MX-5 Miata Mazdaspeed 2004-05 (BP-ZET turbo, no VVT) → AMP EFI Microsquirt (auto)
Before you start
Not confident with automotive wiring? Have a professional harness builder or tuner do it, or check your work before first power-up. A wiring mistake can damage the ECU, the engine or the car, or start a fire.
| Status | proposal · not yet verified: nobody has reported building and running this harness |
|---|---|
| Open errors | none |
| Size of the job | 36 wires · 7 connectors · 0 part lines |
| Tools | Crimp and extraction tools for each terminal family (see Connectors) · wire strippers · multimeter · heat gun + heat-shrink |
| Order of work | 1. Check every part against the parts list. 2. Cut and label every wire (labels: Export → Wire labels). 3. Crimp and pin connector by connector, ticking the build checklist. 4. Run the bench test with nothing plugged in and the battery disconnected. 5. Only then connect the ECU and power up. |
Build checklist
Tick each box as you go. Continuity: meter from end to end, expect under 1 Ω.
| Wire | From | To | Gauge | Colour | Cut | Label | Crimp A | Crimp B | Pin A | Pin B | Continuity |
|---|---|---|---|---|---|---|---|---|---|---|---|
| W1 | OEM-2-P | SP-14V-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W2 | OEM-4-AF | SP-14V-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W3 | SP-14V-1 | MICROSQUIRT-A-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W4 | OEM-3-A | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W5 | OEM-3-B | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W6 | OEM-4-A | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W7 | SP-GND-1 | MICROSQUIRT-A-22 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | SP-GND-1 | MICROSQUIRT-A-23 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | OEM-4-O | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | SP-0V-1 | MICROSQUIRT-A-18 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | SP-0V-1 | MICROSQUIRT-A-19 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | SP-0V-1 | MICROSQUIRT-A-20 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | OEM-4-L | MICROSQUIRT-A-28 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | OEM-3-Y | MICROSQUIRT-A-32 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | OEM-3-V | MICROSQUIRT-A-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | OEM-3-F | MICROSQUIRT-A-11 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-3-I | MICROSQUIRT-A-12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-2-A | MICROSQUIRT-A-9 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-2-D | MICROSQUIRT-A-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-2-G | MICROSQUIRT-A-9 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-2-J | MICROSQUIRT-A-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-4-X | MICROSQUIRT-A-5 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-4-V | MICROSQUIRT-A-27 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-4-P | MICROSQUIRT-A-25 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-2-B | MICROSQUIRT-A-8 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-2-C | MICROSQUIRT-A-16 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-2-K | MICROSQUIRT-A-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-2-M | MICROSQUIRT-A-7 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-3-O | MICROSQUIRT-A-35 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | OEM-4-AE | MICROSQUIRT-A-24 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-4-AA | MICROSQUIRT-A-34 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-4-W | MICROSQUIRT-A-29 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-4-R | MICROSQUIRT-A-26 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-3-T | MICROSQUIRT-A-30 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W35 | OEM-3-S | MICROSQUIRT-A-31 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W36 | OEM-4-B | MICROSQUIRT-A-6 | 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 | MICROSQUIRT-A-1 | MICROSQUIRT-A-18 | open (OL) | +12 V supply must not touch sensor ground | |
| 2 | MICROSQUIRT-A-1 | MICROSQUIRT-A-22 | open (OL) | +12 V supply must not touch power ground | |
| 3 | MICROSQUIRT-A-28 | MICROSQUIRT-A-18 | open (OL) | 5 V sensor reference must not touch sensor ground | |
| 4 | MICROSQUIRT-A-1 | MICROSQUIRT-A-28 | open (OL) | +12 V supply must not touch 5 V sensor reference | |
| 5 | MICROSQUIRT-A-22 | MICROSQUIRT-A-28 | 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
MICROSQUIRT-A
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | +12V In | — | W3 | — | 0.85 | SP-14V-1 | — | — | — |
| 10 | INJ 2 | — | W19 | — | 0.5 | OEM-2-D | — | — | — |
| 10 | INJ 2 | — | W21 | — | 0.5 | OEM-2-J | — | — | — |
| 11 | SPK B (IGN2) | — | W16 | — | 0.5 | OEM-3-F | — | — | — |
| 12 | SPK A (IGN 1) | — | W17 | — | 0.5 | OEM-3-I | — | — | — |
| 13 | RX | — | — | — | — | — | — | — | — |
| 14 | TX | — | — | — | — | — | — | — | — |
| 15 | BOOT LOAD | — | — | — | — | — | — | — | — |
| 16 | ALED | — | W26 | — | 0.5 | OEM-2-C | — | — | — |
| 17 | WLED | — | W27 | — | 0.5 | OEM-2-K | — | — | — |
| 18 | Sensor Ground | — | W10 | — | 0.5 | SP-0V-1 | — | — | — |
| 19 | Serial Ground | — | W11 | — | 0.5 | SP-0V-1 | — | — | — |
| 2 | CANH | — | — | — | — | — | — | — | — |
| 20 | Sensor Ground | — | W12 | — | 0.5 | SP-0V-1 | — | — | — |
| 21 | VR2- | — | — | — | — | — | — | — | — |
| 22 | POWER GROUND | — | W7 | — | 0.85 | SP-GND-1 | — | — | — |
| 23 | POWER GROUND | — | W8 | — | 0.85 | SP-GND-1 | — | — | — |
| 24 | MAP | — | W30 | — | 0.5 | OEM-4-AE | — | — | — |
| 25 | CLT | — | W24 | — | 0.5 | OEM-4-P | — | — | — |
| 26 | MAT | — | W33 | — | 0.5 | OEM-4-R | — | — | — |
| 27 | TPS | — | W23 | — | 0.5 | OEM-4-V | — | — | — |
| 28 | TPS VREF (5V) | — | W13 | — | 0.5 | OEM-4-L | — | — | — |
| 29 | SPAREADC | — | W32 | — | 0.5 | OEM-4-W | — | — | — |
| 3 | CANL | — | — | — | — | — | — | — | — |
| 30 | OPTO+ | — | W34 | — | 0.5 | OEM-3-T | — | — | — |
| 31 | OPTO- | — | W35 | — | 0.5 | OEM-3-S | — | — | — |
| 32 | VR1+ | — | W14 | — | 0.5 | OEM-3-Y | — | — | — |
| 33 | VR1- | — | — | — | — | — | — | — | — |
| 34 | O2 | — | W31 | — | 0.5 | OEM-4-AA | — | — | — |
| 35 | TACHO | — | W29 | — | 0.5 | OEM-3-O | — | — | — |
| 4 | VR2+ | — | W15 | — | 0.5 | OEM-3-V | — | — | — |
| 5 | SPAREADC2 (MAF) | — | W22 | — | 0.5 | OEM-4-X | — | — | — |
| 6 | FLEX | — | W36 | — | 0.5 | OEM-4-B | — | — | — |
| 7 | FIDLE | — | W28 | — | 0.5 | OEM-2-M | — | — | — |
| 8 | FP (pump) | — | W25 | — | 0.5 | OEM-2-B | — | — | — |
| 9 | INJ 1 | — | W18 | — | 0.5 | OEM-2-A | — | — | — |
| 9 | INJ 1 | — | W20 | — | 0.5 | OEM-2-G | — | — | — |
OEM-2
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A | Injector 1 | — | W18 | — | 0.5 | MICROSQUIRT-A-9 | — | — | — |
| B | Cooling fan relay | — | W25 | — | 0.5 | MICROSQUIRT-A-8 | — | — | — |
| C | Condenser fan relay | — | W26 | — | 0.5 | MICROSQUIRT-A-16 | — | — | — |
| D | Injector 2 | — | W19 | — | 0.5 | MICROSQUIRT-A-10 | — | — | — |
| E | EGR valve | — | — | — | — | — | — | — | — |
| F | EGR valve | — | — | — | — | — | — | — | — |
| G | Injector 3 | — | W20 | — | 0.5 | MICROSQUIRT-A-9 | — | — | — |
| H | EGR valve | — | — | — | — | — | — | — | — |
| I | EGR valve | — | — | — | — | — | — | — | — |
| J | Injector 4 | — | W21 | — | 0.5 | MICROSQUIRT-A-10 | — | — | — |
| K | A/C clutch relay | — | W27 | — | 0.5 | MICROSQUIRT-A-17 | — | — | — |
| L | NC | — | — | — | — | — | — | — | — |
| M | Fuel pump relay | — | W28 | — | 0.5 | MICROSQUIRT-A-7 | — | — | — |
| N | VTCS solenoid (intake butterflies) | — | — | — | — | — | — | — | — |
| O | Fuel pump relay (non-immobiliser) | — | — | — | — | — | — | — | — |
| P | ISC valve +14V feed | — | W1 | — | 0.85 | SP-14V-1 | — | — | — |
| Q | ISC valve low side | — | — | — | — | — | — | — | — |
| R | Malfunction indicator lamp (MIL) | — | — | — | — | — | — | — | — |
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 | Purge solenoid valve | — | — | — | — | — | — | — | — |
| D | EGR boost solenoid | — | — | — | — | — | — | — | — |
| E | NC | — | — | — | — | — | — | — | — |
| F | Ignition 1 (coils 1+4, wasted spark) | — | W16 | — | 0.5 | MICROSQUIRT-A-11 | — | — | — |
| G | NC | — | — | — | — | — | — | — | — |
| H | Main relay | — | — | — | — | — | — | — | — |
| I | Ignition 2 (coils 2+3, wasted spark) | — | W17 | — | 0.5 | MICROSQUIRT-A-12 | — | — | — |
| J | Front O2 heater | — | — | — | — | — | — | — | — |
| K | EVAP leak detection pump | — | — | — | — | — | — | — | — |
| L | NC | — | — | — | — | — | — | — | — |
| M | Alternator control | — | — | — | — | — | — | — | — |
| N | NC | — | — | — | — | — | — | — | — |
| O | Tachometer output | — | W29 | — | 0.5 | MICROSQUIRT-A-35 | — | — | — |
| P | Rear O2 heater | — | — | — | — | — | — | — | — |
| Q | Data link connector (K-line) | — | — | — | — | — | — | — | — |
| R | NC | — | — | — | — | — | — | — | — |
| S | Immobiliser | — | W35 | — | 0.5 | MICROSQUIRT-A-31 | — | — | — |
| T | Vehicle speed | — | W34 | — | 0.5 | MICROSQUIRT-A-30 | — | — | — |
| U | Charge lamp | — | — | — | — | — | — | — | — |
| V | Cam position (CMP) | — | W15 | — | 0.5 | MICROSQUIRT-A-4 | — | — | — |
| W | NC | — | — | — | — | — | — | — | — |
| X | NC | — | — | — | — | — | — | — | — |
| Y | Crank position (CKP) | — | W14 | — | 0.5 | MICROSQUIRT-A-32 | — | — | — |
| Z | NC | — | — | — | — | — | — | — | — |
OEM-4
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A | Power ground | — | W6 | — | 0.85 | SP-GND-1 | — | — | — |
| AA | Rear O2 signal | — | W31 | — | 0.5 | MICROSQUIRT-A-34 | — | — | — |
| AB | NC | — | — | — | — | — | — | — | — |
| AC | Data link connector (DLC TEN, turbo) | — | — | — | — | — | — | — | — |
| AD | Fuel level | — | — | — | — | — | — | — | — |
| AE | BARO/MAP sensor (turbo boost pressure) | — | W30 | — | 0.5 | MICROSQUIRT-A-24 | — | — | — |
| AF | ECU power +14V (main relay) | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
| AG | Constant +12V | — | — | — | — | — | — | — | — |
| AH | EVAP leak detection pump solenoid valve | — | — | — | — | — | — | — | — |
| B | Brake switch | — | W36 | — | 0.5 | MICROSQUIRT-A-6 | — | — | — |
| C | Power steering pressure switch | — | — | — | — | — | — | — | — |
| D | Boost control solenoid (turbo) | — | — | — | — | — | — | — | — |
| E | Boost control solenoid (turbo) | — | — | — | — | — | — | — | — |
| F | A/C request | — | — | — | — | — | — | — | — |
| G | NC | — | — | — | — | — | — | — | — |
| H | Neutral switch | — | — | — | — | — | — | — | — |
| I | Clutch switch | — | — | — | — | — | — | — | — |
| J | VTCS vacuum switch | — | — | — | — | — | — | — | — |
| K | NC | — | — | — | — | — | — | — | — |
| L | +5V sensor supply | — | W13 | — | 0.5 | MICROSQUIRT-A-28 | — | — | — |
| M | Knock sensor | — | — | — | — | — | — | — | — |
| N | Intake air temperature (IAT) | — | — | — | — | — | — | — | — |
| O | Signal ground | — | W9 | — | 0.5 | SP-0V-1 | — | — | — |
| P | Coolant temperature (ECT) | — | W24 | — | 0.5 | MICROSQUIRT-A-25 | — | — | — |
| Q | NC | — | — | — | — | — | — | — | — |
| R | Intake air temperature 2 (IAT2, turbo) | — | W33 | — | 0.5 | MICROSQUIRT-A-26 | — | — | — |
| S | Ignition switch (IG1) sense | — | — | — | — | — | — | — | — |
| T | Generator output voltage (terminal P) | — | — | — | — | — | — | — | — |
| U | NC | — | — | — | — | — | — | — | — |
| V | Throttle position (TPS) | — | W23 | — | 0.5 | MICROSQUIRT-A-27 | — | — | — |
| W | Front O2 signal | — | W32 | — | 0.5 | MICROSQUIRT-A-29 | — | — | — |
| X | Mass air flow (MAF) | — | W22 | — | 0.5 | MICROSQUIRT-A-5 | — | — | — |
| Y | NC | — | — | — | — | — | — | — | — |
| Z | TCM (automatic only) | — | — | — | — | — | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W9 | — | 0.5 | OEM-4-O | — | — | — |
| 1 | — | — | W10 | — | 0.5 | MICROSQUIRT-A-18 | — | — | — |
| 1 | — | — | W11 | — | 0.5 | MICROSQUIRT-A-19 | — | — | — |
| 1 | — | — | W12 | — | 0.5 | MICROSQUIRT-A-20 | — | — | — |
SP-14V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W1 | — | 0.85 | OEM-2-P | — | — | — |
| 1 | — | — | W2 | — | 0.85 | OEM-4-AF | — | — | — |
| 1 | — | — | W3 | — | 0.85 | MICROSQUIRT-A-1 | — | — | — |
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-4-A | — | — | — |
| 1 | — | — | W7 | — | 0.85 | MICROSQUIRT-A-22 | — | — | — |
| 1 | — | — | W8 | — | 0.85 | MICROSQUIRT-A-23 | — | — | — |
Pin map
| OEM point | OEM function | OEM family | Target point | Target function | Target family | Wire colour | Evidence |
|---|---|---|---|---|---|---|---|
| OEM-2-A | Injector 1 | injector_out | MICROSQUIRT-A-9 | INJ 1 | injector_out | corroborated | |
| OEM-2-B | Cooling fan relay | low_side_out | MICROSQUIRT-A-8 | FP (pump) | low_side_out | corroborated | |
| OEM-2-C | Condenser fan relay | low_side_out | MICROSQUIRT-A-16 | ALED | low_side_out | corroborated | |
| OEM-2-D | Injector 2 | injector_out | MICROSQUIRT-A-10 | INJ 2 | injector_out | corroborated | |
| OEM-2-E | EGR valve | low_side_out | — | — | — | corroborated | |
| OEM-2-F | EGR valve | low_side_out | — | — | — | corroborated | |
| OEM-2-G | Injector 3 | injector_out | MICROSQUIRT-A-9 | INJ 1 | injector_out | corroborated | |
| OEM-2-H | EGR valve | low_side_out | — | — | — | corroborated | |
| OEM-2-I | EGR valve | low_side_out | — | — | — | corroborated | |
| OEM-2-J | Injector 4 | injector_out | MICROSQUIRT-A-10 | INJ 2 | injector_out | corroborated | |
| OEM-2-K | A/C clutch relay | low_side_out | MICROSQUIRT-A-17 | WLED | low_side_out | corroborated | |
| OEM-2-L | NC | — | — | — | — | single_source | |
| OEM-2-M | Fuel pump relay | low_side_out | MICROSQUIRT-A-7 | FIDLE | low_side_out | corroborated | |
| OEM-2-N | VTCS solenoid (intake butterflies) | low_side_out | — | — | — | corroborated | |
| OEM-2-O | Fuel pump relay (non-immobiliser) | low_side_out | — | — | — | corroborated | |
| OEM-2-P | ISC valve +14V feed | power_in | MICROSQUIRT-A-1 | +12V In | power_in | corroborated | |
| OEM-2-Q | ISC valve low side | low_side_out | — | — | — | corroborated | |
| OEM-2-R | Malfunction indicator lamp (MIL) | low_side_out | — | — | — | corroborated | |
| OEM-3-A | Power ground | ground | MICROSQUIRT-A-22 + MICROSQUIRT-A-23 | POWER GROUND + POWER GROUND | ground | corroborated | |
| OEM-3-B | Power ground | ground | MICROSQUIRT-A-22 + MICROSQUIRT-A-23 | POWER GROUND + POWER GROUND | ground | corroborated | |
| OEM-3-C | Purge solenoid valve | low_side_out | — | — | — | corroborated | |
| OEM-3-D | EGR boost solenoid | — | — | — | — | conflict | |
| OEM-3-E | NC | — | — | — | — | single_source | |
| OEM-3-F | Ignition 1 (coils 1+4, wasted spark) | ignition_out | MICROSQUIRT-A-11 | SPK B (IGN2) | ignition_out | corroborated | |
| OEM-3-G | NC | — | — | — | — | single_source | |
| OEM-3-H | Main relay | low_side_out | — | — | — | corroborated | |
| OEM-3-I | Ignition 2 (coils 2+3, wasted spark) | ignition_out | MICROSQUIRT-A-12 | SPK A (IGN 1) | ignition_out | corroborated | |
| OEM-3-J | Front O2 heater | low_side_out | — | — | — | corroborated | |
| OEM-3-K | EVAP leak detection pump | low_side_out | — | — | — | corroborated | |
| OEM-3-L | NC | — | — | — | — | single_source | |
| OEM-3-M | Alternator control | low_side_out | — | — | — | corroborated | |
| OEM-3-N | NC | — | — | — | — | single_source | |
| OEM-3-O | Tachometer output | tacho_out | MICROSQUIRT-A-35 | TACHO | tacho_out | corroborated | |
| OEM-3-P | Rear O2 heater | low_side_out | — | — | — | corroborated | |
| OEM-3-Q | Data link connector (K-line) | serial | — | — | — | corroborated | |
| OEM-3-R | NC | — | — | — | — | single_source | |
| OEM-3-S | Immobiliser | digital_in | MICROSQUIRT-A-31 | OPTO- | digital_in | corroborated | |
| OEM-3-T | Vehicle speed | digital_in | MICROSQUIRT-A-30 | OPTO+ | digital_in | corroborated | |
| OEM-3-U | Charge lamp | low_side_out | — | — | — | corroborated | |
| OEM-3-V | Cam position (CMP) | trigger_in | MICROSQUIRT-A-4 | VR2+ | trigger_in | corroborated | |
| OEM-3-W | NC | — | — | — | — | single_source | |
| OEM-3-X | NC | — | — | — | — | single_source | |
| OEM-3-Y | Crank position (CKP) | trigger_in | MICROSQUIRT-A-32 | VR1+ | trigger_in | corroborated | |
| OEM-3-Z | NC | — | — | — | — | single_source | |
| OEM-4-A | Power ground | ground | MICROSQUIRT-A-22 + MICROSQUIRT-A-23 | POWER GROUND + POWER GROUND | ground | corroborated | |
| OEM-4-AA | Rear O2 signal | lambda_nb_in | MICROSQUIRT-A-34 | O2 | lambda_nb_in | corroborated | |
| OEM-4-AB | NC | — | — | — | — | single_source | |
| OEM-4-AC | Data link connector (DLC TEN, turbo) | serial | — | — | — | BrY | single_source |
| OEM-4-AD | Fuel level | analog_in | — | — | — | corroborated | |
| OEM-4-AE | BARO/MAP sensor (turbo boost pressure) | analog_in | MICROSQUIRT-A-24 | MAP | analog_in | LY | single_source |
| OEM-4-AF | ECU power +14V (main relay) | power_in | MICROSQUIRT-A-1 | +12V In | power_in | corroborated | |
| OEM-4-AG | Constant +12V | power_in | — | — | — | corroborated | |
| OEM-4-AH | EVAP leak detection pump solenoid valve | low_side_out | — | — | — | corroborated | |
| OEM-4-B | Brake switch | digital_in | MICROSQUIRT-A-6 | FLEX | digital_in | corroborated | |
| OEM-4-C | Power steering pressure switch | digital_in | — | — | — | corroborated | |
| OEM-4-D | Boost control solenoid (turbo) | high_side_out | — | — | — | Y | single_source |
| OEM-4-E | Boost control solenoid (turbo) | high_side_out | — | — | — | Y | single_source |
| OEM-4-F | A/C request | digital_in | — | — | — | corroborated | |
| OEM-4-G | NC | — | — | — | — | single_source | |
| OEM-4-H | Neutral switch | digital_in | — | — | — | corroborated | |
| OEM-4-I | Clutch switch | digital_in | — | — | — | corroborated | |
| OEM-4-J | VTCS vacuum switch | digital_in | — | — | — | corroborated | |
| OEM-4-K | NC | — | — | — | — | single_source | |
| OEM-4-L | +5V sensor supply | vref | MICROSQUIRT-A-28 | TPS VREF (5V) | vref | corroborated | |
| OEM-4-M | Knock sensor | knock_in | — | — | — | corroborated | |
| OEM-4-N | Intake air temperature (IAT) | temp_in | — | — | — | corroborated | |
| OEM-4-O | Signal ground | sensor_ground | MICROSQUIRT-A-18 + MICROSQUIRT-A-19 + MICROSQUIRT-A-20 | Sensor Ground + Serial Ground + Sensor Ground | sensor_ground | corroborated | |
| OEM-4-P | Coolant temperature (ECT) | temp_in | MICROSQUIRT-A-25 | CLT | temp_in | corroborated | |
| OEM-4-Q | NC | — | — | — | — | single_source | |
| OEM-4-R | Intake air temperature 2 (IAT2, turbo) | temp_in | MICROSQUIRT-A-26 | MAT | temp_in | VY | single_source |
| OEM-4-S | Ignition switch (IG1) sense | digital_in | — | — | — | corroborated | |
| OEM-4-T | Generator output voltage (terminal P) | — | — | — | — | corroborated | |
| OEM-4-U | NC | — | — | — | — | single_source | |
| OEM-4-V | Throttle position (TPS) | analog_in | MICROSQUIRT-A-27 | TPS | analog_in | corroborated | |
| OEM-4-W | Front O2 signal | lambda_nb_in | MICROSQUIRT-A-29 | SPAREADC | analog_in | corroborated | |
| OEM-4-X | Mass air flow (MAF) | analog_in | MICROSQUIRT-A-5 | SPAREADC2 (MAF) | analog_in | corroborated | |
| OEM-4-Y | NC | — | — | — | — | single_source | |
| OEM-4-Z | TCM (automatic only) | — | — | — | — | corroborated |
Cut list
| Wire | From | To | Gauge (mm²) | Colour | Length | Signal | Ident |
|---|---|---|---|---|---|---|---|
| W1 | OEM-2-P | SP-14V-1 | 0.85 | no route | ISC valve +14V feed | — | |
| W2 | OEM-4-AF | SP-14V-1 | 0.85 | no route | ECU power +14V (main relay) | — | |
| W3 | SP-14V-1 | MICROSQUIRT-A-1 | 0.85 | no route | +12V In | — | |
| 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-4-A | SP-GND-1 | 0.85 | no route | Power ground | — | |
| W7 | SP-GND-1 | MICROSQUIRT-A-22 | 0.85 | no route | POWER GROUND | — | |
| W8 | SP-GND-1 | MICROSQUIRT-A-23 | 0.85 | no route | POWER GROUND | — | |
| W9 | OEM-4-O | SP-0V-1 | 0.5 | no route | Signal ground | — | |
| W10 | SP-0V-1 | MICROSQUIRT-A-18 | 0.5 | no route | Sensor Ground | — | |
| W11 | SP-0V-1 | MICROSQUIRT-A-19 | 0.5 | no route | Serial Ground | — | |
| W12 | SP-0V-1 | MICROSQUIRT-A-20 | 0.5 | no route | Sensor Ground | — | |
| W13 | OEM-4-L | MICROSQUIRT-A-28 | 0.5 | no route | +5V sensor supply | — | |
| W14 | OEM-3-Y | MICROSQUIRT-A-32 | 0.5 | no route | Crank position (CKP) | — | |
| W15 | OEM-3-V | MICROSQUIRT-A-4 | 0.5 | no route | Cam position (CMP) | — | |
| W16 | OEM-3-F | MICROSQUIRT-A-11 | 0.5 | no route | Ignition 1 (coils 1+4, wasted spark) | — | |
| W17 | OEM-3-I | MICROSQUIRT-A-12 | 0.5 | no route | Ignition 2 (coils 2+3, wasted spark) | — | |
| W18 | OEM-2-A | MICROSQUIRT-A-9 | 0.5 | no route | Injector 1 | — | |
| W19 | OEM-2-D | MICROSQUIRT-A-10 | 0.5 | no route | Injector 2 | — | |
| W20 | OEM-2-G | MICROSQUIRT-A-9 | 0.5 | no route | Injector 3 | — | |
| W21 | OEM-2-J | MICROSQUIRT-A-10 | 0.5 | no route | Injector 4 | — | |
| W22 | OEM-4-X | MICROSQUIRT-A-5 | 0.5 | no route | Mass air flow (MAF) | — | |
| W23 | OEM-4-V | MICROSQUIRT-A-27 | 0.5 | no route | Throttle position (TPS) | — | |
| W24 | OEM-4-P | MICROSQUIRT-A-25 | 0.5 | no route | Coolant temperature (ECT) | — | |
| W25 | OEM-2-B | MICROSQUIRT-A-8 | 0.5 | no route | Cooling fan relay | — | |
| W26 | OEM-2-C | MICROSQUIRT-A-16 | 0.5 | no route | Condenser fan relay | — | |
| W27 | OEM-2-K | MICROSQUIRT-A-17 | 0.5 | no route | A/C clutch relay | — | |
| W28 | OEM-2-M | MICROSQUIRT-A-7 | 0.5 | no route | Fuel pump relay | — | |
| W29 | OEM-3-O | MICROSQUIRT-A-35 | 0.5 | no route | Tachometer output | — | |
| W30 | OEM-4-AE | MICROSQUIRT-A-24 | 0.5 | no route | BARO/MAP sensor (turbo boost pressure) | — | |
| W31 | OEM-4-AA | MICROSQUIRT-A-34 | 0.5 | no route | Rear O2 signal | — | |
| W32 | OEM-4-W | MICROSQUIRT-A-29 | 0.5 | no route | Front O2 signal | — | |
| W33 | OEM-4-R | MICROSQUIRT-A-26 | 0.5 | no route | Intake air temperature 2 (IAT2, turbo) | — | |
| W34 | OEM-3-T | MICROSQUIRT-A-30 | 0.5 | no route | Vehicle speed | — | |
| W35 | OEM-3-S | MICROSQUIRT-A-31 | 0.5 | no route | Immobiliser | — | |
| W36 | OEM-4-B | MICROSQUIRT-A-6 | 0.5 | no route | Brake switch | — |
Bill of materials
| Category | Part number | Manufacturer | Description | Qty | Unit |
|---|
ECU setup sheet
| Role | Engine ref | Engine signal | Sensor | ECU point | ECU function | ECU class | Setup flag |
|---|---|---|---|---|---|---|---|
| No configured channels. | |||||||
Findings
Open (1)
| Severity | Code | Subject | Message |
|---|---|---|---|
| info | UNMAPPED | OEM | 32 optional OEM pins are not mapped: OEM-2-E EGR valve; OEM-2-F EGR valve; OEM-2-H EGR valve; OEM-2-I EGR valve; OEM-2-N VTCS solenoid (intake butterflies); OEM-2-O Fuel pump relay (non-immobiliser); OEM-2-Q ISC valve low side; OEM-2-R Malfunction indicator lamp (MIL); OEM-3-C Purge solenoid valve; OEM-3-D EGR boost solenoid; OEM-3-H Main relay; OEM-3-J Front O2 heater; OEM-3-K EVAP leak detection pump; OEM-3-M Alternator control; OEM-3-P Rear O2 heater; OEM-3-Q Data link connector (K-line); OEM-3-U Charge lamp; OEM-4-AC Data link connector (DLC TEN, turbo); OEM-4-AD Fuel level; OEM-4-AH EVAP leak detection pump solenoid valve; OEM-4-C Power steering pressure switch; OEM-4-D Boost control solenoid (turbo); OEM-4-E Boost control solenoid (turbo); OEM-4-F A/C request; OEM-4-H Neutral switch; OEM-4-I Clutch switch; OEM-4-J VTCS vacuum switch; OEM-4-M Knock sensor; OEM-4-N Intake air temperature (IAT); OEM-4-S Ignition switch (IG1) sense; OEM-4-T Generator output voltage (terminal P); OEM-4-Z TCM (automatic only) |
Accepted (1)
| Code | Subject | Reason | By |
|---|---|---|---|
| REQUIRED_UNMAPPED | OEM-4-AG | 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 2026-10-17. Review every wire against both manuals before building. Not wired: - OEM-4 AG: Constant +12V: AMP EFI Microsquirt has no battery-constant input; not needed - OEM-4 M: Knock sensor: no free knock input on AMP EFI Microsquirt - OEM-4 S: Ignition switch (IG1) sense: key-on 12 V sense — optional in a swap (the main relay is energized from keyed 12 V, not from this pin); AMP EFI Microsquirt has no dedicated key-on input - OEM-3 H: Main relay: no free relay_control/low_side/heater_low_side/ls_hs/injector rated ≥ 0.2 A on AMP EFI Microsquirt - OEM-2 O: Fuel pump relay (non-immobiliser): no free relay_control/low_side/heater_low_side/ls_hs/injector on AMP EFI Microsquirt - OEM-4 D: Boost control solenoid (turbo): no free high_side/ls_hs on AMP EFI Microsquirt - OEM-4 E: Boost control solenoid (turbo): no free high_side/ls_hs on AMP EFI Microsquirt - OEM-3 J: Front O2 heater: no free heater_low_side/low_side/relay_control/ls_hs/injector on AMP EFI Microsquirt - OEM-3 P: Rear O2 heater: no free heater_low_side/low_side/relay_control/ls_hs/injector on AMP EFI Microsquirt - OEM-2 Q: ISC valve low side: no free low_side/relay_control/heater_low_side/ls_hs/injector rated ≥ 1.0 A on AMP EFI Microsquirt - OEM-2 E: EGR valve: no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI Microsquirt - OEM-2 F: EGR valve: no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI Microsquirt - OEM-2 H: EGR valve: no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI Microsquirt - OEM-2 I: EGR valve: no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI Microsquirt - OEM-2 N: VTCS solenoid (intake butterflies): no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI Microsquirt - OEM-2 R: Malfunction indicator lamp (MIL): no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI Microsquirt - OEM-3 C: Purge solenoid valve: no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI Microsquirt - OEM-3 K: EVAP leak detection pump: no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI Microsquirt - OEM-3 M: Alternator control: no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI Microsquirt - OEM-3 U: Charge lamp: no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI Microsquirt - OEM-4 AH: EVAP leak detection pump solenoid valve: no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI Microsquirt - OEM-4 N: Intake air temperature (IAT): no free thermistor/analog_0_5 on AMP EFI Microsquirt - OEM-4 AD: Fuel level: no free analog_0_5 on AMP EFI Microsquirt - OEM-4 C: Power steering pressure switch: no free switch_in/frequency_in/analog_0_5 on AMP EFI Microsquirt - OEM-4 F: A/C request: no free switch_in/frequency_in/analog_0_5 on AMP EFI Microsquirt - OEM-4 H: Neutral switch: no free switch_in/frequency_in/analog_0_5 on AMP EFI Microsquirt - OEM-4 I: Clutch switch: no free switch_in/frequency_in/analog_0_5 on AMP EFI Microsquirt - OEM-4 J: VTCS vacuum switch: no free switch_in/frequency_in/analog_0_5 on AMP EFI Microsquirt - OEM-3 Q: Data link connector (K-line): no free k_line on AMP EFI Microsquirt - OEM-4 AC: Data link connector (DLC TEN, turbo): no free k_line on AMP EFI Microsquirt - OEM-3 D: EGR boost solenoid: not classified in the library; wire by hand - OEM-4 T: Generator output voltage (terminal P): not classified in the library; wire by hand - OEM-4 Z: TCM (automatic only): not classified in the library; wire by hand
Sources
| Reliability | Kind | Title | URL | Archive | Captured | SHA-256 |
|---|---|---|---|---|---|---|
| 4 | oem_manual | 2005 Mazda MX-5 Miata Engine Performance Control System (PCM terminal voltage reference, BP and BP WITH TC) | https://trull.org/alex/pubmirror/www.mellens.net/mazda/Mazda-Miata-2005/engine_control_system.pdf | — | — | — |
| 4 | vendor_doc | Adaptronic eSel039 Select Plugin ECU for Mazda MX5 / Miata NB8B/C (OEM ECU pinout) | https://www.miataturbo.net/attachments/ecus-tuning-54/04-msm-ecu-pinout-104032/nb8bc_oem_ecu_pinouts-224948d1602912806 | — | — | — |
| 4 | vendor_doc | Link G4X MX5NB2X install manual (NB2 2001-05) | https://linkecu.com/documentation/MX5XNB2.pdf | archive | 2026-10-05 | 741efdd9f2c8 |
| 4 | vendor_doc | MSExtra: Microsquirt hardware 3.4 | http://www.msextra.com/doc/pdf/Microsquirt_Hardware-3.4.pdf | archive | 2026-10-05 | ad920d9160de |