MX-5 Miata NA8 1996-97 (BP-ZE, 1.8, OBD-II) → AMP EFI MS3Pro Mini (auto)
MX-5 Miata NA8 1996-97 (BP-ZE, 1.8, OBD-II) — AMP EFI — MS3Pro Mini
Drawn by Michael Gnankou · Rev 0 · proposal · 2026-10-12
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 | 37 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-4-B | SP-14V-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W2 | SP-14V-1 | MS3PROMINI-A-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W3 | OEM-4-A | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W4 | OEM-4-C | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W5 | OEM-4-D | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W6 | OEM-4-K | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W7 | SP-GND-1 | MS3PROMINI-A-22 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | SP-GND-1 | MS3PROMINI-A-23 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | OEM-3-O | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | OEM-4-H | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | SP-0V-1 | MS3PROMINI-A-21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | OEM-3-I | MS3PROMINI-A-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | OEM-4-E | MS3PROMINI-A-30 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | OEM-4-G | MS3PROMINI-A-32 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | OEM-4-F | MS3PROMINI-A-33 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | OEM-4-N | MS3PROMINI-A-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-4-R | MS3PROMINI-A-18 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-4-U | MS3PROMINI-A-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-4-V | MS3PROMINI-A-11 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-4-W | MS3PROMINI-A-12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-4-X | MS3PROMINI-A-5 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-3-B | MS3PROMINI-A-13 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-3-F | MS3PROMINI-A-28 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-3-G | MS3PROMINI-A-26 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-1-A | MS3PROMINI-A-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-1-B | MS3PROMINI-A-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-1-G | MS3PROMINI-A-6 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-1-U | MS3PROMINI-A-7 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-3-M | MS3PROMINI-A-8 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | OEM-1-E | MS3PROMINI-A-9 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-3-H | MS3PROMINI-A-14 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-3-N | MS3PROMINI-A-15 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-3-C | MS3PROMINI-A-16 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-3-K | MS3PROMINI-A-27 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W35 | OEM-1-M | MS3PROMINI-A-34 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W36 | OEM-1-C | MS3PROMINI-A-29 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W37 | OEM-1-K | MS3PROMINI-A-35 | 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 | MS3PROMINI-A-2 | MS3PROMINI-A-21 | open (OL) | 5 V sensor reference must not touch sensor ground | |
| 2 | MS3PROMINI-A-2 | MS3PROMINI-A-22 | open (OL) | 5 V sensor reference must not touch power ground | |
| 3 | MS3PROMINI-A-2 | MS3PROMINI-A-1 | open (OL) | 5 V sensor reference must not touch +12 V supply | |
| 4 | MS3PROMINI-A-21 | MS3PROMINI-A-1 | open (OL) | sensor ground must not touch +12 V supply | |
| 5 | MS3PROMINI-A-22 | MS3PROMINI-A-1 | open (OL) | power ground must not touch +12 V supply |
If any reading doesn't match, stop and get help before powering up.
Revisions
| Rev | Label | By | Date |
|---|---|---|---|
| No revisions yet. | |||
Schematic
Connectors
MS3PROMINI-A
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | 12V+ switched power in | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
| 10 | Injector out F | — | W18 | — | 0.5 | OEM-4-U | — | — | — |
| 11 | Injector out G | — | W19 | — | 0.5 | OEM-4-V | — | — | — |
| 12 | Injector out H | — | W20 | — | 0.5 | OEM-4-W | — | — | — |
| 13 | Analog in 1 | — | W22 | — | 0.5 | OEM-3-B | — | — | — |
| 14 | Analog in 2 | — | W31 | — | 0.5 | OEM-3-H | — | — | — |
| 15 | Analog in 3 | — | W32 | — | 0.5 | OEM-3-N | — | — | — |
| 16 | Analog in 4 | — | W33 | — | 0.5 | OEM-3-C | — | — | — |
| 17 | Spark out A | — | W16 | — | 0.5 | OEM-4-N | — | — | — |
| 18 | Spark out B | — | W17 | — | 0.5 | OEM-4-R | — | — | — |
| 19 | Spark out C | — | — | — | — | — | — | — | — |
| 2 | +5V VREF out | — | W12 | — | 0.5 | OEM-3-I | — | — | — |
| 20 | Spark out D | — | — | — | — | — | — | — | — |
| 21 | Sensor ground | — | W11 | — | 0.5 | SP-0V-1 | — | — | — |
| 22 | Power ground | — | W7 | — | 0.85 | SP-GND-1 | — | — | — |
| 23 | Power ground | — | W8 | — | 0.85 | SP-GND-1 | — | — | — |
| 24 | CAN Low | — | — | — | — | — | — | — | — |
| 25 | CAN High | — | — | — | — | — | — | — | — |
| 26 | CLT in | — | W24 | — | 0.5 | OEM-3-G | — | — | — |
| 27 | IAT in | — | W34 | — | 0.5 | OEM-3-K | — | — | — |
| 28 | TPS in | — | W23 | — | 0.5 | OEM-3-F | — | — | — |
| 29 | Digital switched in 1 / Flex fuel | — | W36 | — | 0.5 | OEM-1-C | — | — | — |
| 3 | PWM out 1 / Idle | — | W26 | — | 0.5 | OEM-1-B | — | — | — |
| 30 | CKP+ | — | W13 | — | 0.5 | OEM-4-E | — | — | — |
| 31 | CKP- | — | — | — | — | — | — | — | — |
| 32 | CMP+ | — | W14 | — | 0.5 | OEM-4-G | — | — | — |
| 33 | CMP- | — | W15 | — | 0.5 | OEM-4-F | — | — | — |
| 34 | Digital frequency in 1 (Hall) | — | W35 | — | 0.5 | OEM-1-M | — | — | — |
| 35 | Digital frequency in 2 (Hall) | — | W37 | — | 0.5 | OEM-1-K | — | — | — |
| 4 | Fuel pump out | — | W25 | — | 0.5 | OEM-1-A | — | — | — |
| 5 | Injector out A | — | W21 | — | 0.5 | OEM-4-X | — | — | — |
| 6 | Injector out B | — | W27 | — | 0.5 | OEM-1-G | — | — | — |
| 7 | Injector out C | — | W28 | — | 0.5 | OEM-1-U | — | — | — |
| 8 | Injector out D | — | W29 | — | 0.5 | OEM-3-M | — | — | — |
| 9 | Injector out E | — | W30 | — | 0.5 | OEM-1-E | — | — | — |
OEM-1
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A | Cooling fan relay (low-side) | — | W25 | — | 0.5 | MS3PROMINI-A-4 | — | — | — |
| B | A/C condenser fan relay | — | W26 | — | 0.5 | MS3PROMINI-A-3 | — | — | — |
| C | Starter input (12V while cranking) | — | W36 | — | 0.5 | MS3PROMINI-A-29 | — | — | — |
| E | Check engine light (MIL) | — | W30 | — | 0.5 | MS3PROMINI-A-9 | — | — | — |
| G | A/C clutch relay | — | W27 | — | 0.5 | MS3PROMINI-A-6 | — | — | — |
| K | A/C pressure switch (A/C request) | — | W37 | — | 0.5 | MS3PROMINI-A-35 | — | — | — |
| L | Clutch switch | — | — | — | — | — | — | — | — |
| M | Vehicle speed sensor (VSS) | — | W35 | — | 0.5 | MS3PROMINI-A-34 | — | — | — |
| Q | Brake switch | — | — | — | — | — | — | — | — |
| U | Fuel pump relay (low-side) | — | W28 | — | 0.5 | MS3PROMINI-A-7 | — | — | — |
OEM-3
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| B | MAF sensor input | — | W22 | — | 0.5 | MS3PROMINI-A-13 | — | — | — |
| C | Front O2 sensor input | — | W33 | — | 0.5 | MS3PROMINI-A-16 | — | — | — |
| D | Rear O2 sensor input | — | — | — | — | — | — | — | — |
| F | Throttle position (TPS) | — | W23 | — | 0.5 | MS3PROMINI-A-28 | — | — | — |
| G | Engine coolant temp (CLT) | — | W24 | — | 0.5 | MS3PROMINI-A-26 | — | — | — |
| H | EGR boost sensor | — | W31 | — | 0.5 | MS3PROMINI-A-14 | — | — | — |
| I | +5V sensor reference | — | W12 | — | 0.5 | MS3PROMINI-A-2 | — | — | — |
| J | EGR valve position sensor | — | — | — | — | — | — | — | — |
| K | Intake air temp (IAT) | — | W34 | — | 0.5 | MS3PROMINI-A-27 | — | — | — |
| L | Idle switch (closed throttle) | — | — | — | — | — | — | — | — |
| M | Front O2 heater control | — | W29 | — | 0.5 | MS3PROMINI-A-8 | — | — | — |
| N | EGR boost sensor (2nd channel) | — | W32 | — | 0.5 | MS3PROMINI-A-15 | — | — | — |
| O | Sensor ground | — | W9 | — | 0.5 | SP-0V-1 | — | — | — |
| P | Power steering pressure switch | — | — | — | — | — | — | — | — |
OEM-4
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A | Chassis ground | — | W3 | — | 0.85 | SP-GND-1 | — | — | — |
| B | ECU power +12V (main relay) | — | W1 | — | 0.85 | SP-14V-1 | — | — | — |
| C | Chassis ground | — | W4 | — | 0.85 | SP-GND-1 | — | — | — |
| D | Chassis ground | — | W5 | — | 0.85 | SP-GND-1 | — | — | — |
| E | Crank position (CKP) sensor | — | W13 | — | 0.5 | MS3PROMINI-A-30 | — | — | — |
| F | CAS SGT (cam trigger) | — | W15 | — | 0.5 | MS3PROMINI-A-33 | — | — | — |
| G | CAS SGC (cam sync) | — | W14 | — | 0.5 | MS3PROMINI-A-32 | — | — | — |
| H | Crank pickup timing ground (CKP gnd) | — | W10 | — | 0.5 | SP-0V-1 | — | — | — |
| I | Permanent +12V (battery) | — | — | — | — | — | — | — | — |
| J | PRC solenoid (FPR control) | — | — | — | — | — | — | — | — |
| K | Chassis ground | — | W6 | — | 0.85 | SP-GND-1 | — | — | — |
| L | Tachometer output | — | — | — | — | — | — | — | — |
| N | Ignition coil trigger (cyl 1&4) | — | W16 | — | 0.5 | MS3PROMINI-A-17 | — | — | — |
| O | EGR vent solenoid | — | — | — | — | — | — | — | — |
| P | EGR vacuum solenoid | — | — | — | — | — | — | — | — |
| Q | Idle air control (IAC) valve | — | — | — | — | — | — | — | — |
| R | Ignition coil trigger (cyl 2&3) | — | W17 | — | 0.5 | MS3PROMINI-A-18 | — | — | — |
| T | EVAP purge solenoid | — | — | — | — | — | — | — | — |
| U | Injector 1 (cyl 1) | — | W18 | — | 0.5 | MS3PROMINI-A-10 | — | — | — |
| V | Injector 2 (cyl 2) | — | W19 | — | 0.5 | MS3PROMINI-A-11 | — | — | — |
| W | Injector 3 (cyl 3) | — | W20 | — | 0.5 | MS3PROMINI-A-12 | — | — | — |
| X | Injector 4 (cyl 4) | — | W21 | — | 0.5 | MS3PROMINI-A-5 | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W9 | — | 0.5 | OEM-3-O | — | — | — |
| 1 | — | — | W10 | — | 0.5 | OEM-4-H | — | — | — |
| 1 | — | — | W11 | — | 0.5 | MS3PROMINI-A-21 | — | — | — |
SP-14V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W1 | — | 0.85 | OEM-4-B | — | — | — |
| 1 | — | — | W2 | — | 0.85 | MS3PROMINI-A-1 | — | — | — |
SP-GND
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W3 | — | 0.85 | OEM-4-A | — | — | — |
| 1 | — | — | W4 | — | 0.85 | OEM-4-C | — | — | — |
| 1 | — | — | W5 | — | 0.85 | OEM-4-D | — | — | — |
| 1 | — | — | W6 | — | 0.85 | OEM-4-K | — | — | — |
| 1 | — | — | W7 | — | 0.85 | MS3PROMINI-A-22 | — | — | — |
| 1 | — | — | W8 | — | 0.85 | MS3PROMINI-A-23 | — | — | — |
Pin map
| OEM point | OEM function | OEM family | Target point | Target function | Target family | Wire colour | Evidence |
|---|---|---|---|---|---|---|---|
| OEM-1-A | Cooling fan relay (low-side) | low_side_out | MS3PROMINI-A-4 | Fuel pump out | low_side_out | corroborated | |
| OEM-1-B | A/C condenser fan relay | low_side_out | MS3PROMINI-A-3 | PWM out 1 / Idle | low_side_out | corroborated | |
| OEM-1-C | Starter input (12V while cranking) | digital_in | MS3PROMINI-A-29 | Digital switched in 1 / Flex fuel | digital_in | corroborated | |
| OEM-1-E | Check engine light (MIL) | low_side_out | MS3PROMINI-A-9 | Injector out E | injector_out | corroborated | |
| OEM-1-G | A/C clutch relay | low_side_out | MS3PROMINI-A-6 | Injector out B | injector_out | corroborated | |
| OEM-1-K | A/C pressure switch (A/C request) | digital_in | MS3PROMINI-A-35 | Digital frequency in 2 (Hall) | digital_in | corroborated | |
| OEM-1-L | Clutch switch | digital_in | — | — | — | corroborated | |
| OEM-1-M | Vehicle speed sensor (VSS) | digital_in | MS3PROMINI-A-34 | Digital frequency in 1 (Hall) | digital_in | corroborated | |
| OEM-1-Q | Brake switch | digital_in | — | — | — | corroborated | |
| OEM-1-U | Fuel pump relay (low-side) | low_side_out | MS3PROMINI-A-7 | Injector out C | injector_out | corroborated | |
| OEM-3-B | MAF sensor input | analog_in | MS3PROMINI-A-13 | Analog in 1 | analog_in | corroborated | |
| OEM-3-C | Front O2 sensor input | lambda_nb_in | MS3PROMINI-A-16 | Analog in 4 | analog_in | corroborated | |
| OEM-3-D | Rear O2 sensor input | lambda_nb_in | — | — | — | corroborated | |
| OEM-3-F | Throttle position (TPS) | analog_in | MS3PROMINI-A-28 | TPS in | analog_in | corroborated | |
| OEM-3-G | Engine coolant temp (CLT) | temp_in | MS3PROMINI-A-26 | CLT in | temp_in | corroborated | |
| OEM-3-H | EGR boost sensor | analog_in | MS3PROMINI-A-14 | Analog in 2 | analog_in | corroborated | |
| OEM-3-I | +5V sensor reference | vref | MS3PROMINI-A-2 | +5V VREF out | vref | corroborated | |
| OEM-3-J | EGR valve position sensor | analog_in | — | — | — | corroborated | |
| OEM-3-K | Intake air temp (IAT) | temp_in | MS3PROMINI-A-27 | IAT in | temp_in | corroborated | |
| OEM-3-L | Idle switch (closed throttle) | digital_in | — | — | — | corroborated | |
| OEM-3-M | Front O2 heater control | low_side_out | MS3PROMINI-A-8 | Injector out D | injector_out | corroborated | |
| OEM-3-N | EGR boost sensor (2nd channel) | analog_in | MS3PROMINI-A-15 | Analog in 3 | analog_in | corroborated | |
| OEM-3-O | Sensor ground | sensor_ground | MS3PROMINI-A-21 | Sensor ground | sensor_ground | corroborated | |
| OEM-3-P | Power steering pressure switch | digital_in | — | — | — | corroborated | |
| OEM-4-A | Chassis ground | ground | MS3PROMINI-A-22 + MS3PROMINI-A-23 | Power ground + Power ground | ground | corroborated | |
| OEM-4-B | ECU power +12V (main relay) | power_in | MS3PROMINI-A-1 | 12V+ switched power in | power_in | corroborated | |
| OEM-4-C | Chassis ground | ground | MS3PROMINI-A-22 + MS3PROMINI-A-23 | Power ground + Power ground | ground | corroborated | |
| OEM-4-D | Chassis ground | ground | MS3PROMINI-A-22 + MS3PROMINI-A-23 | Power ground + Power ground | ground | corroborated | |
| OEM-4-E | Crank position (CKP) sensor | trigger_in | MS3PROMINI-A-30 | CKP+ | trigger_in | corroborated | |
| OEM-4-F | CAS SGT (cam trigger) | trigger_in | MS3PROMINI-A-33 | CMP- | trigger_in | corroborated | |
| OEM-4-G | CAS SGC (cam sync) | trigger_in | MS3PROMINI-A-32 | CMP+ | trigger_in | corroborated | |
| OEM-4-H | Crank pickup timing ground (CKP gnd) | sensor_ground | MS3PROMINI-A-21 | Sensor ground | sensor_ground | corroborated | |
| OEM-4-I | Permanent +12V (battery) | power_in | — | — | — | corroborated | |
| OEM-4-J | PRC solenoid (FPR control) | low_side_out | — | — | — | corroborated | |
| OEM-4-K | Chassis ground | ground | MS3PROMINI-A-22 + MS3PROMINI-A-23 | Power ground + Power ground | ground | corroborated | |
| OEM-4-L | Tachometer output | tacho_out | — | — | — | corroborated | |
| OEM-4-N | Ignition coil trigger (cyl 1&4) | ignition_out | MS3PROMINI-A-17 | Spark out A | ignition_out | corroborated | |
| OEM-4-O | EGR vent solenoid | low_side_out | — | — | — | corroborated | |
| OEM-4-P | EGR vacuum solenoid | low_side_out | — | — | — | corroborated | |
| OEM-4-Q | Idle air control (IAC) valve | low_side_out | — | — | — | corroborated | |
| OEM-4-R | Ignition coil trigger (cyl 2&3) | ignition_out | MS3PROMINI-A-18 | Spark out B | ignition_out | corroborated | |
| OEM-4-T | EVAP purge solenoid | low_side_out | — | — | — | corroborated | |
| OEM-4-U | Injector 1 (cyl 1) | injector_out | MS3PROMINI-A-10 | Injector out F | injector_out | corroborated | |
| OEM-4-V | Injector 2 (cyl 2) | injector_out | MS3PROMINI-A-11 | Injector out G | injector_out | corroborated | |
| OEM-4-W | Injector 3 (cyl 3) | injector_out | MS3PROMINI-A-12 | Injector out H | injector_out | corroborated | |
| OEM-4-X | Injector 4 (cyl 4) | injector_out | MS3PROMINI-A-5 | Injector out A | injector_out | corroborated |
Cut list
| Wire | From | To | Gauge (mm²) | Colour | Length | Signal | Ident |
|---|---|---|---|---|---|---|---|
| W1 | OEM-4-B | SP-14V-1 | 0.85 | no route | ECU power +12V (main relay) | — | |
| W2 | SP-14V-1 | MS3PROMINI-A-1 | 0.85 | no route | 12V+ switched power in | — | |
| W3 | OEM-4-A | SP-GND-1 | 0.85 | no route | Chassis ground | — | |
| W4 | OEM-4-C | SP-GND-1 | 0.85 | no route | Chassis ground | — | |
| W5 | OEM-4-D | SP-GND-1 | 0.85 | no route | Chassis ground | — | |
| W6 | OEM-4-K | SP-GND-1 | 0.85 | no route | Chassis ground | — | |
| W7 | SP-GND-1 | MS3PROMINI-A-22 | 0.85 | no route | Power ground | — | |
| W8 | SP-GND-1 | MS3PROMINI-A-23 | 0.85 | no route | Power ground | — | |
| W9 | OEM-3-O | SP-0V-1 | 0.5 | no route | Sensor ground | — | |
| W10 | OEM-4-H | SP-0V-1 | 0.5 | no route | Crank pickup timing ground (CKP gnd) | — | |
| W11 | SP-0V-1 | MS3PROMINI-A-21 | 0.5 | no route | Sensor ground | — | |
| W12 | OEM-3-I | MS3PROMINI-A-2 | 0.5 | no route | +5V sensor reference | — | |
| W13 | OEM-4-E | MS3PROMINI-A-30 | 0.5 | no route | Crank position (CKP) sensor | — | |
| W14 | OEM-4-G | MS3PROMINI-A-32 | 0.5 | no route | CAS SGC (cam sync) | — | |
| W15 | OEM-4-F | MS3PROMINI-A-33 | 0.5 | no route | CAS SGT (cam trigger) | — | |
| W16 | OEM-4-N | MS3PROMINI-A-17 | 0.5 | no route | Ignition coil trigger (cyl 1&4) | — | |
| W17 | OEM-4-R | MS3PROMINI-A-18 | 0.5 | no route | Ignition coil trigger (cyl 2&3) | — | |
| W18 | OEM-4-U | MS3PROMINI-A-10 | 0.5 | no route | Injector 1 (cyl 1) | — | |
| W19 | OEM-4-V | MS3PROMINI-A-11 | 0.5 | no route | Injector 2 (cyl 2) | — | |
| W20 | OEM-4-W | MS3PROMINI-A-12 | 0.5 | no route | Injector 3 (cyl 3) | — | |
| W21 | OEM-4-X | MS3PROMINI-A-5 | 0.5 | no route | Injector 4 (cyl 4) | — | |
| W22 | OEM-3-B | MS3PROMINI-A-13 | 0.5 | no route | MAF sensor input | — | |
| W23 | OEM-3-F | MS3PROMINI-A-28 | 0.5 | no route | Throttle position (TPS) | — | |
| W24 | OEM-3-G | MS3PROMINI-A-26 | 0.5 | no route | Engine coolant temp (CLT) | — | |
| W25 | OEM-1-A | MS3PROMINI-A-4 | 0.5 | no route | Cooling fan relay (low-side) | — | |
| W26 | OEM-1-B | MS3PROMINI-A-3 | 0.5 | no route | A/C condenser fan relay | — | |
| W27 | OEM-1-G | MS3PROMINI-A-6 | 0.5 | no route | A/C clutch relay | — | |
| W28 | OEM-1-U | MS3PROMINI-A-7 | 0.5 | no route | Fuel pump relay (low-side) | — | |
| W29 | OEM-3-M | MS3PROMINI-A-8 | 0.5 | no route | Front O2 heater control | — | |
| W30 | OEM-1-E | MS3PROMINI-A-9 | 0.5 | no route | Check engine light (MIL) | — | |
| W31 | OEM-3-H | MS3PROMINI-A-14 | 0.5 | no route | EGR boost sensor | — | |
| W32 | OEM-3-N | MS3PROMINI-A-15 | 0.5 | no route | EGR boost sensor (2nd channel) | — | |
| W33 | OEM-3-C | MS3PROMINI-A-16 | 0.5 | no route | Front O2 sensor input | — | |
| W34 | OEM-3-K | MS3PROMINI-A-27 | 0.5 | no route | Intake air temp (IAT) | — | |
| W35 | OEM-1-M | MS3PROMINI-A-34 | 0.5 | no route | Vehicle speed sensor (VSS) | — | |
| W36 | OEM-1-C | MS3PROMINI-A-29 | 0.5 | no route | Starter input (12V while cranking) | — | |
| W37 | OEM-1-K | MS3PROMINI-A-35 | 0.5 | no route | A/C pressure switch (A/C request) | — |
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 (5)
| Severity | Code | Subject | Message |
|---|---|---|---|
| info | NET_FAMILY | OEM-1-E ↔ MS3PROMINI-A-9 | OEM-1-E "Check engine light (MIL)" [low_side_out] is wired to MS3PROMINI-A-9 "Injector out E" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-1-G ↔ MS3PROMINI-A-6 | OEM-1-G "A/C clutch relay" [low_side_out] is wired to MS3PROMINI-A-6 "Injector out B" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-1-U ↔ MS3PROMINI-A-7 | OEM-1-U "Fuel pump relay (low-side)" [low_side_out] is wired to MS3PROMINI-A-7 "Injector out C" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-3-M ↔ MS3PROMINI-A-8 | OEM-3-M "Front O2 heater control" [low_side_out] is wired to MS3PROMINI-A-8 "Injector out D" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | UNMAPPED | OEM | 12 optional OEM pins are not mapped: OEM-1-L Clutch switch; OEM-1-Q Brake switch; OEM-3-D Rear O2 sensor input; OEM-3-J EGR valve position sensor; OEM-3-L Idle switch (closed throttle); OEM-3-P Power steering pressure switch; OEM-4-J PRC solenoid (FPR control); OEM-4-L Tachometer output; OEM-4-O EGR vent solenoid; OEM-4-P EGR vacuum solenoid; OEM-4-Q Idle air control (IAC) valve; OEM-4-T EVAP purge solenoid |
Accepted (1)
| Code | Subject | Reason | By |
|---|---|---|---|
| REQUIRED_UNMAPPED | OEM-4-I | 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 2026-10-11. Review every wire against both manuals before building. Not wired: - OEM-4 I: Permanent +12V (battery): AMP EFI MS3Pro Mini has no battery-constant input; not needed - OEM-4 J: PRC solenoid (FPR control): no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI MS3Pro Mini - OEM-4 O: EGR vent solenoid: no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI MS3Pro Mini - OEM-4 P: EGR vacuum solenoid: no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI MS3Pro Mini - OEM-4 Q: Idle air control (IAC) valve: no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI MS3Pro Mini - OEM-4 T: EVAP purge solenoid: no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI MS3Pro Mini - OEM-4 L: Tachometer output: no free tacho/frequency_out/low_side/ls_hs on AMP EFI MS3Pro Mini - OEM-3 D: Rear O2 sensor input: no free o2_narrowband/analog_0_5 on AMP EFI MS3Pro Mini - OEM-3 J: EGR valve position sensor: no free analog_0_5 on AMP EFI MS3Pro Mini - OEM-1 L: Clutch switch: no free switch_in/frequency_in/analog_0_5 on AMP EFI MS3Pro Mini - OEM-1 Q: Brake switch: no free switch_in/frequency_in/analog_0_5 on AMP EFI MS3Pro Mini - OEM-3 L: Idle switch (closed throttle): no free switch_in/frequency_in/analog_0_5 on AMP EFI MS3Pro Mini - OEM-3 P: Power steering pressure switch: no free switch_in/frequency_in/analog_0_5 on AMP EFI MS3Pro Mini
Sources
| Reliability | Kind | Title | URL | Archive | Captured | SHA-256 |
|---|---|---|---|---|---|---|
| 4 | vendor_doc | AEM EMS 30-1720 Plug-and-Play adapter manual (1996-97 Miata) | https://static.summitracing.com/global/images/instructions/avm-30-1720.pdf | — | — | — |
| 4 | vendor_doc | AMP EFI: MS3Pro Mini manual (fw 1.6.1) pinout & output ratings | https://cdn.shopify.com/s/files/1/0960/0014/7754/files/MS3Pro_User_Manual_Firmware_1.6.1_Mini.pdf?v=1760643335 | archive | 2026-10-05 | bed7d8ae8408 |
| 3 | community_copy | Mellens.net: 1996 Mazda Miata wiring diagrams (FSM-derived) | http://www.mellens.net/mazda/mazda_miata_extra_manual/1996_wiring.pdf | — | — | — |