MX-5 Miata NA8 1994-95 (BP-ZE, 1.8, OBD-I) → MaxxECU MaxxECU GEN2 RACE (auto)
MX-5 Miata NA8 1994-95 (BP-ZE, 1.8, OBD-I) — MaxxECU — MaxxECU GEN2 RACE
⚠ 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 · 9 connectors · 2 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 | SP-14V-1 | MAXXECUGEN2R-MX1-25 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W3 | SP-14V-1 | MAXXECUGEN2R-MX2-25 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W4 | OEM-2-A | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W5 | OEM-2-B | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W6 | SP-GND-1 | MAXXECUGEN2R-MX1-9 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W7 | SP-GND-1 | MAXXECUGEN2R-MX2-9 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | SP-GND-1 | MAXXECUGEN2R-MX3-9 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | OEM-2-C | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | OEM-2-D | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | OEM-2-F | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | SP-0V-1 | MAXXECUGEN2R-MX1-14 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | OEM-2-K | MAXXECUGEN2R-MX1-12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | OEM-2-E | MAXXECUGEN2R-MX1-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | OEM-2-G | MAXXECUGEN2R-MX1-18 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | OEM-1-G | MAXXECUGEN2R-MX1-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-1-H | MAXXECUGEN2R-MX1-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-2-U | MAXXECUGEN2R-MX1-31 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-2-V | MAXXECUGEN2R-MX1-32 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-2-Y | MAXXECUGEN2R-MX1-33 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-2-Z | MAXXECUGEN2R-MX1-34 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-1-J | MAXXECUGEN2R-MX1-5 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-1-R | MAXXECUGEN2R-MX1-6 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-2-S | MAXXECUGEN2R-MX1-7 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-2-T | MAXXECUGEN2R-MX1-8 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-1-L | MAXXECUGEN2R-MX1-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-2-L | MAXXECUGEN2R-MX2-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-2-W | MAXXECUGEN2R-MX2-33 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-1-E | MAXXECUGEN2R-MX2-34 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | OEM-2-R | MAXXECUGEN2R-MX3-29 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-2-X | MAXXECUGEN2R-MX3-30 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-2-O | MAXXECUGEN2R-MX1-26 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-2-M | MAXXECUGEN2R-MX1-27 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-2-N | MAXXECUGEN2R-MX1-28 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W35 | OEM-2-Q | MAXXECUGEN2R-MX1-29 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W36 | OEM-2-P | MAXXECUGEN2R-MX1-30 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W37 | OEM-1-M | MAXXECUGEN2R-MX1-23 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W38 | OEM-1-C | MAXXECUGEN2R-MX1-24 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W39 | OEM-1-O | MAXXECUGEN2R-MX4-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W40 | OEM-1-P | MAXXECUGEN2R-MX4-6 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W41 | OEM-1-Q | MAXXECUGEN2R-MX4-9 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W42 | OEM-1-V | MAXXECUGEN2R-MX4-28 | 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 | MAXXECUGEN2R-MX1-25 | MAXXECUGEN2R-MX1-14 | open (OL) | +12 V supply must not touch sensor ground | |
| 2 | MAXXECUGEN2R-MX1-25 | MAXXECUGEN2R-MX1-9 | open (OL) | +12 V supply must not touch power ground | |
| 3 | MAXXECUGEN2R-MX1-14 | MAXXECUGEN2R-MX1-12 | open (OL) | sensor ground must not touch 5 V sensor reference | |
| 4 | MAXXECUGEN2R-MX1-25 | MAXXECUGEN2R-MX1-12 | open (OL) | +12 V supply must not touch 5 V sensor reference | |
| 5 | MAXXECUGEN2R-MX1-9 | MAXXECUGEN2R-MX1-12 | open (OL) | power 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
MAXXECUGEN2R-MX1
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Ignition 1 | — | W16 | — | 0.5 | OEM-1-G | — | — | — |
| 10 | Digital/VR 1 SIGNAL + | — | W14 | — | 0.5 | OEM-2-E | — | — | — |
| 11 | Digital/VR 1 SIGNAL - | — | — | — | — | — | — | — | — |
| 12 | Digital/VR 1 POWER SUPPLY | — | W13 | — | 0.5 | OEM-2-K | — | — | — |
| 13 | Digital/VR 1 SHIELD | — | — | — | — | — | — | — | — |
| 14 | SENSOR GND | — | W12 | — | 0.5 | SP-0V-1 | — | — | — |
| 15 | CAN L | — | — | — | — | — | — | — | — |
| 16 | CAN H | — | — | — | — | — | — | — | — |
| 17 | GP out 5 (GND) | — | W26 | — | 0.5 | OEM-1-L | — | — | — |
| 18 | Digital/VR 2 SIGNAL + | — | W15 | — | 0.5 | OEM-2-G | — | — | — |
| 19 | Digital/VR 2 SIGNAL - | — | — | — | — | — | — | — | — |
| 2 | Ignition 2 | — | W17 | — | 0.5 | OEM-1-H | — | — | — |
| 20 | Digital/VR 2 POWER SUPPLY | — | — | — | — | — | — | — | — |
| 21 | Digital/VR 2 SHIELD | — | — | — | — | — | — | — | — |
| 22 | 5V power supply | — | — | — | — | — | — | — | — |
| 23 | Digital/VR 3 SIGNAL + | — | W37 | — | 0.5 | OEM-1-M | — | — | — |
| 24 | Digital/VR 4 SIGNAL + | — | W38 | — | 0.5 | OEM-1-C | — | — | — |
| 25 | 12V supply 1 | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
| 26 | AIN 1 | — | W32 | — | 0.5 | OEM-2-O | — | — | — |
| 27 | AIN 2 | — | W33 | — | 0.5 | OEM-2-M | — | — | — |
| 28 | AIN 3 | — | W34 | — | 0.5 | OEM-2-N | — | — | — |
| 29 | AIN 4 | — | W35 | — | 0.5 | OEM-2-Q | — | — | — |
| 3 | Ignition 3 | — | — | — | — | — | — | — | — |
| 30 | AIN 5 | — | W36 | — | 0.5 | OEM-2-P | — | — | — |
| 31 | INJECTOR 1 | — | W18 | — | 0.5 | OEM-2-U | — | — | — |
| 32 | INJECTOR 2 | — | W19 | — | 0.5 | OEM-2-V | — | — | — |
| 33 | INJECTOR 3 | — | W20 | — | 0.5 | OEM-2-Y | — | — | — |
| 34 | INJECTOR 4 | — | W21 | — | 0.5 | OEM-2-Z | — | — | — |
| 4 | Ignition 4 | — | — | — | — | — | — | — | — |
| 5 | GP out 1 (GND) | — | W22 | — | 0.5 | OEM-1-J | — | — | — |
| 6 | GP out 2 (GND) | — | W23 | — | 0.5 | OEM-1-R | — | — | — |
| 7 | GP out 3 (GND) | — | W24 | — | 0.5 | OEM-2-S | — | — | — |
| 8 | GP out 4 (GND) | — | W25 | — | 0.5 | OEM-2-T | — | — | — |
| 9 | Engine gnd | — | W6 | — | 0.85 | SP-GND-1 | — | — | — |
MAXXECUGEN2R-MX2
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Ignition 5 | — | — | — | — | — | — | — | — |
| 10 | WBO2 Sensor 1 VS | — | — | — | — | — | — | — | — |
| 11 | WBO2 Sensor 1 COM/VREF | — | — | — | — | — | — | — | — |
| 12 | GP OUT 7 / WBO2 Sensor 1 H- | — | — | — | — | — | — | — | — |
| 13 | AIN 9 | — | — | — | — | — | — | — | — |
| 14 | AIN 10 | — | — | — | — | — | — | — | — |
| 15 | AIN 11 | — | — | — | — | — | — | — | — |
| 16 | AIN 12 | — | — | — | — | — | — | — | — |
| 17 | AIN 13 | — | — | — | — | — | — | — | — |
| 18 | WBO2 sensor 1 RCAL | — | — | — | — | — | — | — | — |
| 19 | WBO2 sensor 1 IP | — | — | — | — | — | — | — | — |
| 2 | Ignition 6 | — | — | — | — | — | — | — | — |
| 20 | 12V WBO2 sensor 1 H+ | — | — | — | — | — | — | — | — |
| 21 | WBO2 sensor 1 SHIELD | — | — | — | — | — | — | — | — |
| 22 | AIN 14 | — | — | — | — | — | — | — | — |
| 23 | AIN 15 | — | — | — | — | — | — | — | — |
| 24 | 12V supply 3 | — | — | — | — | — | — | — | — |
| 25 | 12V supply 2 | — | W3 | — | 0.85 | SP-14V-1 | — | — | — |
| 26 | KNOCK1 SHIELD | — | — | — | — | — | — | — | — |
| 27 | KNOCK 1- | — | — | — | — | — | — | — | — |
| 28 | KNOCK 1+ | — | — | — | — | — | — | — | — |
| 29 | KNOCK 2 SHIELD | — | — | — | — | — | — | — | — |
| 3 | GP out 6 (GND) | — | W27 | — | 0.5 | OEM-2-L | — | — | — |
| 30 | KNOCK 2- | — | — | — | — | — | — | — | — |
| 31 | KNOCK 2+ | — | — | — | — | — | — | — | — |
| 32 | AIN 16 | — | — | — | — | — | — | — | — |
| 33 | INJECTOR 5 | — | W28 | — | 0.5 | OEM-2-W | — | — | — |
| 34 | INJECTOR 6 | — | W29 | — | 0.5 | OEM-1-E | — | — | — |
| 4 | AIN 6 | — | — | — | — | — | — | — | — |
| 5 | AIN 7 | — | — | — | — | — | — | — | — |
| 6 | AIN 8 | — | — | — | — | — | — | — | — |
| 7 | GP out 13 (H-BRIDGE 1) | — | — | — | — | — | — | — | — |
| 8 | GP out 14 (H-BRIDGE 1) | — | — | — | — | — | — | — | — |
| 9 | Engine gnd | — | W7 | — | 0.85 | SP-GND-1 | — | — | — |
MAXXECUGEN2R-MX3
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | GP out 15 (H-BRIDGE 2) | — | — | — | — | — | — | — | — |
| 10 | WBO2 sensor 2 VS | — | — | — | — | — | — | — | — |
| 11 | WBO2 sensor 2 COM/VREF | — | — | — | — | — | — | — | — |
| 12 | GP Out 8 (GND) / WBO2 Sensor 2 H- | — | — | — | — | — | — | — | — |
| 13 | WBO2 sensor 2 SHIELD | — | — | — | — | — | — | — | — |
| 14 | GP OUT 9 (12V) | — | — | — | — | — | — | — | — |
| 15 | GP OUT 10 (12V) | — | — | — | — | — | — | — | — |
| 16 | GP OUT 11 (12V) | — | — | — | — | — | — | — | — |
| 17 | GP OUT 12 (12V) | — | — | — | — | — | — | — | — |
| 18 | WBO2 sensor 2 RCAL | — | — | — | — | — | — | — | — |
| 19 | WBO2 sensor 2 IP | — | — | — | — | — | — | — | — |
| 2 | GP out 16 (H-BRIDGE 2) | — | — | — | — | — | — | — | — |
| 20 | 12V WBO2 sensor 2 (H+) | — | — | — | — | — | — | — | — |
| 21 | AIN 17 | — | — | — | — | — | — | — | — |
| 22 | AIN 18 | — | — | — | — | — | — | — | — |
| 23 | AIN 19 | — | — | — | — | — | — | — | — |
| 24 | AIN 20 | — | — | — | — | — | — | — | — |
| 25 | AIN 21 | — | — | — | — | — | — | — | — |
| 26 | AIN 22 | — | — | — | — | — | — | — | — |
| 27 | AIN 23 | — | — | — | — | — | — | — | — |
| 28 | AIN 24 | — | — | — | — | — | — | — | — |
| 29 | INJECTOR 7 | — | W30 | — | 0.5 | OEM-2-R | — | — | — |
| 3 | Ignition 7 | — | — | — | — | — | — | — | — |
| 30 | INJECTOR 8 | — | W31 | — | 0.5 | OEM-2-X | — | — | — |
| 31 | INJECTOR 9 | — | — | — | — | — | — | — | — |
| 32 | INJECTOR 10 | — | — | — | — | — | — | — | — |
| 33 | INJECTOR 11 | — | — | — | — | — | — | — | — |
| 34 | INJECTOR 12 | — | — | — | — | — | — | — | — |
| 4 | Ignition 8 | — | — | — | — | — | — | — | — |
| 5 | Ignition 9 | — | — | — | — | — | — | — | — |
| 6 | Ignition 10 | — | — | — | — | — | — | — | — |
| 7 | Ignition 11 | — | — | — | — | — | — | — | — |
| 8 | Ignition 12 | — | — | — | — | — | — | — | — |
| 9 | Engine gnd | — | W8 | — | 0.85 | SP-GND-1 | — | — | — |
MAXXECUGEN2R-MX4
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Digital/VR 5 SHIELD | — | — | — | — | — | — | — | — |
| 10 | EGT 1 + | — | — | — | — | — | — | — | — |
| 11 | EGT 2 + | — | — | — | — | — | — | — | — |
| 12 | EGT 3 + | — | — | — | — | — | — | — | — |
| 13 | EGT 4 + | — | — | — | — | — | — | — | — |
| 14 | EGT 5 + | — | — | — | — | — | — | — | — |
| 15 | EGT 6 + | — | — | — | — | — | — | — | — |
| 16 | EGT 7 + | — | — | — | — | — | — | — | — |
| 17 | EGT 8 + | — | — | — | — | — | — | — | — |
| 18 | EGT 1 - | — | — | — | — | — | — | — | — |
| 19 | EGT 2 - | — | — | — | — | — | — | — | — |
| 2 | Digital/VR 5 SIGNAL - | — | — | — | — | — | — | — | — |
| 20 | EGT 3 - | — | — | — | — | — | — | — | — |
| 21 | EGT 4 - | — | — | — | — | — | — | — | — |
| 22 | EGT 5 - | — | — | — | — | — | — | — | — |
| 23 | EGT 6 - | — | — | — | — | — | — | — | — |
| 24 | EGT 7 - | — | — | — | — | — | — | — | — |
| 25 | EGT 8 - | — | — | — | — | — | — | — | — |
| 26 | Digital/VR 8 SHIELD | — | — | — | — | — | — | — | — |
| 27 | Digital/VR 8 SIGNAL - | — | — | — | — | — | — | — | — |
| 28 | Digital/VR 8 SIGNAL + | — | W42 | — | 0.5 | OEM-1-V | — | — | — |
| 29 | CAN 2 L | — | — | — | — | — | — | — | — |
| 3 | Digital/VR 5 SIGNAL + | — | W39 | — | 0.5 | OEM-1-O | — | — | — |
| 30 | CAN 2 H | — | — | — | — | — | — | — | — |
| 31 | INJECTOR 13 | — | — | — | — | — | — | — | — |
| 32 | INJECTOR 14 | — | — | — | — | — | — | — | — |
| 33 | INJECTOR 15 | — | — | — | — | — | — | — | — |
| 34 | INJECTOR 16 | — | — | — | — | — | — | — | — |
| 4 | Digital/VR 6 SHIELD | — | — | — | — | — | — | — | — |
| 5 | Digital/VR 6 SIGNAL - | — | — | — | — | — | — | — | — |
| 6 | Digital/VR 6 SIGNAL + | — | W40 | — | 0.5 | OEM-1-P | — | — | — |
| 7 | Digital/VR 7 SHIELD | — | — | — | — | — | — | — | — |
| 8 | Digital/VR 7 SIGNAL - | — | — | — | — | — | — | — | — |
| 9 | Digital/VR 7 SIGNAL + | — | W41 | — | 0.5 | OEM-1-Q | — | — | — |
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 | MAXXECUGEN2R-MX1-24 | — | — | — |
| D | Data link connector | — | — | — | — | — | — | — | — |
| E | Malfunction indicator lamp (MIL) | — | W29 | — | 0.5 | MAXXECUGEN2R-MX2-34 | — | — | — |
| G | Ignition 1 (coils 1+4, wasted spark) | — | W16 | — | 0.5 | MAXXECUGEN2R-MX1-1 | — | — | — |
| H | Ignition 2 (coils 2+3, wasted spark) | — | W17 | — | 0.5 | MAXXECUGEN2R-MX1-2 | — | — | — |
| I | Powertrain control module (transmission) | — | — | — | — | — | — | — | — |
| J | A/C relay | — | W22 | — | 0.5 | MAXXECUGEN2R-MX1-5 | — | — | — |
| L | Coolant fan relay | — | W26 | — | 0.5 | MAXXECUGEN2R-MX1-17 | — | — | — |
| M | Vehicle speed | — | W37 | — | 0.5 | MAXXECUGEN2R-MX1-23 | — | — | — |
| N | Powertrain control module (transmission) | — | — | — | — | — | — | — | — |
| O | Stop light switch | — | W39 | — | 0.5 | MAXXECUGEN2R-MX4-3 | — | — | — |
| P | Power steering pressure switch | — | W40 | — | 0.5 | MAXXECUGEN2R-MX4-6 | — | — | — |
| Q | A/C request | — | W41 | — | 0.5 | MAXXECUGEN2R-MX4-9 | — | — | — |
| R | Cooling fan relay | — | W23 | — | 0.5 | MAXXECUGEN2R-MX1-6 | — | — | — |
| S | Heater control unit | — | — | — | — | — | — | — | — |
| T | Unknown | — | — | — | — | — | — | — | — |
| U | Unknown | — | — | — | — | — | — | — | — |
| V | Neutral/clutch switch | — | W42 | — | 0.5 | MAXXECUGEN2R-MX4-28 | — | — | — |
OEM-2
| 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 | Sensor ground (E2) | — | W9 | — | 0.5 | SP-0V-1 | — | — | — |
| D | Sensor ground (E2) | — | W10 | — | 0.5 | SP-0V-1 | — | — | — |
| E | Crank position (CAS NE) | — | W14 | — | 0.5 | MAXXECUGEN2R-MX1-10 | — | — | — |
| F | MAF ground | — | W11 | — | 0.5 | SP-0V-1 | — | — | — |
| G | Cam position (CAS G) | — | W15 | — | 0.5 | MAXXECUGEN2R-MX1-18 | — | — | — |
| H | Data link connector | — | — | — | — | — | — | — | — |
| I | Tachometer output | — | — | — | — | — | — | — | — |
| J | EGR function sensor | — | — | — | — | — | — | — | — |
| K | +5V sensor supply | — | W13 | — | 0.5 | MAXXECUGEN2R-MX1-12 | — | — | — |
| L | Rear defroster relay | — | W27 | — | 0.5 | MAXXECUGEN2R-MX2-3 | — | — | — |
| M | Throttle position (TPS) | — | W33 | — | 0.5 | MAXXECUGEN2R-MX1-27 | — | — | — |
| N | O2 sensor | — | W34 | — | 0.5 | MAXXECUGEN2R-MX1-28 | — | — | — |
| O | Mass air flow (MAF) | — | W32 | — | 0.5 | MAXXECUGEN2R-MX1-26 | — | — | — |
| P | Intake air temperature (IAT) | — | W36 | — | 0.5 | MAXXECUGEN2R-MX1-30 | — | — | — |
| Q | Coolant temperature (ECT) | — | W35 | — | 0.5 | MAXXECUGEN2R-MX1-29 | — | — | — |
| R | PRC solenoid (fuel pressure regulator) | — | W30 | — | 0.5 | MAXXECUGEN2R-MX3-29 | — | — | — |
| S | Condenser fan relay | — | W24 | — | 0.5 | MAXXECUGEN2R-MX1-7 | — | — | — |
| T | Fuel pump relay | — | W25 | — | 0.5 | MAXXECUGEN2R-MX1-8 | — | — | — |
| U | Injector 1 | — | W18 | — | 0.5 | MAXXECUGEN2R-MX1-31 | — | — | — |
| V | Injector 2 | — | W19 | — | 0.5 | MAXXECUGEN2R-MX1-32 | — | — | — |
| W | ISC solenoid | — | W28 | — | 0.5 | MAXXECUGEN2R-MX2-33 | — | — | — |
| X | Evap purge solenoid | — | W31 | — | 0.5 | MAXXECUGEN2R-MX3-30 | — | — | — |
| Y | Injector 3 | — | W20 | — | 0.5 | MAXXECUGEN2R-MX1-33 | — | — | — |
| Z | Injector 4 | — | W21 | — | 0.5 | MAXXECUGEN2R-MX1-34 | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W9 | — | 0.5 | OEM-2-C | — | — | — |
| 1 | — | — | W10 | — | 0.5 | OEM-2-D | — | — | — |
| 1 | — | — | W11 | — | 0.5 | OEM-2-F | — | — | — |
| 1 | — | — | W12 | — | 0.5 | MAXXECUGEN2R-MX1-14 | — | — | — |
SP-14V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W1 | — | 0.85 | OEM-1-B | — | — | — |
| 1 | — | — | W2 | — | 0.85 | MAXXECUGEN2R-MX1-25 | — | — | — |
| 1 | — | — | W3 | — | 0.85 | MAXXECUGEN2R-MX2-25 | — | — | — |
SP-GND
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W4 | — | 0.85 | OEM-2-A | — | — | — |
| 1 | — | — | W5 | — | 0.85 | OEM-2-B | — | — | — |
| 1 | — | — | W6 | — | 0.85 | MAXXECUGEN2R-MX1-9 | — | — | — |
| 1 | — | — | W7 | — | 0.85 | MAXXECUGEN2R-MX2-9 | — | — | — |
| 1 | — | — | W8 | — | 0.85 | MAXXECUGEN2R-MX3-9 | — | — | — |
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 | MAXXECUGEN2R-MX1-25 + MAXXECUGEN2R-MX2-25 | 12V supply 1 + 12V supply 2 | power_in | WR | single_source |
| OEM-1-C | Start signal | digital_in | MAXXECUGEN2R-MX1-24 | Digital/VR 4 SIGNAL + | 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 | MAXXECUGEN2R-MX2-34 | INJECTOR 6 | injector_out | YB | single_source |
| OEM-1-G | Ignition 1 (coils 1+4, wasted spark) | ignition_out | MAXXECUGEN2R-MX1-1 | Ignition 1 | ignition_out | BrY | single_source |
| OEM-1-H | Ignition 2 (coils 2+3, wasted spark) | ignition_out | MAXXECUGEN2R-MX1-2 | Ignition 2 | ignition_out | Br | single_source |
| OEM-1-I | Powertrain control module (transmission) | — | — | — | — | LW | single_source |
| OEM-1-J | A/C relay | low_side_out | MAXXECUGEN2R-MX1-5 | GP out 1 (GND) | low_side_out | single_source | |
| OEM-1-L | Coolant fan relay | low_side_out | MAXXECUGEN2R-MX1-17 | GP out 5 (GND) | low_side_out | BG | single_source |
| OEM-1-M | Vehicle speed | digital_in | MAXXECUGEN2R-MX1-23 | Digital/VR 3 SIGNAL + | digital_in | GR | single_source |
| OEM-1-N | Powertrain control module (transmission) | — | — | — | — | R | single_source |
| OEM-1-O | Stop light switch | digital_in | MAXXECUGEN2R-MX4-3 | Digital/VR 5 SIGNAL + | digital_in | GB | single_source |
| OEM-1-P | Power steering pressure switch | digital_in | MAXXECUGEN2R-MX4-6 | Digital/VR 6 SIGNAL + | digital_in | LY | single_source |
| OEM-1-Q | A/C request | digital_in | MAXXECUGEN2R-MX4-9 | Digital/VR 7 SIGNAL + | digital_in | LgB | single_source |
| OEM-1-R | Cooling fan relay | low_side_out | MAXXECUGEN2R-MX1-6 | GP out 2 (GND) | low_side_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 | MAXXECUGEN2R-MX4-28 | Digital/VR 8 SIGNAL + | digital_in | BrW | single_source |
| OEM-2-A | Power ground | ground | MAXXECUGEN2R-MX1-9 + MAXXECUGEN2R-MX2-9 + MAXXECUGEN2R-MX3-9 | Engine gnd + Engine gnd + Engine gnd | ground | B | single_source |
| OEM-2-B | Power ground | ground | MAXXECUGEN2R-MX1-9 + MAXXECUGEN2R-MX2-9 + MAXXECUGEN2R-MX3-9 | Engine gnd + Engine gnd + Engine gnd | ground | B | single_source |
| OEM-2-C | Sensor ground (E2) | sensor_ground | MAXXECUGEN2R-MX1-14 | SENSOR GND | sensor_ground | BLg | corroborated |
| OEM-2-D | Sensor ground (E2) | sensor_ground | MAXXECUGEN2R-MX1-14 | SENSOR GND | sensor_ground | BL | corroborated |
| OEM-2-E | Crank position (CAS NE) | trigger_in | MAXXECUGEN2R-MX1-10 | Digital/VR 1 SIGNAL + | trigger_in | W | single_source |
| OEM-2-F | MAF ground | sensor_ground | MAXXECUGEN2R-MX1-14 | SENSOR GND | sensor_ground | BR | single_source |
| OEM-2-G | Cam position (CAS G) | trigger_in | MAXXECUGEN2R-MX1-18 | Digital/VR 2 SIGNAL + | 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 | MAXXECUGEN2R-MX1-12 | Digital/VR 1 POWER SUPPLY | vref | LgW | single_source |
| OEM-2-L | Rear defroster relay | low_side_out | MAXXECUGEN2R-MX2-3 | GP out 6 (GND) | low_side_out | LR | single_source |
| OEM-2-M | Throttle position (TPS) | analog_in | MAXXECUGEN2R-MX1-27 | AIN 2 | analog_in | RB | single_source |
| OEM-2-N | O2 sensor | lambda_nb_in | MAXXECUGEN2R-MX1-28 | AIN 3 | analog_in | RL | single_source |
| OEM-2-O | Mass air flow (MAF) | analog_in | MAXXECUGEN2R-MX1-26 | AIN 1 | analog_in | R | single_source |
| OEM-2-P | Intake air temperature (IAT) | temp_in | MAXXECUGEN2R-MX1-30 | AIN 5 | analog_in | RB | single_source |
| OEM-2-Q | Coolant temperature (ECT) | temp_in | MAXXECUGEN2R-MX1-29 | AIN 4 | analog_in | LW | single_source |
| OEM-2-R | PRC solenoid (fuel pressure regulator) | low_side_out | MAXXECUGEN2R-MX3-29 | INJECTOR 7 | injector_out | YG | single_source |
| OEM-2-S | Condenser fan relay | low_side_out | MAXXECUGEN2R-MX1-7 | GP out 3 (GND) | low_side_out | LW | single_source |
| OEM-2-T | Fuel pump relay | low_side_out | MAXXECUGEN2R-MX1-8 | GP out 4 (GND) | low_side_out | Lg | single_source |
| OEM-2-U | Injector 1 | injector_out | MAXXECUGEN2R-MX1-31 | INJECTOR 1 | injector_out | Y | single_source |
| OEM-2-V | Injector 2 | injector_out | MAXXECUGEN2R-MX1-32 | INJECTOR 2 | injector_out | YB | single_source |
| OEM-2-W | ISC solenoid | low_side_out | MAXXECUGEN2R-MX2-33 | INJECTOR 5 | injector_out | LOr | single_source |
| OEM-2-X | Evap purge solenoid | low_side_out | MAXXECUGEN2R-MX3-30 | INJECTOR 8 | injector_out | YR | single_source |
| OEM-2-Y | Injector 3 | injector_out | MAXXECUGEN2R-MX1-33 | INJECTOR 3 | injector_out | GW | single_source |
| OEM-2-Z | Injector 4 | injector_out | MAXXECUGEN2R-MX1-34 | INJECTOR 4 | 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 | MAXXECUGEN2R-MX1-25 | 0.85 | no route | 12V supply 1 | — | |
| W3 | SP-14V-1 | MAXXECUGEN2R-MX2-25 | 0.85 | no route | 12V supply 2 | — | |
| W4 | OEM-2-A | SP-GND-1 | 0.85 | no route | Power ground | — | |
| W5 | OEM-2-B | SP-GND-1 | 0.85 | no route | Power ground | — | |
| W6 | SP-GND-1 | MAXXECUGEN2R-MX1-9 | 0.85 | no route | Engine gnd | — | |
| W7 | SP-GND-1 | MAXXECUGEN2R-MX2-9 | 0.85 | no route | Engine gnd | — | |
| W8 | SP-GND-1 | MAXXECUGEN2R-MX3-9 | 0.85 | no route | Engine gnd | — | |
| W9 | OEM-2-C | SP-0V-1 | 0.5 | no route | Sensor ground (E2) | — | |
| W10 | OEM-2-D | SP-0V-1 | 0.5 | no route | Sensor ground (E2) | — | |
| W11 | OEM-2-F | SP-0V-1 | 0.5 | no route | MAF ground | — | |
| W12 | SP-0V-1 | MAXXECUGEN2R-MX1-14 | 0.5 | no route | SENSOR GND | — | |
| W13 | OEM-2-K | MAXXECUGEN2R-MX1-12 | 0.5 | no route | +5V sensor supply | — | |
| W14 | OEM-2-E | MAXXECUGEN2R-MX1-10 | 0.5 | no route | Crank position (CAS NE) | — | |
| W15 | OEM-2-G | MAXXECUGEN2R-MX1-18 | 0.5 | no route | Cam position (CAS G) | — | |
| W16 | OEM-1-G | MAXXECUGEN2R-MX1-1 | 0.5 | no route | Ignition 1 (coils 1+4, wasted spark) | — | |
| W17 | OEM-1-H | MAXXECUGEN2R-MX1-2 | 0.5 | no route | Ignition 2 (coils 2+3, wasted spark) | — | |
| W18 | OEM-2-U | MAXXECUGEN2R-MX1-31 | 0.5 | no route | Injector 1 | — | |
| W19 | OEM-2-V | MAXXECUGEN2R-MX1-32 | 0.5 | no route | Injector 2 | — | |
| W20 | OEM-2-Y | MAXXECUGEN2R-MX1-33 | 0.5 | no route | Injector 3 | — | |
| W21 | OEM-2-Z | MAXXECUGEN2R-MX1-34 | 0.5 | no route | Injector 4 | — | |
| W22 | OEM-1-J | MAXXECUGEN2R-MX1-5 | 0.5 | no route | A/C relay | — | |
| W23 | OEM-1-R | MAXXECUGEN2R-MX1-6 | 0.5 | no route | Cooling fan relay | — | |
| W24 | OEM-2-S | MAXXECUGEN2R-MX1-7 | 0.5 | no route | Condenser fan relay | — | |
| W25 | OEM-2-T | MAXXECUGEN2R-MX1-8 | 0.5 | no route | Fuel pump relay | — | |
| W26 | OEM-1-L | MAXXECUGEN2R-MX1-17 | 0.5 | no route | Coolant fan relay | — | |
| W27 | OEM-2-L | MAXXECUGEN2R-MX2-3 | 0.5 | no route | Rear defroster relay | — | |
| W28 | OEM-2-W | MAXXECUGEN2R-MX2-33 | 0.5 | no route | ISC solenoid | — | |
| W29 | OEM-1-E | MAXXECUGEN2R-MX2-34 | 0.5 | no route | Malfunction indicator lamp (MIL) | — | |
| W30 | OEM-2-R | MAXXECUGEN2R-MX3-29 | 0.5 | no route | PRC solenoid (fuel pressure regulator) | — | |
| W31 | OEM-2-X | MAXXECUGEN2R-MX3-30 | 0.5 | no route | Evap purge solenoid | — | |
| W32 | OEM-2-O | MAXXECUGEN2R-MX1-26 | 0.5 | no route | Mass air flow (MAF) | — | |
| W33 | OEM-2-M | MAXXECUGEN2R-MX1-27 | 0.5 | no route | Throttle position (TPS) | — | |
| W34 | OEM-2-N | MAXXECUGEN2R-MX1-28 | 0.5 | no route | O2 sensor | — | |
| W35 | OEM-2-Q | MAXXECUGEN2R-MX1-29 | 0.5 | no route | Coolant temperature (ECT) | — | |
| W36 | OEM-2-P | MAXXECUGEN2R-MX1-30 | 0.5 | no route | Intake air temperature (IAT) | — | |
| W37 | OEM-1-M | MAXXECUGEN2R-MX1-23 | 0.5 | no route | Vehicle speed | — | |
| W38 | OEM-1-C | MAXXECUGEN2R-MX1-24 | 0.5 | no route | Start signal | — | |
| W39 | OEM-1-O | MAXXECUGEN2R-MX4-3 | 0.5 | no route | Stop light switch | — | |
| W40 | OEM-1-P | MAXXECUGEN2R-MX4-6 | 0.5 | no route | Power steering pressure switch | — | |
| W41 | OEM-1-Q | MAXXECUGEN2R-MX4-9 | 0.5 | no route | A/C request | — | |
| W42 | OEM-1-V | MAXXECUGEN2R-MX4-28 | 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 |
ECU setup sheet
| Role | Engine ref | Engine signal | Sensor | ECU point | ECU function | ECU class | Setup flag |
|---|---|---|---|---|---|---|---|
| No configured channels. | |||||||
Findings
Open (7)
| Severity | Code | Subject | Message |
|---|---|---|---|
| info | NET_FAMILY | OEM-1-E ↔ MAXXECUGEN2R-MX2-34 | OEM-1-E "Malfunction indicator lamp (MIL)" [low_side_out] is wired to MAXXECUGEN2R-MX2-34 "INJECTOR 6" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-2-P ↔ MAXXECUGEN2R-MX1-30 | OEM-2-P "Intake air temperature (IAT)" [temp_in] is wired to MAXXECUGEN2R-MX1-30 "AIN 5" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one. |
| info | NET_FAMILY | OEM-2-Q ↔ MAXXECUGEN2R-MX1-29 | OEM-2-Q "Coolant temperature (ECT)" [temp_in] is wired to MAXXECUGEN2R-MX1-29 "AIN 4" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one. |
| info | NET_FAMILY | OEM-2-R ↔ MAXXECUGEN2R-MX3-29 | OEM-2-R "PRC solenoid (fuel pressure regulator)" [low_side_out] is wired to MAXXECUGEN2R-MX3-29 "INJECTOR 7" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-2-W ↔ MAXXECUGEN2R-MX2-33 | OEM-2-W "ISC solenoid" [low_side_out] is wired to MAXXECUGEN2R-MX2-33 "INJECTOR 5" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-2-X ↔ MAXXECUGEN2R-MX3-30 | OEM-2-X "Evap purge solenoid" [low_side_out] is wired to MAXXECUGEN2R-MX3-30 "INJECTOR 8" [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 (only a modified "MX5 NA cam trigger with missing tooth" entry) 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: MaxxECU MaxxECU GEN2 RACE has no battery-constant input; not needed - OEM-2 I: Tachometer output: no free tacho/frequency_out/low_side/ls_hs on MaxxECU MaxxECU GEN2 RACE - OEM-1 D: Data link connector: no free k_line on MaxxECU MaxxECU GEN2 RACE - OEM-2 H: Data link connector: no free k_line on MaxxECU MaxxECU GEN2 RACE - 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 - MAXXECUGEN2R-MX2 24: 12V supply 3: not fed (the stock ECU has no ignition-sense pin); feed it from a switched-ignition source
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 | MaxxECU GEN2 pinout (RACE MX1–MX4 / TRACK MX1–MX3) | http://www.maxxecu.com/webhelp/wirings-maxxecu_gen2_pinout.html | archive | 2026-10-05 | f689b8b6b08f |
| 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 |