MX-5 Miata NA8 1994-97 (BP-ZE, 1.8) → AMP EFI Microsquirt (auto)
MX-5 Miata NA8 1994-97 (BP-ZE, 1.8) — AMP EFI — Microsquirt
⚠ NOT CHECKED. Don't build from this.
Drawn by Michael Gnankou · Rev 0 · draft · 2026-10-05
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 | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
| 10 | INJ 2 | — | W19 | — | 0.5 | OEM-2-V | — | — | — |
| 11 | SPK B (IGN2) | — | W16 | — | 0.5 | OEM-1-G | — | — | — |
| 12 | SPK A (IGN 1) | — | W17 | — | 0.5 | OEM-1-H | — | — | — |
| 13 | RX | — | — | — | — | — | — | — | — |
| 14 | TX | — | — | — | — | — | — | — | — |
| 15 | BOOT LOAD | — | — | — | — | — | — | — | — |
| 16 | ALED | — | W21 | — | 0.5 | OEM-1-R | — | — | — |
| 17 | WLED | — | W22 | — | 0.5 | OEM-2-S | — | — | — |
| 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 | — | — | — | — | — | — | — | — |
| 25 | CLT | — | W28 | — | 0.5 | OEM-2-Q | — | — | — |
| 26 | MAT | — | W29 | — | 0.5 | OEM-2-P | — | — | — |
| 27 | TPS | — | W26 | — | 0.5 | OEM-2-M | — | — | — |
| 28 | TPS VREF (5V) | — | W13 | — | 0.5 | OEM-2-K | — | — | — |
| 29 | SPAREADC | — | W33 | — | 0.5 | OEM-1-Q | — | — | — |
| 3 | CANL | — | — | — | — | — | — | — | — |
| 30 | OPTO+ | — | W30 | — | 0.5 | OEM-1-M | — | — | — |
| 31 | OPTO- | — | W31 | — | 0.5 | OEM-1-C | — | — | — |
| 32 | VR1+ | — | W14 | — | 0.5 | OEM-2-E | — | — | — |
| 33 | VR1- | — | — | — | — | — | — | — | — |
| 34 | O2 | — | W27 | — | 0.5 | OEM-2-N | — | — | — |
| 35 | TACHO | — | W24 | — | 0.5 | OEM-2-I | — | — | — |
| 4 | VR2+ | — | W15 | — | 0.5 | OEM-2-G | — | — | — |
| 5 | SPAREADC2 (MAF) | — | W25 | — | 0.5 | OEM-2-O | — | — | — |
| 6 | FLEX | — | W32 | — | 0.5 | OEM-1-P | — | — | — |
| 7 | FIDLE | — | W23 | — | 0.5 | OEM-2-T | — | — | — |
| 8 | FP (pump) | — | W20 | — | 0.5 | OEM-1-J | — | — | — |
| 9 | INJ 1 | — | W18 | — | 0.5 | OEM-2-U | — | — | — |
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 | — | W31 | — | 0.5 | MICROSQUIRT-A-31 | — | — | — |
| E | Malfunction indicator lamp (MIL) | — | — | — | — | — | — | — | — |
| G | Ignition 1 (coils 1+4, wasted spark) | — | W16 | — | 0.5 | MICROSQUIRT-A-11 | — | — | — |
| H | Ignition 2 (coils 2+3, wasted spark) | — | W17 | — | 0.5 | MICROSQUIRT-A-12 | — | — | — |
| J | A/C relay | — | W20 | — | 0.5 | MICROSQUIRT-A-8 | — | — | — |
| M | Vehicle speed | — | W30 | — | 0.5 | MICROSQUIRT-A-30 | — | — | — |
| P | Power steering pressure switch | — | W32 | — | 0.5 | MICROSQUIRT-A-6 | — | — | — |
| Q | A/C request | — | W33 | — | 0.5 | MICROSQUIRT-A-29 | — | — | — |
| R | Cooling fan relay | — | W21 | — | 0.5 | MICROSQUIRT-A-16 | — | — | — |
| 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 | Power ground | — | W5 | — | 0.85 | SP-GND-1 | — | — | — |
| D | Power ground | — | W6 | — | 0.85 | SP-GND-1 | — | — | — |
| E | Crank position (CAS NE) | — | W14 | — | 0.5 | MICROSQUIRT-A-32 | — | — | — |
| F | MAF ground | — | W9 | — | 0.5 | SP-0V-1 | — | — | — |
| G | Cam position (CAS G) | — | W15 | — | 0.5 | MICROSQUIRT-A-4 | — | — | — |
| I | Tachometer output | — | W24 | — | 0.5 | MICROSQUIRT-A-35 | — | — | — |
| K | +5V sensor supply | — | W13 | — | 0.5 | MICROSQUIRT-A-28 | — | — | — |
| M | Throttle position (TPS) | — | W26 | — | 0.5 | MICROSQUIRT-A-27 | — | — | — |
| N | O2 sensor | — | W27 | — | 0.5 | MICROSQUIRT-A-34 | — | — | — |
| O | Mass air flow (MAF) | — | W25 | — | 0.5 | MICROSQUIRT-A-5 | — | — | — |
| P | Intake air temperature (IAT) | — | W29 | — | 0.5 | MICROSQUIRT-A-26 | — | — | — |
| Q | Coolant temperature (ECT) | — | W28 | — | 0.5 | MICROSQUIRT-A-25 | — | — | — |
| R | PRC solenoid (fuel pressure regulator) | — | — | — | — | — | — | — | — |
| S | Condenser fan relay | — | W22 | — | 0.5 | MICROSQUIRT-A-17 | — | — | — |
| T | Fuel pump relay | — | W23 | — | 0.5 | MICROSQUIRT-A-7 | — | — | — |
| U | Injector 1 | — | W18 | — | 0.5 | MICROSQUIRT-A-9 | — | — | — |
| V | Injector 2 | — | W19 | — | 0.5 | MICROSQUIRT-A-10 | — | — | — |
| W | ISC solenoid | — | — | — | — | — | — | — | — |
| X | Evap purge solenoid | — | — | — | — | — | — | — | — |
| Y | Injector 3 | — | — | — | — | — | — | — | — |
| Z | Injector 4 | — | — | — | — | — | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W9 | — | 0.5 | OEM-2-F | — | — | — |
| 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-1-B | — | — | — |
| 1 | — | — | W2 | — | 0.85 | MICROSQUIRT-A-1 | — | — | — |
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 | OEM-2-C | — | — | — |
| 1 | — | — | W6 | — | 0.85 | OEM-2-D | — | — | — |
| 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-1-A | Constant +12V | power_in | — | — | — | single_source | |
| OEM-1-B | ECU power +14V (main relay) | power_in | MICROSQUIRT-A-1 | +12V In | power_in | single_source | |
| OEM-1-C | Start signal | digital_in | MICROSQUIRT-A-31 | OPTO- | digital_in | single_source | |
| OEM-1-E | Malfunction indicator lamp (MIL) | low_side_out | — | — | — | single_source | |
| OEM-1-G | Ignition 1 (coils 1+4, wasted spark) | ignition_out | MICROSQUIRT-A-11 | SPK B (IGN2) | ignition_out | single_source | |
| OEM-1-H | Ignition 2 (coils 2+3, wasted spark) | ignition_out | MICROSQUIRT-A-12 | SPK A (IGN 1) | ignition_out | single_source | |
| OEM-1-J | A/C relay | low_side_out | MICROSQUIRT-A-8 | FP (pump) | low_side_out | single_source | |
| OEM-1-M | Vehicle speed | digital_in | MICROSQUIRT-A-30 | OPTO+ | digital_in | single_source | |
| OEM-1-P | Power steering pressure switch | digital_in | MICROSQUIRT-A-6 | FLEX | digital_in | single_source | |
| OEM-1-Q | A/C request | digital_in | MICROSQUIRT-A-29 | SPAREADC | analog_in | single_source | |
| OEM-1-R | Cooling fan relay | low_side_out | MICROSQUIRT-A-16 | ALED | low_side_out | single_source | |
| OEM-1-V | Neutral/clutch switch | digital_in | — | — | — | single_source | |
| OEM-2-A | Power ground | ground | MICROSQUIRT-A-22 + MICROSQUIRT-A-23 | POWER GROUND + POWER GROUND | ground | single_source | |
| OEM-2-B | Power ground | ground | MICROSQUIRT-A-22 + MICROSQUIRT-A-23 | POWER GROUND + POWER GROUND | ground | single_source | |
| OEM-2-C | Power ground | ground | MICROSQUIRT-A-22 + MICROSQUIRT-A-23 | POWER GROUND + POWER GROUND | ground | single_source | |
| OEM-2-D | Power ground | ground | MICROSQUIRT-A-22 + MICROSQUIRT-A-23 | POWER GROUND + POWER GROUND | ground | single_source | |
| OEM-2-E | Crank position (CAS NE) | trigger_in | MICROSQUIRT-A-32 | VR1+ | trigger_in | single_source | |
| OEM-2-F | MAF ground | sensor_ground | MICROSQUIRT-A-18 + MICROSQUIRT-A-19 + MICROSQUIRT-A-20 | Sensor Ground + Serial Ground + Sensor Ground | sensor_ground | single_source | |
| OEM-2-G | Cam position (CAS G) | trigger_in | MICROSQUIRT-A-4 | VR2+ | trigger_in | single_source | |
| OEM-2-I | Tachometer output | tacho_out | MICROSQUIRT-A-35 | TACHO | tacho_out | single_source | |
| OEM-2-K | +5V sensor supply | vref | MICROSQUIRT-A-28 | TPS VREF (5V) | vref | single_source | |
| OEM-2-M | Throttle position (TPS) | analog_in | MICROSQUIRT-A-27 | TPS | analog_in | single_source | |
| OEM-2-N | O2 sensor | lambda_nb_in | MICROSQUIRT-A-34 | O2 | lambda_nb_in | single_source | |
| OEM-2-O | Mass air flow (MAF) | analog_in | MICROSQUIRT-A-5 | SPAREADC2 (MAF) | analog_in | single_source | |
| OEM-2-P | Intake air temperature (IAT) | temp_in | MICROSQUIRT-A-26 | MAT | temp_in | single_source | |
| OEM-2-Q | Coolant temperature (ECT) | temp_in | MICROSQUIRT-A-25 | CLT | temp_in | single_source | |
| OEM-2-R | PRC solenoid (fuel pressure regulator) | low_side_out | — | — | — | single_source | |
| OEM-2-S | Condenser fan relay | low_side_out | MICROSQUIRT-A-17 | WLED | low_side_out | single_source | |
| OEM-2-T | Fuel pump relay | low_side_out | MICROSQUIRT-A-7 | FIDLE | low_side_out | single_source | |
| OEM-2-U | Injector 1 | injector_out | MICROSQUIRT-A-9 | INJ 1 | injector_out | single_source | |
| OEM-2-V | Injector 2 | injector_out | MICROSQUIRT-A-10 | INJ 2 | injector_out | single_source | |
| OEM-2-W | ISC solenoid | low_side_out | — | — | — | single_source | |
| OEM-2-X | Evap purge solenoid | low_side_out | — | — | — | single_source | |
| OEM-2-Y | Injector 3 | injector_out | — | — | — | single_source | |
| OEM-2-Z | 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 | SP-14V-1 | MICROSQUIRT-A-1 | 0.85 | no route | +12V In | — | |
| 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 | OEM-2-C | SP-GND-1 | 0.85 | no route | Power ground | — | |
| W6 | OEM-2-D | 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-2-F | SP-0V-1 | 0.5 | no route | MAF 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-2-K | MICROSQUIRT-A-28 | 0.5 | no route | +5V sensor supply | — | |
| W14 | OEM-2-E | MICROSQUIRT-A-32 | 0.5 | no route | Crank position (CAS NE) | — | |
| W15 | OEM-2-G | MICROSQUIRT-A-4 | 0.5 | no route | Cam position (CAS G) | — | |
| W16 | OEM-1-G | MICROSQUIRT-A-11 | 0.5 | no route | Ignition 1 (coils 1+4, wasted spark) | — | |
| W17 | OEM-1-H | MICROSQUIRT-A-12 | 0.5 | no route | Ignition 2 (coils 2+3, wasted spark) | — | |
| W18 | OEM-2-U | MICROSQUIRT-A-9 | 0.5 | no route | Injector 1 | — | |
| W19 | OEM-2-V | MICROSQUIRT-A-10 | 0.5 | no route | Injector 2 | — | |
| W20 | OEM-1-J | MICROSQUIRT-A-8 | 0.5 | no route | A/C relay | — | |
| W21 | OEM-1-R | MICROSQUIRT-A-16 | 0.5 | no route | Cooling fan relay | — | |
| W22 | OEM-2-S | MICROSQUIRT-A-17 | 0.5 | no route | Condenser fan relay | — | |
| W23 | OEM-2-T | MICROSQUIRT-A-7 | 0.5 | no route | Fuel pump relay | — | |
| W24 | OEM-2-I | MICROSQUIRT-A-35 | 0.5 | no route | Tachometer output | — | |
| W25 | OEM-2-O | MICROSQUIRT-A-5 | 0.5 | no route | Mass air flow (MAF) | — | |
| W26 | OEM-2-M | MICROSQUIRT-A-27 | 0.5 | no route | Throttle position (TPS) | — | |
| W27 | OEM-2-N | MICROSQUIRT-A-34 | 0.5 | no route | O2 sensor | — | |
| W28 | OEM-2-Q | MICROSQUIRT-A-25 | 0.5 | no route | Coolant temperature (ECT) | — | |
| W29 | OEM-2-P | MICROSQUIRT-A-26 | 0.5 | no route | Intake air temperature (IAT) | — | |
| W30 | OEM-1-M | MICROSQUIRT-A-30 | 0.5 | no route | Vehicle speed | — | |
| W31 | OEM-1-C | MICROSQUIRT-A-31 | 0.5 | no route | Start signal | — | |
| W32 | OEM-1-P | MICROSQUIRT-A-6 | 0.5 | no route | Power steering pressure switch | — | |
| W33 | OEM-1-Q | MICROSQUIRT-A-29 | 0.5 | no route | 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 (4)
| Severity | Code | Subject | Message |
|---|---|---|---|
| error | REQUIRED_UNMAPPED | OEM-2-Y | Required OEM function "Injector 3" (injector_out) is not connected to the new ECU. |
| error | REQUIRED_UNMAPPED | OEM-2-Z | Required OEM function "Injector 4" (injector_out) is not connected to the new ECU. |
| warn | NET_FAMILY | OEM-1-Q ↔ MICROSQUIRT-A-29 | OEM-1-Q "A/C request" [digital_in] is wired to MICROSQUIRT-A-29 "SPAREADC" [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 | 5 optional OEM pins are not mapped: OEM-1-E Malfunction indicator lamp (MIL); OEM-1-V Neutral/clutch switch; 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
Auto-mapped by auto_map() from the library pin data on 2026-10-04. Review every wire against both manuals before building. Open items: - OEM-2 Y: Injector 3: no free injector output on AMP EFI Microsquirt - OEM-2 Z: Injector 4: no free injector output on AMP EFI Microsquirt Not wired: - OEM-1 A: Constant +12V: AMP EFI Microsquirt 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 AMP EFI Microsquirt - OEM-1 E: Malfunction indicator lamp (MIL): no free low_side/ls_hs/injector/hbridge on AMP EFI Microsquirt - OEM-2 R: PRC solenoid (fuel pressure regulator): no free low_side/ls_hs/injector/hbridge on AMP EFI Microsquirt - OEM-2 X: Evap purge solenoid: no free low_side/ls_hs/injector/hbridge on AMP EFI Microsquirt - OEM-1 V: Neutral/clutch switch: no free switch_in/frequency_in/analog_0_5 on AMP EFI Microsquirt
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 | MSExtra: Microsquirt hardware 3.4 | http://www.msextra.com/doc/pdf/Microsquirt_Hardware-3.4.pdf |