MX-5 Miata NA8 1994-95 (BP-ZE, 1.8, OBD-I) → Link G4X MonsoonX (auto)
MX-5 Miata NA8 1994-95 (BP-ZE, 1.8, OBD-I) — Link — G4X MonsoonX
⚠ 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 | 34 wires · 6 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 | G4XMONSOONX-A-A5 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W3 | OEM-2-A | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W4 | OEM-2-B | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W5 | SP-GND-1 | G4XMONSOONX-A-A25 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W6 | SP-GND-1 | G4XMONSOONX-A-A34 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W7 | OEM-2-C | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | OEM-2-D | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | OEM-2-F | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | SP-0V-1 | G4XMONSOONX-A-A24 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | OEM-2-K | G4XMONSOONX-A-A32 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | OEM-2-E | G4XMONSOONX-A-A8 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | OEM-2-G | G4XMONSOONX-A-A9 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | OEM-1-G | G4XMONSOONX-A-A13 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | OEM-1-H | G4XMONSOONX-A-A12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | OEM-2-U | G4XMONSOONX-A-A4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-2-V | G4XMONSOONX-A-A3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-2-Y | G4XMONSOONX-A-A2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-2-Z | G4XMONSOONX-A-A1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-1-J | G4XMONSOONX-A-A21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-1-R | G4XMONSOONX-A-A20 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-2-S | G4XMONSOONX-A-A19 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-2-T | G4XMONSOONX-A-A18 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-1-L | G4XMONSOONX-A-A27 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-2-L | G4XMONSOONX-A-A26 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-2-O | G4XMONSOONX-A-A17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-2-M | G4XMONSOONX-A-A22 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-2-N | G4XMONSOONX-A-A33 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-2-Q | G4XMONSOONX-A-A15 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | OEM-2-P | G4XMONSOONX-A-A16 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-1-M | G4XMONSOONX-A-A30 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-1-C | G4XMONSOONX-A-A31 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-1-O | G4XMONSOONX-A-A23 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-1-P | G4XMONSOONX-A-A14 | 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 | G4XMONSOONX-A-A5 | G4XMONSOONX-A-A24 | open (OL) | +12 V supply must not touch sensor ground | |
| 2 | G4XMONSOONX-A-A5 | G4XMONSOONX-A-A25 | open (OL) | +12 V supply must not touch power ground | |
| 3 | G4XMONSOONX-A-A24 | G4XMONSOONX-A-A32 | open (OL) | sensor ground must not touch 5 V sensor reference | |
| 4 | G4XMONSOONX-A-A25 | G4XMONSOONX-A-A32 | open (OL) | power ground must not touch 5 V sensor reference | |
| 5 | G4XMONSOONX-A-A5 | G4XMONSOONX-A-A32 | open (OL) | +12 V supply 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
G4XMONSOONX-A
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A1 | Injector 4 | — | W19 | — | 0.5 | OEM-2-Z | — | — | — |
| A10 | Ignition 4 | — | — | — | — | — | — | — | — |
| A11 | Ignition 3 | — | — | — | — | — | — | — | — |
| A12 | Ignition 2 | — | W15 | — | 0.5 | OEM-1-H | — | — | — |
| A13 | Ignition 1 | — | W14 | — | 0.5 | OEM-1-G | — | — | — |
| A14 | Analog Volt 4 | — | W34 | — | 0.5 | OEM-1-P | — | — | — |
| A15 | Analog Temp 1 | — | W29 | — | 0.5 | OEM-2-Q | — | — | — |
| A16 | Analog Temp 2 | — | W30 | — | 0.5 | OEM-2-P | — | — | — |
| A17 | Analog Volt 1 | — | W26 | — | 0.5 | OEM-2-O | — | — | — |
| A18 | Aux 4 | — | W23 | — | 0.5 | OEM-2-T | — | — | — |
| A19 | Aux 3 | — | W22 | — | 0.5 | OEM-2-S | — | — | — |
| A2 | Injector 3 | — | W18 | — | 0.5 | OEM-2-Y | — | — | — |
| A20 | Aux 2 | — | W21 | — | 0.5 | OEM-1-R | — | — | — |
| A21 | Aux 1 | — | W20 | — | 0.5 | OEM-1-J | — | — | — |
| A22 | Analog Volt 2 | — | W27 | — | 0.5 | OEM-2-M | — | — | — |
| A23 | Digital Input 3 | — | W33 | — | 0.5 | OEM-1-O | — | — | — |
| A24 | Sensor Ground | — | W10 | — | 0.5 | SP-0V-1 | — | — | — |
| A25 | System Ground | — | W5 | — | 0.85 | SP-GND-1 | — | — | — |
| A26 | Aux 6 | — | W25 | — | 0.5 | OEM-2-L | — | — | — |
| A27 | Aux 5 | — | W24 | — | 0.5 | OEM-1-L | — | — | — |
| A28 | CAN H | — | — | — | — | — | — | — | — |
| A29 | CAN L | — | — | — | — | — | — | — | — |
| A3 | Injector 2 | — | W17 | — | 0.5 | OEM-2-V | — | — | — |
| A30 | Digital Input 1 | — | W31 | — | 0.5 | OEM-1-M | — | — | — |
| A31 | Digital Input 2 | — | W32 | — | 0.5 | OEM-1-C | — | — | — |
| A32 | +5V Out | — | W11 | — | 0.5 | OEM-2-K | — | — | — |
| A33 | Analog Volt 3 | — | W28 | — | 0.5 | OEM-2-N | — | — | — |
| A34 | System Ground | — | W6 | — | 0.85 | SP-GND-1 | — | — | — |
| A4 | Injector 1 | — | W16 | — | 0.5 | OEM-2-U | — | — | — |
| A5 | +14V ECU Power | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
| A6 | Knock 1 / Digital Input 4 | — | — | — | — | — | — | — | — |
| A7 | Shield Ground | — | — | — | — | — | — | — | — |
| A8 | Trigger 1 | — | W12 | — | 0.5 | OEM-2-E | — | — | — |
| A9 | Trigger 2 | — | W13 | — | 0.5 | OEM-2-G | — | — | — |
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 | — | W32 | — | 0.5 | G4XMONSOONX-A-A31 | — | — | — |
| D | Data link connector | — | — | — | — | — | — | — | — |
| E | Malfunction indicator lamp (MIL) | — | — | — | — | — | — | — | — |
| G | Ignition 1 (coils 1+4, wasted spark) | — | W14 | — | 0.5 | G4XMONSOONX-A-A13 | — | — | — |
| H | Ignition 2 (coils 2+3, wasted spark) | — | W15 | — | 0.5 | G4XMONSOONX-A-A12 | — | — | — |
| I | Powertrain control module (transmission) | — | — | — | — | — | — | — | — |
| J | A/C relay | — | W20 | — | 0.5 | G4XMONSOONX-A-A21 | — | — | — |
| L | Coolant fan relay | — | W24 | — | 0.5 | G4XMONSOONX-A-A27 | — | — | — |
| M | Vehicle speed | — | W31 | — | 0.5 | G4XMONSOONX-A-A30 | — | — | — |
| N | Powertrain control module (transmission) | — | — | — | — | — | — | — | — |
| O | Stop light switch | — | W33 | — | 0.5 | G4XMONSOONX-A-A23 | — | — | — |
| P | Power steering pressure switch | — | W34 | — | 0.5 | G4XMONSOONX-A-A14 | — | — | — |
| Q | A/C request | — | — | — | — | — | — | — | — |
| R | Cooling fan relay | — | W21 | — | 0.5 | G4XMONSOONX-A-A20 | — | — | — |
| S | Heater control unit | — | — | — | — | — | — | — | — |
| T | Unknown | — | — | — | — | — | — | — | — |
| U | Unknown | — | — | — | — | — | — | — | — |
| V | Neutral/clutch switch | — | — | — | — | — | — | — | — |
OEM-2
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A | Power ground | — | W3 | — | 0.85 | SP-GND-1 | — | — | — |
| B | Power ground | — | W4 | — | 0.85 | SP-GND-1 | — | — | — |
| C | Sensor ground (E2) | — | W7 | — | 0.5 | SP-0V-1 | — | — | — |
| D | Sensor ground (E2) | — | W8 | — | 0.5 | SP-0V-1 | — | — | — |
| E | Crank position (CAS NE) | — | W12 | — | 0.5 | G4XMONSOONX-A-A8 | — | — | — |
| F | MAF ground | — | W9 | — | 0.5 | SP-0V-1 | — | — | — |
| G | Cam position (CAS G) | — | W13 | — | 0.5 | G4XMONSOONX-A-A9 | — | — | — |
| H | Data link connector | — | — | — | — | — | — | — | — |
| I | Tachometer output | — | — | — | — | — | — | — | — |
| J | EGR function sensor | — | — | — | — | — | — | — | — |
| K | +5V sensor supply | — | W11 | — | 0.5 | G4XMONSOONX-A-A32 | — | — | — |
| L | Rear defroster relay | — | W25 | — | 0.5 | G4XMONSOONX-A-A26 | — | — | — |
| M | Throttle position (TPS) | — | W27 | — | 0.5 | G4XMONSOONX-A-A22 | — | — | — |
| N | O2 sensor | — | W28 | — | 0.5 | G4XMONSOONX-A-A33 | — | — | — |
| O | Mass air flow (MAF) | — | W26 | — | 0.5 | G4XMONSOONX-A-A17 | — | — | — |
| P | Intake air temperature (IAT) | — | W30 | — | 0.5 | G4XMONSOONX-A-A16 | — | — | — |
| Q | Coolant temperature (ECT) | — | W29 | — | 0.5 | G4XMONSOONX-A-A15 | — | — | — |
| R | PRC solenoid (fuel pressure regulator) | — | — | — | — | — | — | — | — |
| S | Condenser fan relay | — | W22 | — | 0.5 | G4XMONSOONX-A-A19 | — | — | — |
| T | Fuel pump relay | — | W23 | — | 0.5 | G4XMONSOONX-A-A18 | — | — | — |
| U | Injector 1 | — | W16 | — | 0.5 | G4XMONSOONX-A-A4 | — | — | — |
| V | Injector 2 | — | W17 | — | 0.5 | G4XMONSOONX-A-A3 | — | — | — |
| W | ISC solenoid | — | — | — | — | — | — | — | — |
| X | Evap purge solenoid | — | — | — | — | — | — | — | — |
| Y | Injector 3 | — | W18 | — | 0.5 | G4XMONSOONX-A-A2 | — | — | — |
| Z | Injector 4 | — | W19 | — | 0.5 | G4XMONSOONX-A-A1 | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W7 | — | 0.5 | OEM-2-C | — | — | — |
| 1 | — | — | W8 | — | 0.5 | OEM-2-D | — | — | — |
| 1 | — | — | W9 | — | 0.5 | OEM-2-F | — | — | — |
| 1 | — | — | W10 | — | 0.5 | G4XMONSOONX-A-A24 | — | — | — |
SP-14V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W1 | — | 0.85 | OEM-1-B | — | — | — |
| 1 | — | — | W2 | — | 0.85 | G4XMONSOONX-A-A5 | — | — | — |
SP-GND
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W3 | — | 0.85 | OEM-2-A | — | — | — |
| 1 | — | — | W4 | — | 0.85 | OEM-2-B | — | — | — |
| 1 | — | — | W5 | — | 0.85 | G4XMONSOONX-A-A25 | — | — | — |
| 1 | — | — | W6 | — | 0.85 | G4XMONSOONX-A-A34 | — | — | — |
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 | G4XMONSOONX-A-A5 | +14V ECU Power | power_in | WR | single_source |
| OEM-1-C | Start signal | digital_in | G4XMONSOONX-A-A31 | Digital Input 2 | digital_in | V | single_source |
| OEM-1-D | Data link connector | serial | — | — | — | WG | single_source |
| OEM-1-E | Malfunction indicator lamp (MIL) | low_side_out | — | — | — | YB | single_source |
| OEM-1-G | Ignition 1 (coils 1+4, wasted spark) | ignition_out | G4XMONSOONX-A-A13 | Ignition 1 | ignition_out | BrY | single_source |
| OEM-1-H | Ignition 2 (coils 2+3, wasted spark) | ignition_out | G4XMONSOONX-A-A12 | 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 | G4XMONSOONX-A-A21 | Aux 1 | low_side_out | single_source | |
| OEM-1-L | Coolant fan relay | low_side_out | G4XMONSOONX-A-A27 | Aux 5 | low_side_out | BG | single_source |
| OEM-1-M | Vehicle speed | digital_in | G4XMONSOONX-A-A30 | Digital Input 1 | digital_in | GR | single_source |
| OEM-1-N | Powertrain control module (transmission) | — | — | — | — | R | single_source |
| OEM-1-O | Stop light switch | digital_in | G4XMONSOONX-A-A23 | Digital Input 3 | digital_in | GB | single_source |
| OEM-1-P | Power steering pressure switch | digital_in | G4XMONSOONX-A-A14 | Analog Volt 4 | analog_in | LY | single_source |
| OEM-1-Q | A/C request | digital_in | — | — | — | LgB | single_source |
| OEM-1-R | Cooling fan relay | low_side_out | G4XMONSOONX-A-A20 | Aux 2 | 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 | — | — | — | BrW | single_source |
| OEM-2-A | Power ground | ground | G4XMONSOONX-A-A25 + G4XMONSOONX-A-A34 | System Ground + System Ground | ground | B | single_source |
| OEM-2-B | Power ground | ground | G4XMONSOONX-A-A25 + G4XMONSOONX-A-A34 | System Ground + System Ground | ground | B | single_source |
| OEM-2-C | Sensor ground (E2) | sensor_ground | G4XMONSOONX-A-A24 | Sensor Ground | sensor_ground | BLg | corroborated |
| OEM-2-D | Sensor ground (E2) | sensor_ground | G4XMONSOONX-A-A24 | Sensor Ground | sensor_ground | BL | corroborated |
| OEM-2-E | Crank position (CAS NE) | trigger_in | G4XMONSOONX-A-A8 | Trigger 1 | trigger_in | W | single_source |
| OEM-2-F | MAF ground | sensor_ground | G4XMONSOONX-A-A24 | Sensor Ground | sensor_ground | BR | single_source |
| OEM-2-G | Cam position (CAS G) | trigger_in | G4XMONSOONX-A-A9 | Trigger 2 | 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 | G4XMONSOONX-A-A32 | +5V Out | vref | LgW | single_source |
| OEM-2-L | Rear defroster relay | low_side_out | G4XMONSOONX-A-A26 | Aux 6 | low_side_out | LR | single_source |
| OEM-2-M | Throttle position (TPS) | analog_in | G4XMONSOONX-A-A22 | Analog Volt 2 | analog_in | RB | single_source |
| OEM-2-N | O2 sensor | lambda_nb_in | G4XMONSOONX-A-A33 | Analog Volt 3 | analog_in | RL | single_source |
| OEM-2-O | Mass air flow (MAF) | analog_in | G4XMONSOONX-A-A17 | Analog Volt 1 | analog_in | R | single_source |
| OEM-2-P | Intake air temperature (IAT) | temp_in | G4XMONSOONX-A-A16 | Analog Temp 2 | temp_in | RB | single_source |
| OEM-2-Q | Coolant temperature (ECT) | temp_in | G4XMONSOONX-A-A15 | Analog Temp 1 | temp_in | LW | single_source |
| OEM-2-R | PRC solenoid (fuel pressure regulator) | low_side_out | — | — | — | YG | single_source |
| OEM-2-S | Condenser fan relay | low_side_out | G4XMONSOONX-A-A19 | Aux 3 | low_side_out | LW | single_source |
| OEM-2-T | Fuel pump relay | low_side_out | G4XMONSOONX-A-A18 | Aux 4 | low_side_out | Lg | single_source |
| OEM-2-U | Injector 1 | injector_out | G4XMONSOONX-A-A4 | Injector 1 | injector_out | Y | single_source |
| OEM-2-V | Injector 2 | injector_out | G4XMONSOONX-A-A3 | Injector 2 | injector_out | YB | single_source |
| OEM-2-W | ISC solenoid | low_side_out | — | — | — | LOr | single_source |
| OEM-2-X | Evap purge solenoid | low_side_out | — | — | — | YR | single_source |
| OEM-2-Y | Injector 3 | injector_out | G4XMONSOONX-A-A2 | Injector 3 | injector_out | GW | single_source |
| OEM-2-Z | Injector 4 | injector_out | G4XMONSOONX-A-A1 | 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 | G4XMONSOONX-A-A5 | 0.85 | no route | +14V ECU Power | — | |
| W3 | OEM-2-A | SP-GND-1 | 0.85 | no route | Power ground | — | |
| W4 | OEM-2-B | SP-GND-1 | 0.85 | no route | Power ground | — | |
| W5 | SP-GND-1 | G4XMONSOONX-A-A25 | 0.85 | no route | System Ground | — | |
| W6 | SP-GND-1 | G4XMONSOONX-A-A34 | 0.85 | no route | System Ground | — | |
| W7 | OEM-2-C | SP-0V-1 | 0.5 | no route | Sensor ground (E2) | — | |
| W8 | OEM-2-D | SP-0V-1 | 0.5 | no route | Sensor ground (E2) | — | |
| W9 | OEM-2-F | SP-0V-1 | 0.5 | no route | MAF ground | — | |
| W10 | SP-0V-1 | G4XMONSOONX-A-A24 | 0.5 | no route | Sensor Ground | — | |
| W11 | OEM-2-K | G4XMONSOONX-A-A32 | 0.5 | no route | +5V sensor supply | — | |
| W12 | OEM-2-E | G4XMONSOONX-A-A8 | 0.5 | no route | Crank position (CAS NE) | — | |
| W13 | OEM-2-G | G4XMONSOONX-A-A9 | 0.5 | no route | Cam position (CAS G) | — | |
| W14 | OEM-1-G | G4XMONSOONX-A-A13 | 0.5 | no route | Ignition 1 (coils 1+4, wasted spark) | — | |
| W15 | OEM-1-H | G4XMONSOONX-A-A12 | 0.5 | no route | Ignition 2 (coils 2+3, wasted spark) | — | |
| W16 | OEM-2-U | G4XMONSOONX-A-A4 | 0.5 | no route | Injector 1 | — | |
| W17 | OEM-2-V | G4XMONSOONX-A-A3 | 0.5 | no route | Injector 2 | — | |
| W18 | OEM-2-Y | G4XMONSOONX-A-A2 | 0.5 | no route | Injector 3 | — | |
| W19 | OEM-2-Z | G4XMONSOONX-A-A1 | 0.5 | no route | Injector 4 | — | |
| W20 | OEM-1-J | G4XMONSOONX-A-A21 | 0.5 | no route | A/C relay | — | |
| W21 | OEM-1-R | G4XMONSOONX-A-A20 | 0.5 | no route | Cooling fan relay | — | |
| W22 | OEM-2-S | G4XMONSOONX-A-A19 | 0.5 | no route | Condenser fan relay | — | |
| W23 | OEM-2-T | G4XMONSOONX-A-A18 | 0.5 | no route | Fuel pump relay | — | |
| W24 | OEM-1-L | G4XMONSOONX-A-A27 | 0.5 | no route | Coolant fan relay | — | |
| W25 | OEM-2-L | G4XMONSOONX-A-A26 | 0.5 | no route | Rear defroster relay | — | |
| W26 | OEM-2-O | G4XMONSOONX-A-A17 | 0.5 | no route | Mass air flow (MAF) | — | |
| W27 | OEM-2-M | G4XMONSOONX-A-A22 | 0.5 | no route | Throttle position (TPS) | — | |
| W28 | OEM-2-N | G4XMONSOONX-A-A33 | 0.5 | no route | O2 sensor | — | |
| W29 | OEM-2-Q | G4XMONSOONX-A-A15 | 0.5 | no route | Coolant temperature (ECT) | — | |
| W30 | OEM-2-P | G4XMONSOONX-A-A16 | 0.5 | no route | Intake air temperature (IAT) | — | |
| W31 | OEM-1-M | G4XMONSOONX-A-A30 | 0.5 | no route | Vehicle speed | — | |
| W32 | OEM-1-C | G4XMONSOONX-A-A31 | 0.5 | no route | Start signal | — | |
| W33 | OEM-1-O | G4XMONSOONX-A-A23 | 0.5 | no route | Stop light switch | — | |
| W34 | OEM-1-P | G4XMONSOONX-A-A14 | 0.5 | no route | Power steering pressure 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 (6)
| Severity | Code | Subject | Message |
|---|---|---|---|
| warn | LOAD_UNKNOWN | G4XMONSOONX-A-A18 | G4XMONSOONX-A-A18 "Aux 4" drives OEM-2-T Fuel pump relay (load 0.2 A) but its current rating is unknown. Check the ECU manual. |
| warn | LOAD_UNKNOWN | G4XMONSOONX-A-A19 | G4XMONSOONX-A-A19 "Aux 3" drives OEM-2-S Condenser fan relay (load 0.2 A) but its current rating is unknown. Check the ECU manual. |
| warn | LOAD_UNKNOWN | G4XMONSOONX-A-A20 | G4XMONSOONX-A-A20 "Aux 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 | G4XMONSOONX-A-A21 | G4XMONSOONX-A-A21 "Aux 1" drives OEM-1-J A/C relay (load 0.2 A) but its current rating is unknown. Check the ECU manual. |
| warn | NET_FAMILY | OEM-1-P ↔ G4XMONSOONX-A-A14 | OEM-1-P "Power steering pressure switch" [digital_in] is wired to G4XMONSOONX-A-A14 "Analog Volt 4" [analog_in]. Analog and digital on one net. A switch on an analog input works with a pull-up and a threshold; an analog sensor on a digital input loses its value. |
| info | UNMAPPED | OEM | 15 optional OEM pins are not mapped: OEM-1-D Data link connector; OEM-1-E Malfunction indicator lamp (MIL); OEM-1-I Powertrain control module (transmission); OEM-1-N Powertrain control module (transmission); OEM-1-Q A/C request; OEM-1-S Heater control unit; OEM-1-T Unknown; OEM-1-U Unknown; OEM-1-V Neutral/clutch switch; OEM-2-H Data link connector; OEM-2-I Tachometer output; OEM-2-J EGR function sensor; OEM-2-R PRC solenoid (fuel pressure regulator); OEM-2-W ISC solenoid; OEM-2-X Evap purge solenoid |
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 (Link's trigger-mode list is only inside PCLink, not online) 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: Link G4X MonsoonX has no battery-constant input; not needed - OEM-2 W: ISC solenoid: no free low_side/ls_hs/injector/hbridge rated ≥ 1.0 A on Link G4X MonsoonX - OEM-1 E: Malfunction indicator lamp (MIL): no free low_side/ls_hs/injector/hbridge on Link G4X MonsoonX - OEM-2 R: PRC solenoid (fuel pressure regulator): no free low_side/ls_hs/injector/hbridge on Link G4X MonsoonX - OEM-2 X: Evap purge solenoid: no free low_side/ls_hs/injector/hbridge on Link G4X MonsoonX - OEM-2 I: Tachometer output: no free tacho/frequency_out/low_side/ls_hs on Link G4X MonsoonX - OEM-1 Q: A/C request: no free switch_in/frequency_in/analog_0_5 on Link G4X MonsoonX - OEM-1 V: Neutral/clutch switch: no free switch_in/frequency_in/analog_0_5 on Link G4X MonsoonX - OEM-1 D: Data link connector: no free k_line on Link G4X MonsoonX - OEM-2 H: Data link connector: no free k_line on Link G4X MonsoonX - OEM-1 I: Powertrain control module (transmission): not classified in the library; wire by hand - OEM-1 N: Powertrain control module (transmission): not classified in the library; wire by hand - OEM-1 S: Heater control unit: not classified in the library; wire by hand - OEM-1 T: Unknown: not classified in the library; wire by hand - OEM-1 U: Unknown: not classified in the library; wire by hand - OEM-2 J: EGR function sensor: not classified in the library; wire by hand
Sources
| Reliability | Kind | Title | URL | Archive | Captured | SHA-256 |
|---|---|---|---|---|---|---|
| 4 | vendor_doc | Link G4X MX5X install manual (NA 1.6/1.8) | https://linkecu.com/documentation/MX5X.pdf | archive | 2026-10-05 | b7f730de9f6e |
| 4 | vendor_doc | Link: G4X MonsoonX quickstart + RET 115-1000 | https://linkecu.com/documentation/MonsoonXQuickstartGuide.pdf | archive | 2026-10-05 | e8d432b273d6 |
| 3 | community_copy | YourSpec: Link G4X MonsoonX flying-lead harness wiring list | https://wpm.yourspec.com/projects/view/1469 | — | — | — |
| 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 |