MX-5 Miata NB1 1999-00 (BP-4W) → Link G4X MonsoonX (auto)
MX-5 Miata NB1 1999-00 (BP-4W) — Link — G4X MonsoonX
⚠ NOT CHECKED. Don't build from this.
Drawn by Michael Gnankou · Rev 0 · draft · 2026-10-08
Before you start
| Status | draft · not yet verified: nobody has reported building and running this harness |
|---|---|
| Open errors | none |
| Size of the job | 35 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 | G4XMONSOONX-A-A5 | 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 | G4XMONSOONX-A-A25 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | SP-GND-1 | G4XMONSOONX-A-A34 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | OEM-3-F | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | SP-0V-1 | G4XMONSOONX-A-A24 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | OEM-2-I | G4XMONSOONX-A-A32 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | OEM-2-J | G4XMONSOONX-A-A8 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | OEM-2-H | G4XMONSOONX-A-A9 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | OEM-2-F | G4XMONSOONX-A-A6 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | OEM-3-G | G4XMONSOONX-A-A13 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | OEM-3-H | G4XMONSOONX-A-A12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-3-W | G4XMONSOONX-A-A4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-3-X | G4XMONSOONX-A-A3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-3-Y | G4XMONSOONX-A-A2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-3-Z | G4XMONSOONX-A-A1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-1-I | G4XMONSOONX-A-A21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-1-R | G4XMONSOONX-A-A20 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-1-S | G4XMONSOONX-A-A19 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-3-N | G4XMONSOONX-A-A18 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-1-U | G4XMONSOONX-A-A27 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-3-V | G4XMONSOONX-A-A26 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-2-L | G4XMONSOONX-A-A17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-3-E | G4XMONSOONX-A-A22 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-2-C | G4XMONSOONX-A-A33 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | OEM-3-J | G4XMONSOONX-A-A14 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-2-E | G4XMONSOONX-A-A15 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-2-B | G4XMONSOONX-A-A16 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-2-D | G4XMONSOONX-A-A30 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-1-F | G4XMONSOONX-A-A31 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W35 | OEM-1-G | G4XMONSOONX-A-A23 | 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-A32 | G4XMONSOONX-A-A24 | open (OL) | 5 V sensor reference must not touch sensor ground | |
| 2 | G4XMONSOONX-A-A32 | G4XMONSOONX-A-A25 | open (OL) | 5 V sensor reference must not touch power ground | |
| 3 | G4XMONSOONX-A-A5 | G4XMONSOONX-A-A24 | open (OL) | +12 V supply must not touch sensor ground | |
| 4 | G4XMONSOONX-A-A5 | G4XMONSOONX-A-A25 | open (OL) | +12 V supply must not touch power ground | |
| 5 | G4XMONSOONX-A-A5 | G4XMONSOONX-A-A32 | open (OL) | +12 V supply must not touch 5 V sensor reference |
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 | — | W20 | — | 0.5 | OEM-3-Z | — | — | — |
| A10 | Ignition 4 | — | — | — | — | — | — | — | — |
| A11 | Ignition 3 | — | — | — | — | — | — | — | — |
| A12 | Ignition 2 | — | W16 | — | 0.5 | OEM-3-H | — | — | — |
| A13 | Ignition 1 | — | W15 | — | 0.5 | OEM-3-G | — | — | — |
| A14 | Analog Volt 4 | — | W30 | — | 0.5 | OEM-3-J | — | — | — |
| A15 | Analog Temp 1 | — | W31 | — | 0.5 | OEM-2-E | — | — | — |
| A16 | Analog Temp 2 | — | W32 | — | 0.5 | OEM-2-B | — | — | — |
| A17 | Analog Volt 1 | — | W27 | — | 0.5 | OEM-2-L | — | — | — |
| A18 | Aux 4 | — | W24 | — | 0.5 | OEM-3-N | — | — | — |
| A19 | Aux 3 | — | W23 | — | 0.5 | OEM-1-S | — | — | — |
| A2 | Injector 3 | — | W19 | — | 0.5 | OEM-3-Y | — | — | — |
| A20 | Aux 2 | — | W22 | — | 0.5 | OEM-1-R | — | — | — |
| A21 | Aux 1 | — | W21 | — | 0.5 | OEM-1-I | — | — | — |
| A22 | Analog Volt 2 | — | W28 | — | 0.5 | OEM-3-E | — | — | — |
| A23 | Digital Input 3 | — | W35 | — | 0.5 | OEM-1-G | — | — | — |
| A24 | Sensor Ground | — | W10 | — | 0.5 | SP-0V-1 | — | — | — |
| A25 | System Ground | — | W7 | — | 0.85 | SP-GND-1 | — | — | — |
| A26 | Aux 6 | — | W26 | — | 0.5 | OEM-3-V | — | — | — |
| A27 | Aux 5 | — | W25 | — | 0.5 | OEM-1-U | — | — | — |
| A28 | CAN H | — | — | — | — | — | — | — | — |
| A29 | CAN L | — | — | — | — | — | — | — | — |
| A3 | Injector 2 | — | W18 | — | 0.5 | OEM-3-X | — | — | — |
| A30 | Digital Input 1 | — | W33 | — | 0.5 | OEM-2-D | — | — | — |
| A31 | Digital Input 2 | — | W34 | — | 0.5 | OEM-1-F | — | — | — |
| A32 | +5V Out | — | W11 | — | 0.5 | OEM-2-I | — | — | — |
| A33 | Analog Volt 3 | — | W29 | — | 0.5 | OEM-2-C | — | — | — |
| A34 | System Ground | — | W8 | — | 0.85 | SP-GND-1 | — | — | — |
| A4 | Injector 1 | — | W17 | — | 0.5 | OEM-3-W | — | — | — |
| A5 | +14V ECU Power | — | W3 | — | 0.85 | SP-14V-1 | — | — | — |
| A6 | Knock 1 / Digital Input 4 | — | W14 | — | 0.5 | OEM-2-F | — | — | — |
| A7 | Shield Ground | — | — | — | — | — | — | — | — |
| A8 | Trigger 1 | — | W12 | — | 0.5 | OEM-2-J | — | — | — |
| A9 | Trigger 2 | — | W13 | — | 0.5 | OEM-2-H | — | — | — |
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) | — | — | — | — | — | — | — | — |
| F | Brake switch | — | W34 | — | 0.5 | G4XMONSOONX-A-A31 | — | — | — |
| G | Power steering pressure switch | — | W35 | — | 0.5 | G4XMONSOONX-A-A23 | — | — | — |
| I | Condenser fan relay | — | W21 | — | 0.5 | G4XMONSOONX-A-A21 | — | — | — |
| O | Alternator control | — | — | — | — | — | — | — | — |
| P | A/C request | — | — | — | — | — | — | — | — |
| Q | Charge lamp | — | — | — | — | — | — | — | — |
| R | Cooling fan relay | — | W22 | — | 0.5 | G4XMONSOONX-A-A20 | — | — | — |
| S | A/C clutch relay | — | W23 | — | 0.5 | G4XMONSOONX-A-A19 | — | — | — |
| U | Front O2 heater | — | W25 | — | 0.5 | G4XMONSOONX-A-A27 | — | — | — |
| V | Neutral switch | — | — | — | — | — | — | — | — |
OEM-2
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A | Fuel tank pressure | — | — | — | — | — | — | — | — |
| B | Intake air temperature (IAT) | — | W32 | — | 0.5 | G4XMONSOONX-A-A16 | — | — | — |
| C | Front O2 signal | — | W29 | — | 0.5 | G4XMONSOONX-A-A33 | — | — | — |
| D | Vehicle speed | — | W33 | — | 0.5 | G4XMONSOONX-A-A30 | — | — | — |
| E | Coolant temperature (ECT) | — | W31 | — | 0.5 | G4XMONSOONX-A-A15 | — | — | — |
| F | Knock sensor | — | W14 | — | 0.5 | G4XMONSOONX-A-A6 | — | — | — |
| H | Cam position (CMP) | — | W13 | — | 0.5 | G4XMONSOONX-A-A9 | — | — | — |
| I | +5V sensor supply | — | W11 | — | 0.5 | G4XMONSOONX-A-A32 | — | — | — |
| J | Crank position (CKP) | — | W12 | — | 0.5 | G4XMONSOONX-A-A8 | — | — | — |
| K | Tachometer output | — | — | — | — | — | — | — | — |
| L | Mass air flow (MAF) | — | W27 | — | 0.5 | G4XMONSOONX-A-A17 | — | — | — |
| M | EGR valve | — | — | — | — | — | — | — | — |
| 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) | — | W28 | — | 0.5 | G4XMONSOONX-A-A22 | — | — | — |
| F | Signal ground | — | W9 | — | 0.5 | SP-0V-1 | — | — | — |
| G | Ignition 1 (coils 1+4, wasted spark) | — | W15 | — | 0.5 | G4XMONSOONX-A-A13 | — | — | — |
| H | Ignition 2 (coils 2+3, wasted spark) | — | W16 | — | 0.5 | G4XMONSOONX-A-A12 | — | — | — |
| I | Clutch switch | — | — | — | — | — | — | — | — |
| J | Rear O2 signal | — | W30 | — | 0.5 | G4XMONSOONX-A-A14 | — | — | — |
| K | Fuel level | — | — | — | — | — | — | — | — |
| L | Evap purge solenoid | — | — | — | — | — | — | — | — |
| M | ISC valve +14V feed | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
| N | Fuel pump relay | — | W24 | — | 0.5 | G4XMONSOONX-A-A18 | — | — | — |
| O | ISC valve low side | — | — | — | — | — | — | — | — |
| Q | VICS solenoid (intake butterflies) | — | — | — | — | — | — | — | — |
| S | EGR boost sensor | — | — | — | — | — | — | — | — |
| T | EGR boost solenoid | — | — | — | — | — | — | — | — |
| U | Canister drain cut valve (CDCV) | — | — | — | — | — | — | — | — |
| V | Rear O2 heater | — | W26 | — | 0.5 | G4XMONSOONX-A-A26 | — | — | — |
| W | Injector 1 | — | W17 | — | 0.5 | G4XMONSOONX-A-A4 | — | — | — |
| X | Injector 2 | — | W18 | — | 0.5 | G4XMONSOONX-A-A3 | — | — | — |
| Y | Injector 3 | — | W19 | — | 0.5 | G4XMONSOONX-A-A2 | — | — | — |
| Z | Injector 4 | — | W20 | — | 0.5 | G4XMONSOONX-A-A1 | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W9 | — | 0.5 | OEM-3-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 | OEM-3-M | — | — | — |
| 1 | — | — | W3 | — | 0.85 | G4XMONSOONX-A-A5 | — | — | — |
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 | G4XMONSOONX-A-A25 | — | — | — |
| 1 | — | — | W8 | — | 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 | — | — | — | single_source | |
| OEM-1-B | ECU power +14V (main relay) | power_in | G4XMONSOONX-A-A5 | +14V ECU Power | power_in | single_source | |
| OEM-1-E | Malfunction indicator lamp (MIL) | low_side_out | — | — | — | single_source | |
| OEM-1-F | Brake switch | digital_in | G4XMONSOONX-A-A31 | Digital Input 2 | digital_in | single_source | |
| OEM-1-G | Power steering pressure switch | digital_in | G4XMONSOONX-A-A23 | Digital Input 3 | digital_in | single_source | |
| OEM-1-I | Condenser fan relay | low_side_out | G4XMONSOONX-A-A21 | Aux 1 | low_side_out | single_source | |
| OEM-1-O | Alternator control | low_side_out | — | — | — | single_source | |
| OEM-1-P | A/C request | digital_in | — | — | — | single_source | |
| OEM-1-Q | Charge lamp | low_side_out | — | — | — | single_source | |
| OEM-1-R | Cooling fan relay | low_side_out | G4XMONSOONX-A-A20 | Aux 2 | low_side_out | single_source | |
| OEM-1-S | A/C clutch relay | low_side_out | G4XMONSOONX-A-A19 | Aux 3 | low_side_out | single_source | |
| OEM-1-U | Front O2 heater | low_side_out | G4XMONSOONX-A-A27 | Aux 5 | low_side_out | single_source | |
| OEM-1-V | Neutral switch | digital_in | — | — | — | single_source | |
| OEM-2-A | Fuel tank pressure | analog_in | — | — | — | single_source | |
| OEM-2-B | Intake air temperature (IAT) | temp_in | G4XMONSOONX-A-A16 | Analog Temp 2 | temp_in | single_source | |
| OEM-2-C | Front O2 signal | lambda_nb_in | G4XMONSOONX-A-A33 | Analog Volt 3 | analog_in | single_source | |
| OEM-2-D | Vehicle speed | digital_in | G4XMONSOONX-A-A30 | Digital Input 1 | digital_in | single_source | |
| OEM-2-E | Coolant temperature (ECT) | temp_in | G4XMONSOONX-A-A15 | Analog Temp 1 | temp_in | single_source | |
| OEM-2-F | Knock sensor | knock_in | G4XMONSOONX-A-A6 | Knock 1 / Digital Input 4 | knock_in | single_source | |
| OEM-2-H | Cam position (CMP) | trigger_in | G4XMONSOONX-A-A9 | Trigger 2 | trigger_in | single_source | |
| OEM-2-I | +5V sensor supply | vref | G4XMONSOONX-A-A32 | +5V Out | vref | single_source | |
| OEM-2-J | Crank position (CKP) | trigger_in | G4XMONSOONX-A-A8 | Trigger 1 | trigger_in | single_source | |
| OEM-2-K | Tachometer output | tacho_out | — | — | — | single_source | |
| OEM-2-L | Mass air flow (MAF) | analog_in | G4XMONSOONX-A-A17 | Analog Volt 1 | analog_in | single_source | |
| OEM-2-M | EGR valve | low_side_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 | G4XMONSOONX-A-A25 + G4XMONSOONX-A-A34 | System Ground + System Ground | ground | single_source | |
| OEM-3-B | Power ground | ground | G4XMONSOONX-A-A25 + G4XMONSOONX-A-A34 | System Ground + System Ground | ground | single_source | |
| OEM-3-C | Power ground | ground | G4XMONSOONX-A-A25 + G4XMONSOONX-A-A34 | System Ground + System Ground | ground | single_source | |
| OEM-3-E | Throttle position (TPS) | analog_in | G4XMONSOONX-A-A22 | Analog Volt 2 | analog_in | single_source | |
| OEM-3-F | Signal ground | sensor_ground | G4XMONSOONX-A-A24 | Sensor Ground | sensor_ground | single_source | |
| OEM-3-G | Ignition 1 (coils 1+4, wasted spark) | ignition_out | G4XMONSOONX-A-A13 | Ignition 1 | ignition_out | single_source | |
| OEM-3-H | Ignition 2 (coils 2+3, wasted spark) | ignition_out | G4XMONSOONX-A-A12 | Ignition 2 | ignition_out | single_source | |
| OEM-3-I | Clutch switch | digital_in | — | — | — | single_source | |
| OEM-3-J | Rear O2 signal | lambda_nb_in | G4XMONSOONX-A-A14 | Analog Volt 4 | analog_in | single_source | |
| OEM-3-K | Fuel level | analog_in | — | — | — | single_source | |
| OEM-3-L | Evap purge solenoid | low_side_out | — | — | — | single_source | |
| OEM-3-M | ISC valve +14V feed | power_in | G4XMONSOONX-A-A5 | +14V ECU Power | power_in | single_source | |
| OEM-3-N | Fuel pump relay | low_side_out | G4XMONSOONX-A-A18 | Aux 4 | low_side_out | single_source | |
| OEM-3-O | ISC valve low side | 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 | — | — | — | 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 | G4XMONSOONX-A-A26 | Aux 6 | low_side_out | single_source | |
| OEM-3-W | Injector 1 | injector_out | G4XMONSOONX-A-A4 | Injector 1 | injector_out | single_source | |
| OEM-3-X | Injector 2 | injector_out | G4XMONSOONX-A-A3 | Injector 2 | injector_out | single_source | |
| OEM-3-Y | Injector 3 | injector_out | G4XMONSOONX-A-A2 | Injector 3 | injector_out | single_source | |
| OEM-3-Z | Injector 4 | injector_out | G4XMONSOONX-A-A1 | Injector 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 | G4XMONSOONX-A-A5 | 0.85 | no route | +14V ECU Power | — | |
| 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 | G4XMONSOONX-A-A25 | 0.85 | no route | System Ground | — | |
| W8 | SP-GND-1 | G4XMONSOONX-A-A34 | 0.85 | no route | System Ground | — | |
| W9 | OEM-3-F | SP-0V-1 | 0.5 | no route | Signal ground | — | |
| W10 | SP-0V-1 | G4XMONSOONX-A-A24 | 0.5 | no route | Sensor Ground | — | |
| W11 | OEM-2-I | G4XMONSOONX-A-A32 | 0.5 | no route | +5V sensor supply | — | |
| W12 | OEM-2-J | G4XMONSOONX-A-A8 | 0.5 | no route | Crank position (CKP) | — | |
| W13 | OEM-2-H | G4XMONSOONX-A-A9 | 0.5 | no route | Cam position (CMP) | — | |
| W14 | OEM-2-F | G4XMONSOONX-A-A6 | 0.5 | no route | Knock sensor | — | |
| W15 | OEM-3-G | G4XMONSOONX-A-A13 | 0.5 | no route | Ignition 1 (coils 1+4, wasted spark) | — | |
| W16 | OEM-3-H | G4XMONSOONX-A-A12 | 0.5 | no route | Ignition 2 (coils 2+3, wasted spark) | — | |
| W17 | OEM-3-W | G4XMONSOONX-A-A4 | 0.5 | no route | Injector 1 | — | |
| W18 | OEM-3-X | G4XMONSOONX-A-A3 | 0.5 | no route | Injector 2 | — | |
| W19 | OEM-3-Y | G4XMONSOONX-A-A2 | 0.5 | no route | Injector 3 | — | |
| W20 | OEM-3-Z | G4XMONSOONX-A-A1 | 0.5 | no route | Injector 4 | — | |
| W21 | OEM-1-I | G4XMONSOONX-A-A21 | 0.5 | no route | Condenser fan relay | — | |
| W22 | OEM-1-R | G4XMONSOONX-A-A20 | 0.5 | no route | Cooling fan relay | — | |
| W23 | OEM-1-S | G4XMONSOONX-A-A19 | 0.5 | no route | A/C clutch relay | — | |
| W24 | OEM-3-N | G4XMONSOONX-A-A18 | 0.5 | no route | Fuel pump relay | — | |
| W25 | OEM-1-U | G4XMONSOONX-A-A27 | 0.5 | no route | Front O2 heater | — | |
| W26 | OEM-3-V | G4XMONSOONX-A-A26 | 0.5 | no route | Rear O2 heater | — | |
| W27 | OEM-2-L | G4XMONSOONX-A-A17 | 0.5 | no route | Mass air flow (MAF) | — | |
| W28 | OEM-3-E | G4XMONSOONX-A-A22 | 0.5 | no route | Throttle position (TPS) | — | |
| W29 | OEM-2-C | G4XMONSOONX-A-A33 | 0.5 | no route | Front O2 signal | — | |
| W30 | OEM-3-J | G4XMONSOONX-A-A14 | 0.5 | no route | Rear O2 signal | — | |
| W31 | OEM-2-E | G4XMONSOONX-A-A15 | 0.5 | no route | Coolant temperature (ECT) | — | |
| W32 | OEM-2-B | G4XMONSOONX-A-A16 | 0.5 | no route | Intake air temperature (IAT) | — | |
| W33 | OEM-2-D | G4XMONSOONX-A-A30 | 0.5 | no route | Vehicle speed | — | |
| W34 | OEM-1-F | G4XMONSOONX-A-A31 | 0.5 | no route | Brake switch | — | |
| W35 | OEM-1-G | G4XMONSOONX-A-A23 | 0.5 | no route | Power steering pressure 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 (5)
| Severity | Code | Subject | Message |
|---|---|---|---|
| warn | LOAD_UNKNOWN | G4XMONSOONX-A-A18 | G4XMONSOONX-A-A18 "Aux 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 | G4XMONSOONX-A-A19 | G4XMONSOONX-A-A19 "Aux 3" drives OEM-1-S A/C clutch relay (load 0.2 A) but its current rating is unknown. Check the ECU manual. |
| warn | LOAD_UNKNOWN | 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-I Condenser fan relay (load 0.2 A) but its current rating is unknown. Check the ECU manual. |
| info | UNMAPPED | OEM | 19 optional OEM pins are not mapped: OEM-1-E Malfunction indicator lamp (MIL); OEM-1-O Alternator control; OEM-1-P A/C request; OEM-1-Q Charge lamp; OEM-1-V Neutral switch; OEM-2-A Fuel tank pressure; OEM-2-K Tachometer output; OEM-2-M EGR valve; OEM-2-N EGR valve; OEM-2-O EGR valve; OEM-2-P EGR valve; OEM-3-I Clutch switch; OEM-3-K Fuel level; OEM-3-L Evap purge solenoid; OEM-3-O ISC valve low side; OEM-3-Q VICS solenoid (intake butterflies); OEM-3-S EGR boost sensor; 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
Fit check: unconfirmed. Confirm these before building: - Trigger pattern for Mazda BP-4W 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 2026-10-06. 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-3 O: ISC valve low side: 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-1 O: Alternator control: no free low_side/ls_hs/injector/hbridge on Link G4X MonsoonX - OEM-1 Q: Charge lamp: no free low_side/ls_hs/injector/hbridge on Link G4X MonsoonX - OEM-2 M: EGR valve: no free low_side/ls_hs/injector/hbridge on Link G4X MonsoonX - OEM-2 N: EGR valve: no free low_side/ls_hs/injector/hbridge on Link G4X MonsoonX - OEM-2 O: EGR valve: no free low_side/ls_hs/injector/hbridge on Link G4X MonsoonX - OEM-2 P: EGR valve: no free low_side/ls_hs/injector/hbridge on Link G4X MonsoonX - OEM-3 L: Evap purge solenoid: no free low_side/ls_hs/injector/hbridge on Link G4X MonsoonX - OEM-3 Q: VICS solenoid (intake butterflies): no free low_side/ls_hs/injector/hbridge on Link G4X MonsoonX - OEM-3 T: EGR boost solenoid: no free low_side/ls_hs/injector/hbridge on Link G4X MonsoonX - OEM-3 U: Canister drain cut valve (CDCV): no free low_side/ls_hs/injector/hbridge on Link G4X MonsoonX - OEM-2 K: Tachometer output: no free tacho/frequency_out/low_side/ls_hs on Link G4X MonsoonX - OEM-2 A: Fuel tank pressure: no free analog_0_5 on Link G4X MonsoonX - OEM-3 K: Fuel level: no free analog_0_5 on Link G4X MonsoonX - OEM-3 S: EGR boost sensor: no free analog_0_5 on Link G4X MonsoonX - OEM-1 P: A/C request: no free switch_in/frequency_in/analog_0_5 on Link G4X MonsoonX - OEM-1 V: Neutral switch: no free switch_in/frequency_in/analog_0_5 on Link G4X MonsoonX - OEM-3 I: Clutch switch: no free switch_in/frequency_in/analog_0_5 on Link G4X MonsoonX
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 | 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 | — | — | — |