecu.com/webhelp/wirings-maxxecu_pinout.html | archive | 2026-10-05 | 2e37b6814690 |