MX-5 Miata NA6 1990-93 (B6-ZE, 1.6) → Speeduino Speeduino v0.4 (auto)
MX-5 Miata NA6 1990-93 (B6-ZE, 1.6) — Speeduino — Speeduino
⚠ NOT CHECKED. Don't build from this.
Drawn by Michael Gnankou · Rev 0 · draft · 2026-10-04
Revisions
| Rev | Label | By | Date |
|---|---|---|---|
| No revisions yet. | |||
Schematic
Connectors
OEM-1
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A | Constant +12V | — | — | — | — | — | — | — | — |
| B | ECU power +14V (main relay) | — | — | — | — | — | — | — | — |
| C | Start signal | — | W24 | — | 0.5 | SPEEDUINO-A-18 | — | — | — |
| E | Malfunction indicator lamp (MIL) | — | W19 | — | 0.5 | SPEEDUINO-A-15 | — | — | — |
| G | Ignition 1 (coils 1+4, wasted spark) | — | W13 | — | 0.5 | SPEEDUINO-A-7 | — | — | — |
| H | Ignition 2 (coils 2+3, wasted spark) | — | W14 | — | 0.5 | SPEEDUINO-A-34 | — | — | — |
| N | Wide-open throttle switch | — | W25 | — | 0.5 | SPEEDUINO-A-14 | — | — | — |
| P | Power steering pressure switch | — | — | — | — | — | — | — | — |
| Q | A/C request | — | — | — | — | — | — | — | — |
| V | Neutral/clutch switch | — | — | — | — | — | — | — | — |
OEM-2
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A | Power ground | — | W1 | — | 0.85 | SP-GND-1 | — | — | — |
| B | Power ground | — | W2 | — | 0.85 | SP-GND-1 | — | — | — |
| C | Power ground | — | W3 | — | 0.85 | SP-GND-1 | — | — | — |
| D | Power ground | — | W4 | — | 0.85 | SP-GND-1 | — | — | — |
| E | Crank position (CAS NE) | — | W11 | — | 0.5 | SPEEDUINO-A-25 | — | — | — |
| F | AFM ground | — | W7 | — | 0.5 | SP-0V-1 | — | — | — |
| G | Cam position (CAS G) | — | W12 | — | 0.5 | SPEEDUINO-A-24 | — | — | — |
| I | Tachometer output | — | W20 | — | 0.5 | SPEEDUINO-A-17 | — | — | — |
| K | +5V sensor supply | — | W10 | — | 0.5 | SPEEDUINO-A-13 | — | — | — |
| L | Idle switch (TPS) | — | — | — | — | — | — | — | — |
| N | O2 sensor | — | W21 | — | 0.5 | SPEEDUINO-A-21 | — | — | — |
| O | Air flow meter (AFM) | — | — | — | — | — | — | — | — |
| P | Intake air temperature (IAT) | — | W23 | — | 0.5 | SPEEDUINO-A-20 | — | — | — |
| Q | Coolant temperature (ECT) | — | W22 | — | 0.5 | SPEEDUINO-A-19 | — | — | — |
| U | Injector 1 | — | W15 | — | 0.5 | SPEEDUINO-A-1 | — | — | — |
| V | Injector 2 | — | W16 | — | 0.5 | SPEEDUINO-A-2 | — | — | — |
| Y | Injector 3 | — | W17 | — | 0.5 | SPEEDUINO-A-3 | — | — | — |
| Z | Injector 4 | — | W18 | — | 0.5 | SPEEDUINO-A-5 | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W7 | — | 0.5 | OEM-2-F | — | — | — |
| 1 | — | — | W8 | — | 0.5 | SPEEDUINO-A-12 | — | — | — |
| 1 | — | — | W9 | — | 0.5 | SPEEDUINO-A-23 | — | — | — |
SP-GND
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W1 | — | 0.85 | OEM-2-A | — | — | — |
| 1 | — | — | W2 | — | 0.85 | OEM-2-B | — | — | — |
| 1 | — | — | W3 | — | 0.85 | OEM-2-C | — | — | — |
| 1 | — | — | W4 | — | 0.85 | OEM-2-D | — | — | — |
| 1 | — | — | W5 | — | 0.85 | SPEEDUINO-A-10 | — | — | — |
| 1 | — | — | W6 | — | 0.85 | SPEEDUINO-A-9 | — | — | — |
SPEEDUINO-A
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Injector 1 | — | W15 | — | 0.5 | OEM-2-U | — | — | — |
| 10 | Ground | — | W5 | — | 0.85 | SP-GND-1 | — | — | — |
| 11 | MAP sensor (0-5V) | — | — | — | — | — | — | — | — |
| 12 | Ground | — | W8 | — | 0.5 | SP-0V-1 | — | — | — |
| 13 | 5V | — | W10 | — | 0.5 | OEM-2-K | — | — | — |
| 14 | Proto area 1 (flex fuel) | — | W25 | — | 0.5 | OEM-1-N | — | — | — |
| 15 | Proto area 2 (fan) | — | W19 | — | 0.5 | OEM-1-E | — | — | — |
| 16 | Proto area 3 (fuel pump) | — | — | — | — | — | — | — | — |
| 17 | Proto area 4 (tachometer) | — | W20 | — | 0.5 | OEM-2-I | — | — | — |
| 18 | Proto area 5 (clutch) | — | W24 | — | 0.5 | OEM-1-C | — | — | — |
| 19 | Coolant temp (CLT) | — | W22 | — | 0.5 | OEM-2-Q | — | — | — |
| 2 | Injector 2 | — | W16 | — | 0.5 | OEM-2-V | — | — | — |
| 20 | Inlet air temp (IAT) | — | W23 | — | 0.5 | OEM-2-P | — | — | — |
| 21 | O2 sensor | — | W21 | — | 0.5 | OEM-2-N | — | — | — |
| 22 | TPS input | — | — | — | — | — | — | — | — |
| 23 | Ground | — | W9 | — | 0.5 | SP-0V-1 | — | — | — |
| 24 | Cam input / VR2+ | — | W12 | — | 0.5 | OEM-2-G | — | — | — |
| 25 | Crank input / VR1+ | — | W11 | — | 0.5 | OEM-2-E | — | — | — |
| 26 | VR2- | — | — | — | — | — | — | — | — |
| 27 | VR1- | — | — | — | — | — | — | — | — |
| 28 | 5V | — | — | — | — | — | — | — | — |
| 29 | Idle stepper 2B | — | — | — | — | — | — | — | — |
| 3 | Injector 3 | — | W17 | — | 0.5 | OEM-2-Y | — | — | — |
| 30 | Idle stepper 2A | — | — | — | — | — | — | — | — |
| 31 | Idle stepper 1A | — | — | — | — | — | — | — | — |
| 32 | Idle stepper 1B | — | — | — | — | — | — | — | — |
| 33 | Ignition 3 | — | — | — | — | — | — | — | — |
| 34 | Ignition 2 | — | W14 | — | 0.5 | OEM-1-H | — | — | — |
| 35 | Boost | — | — | — | — | — | — | — | — |
| 36 | Idle 2 (3-wire idle) | — | — | — | — | — | — | — | — |
| 37 | PWM idle | — | — | — | — | — | — | — | — |
| 38 | VVT | — | — | — | — | — | — | — | — |
| 5 | Injector 4 | — | W18 | — | 0.5 | OEM-2-Z | — | — | — |
| 7 | Ignition 1 | — | W13 | — | 0.5 | OEM-1-G | — | — | — |
| 8 | Ignition 4 | — | — | — | — | — | — | — | — |
| 9 | Ground | — | W6 | — | 0.85 | SP-GND-1 | — | — | — |
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 | — | — | — | single_source | |
| OEM-1-C | Start signal | digital_in | SPEEDUINO-A-18 | Proto area 5 (clutch) | digital_in | single_source | |
| OEM-1-E | Malfunction indicator lamp (MIL) | low_side_out | SPEEDUINO-A-15 | Proto area 2 (fan) | low_side_out | single_source | |
| OEM-1-G | Ignition 1 (coils 1+4, wasted spark) | ignition_out | SPEEDUINO-A-7 | Ignition 1 | ignition_out | single_source | |
| OEM-1-H | Ignition 2 (coils 2+3, wasted spark) | ignition_out | SPEEDUINO-A-34 | Ignition 2 | ignition_out | single_source | |
| OEM-1-N | Wide-open throttle switch | digital_in | SPEEDUINO-A-14 | Proto area 1 (flex fuel) | digital_in | single_source | |
| OEM-1-P | Power steering pressure switch | digital_in | — | — | — | single_source | |
| OEM-1-Q | A/C request | digital_in | — | — | — | single_source | |
| OEM-1-V | Neutral/clutch switch | digital_in | — | — | — | single_source | |
| OEM-2-A | Power ground | ground | SPEEDUINO-A-10 + SPEEDUINO-A-9 | Ground + Ground | ground | single_source | |
| OEM-2-B | Power ground | ground | SPEEDUINO-A-10 + SPEEDUINO-A-9 | Ground + Ground | ground | single_source | |
| OEM-2-C | Power ground | ground | SPEEDUINO-A-10 + SPEEDUINO-A-9 | Ground + Ground | ground | single_source | |
| OEM-2-D | Power ground | ground | SPEEDUINO-A-10 + SPEEDUINO-A-9 | Ground + Ground | ground | single_source | |
| OEM-2-E | Crank position (CAS NE) | trigger_in | SPEEDUINO-A-25 | Crank input / VR1+ | trigger_in | single_source | |
| OEM-2-F | AFM ground | sensor_ground | SPEEDUINO-A-12 + SPEEDUINO-A-23 | Ground + Ground | sensor_ground | single_source | |
| OEM-2-G | Cam position (CAS G) | trigger_in | SPEEDUINO-A-24 | Cam input / VR2+ | trigger_in | single_source | |
| OEM-2-I | Tachometer output | tacho_out | SPEEDUINO-A-17 | Proto area 4 (tachometer) | tacho_out | single_source | |
| OEM-2-K | +5V sensor supply | vref | SPEEDUINO-A-13 | 5V | vref | single_source | |
| OEM-2-L | Idle switch (TPS) | digital_in | — | — | — | single_source | |
| OEM-2-N | O2 sensor | lambda_nb_in | SPEEDUINO-A-21 | O2 sensor | lambda_nb_in | single_source | |
| OEM-2-O | Air flow meter (AFM) | analog_in | — | — | — | single_source | |
| OEM-2-P | Intake air temperature (IAT) | temp_in | SPEEDUINO-A-20 | Inlet air temp (IAT) | temp_in | single_source | |
| OEM-2-Q | Coolant temperature (ECT) | temp_in | SPEEDUINO-A-19 | Coolant temp (CLT) | temp_in | single_source | |
| OEM-2-U | Injector 1 | injector_out | SPEEDUINO-A-1 | Injector 1 | injector_out | single_source | |
| OEM-2-V | Injector 2 | injector_out | SPEEDUINO-A-2 | Injector 2 | injector_out | single_source | |
| OEM-2-Y | Injector 3 | injector_out | SPEEDUINO-A-3 | Injector 3 | injector_out | single_source | |
| OEM-2-Z | Injector 4 | injector_out | SPEEDUINO-A-5 | Injector 4 | injector_out | single_source |
Cut list
| Wire | From | To | Gauge (mm²) | Colour | Length | Signal | Ident |
|---|---|---|---|---|---|---|---|
| W1 | OEM-2-A | SP-GND-1 | 0.85 | no route | Power ground | — | |
| W2 | OEM-2-B | SP-GND-1 | 0.85 | no route | Power ground | — | |
| W3 | OEM-2-C | SP-GND-1 | 0.85 | no route | Power ground | — | |
| W4 | OEM-2-D | SP-GND-1 | 0.85 | no route | Power ground | — | |
| W5 | SP-GND-1 | SPEEDUINO-A-10 | 0.85 | no route | Ground | — | |
| W6 | SP-GND-1 | SPEEDUINO-A-9 | 0.85 | no route | Ground | — | |
| W7 | OEM-2-F | SP-0V-1 | 0.5 | no route | AFM ground | — | |
| W8 | SP-0V-1 | SPEEDUINO-A-12 | 0.5 | no route | Ground | — | |
| W9 | SP-0V-1 | SPEEDUINO-A-23 | 0.5 | no route | Ground | — | |
| W10 | OEM-2-K | SPEEDUINO-A-13 | 0.5 | no route | +5V sensor supply | — | |
| W11 | OEM-2-E | SPEEDUINO-A-25 | 0.5 | no route | Crank position (CAS NE) | — | |
| W12 | OEM-2-G | SPEEDUINO-A-24 | 0.5 | no route | Cam position (CAS G) | — | |
| W13 | OEM-1-G | SPEEDUINO-A-7 | 0.5 | no route | Ignition 1 (coils 1+4, wasted spark) | — | |
| W14 | OEM-1-H | SPEEDUINO-A-34 | 0.5 | no route | Ignition 2 (coils 2+3, wasted spark) | — | |
| W15 | OEM-2-U | SPEEDUINO-A-1 | 0.5 | no route | Injector 1 | — | |
| W16 | OEM-2-V | SPEEDUINO-A-2 | 0.5 | no route | Injector 2 | — | |
| W17 | OEM-2-Y | SPEEDUINO-A-3 | 0.5 | no route | Injector 3 | — | |
| W18 | OEM-2-Z | SPEEDUINO-A-5 | 0.5 | no route | Injector 4 | — | |
| W19 | OEM-1-E | SPEEDUINO-A-15 | 0.5 | no route | Malfunction indicator lamp (MIL) | — | |
| W20 | OEM-2-I | SPEEDUINO-A-17 | 0.5 | no route | Tachometer output | — | |
| W21 | OEM-2-N | SPEEDUINO-A-21 | 0.5 | no route | O2 sensor | — | |
| W22 | OEM-2-Q | SPEEDUINO-A-19 | 0.5 | no route | Coolant temperature (ECT) | — | |
| W23 | OEM-2-P | SPEEDUINO-A-20 | 0.5 | no route | Intake air temperature (IAT) | — | |
| W24 | OEM-1-C | SPEEDUINO-A-18 | 0.5 | no route | Start signal | — | |
| W25 | OEM-1-N | SPEEDUINO-A-14 | 0.5 | no route | Wide-open throttle 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 (2)
| Severity | Code | Subject | Message |
|---|---|---|---|
| error | REQUIRED_UNMAPPED | OEM-1-B | Required OEM function "ECU power +14V (main relay)" (power_in) is not connected to the new ECU. |
| info | UNMAPPED | OEM | 5 optional OEM pins are not mapped: OEM-1-P Power steering pressure switch; OEM-1-Q A/C request; OEM-1-V Neutral/clutch switch; OEM-2-L Idle switch (TPS); OEM-2-O Air flow meter (AFM) |
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
Auto-mapped by auto_map() from the library pin data on 2026-10-04. Review every wire against both manuals before building. Open items: - Main-relay feed: no ecu_main_power pin on the stock or the new ECU - OEM-1 B: ECU power +14V (main relay): no rule for class ecu_main_power; wire by hand Not wired: - OEM-1 A: Constant +12V: Speeduino Speeduino has no battery-constant input; not needed - OEM-2 O: Air flow meter (AFM): no free maf/analog_0_5 on Speeduino Speeduino - OEM-1 P: Power steering pressure switch: no free switch_in/frequency_in/analog_0_5 on Speeduino Speeduino - OEM-1 Q: A/C request: no free switch_in/frequency_in/analog_0_5 on Speeduino Speeduino - OEM-1 V: Neutral/clutch switch: no free switch_in/frequency_in/analog_0_5 on Speeduino Speeduino - OEM-2 L: Idle switch (TPS): no free switch_in/frequency_in/analog_0_5 on Speeduino Speeduino
Sources
| Reliability | Kind | Title | URL |
|---|---|---|---|
| 4 | vendor_doc | Link G4X MX5X install manual (NA 1.6/1.8) | https://linkecu.com/documentation/MX5X.pdf |
| 4 | vendor_doc | Speeduino Manual (08/04/25) — V0.4 board IDC40 pinout & features | https://speeduino.com/Speeduino_manual.pdf |