MX-5 Miata NB1 1999-00 (BP-4W) → Emtron SL8 (auto)
MX-5 Miata NB1 1999-00 (BP-4W) — Emtron — SL8
Drawn by Michael Gnankou · Rev 0 · proposal · 2026-10-08
Before you start
| Status | proposal · not yet verified: nobody has reported building and running this harness |
|---|---|
| Open errors | none |
| Size of the job | 53 wires · 8 connectors · 6 part lines |
| Tools | Crimp and extraction tools for each terminal family (see Connectors) · wire strippers · multimeter · heat gun + heat-shrink |
| Terminals | 3-1447221-4 |
| 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 | SL8-A-34 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W4 | SP-14V-1 | SL8-B-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W5 | OEM-3-A | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W6 | OEM-3-B | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W7 | OEM-3-C | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | SP-GND-1 | SL8-B-18 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | SP-GND-1 | SL8-B-26 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | OEM-3-F | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | SP-0V-1 | SL8-B-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | OEM-2-I | SL8-B-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | OEM-2-J | SL8-B-5 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | SP-0V-1 | SL8-B-6 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | OEM-2-H | SL8-B-7 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | SP-0V-1 | SL8-B-8 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-2-F | SL8-B-16 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-3-G | SL8-A-26 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-3-H | SL8-A-27 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-3-W | SL8-A-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-3-X | SL8-A-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-3-Y | SL8-A-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-3-Z | SL8-A-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-1-I | SL8-B-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-1-R | SL8-A-14 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-1-S | SL8-A-15 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-3-N | SL8-A-16 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-1-U | SL8-A-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-3-V | SL8-A-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | OEM-3-O | SL8-A-11 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-1-E | SL8-A-12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-1-O | SL8-A-13 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-1-Q | SL8-A-5 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-2-M | SL8-A-6 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W35 | OEM-2-N | SL8-A-7 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W36 | OEM-2-O | SL8-A-8 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W37 | OEM-2-P | SL8-A-18 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W38 | OEM-3-L | SL8-A-19 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W39 | OEM-2-L | SL8-B-11 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W40 | OEM-3-E | SL8-B-12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W41 | OEM-2-C | SL8-B-13 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W42 | OEM-3-J | SL8-B-14 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W43 | OEM-2-E | SL8-B-15 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W44 | OEM-2-B | SL8-B-19 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W45 | OEM-2-A | SL8-B-20 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W46 | OEM-3-K | SL8-B-21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W47 | OEM-3-S | SL8-B-22 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W48 | OEM-2-D | SL8-A-20 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W49 | OEM-1-F | SL8-A-21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W50 | OEM-1-G | SL8-A-22 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W51 | OEM-1-P | SL8-A-23 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W52 | OEM-1-V | SL8-A-24 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W53 | OEM-3-I | SL8-A-25 | 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 | SL8-A-34 | SL8-B-10 | open (OL) | +12 V supply must not touch sensor ground | |
| 2 | SL8-A-34 | SL8-B-18 | open (OL) | +12 V supply must not touch power ground | |
| 3 | SL8-B-2 | SL8-B-10 | open (OL) | 5 V sensor reference must not touch sensor ground | |
| 4 | SL8-B-2 | SL8-B-18 | open (OL) | 5 V sensor reference must not touch power ground | |
| 5 | SL8-A-34 | SL8-B-2 | open (OL) | +12 V supply must not touch 5 V sensor reference |
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) | — | W1 | — | 0.85 | SP-14V-1 | — | — | — |
| E | Malfunction indicator lamp (MIL) | — | W31 | — | 0.5 | SL8-A-12 | — | — | — |
| F | Brake switch | — | W49 | — | 0.5 | SL8-A-21 | — | — | — |
| G | Power steering pressure switch | — | W50 | — | 0.5 | SL8-A-22 | — | — | — |
| I | Condenser fan relay | — | W24 | — | 0.5 | SL8-B-3 | — | — | — |
| O | Alternator control | — | W32 | — | 0.5 | SL8-A-13 | — | — | — |
| P | A/C request | — | W51 | — | 0.5 | SL8-A-23 | — | — | — |
| Q | Charge lamp | — | W33 | — | 0.5 | SL8-A-5 | — | — | — |
| R | Cooling fan relay | — | W25 | — | 0.5 | SL8-A-14 | — | — | — |
| S | A/C clutch relay | — | W26 | — | 0.5 | SL8-A-15 | — | — | — |
| U | Front O2 heater | — | W28 | — | 0.5 | SL8-A-17 | — | — | — |
| V | Neutral switch | — | W52 | — | 0.5 | SL8-A-24 | — | — | — |
OEM-2
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A | Fuel tank pressure | — | W45 | — | 0.5 | SL8-B-20 | — | — | — |
| B | Intake air temperature (IAT) | — | W44 | — | 0.5 | SL8-B-19 | — | — | — |
| C | Front O2 signal | — | W41 | — | 0.5 | SL8-B-13 | — | — | — |
| D | Vehicle speed | — | W48 | — | 0.5 | SL8-A-20 | — | — | — |
| E | Coolant temperature (ECT) | — | W43 | — | 0.5 | SL8-B-15 | — | — | — |
| F | Knock sensor | — | W17 | — | 0.5 | SL8-B-16 | — | — | — |
| H | Cam position (CMP) | — | W15 | — | 0.5 | SL8-B-7 | — | — | — |
| I | +5V sensor supply | — | W12 | — | 0.5 | SL8-B-2 | — | — | — |
| J | Crank position (CKP) | — | W13 | — | 0.5 | SL8-B-5 | — | — | — |
| K | Tachometer output | — | — | — | — | — | — | — | — |
| L | Mass air flow (MAF) | — | W39 | — | 0.5 | SL8-B-11 | — | — | — |
| M | EGR valve | — | W34 | — | 0.5 | SL8-A-6 | — | — | — |
| N | EGR valve | — | W35 | — | 0.5 | SL8-A-7 | — | — | — |
| O | EGR valve | — | W36 | — | 0.5 | SL8-A-8 | — | — | — |
| P | EGR valve | — | W37 | — | 0.5 | SL8-A-18 | — | — | — |
OEM-3
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A | Power ground | — | W5 | — | 0.85 | SP-GND-1 | — | — | — |
| B | Power ground | — | W6 | — | 0.85 | SP-GND-1 | — | — | — |
| C | Power ground | — | W7 | — | 0.85 | SP-GND-1 | — | — | — |
| E | Throttle position (TPS) | — | W40 | — | 0.5 | SL8-B-12 | — | — | — |
| F | Signal ground | — | W10 | — | 0.5 | SP-0V-1 | — | — | — |
| G | Ignition 1 (coils 1+4, wasted spark) | — | W18 | — | 0.5 | SL8-A-26 | — | — | — |
| H | Ignition 2 (coils 2+3, wasted spark) | — | W19 | — | 0.5 | SL8-A-27 | — | — | — |
| I | Clutch switch | — | W53 | — | 0.5 | SL8-A-25 | — | — | — |
| J | Rear O2 signal | — | W42 | — | 0.5 | SL8-B-14 | — | — | — |
| K | Fuel level | — | W46 | — | 0.5 | SL8-B-21 | — | — | — |
| L | Evap purge solenoid | — | W38 | — | 0.5 | SL8-A-19 | — | — | — |
| M | ISC valve +14V feed | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
| N | Fuel pump relay | — | W27 | — | 0.5 | SL8-A-16 | — | — | — |
| O | ISC valve low side | — | W30 | — | 0.5 | SL8-A-11 | — | — | — |
| Q | VICS solenoid (intake butterflies) | — | — | — | — | — | — | — | — |
| S | EGR boost sensor | — | W47 | — | 0.5 | SL8-B-22 | — | — | — |
| T | EGR boost solenoid | — | — | — | — | — | — | — | — |
| U | Canister drain cut valve (CDCV) | — | — | — | — | — | — | — | — |
| V | Rear O2 heater | — | W29 | — | 0.5 | SL8-A-10 | — | — | — |
| W | Injector 1 | — | W20 | — | 0.5 | SL8-A-1 | — | — | — |
| X | Injector 2 | — | W21 | — | 0.5 | SL8-A-2 | — | — | — |
| Y | Injector 3 | — | W22 | — | 0.5 | SL8-A-3 | — | — | — |
| Z | Injector 4 | — | W23 | — | 0.5 | SL8-A-4 | — | — | — |
SL8-A
Mating face
Wire side
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Injection channel 1 | — | W20 | — | 0.5 | OEM-3-W | — | — | — |
| 2 | Injection channel 2 | — | W21 | — | 0.5 | OEM-3-X | — | — | — |
| 3 | Injection channel 3 | — | W22 | — | 0.5 | OEM-3-Y | — | — | — |
| 4 | Injection channel 4 | — | W23 | — | 0.5 | OEM-3-Z | — | — | — |
| 5 | Injection channel 5 | — | W33 | — | 0.5 | OEM-1-Q | — | — | — |
| 6 | Injection channel 6 | — | W34 | — | 0.5 | OEM-2-M | — | — | — |
| 7 | Injection channel 7 | — | W35 | — | 0.5 | OEM-2-N | — | — | — |
| 8 | Injection channel 8 | — | W36 | — | 0.5 | OEM-2-O | — | — | — |
| 9 | Sensor supply 8V | — | — | — | — | — | — | — | — |
| 10 | Auxiliary output 1 | — | W29 | — | 0.5 | OEM-3-V | — | — | — |
| 11 | Auxiliary output 2 | — | W30 | — | 0.5 | OEM-3-O | — | — | — |
| 12 | Auxiliary output 3 | — | W31 | — | 0.5 | OEM-1-E | — | — | — |
| 13 | Auxiliary output 4 | — | W32 | — | 0.5 | OEM-1-O | — | — | — |
| 14 | Auxiliary output 5 | — | W25 | — | 0.5 | OEM-1-R | — | — | — |
| 15 | Auxiliary output 6 | — | W26 | — | 0.5 | OEM-1-S | — | — | — |
| 16 | Auxiliary output 7 | — | W27 | — | 0.5 | OEM-3-N | — | — | — |
| 17 | Auxiliary output 8 | — | W28 | — | 0.5 | OEM-1-U | — | — | — |
| 18 | Auxiliary output 9 | — | W37 | — | 0.5 | OEM-2-P | — | — | — |
| 19 | Auxiliary output 10 | — | W38 | — | 0.5 | OEM-3-L | — | — | — |
| 20 | Digital input 1 | — | W48 | — | 0.5 | OEM-2-D | — | — | — |
| 21 | Digital input 2 | — | W49 | — | 0.5 | OEM-1-F | — | — | — |
| 22 | Digital input 3 | — | W50 | — | 0.5 | OEM-1-G | — | — | — |
| 23 | Digital input 4 | — | W51 | — | 0.5 | OEM-1-P | — | — | — |
| 24 | Digital input 5 | — | W52 | — | 0.5 | OEM-1-V | — | — | — |
| 25 | Digital input 6 | — | W53 | — | 0.5 | OEM-3-I | — | — | — |
| 26 | Ignition channel 1 | — | W18 | — | 0.5 | OEM-3-G | — | — | — |
| 27 | Ignition channel 2 | — | W19 | — | 0.5 | OEM-3-H | — | — | — |
| 28 | Ignition channel 3 | — | — | — | — | — | — | — | — |
| 29 | Ignition channel 4 | — | — | — | — | — | — | — | — |
| 30 | Ignition channel 5 | — | — | — | — | — | — | — | — |
| 31 | Ignition channel 6 | — | — | — | — | — | — | — | — |
| 32 | Ignition channel 7 | — | — | — | — | — | — | — | — |
| 33 | Ignition channel 8 | — | — | — | — | — | — | — | — |
| 34 | Aux 9–10 14V supply | — | W3 | — | 0.85 | SP-14V-1 | — | — | — |
SL8-B
Mating face
Wire side
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | ECU 14V supply | — | W4 | — | 0.85 | SP-14V-1 | — | — | — |
| 2 | Sensor supply Vref1 5.0V | — | W12 | — | 0.5 | OEM-2-I | — | — | — |
| 3 | EFI relay output (low side, 200 mA) | — | W24 | — | 0.5 | OEM-1-I | — | — | — |
| 4 | Ignition switch input | — | — | — | — | — | — | — | — |
| 5 | Crank index sensor + | — | W13 | — | 0.5 | OEM-2-J | — | — | — |
| 6 | Crank index sensor − | — | W14 | — | 0.5 | SP-0V-1 | — | — | — |
| 7 | Sync sensor + | — | W15 | — | 0.5 | OEM-2-H | — | — | — |
| 8 | Sync sensor − | — | W16 | — | 0.5 | SP-0V-1 | — | — | — |
| 9 | Shield (crank/sync/knock) | — | — | — | — | — | — | — | — |
| 10 | Analog sensor 0V reference | — | W11 | — | 0.5 | SP-0V-1 | — | — | — |
| 11 | Analog input 1 | — | W39 | — | 0.5 | OEM-2-L | — | — | — |
| 12 | Analog input 2 | — | W40 | — | 0.5 | OEM-3-E | — | — | — |
| 13 | Analog input 3 | — | W41 | — | 0.5 | OEM-2-C | — | — | — |
| 14 | Analog input 4 | — | W42 | — | 0.5 | OEM-3-J | — | — | — |
| 15 | Analog input 5 | — | W43 | — | 0.5 | OEM-2-E | — | — | — |
| 16 | Knock 1 + | — | W17 | — | 0.5 | OEM-2-F | — | — | — |
| 17 | Knock 1 − | — | — | — | — | — | — | — | — |
| 18 | ECU ground | — | W8 | — | 0.85 | SP-GND-1 | — | — | — |
| 19 | Analog input 6 | — | W44 | — | 0.5 | OEM-2-B | — | — | — |
| 20 | Analog input 7 (switchable 1k pull-up) | — | W45 | — | 0.5 | OEM-2-A | — | — | — |
| 21 | Analog input 8 (switchable 1k pull-up) | — | W46 | — | 0.5 | OEM-3-K | — | — | — |
| 22 | Analog input 9 (switchable 1k pull-up) | — | W47 | — | 0.5 | OEM-3-S | — | — | — |
| 23 | Analog input 10 (switchable 1k pull-up) | — | — | — | — | — | — | — | — |
| 24 | Knock 2 + | — | — | — | — | — | — | — | — |
| 25 | Knock 2 − | — | — | — | — | — | — | — | — |
| 26 | ECU ground | — | W9 | — | 0.85 | SP-GND-1 | — | — | — |
| 27 | CAN 1 H | — | — | — | — | — | — | — | — |
| 28 | CAN 1 L | — | — | — | — | — | — | — | — |
| 29 | NC | — | — | — | — | — | — | — | — |
| 30 | NC | — | — | — | — | — | — | — | — |
| 31 | Ethernet Tx + | — | — | — | — | — | — | — | — |
| 32 | Ethernet Tx − | — | — | — | — | — | — | — | — |
| 33 | Ethernet Rx + | — | — | — | — | — | — | — | — |
| 34 | Ethernet Rx − | — | — | — | — | — | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W16 | — | 0.5 | SL8-B-8 | — | — | — |
| 1 | — | — | W10 | — | 0.5 | OEM-3-F | — | — | — |
| 1 | — | — | W11 | — | 0.5 | SL8-B-10 | — | — | — |
| 1 | — | — | W14 | — | 0.5 | SL8-B-6 | — | — | — |
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 | SL8-A-34 | — | — | — |
| 1 | — | — | W4 | — | 0.85 | SL8-B-1 | — | — | — |
SP-GND
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W5 | — | 0.85 | OEM-3-A | — | — | — |
| 1 | — | — | W6 | — | 0.85 | OEM-3-B | — | — | — |
| 1 | — | — | W7 | — | 0.85 | OEM-3-C | — | — | — |
| 1 | — | — | W8 | — | 0.85 | SL8-B-18 | — | — | — |
| 1 | — | — | W9 | — | 0.85 | SL8-B-26 | — | — | — |
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 | SL8-A-34 + SL8-B-1 | Aux 9–10 14V supply + ECU 14V supply | power_in | single_source | |
| OEM-1-E | Malfunction indicator lamp (MIL) | low_side_out | SL8-A-12 | Auxiliary output 3 | switch_out | single_source | |
| OEM-1-F | Brake switch | digital_in | SL8-A-21 | Digital input 2 | digital_in | single_source | |
| OEM-1-G | Power steering pressure switch | digital_in | SL8-A-22 | Digital input 3 | digital_in | single_source | |
| OEM-1-I | Condenser fan relay | low_side_out | SL8-B-3 | EFI relay output (low side, 200 mA) | low_side_out | single_source | |
| OEM-1-O | Alternator control | low_side_out | SL8-A-13 | Auxiliary output 4 | switch_out | single_source | |
| OEM-1-P | A/C request | digital_in | SL8-A-23 | Digital input 4 | digital_in | single_source | |
| OEM-1-Q | Charge lamp | low_side_out | SL8-A-5 | Injection channel 5 | injector_out | single_source | |
| OEM-1-R | Cooling fan relay | low_side_out | SL8-A-14 | Auxiliary output 5 | switch_out | single_source | |
| OEM-1-S | A/C clutch relay | low_side_out | SL8-A-15 | Auxiliary output 6 | switch_out | single_source | |
| OEM-1-U | Front O2 heater | low_side_out | SL8-A-17 | Auxiliary output 8 | switch_out | single_source | |
| OEM-1-V | Neutral switch | digital_in | SL8-A-24 | Digital input 5 | digital_in | single_source | |
| OEM-2-A | Fuel tank pressure | analog_in | SL8-B-20 | Analog input 7 (switchable 1k pull-up) | analog_in | single_source | |
| OEM-2-B | Intake air temperature (IAT) | temp_in | SL8-B-19 | Analog input 6 | analog_in | single_source | |
| OEM-2-C | Front O2 signal | lambda_nb_in | SL8-B-13 | Analog input 3 | analog_in | single_source | |
| OEM-2-D | Vehicle speed | digital_in | SL8-A-20 | Digital input 1 | digital_in | single_source | |
| OEM-2-E | Coolant temperature (ECT) | temp_in | SL8-B-15 | Analog input 5 | analog_in | single_source | |
| OEM-2-F | Knock sensor | knock_in | SL8-B-16 | Knock 1 + | knock_in | single_source | |
| OEM-2-H | Cam position (CMP) | trigger_in | SL8-B-7 | Sync sensor + | trigger_in | single_source | |
| OEM-2-I | +5V sensor supply | vref | SL8-B-2 | Sensor supply Vref1 5.0V | vref | single_source | |
| OEM-2-J | Crank position (CKP) | trigger_in | SL8-B-5 | Crank index sensor + | trigger_in | single_source | |
| OEM-2-K | Tachometer output | tacho_out | — | — | — | single_source | |
| OEM-2-L | Mass air flow (MAF) | analog_in | SL8-B-11 | Analog input 1 | analog_in | single_source | |
| OEM-2-M | EGR valve | low_side_out | SL8-A-6 | Injection channel 6 | injector_out | single_source | |
| OEM-2-N | EGR valve | low_side_out | SL8-A-7 | Injection channel 7 | injector_out | single_source | |
| OEM-2-O | EGR valve | low_side_out | SL8-A-8 | Injection channel 8 | injector_out | single_source | |
| OEM-2-P | EGR valve | low_side_out | SL8-A-18 | Auxiliary output 9 | hbridge_out | single_source | |
| OEM-3-A | Power ground | ground | SL8-B-18 + SL8-B-26 | ECU ground + ECU ground | ground | single_source | |
| OEM-3-B | Power ground | ground | SL8-B-18 + SL8-B-26 | ECU ground + ECU ground | ground | single_source | |
| OEM-3-C | Power ground | ground | SL8-B-18 + SL8-B-26 | ECU ground + ECU ground | ground | single_source | |
| OEM-3-E | Throttle position (TPS) | analog_in | SL8-B-12 | Analog input 2 | analog_in | single_source | |
| OEM-3-F | Signal ground | sensor_ground | SL8-B-10 + SL8-B-6 + SL8-B-8 | Analog sensor 0V reference + Crank index sensor − + Sync sensor − | sensor_ground + trigger_in | single_source | |
| OEM-3-G | Ignition 1 (coils 1+4, wasted spark) | ignition_out | SL8-A-26 | Ignition channel 1 | ignition_out | single_source | |
| OEM-3-H | Ignition 2 (coils 2+3, wasted spark) | ignition_out | SL8-A-27 | Ignition channel 2 | ignition_out | single_source | |
| OEM-3-I | Clutch switch | digital_in | SL8-A-25 | Digital input 6 | digital_in | single_source | |
| OEM-3-J | Rear O2 signal | lambda_nb_in | SL8-B-14 | Analog input 4 | analog_in | single_source | |
| OEM-3-K | Fuel level | analog_in | SL8-B-21 | Analog input 8 (switchable 1k pull-up) | analog_in | single_source | |
| OEM-3-L | Evap purge solenoid | low_side_out | SL8-A-19 | Auxiliary output 10 | hbridge_out | single_source | |
| OEM-3-M | ISC valve +14V feed | power_in | SL8-A-34 + SL8-B-1 | Aux 9–10 14V supply + ECU 14V supply | power_in | single_source | |
| OEM-3-N | Fuel pump relay | low_side_out | SL8-A-16 | Auxiliary output 7 | switch_out | single_source | |
| OEM-3-O | ISC valve low side | low_side_out | SL8-A-11 | Auxiliary output 2 | switch_out | single_source | |
| OEM-3-Q | VICS solenoid (intake butterflies) | low_side_out | — | — | — | single_source | |
| OEM-3-S | EGR boost sensor | analog_in | SL8-B-22 | Analog input 9 (switchable 1k pull-up) | 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 | SL8-A-10 | Auxiliary output 1 | switch_out | single_source | |
| OEM-3-W | Injector 1 | injector_out | SL8-A-1 | Injection channel 1 | injector_out | single_source | |
| OEM-3-X | Injector 2 | injector_out | SL8-A-2 | Injection channel 2 | injector_out | single_source | |
| OEM-3-Y | Injector 3 | injector_out | SL8-A-3 | Injection channel 3 | injector_out | single_source | |
| OEM-3-Z | Injector 4 | injector_out | SL8-A-4 | Injection channel 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 | SL8-A-34 | 0.85 | no route | Aux 9–10 14V supply | — | |
| W4 | SP-14V-1 | SL8-B-1 | 0.85 | no route | ECU 14V supply | — | |
| W5 | OEM-3-A | SP-GND-1 | 0.85 | no route | Power ground | — | |
| W6 | OEM-3-B | SP-GND-1 | 0.85 | no route | Power ground | — | |
| W7 | OEM-3-C | SP-GND-1 | 0.85 | no route | Power ground | — | |
| W8 | SP-GND-1 | SL8-B-18 | 0.85 | no route | ECU ground | — | |
| W9 | SP-GND-1 | SL8-B-26 | 0.85 | no route | ECU ground | — | |
| W10 | OEM-3-F | SP-0V-1 | 0.5 | no route | Signal ground | — | |
| W11 | SP-0V-1 | SL8-B-10 | 0.5 | no route | Analog sensor 0V reference | — | |
| W12 | OEM-2-I | SL8-B-2 | 0.5 | no route | +5V sensor supply | — | |
| W13 | OEM-2-J | SL8-B-5 | 0.5 | no route | Crank position (CKP) | — | |
| W14 | SP-0V-1 | SL8-B-6 | 0.5 | no route | Crank index sensor − | — | |
| W15 | OEM-2-H | SL8-B-7 | 0.5 | no route | Cam position (CMP) | — | |
| W16 | SP-0V-1 | SL8-B-8 | 0.5 | no route | Sync sensor − | — | |
| W17 | OEM-2-F | SL8-B-16 | 0.5 | no route | Knock sensor | — | |
| W18 | OEM-3-G | SL8-A-26 | 0.5 | no route | Ignition 1 (coils 1+4, wasted spark) | — | |
| W19 | OEM-3-H | SL8-A-27 | 0.5 | no route | Ignition 2 (coils 2+3, wasted spark) | — | |
| W20 | OEM-3-W | SL8-A-1 | 0.5 | no route | Injector 1 | — | |
| W21 | OEM-3-X | SL8-A-2 | 0.5 | no route | Injector 2 | — | |
| W22 | OEM-3-Y | SL8-A-3 | 0.5 | no route | Injector 3 | — | |
| W23 | OEM-3-Z | SL8-A-4 | 0.5 | no route | Injector 4 | — | |
| W24 | OEM-1-I | SL8-B-3 | 0.5 | no route | Condenser fan relay | — | |
| W25 | OEM-1-R | SL8-A-14 | 0.5 | no route | Cooling fan relay | — | |
| W26 | OEM-1-S | SL8-A-15 | 0.5 | no route | A/C clutch relay | — | |
| W27 | OEM-3-N | SL8-A-16 | 0.5 | no route | Fuel pump relay | — | |
| W28 | OEM-1-U | SL8-A-17 | 0.5 | no route | Front O2 heater | — | |
| W29 | OEM-3-V | SL8-A-10 | 0.5 | no route | Rear O2 heater | — | |
| W30 | OEM-3-O | SL8-A-11 | 0.5 | no route | ISC valve low side | — | |
| W31 | OEM-1-E | SL8-A-12 | 0.5 | no route | Malfunction indicator lamp (MIL) | — | |
| W32 | OEM-1-O | SL8-A-13 | 0.5 | no route | Alternator control | — | |
| W33 | OEM-1-Q | SL8-A-5 | 0.5 | no route | Charge lamp | — | |
| W34 | OEM-2-M | SL8-A-6 | 0.5 | no route | EGR valve | — | |
| W35 | OEM-2-N | SL8-A-7 | 0.5 | no route | EGR valve | — | |
| W36 | OEM-2-O | SL8-A-8 | 0.5 | no route | EGR valve | — | |
| W37 | OEM-2-P | SL8-A-18 | 0.5 | no route | EGR valve | — | |
| W38 | OEM-3-L | SL8-A-19 | 0.5 | no route | Evap purge solenoid | — | |
| W39 | OEM-2-L | SL8-B-11 | 0.5 | no route | Mass air flow (MAF) | — | |
| W40 | OEM-3-E | SL8-B-12 | 0.5 | no route | Throttle position (TPS) | — | |
| W41 | OEM-2-C | SL8-B-13 | 0.5 | no route | Front O2 signal | — | |
| W42 | OEM-3-J | SL8-B-14 | 0.5 | no route | Rear O2 signal | — | |
| W43 | OEM-2-E | SL8-B-15 | 0.5 | no route | Coolant temperature (ECT) | — | |
| W44 | OEM-2-B | SL8-B-19 | 0.5 | no route | Intake air temperature (IAT) | — | |
| W45 | OEM-2-A | SL8-B-20 | 0.5 | no route | Fuel tank pressure | — | |
| W46 | OEM-3-K | SL8-B-21 | 0.5 | no route | Fuel level | — | |
| W47 | OEM-3-S | SL8-B-22 | 0.5 | no route | EGR boost sensor | — | |
| W48 | OEM-2-D | SL8-A-20 | 0.5 | no route | Vehicle speed | — | |
| W49 | OEM-1-F | SL8-A-21 | 0.5 | no route | Brake switch | — | |
| W50 | OEM-1-G | SL8-A-22 | 0.5 | no route | Power steering pressure switch | — | |
| W51 | OEM-1-P | SL8-A-23 | 0.5 | no route | A/C request | — | |
| W52 | OEM-1-V | SL8-A-24 | 0.5 | no route | Neutral switch | — | |
| W53 | OEM-3-I | SL8-A-25 | 0.5 | no route | Clutch 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 |
| connector | 4-1437290-0 | TE | Superseal 1.0 34-way plug, Key 1 | 1.000 | ea |
| connector | 4-1437290-1 | TE | Superseal 1.0 34-way plug, Key 2 | 1.000 | ea |
| terminal | 3-1447221-4 | TE | Superseal 1.0 socket terminal, 20 AWG (0.5 sq mm) | 47.000 | ea |
ECU setup sheet
| Role | Engine ref | Engine signal | Sensor | ECU point | ECU function | ECU class | Setup flag |
|---|---|---|---|---|---|---|---|
| No configured channels. | |||||||
Findings
Open (18)
| Severity | Code | Subject | Message |
|---|---|---|---|
| warn | NET_FAMILY | OEM-2-P ↔ SL8-A-18 | OEM-2-P "EGR valve" [low_side_out] is wired to SL8-A-18 "Auxiliary output 9" [hbridge_out]. A half-bridge can act as a low-side switch only if configured that way. |
| warn | NET_FAMILY | OEM-3-L ↔ SL8-A-19 | OEM-3-L "Evap purge solenoid" [low_side_out] is wired to SL8-A-19 "Auxiliary output 10" [hbridge_out]. A half-bridge can act as a low-side switch only if configured that way. |
| info | NET_FAMILY | OEM-1-E ↔ SL8-A-12 | OEM-1-E "Malfunction indicator lamp (MIL)" [low_side_out] is wired to SL8-A-12 "Auxiliary output 3" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-1-O ↔ SL8-A-13 | OEM-1-O "Alternator control" [low_side_out] is wired to SL8-A-13 "Auxiliary output 4" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-1-Q ↔ SL8-A-5 | OEM-1-Q "Charge lamp" [low_side_out] is wired to SL8-A-5 "Injection channel 5" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-1-R ↔ SL8-A-14 | OEM-1-R "Cooling fan relay" [low_side_out] is wired to SL8-A-14 "Auxiliary output 5" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-1-S ↔ SL8-A-15 | OEM-1-S "A/C clutch relay" [low_side_out] is wired to SL8-A-15 "Auxiliary output 6" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-1-U ↔ SL8-A-17 | OEM-1-U "Front O2 heater" [low_side_out] is wired to SL8-A-17 "Auxiliary output 8" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-2-B ↔ SL8-B-19 | OEM-2-B "Intake air temperature (IAT)" [temp_in] is wired to SL8-B-19 "Analog input 6" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one. |
| info | NET_FAMILY | OEM-2-E ↔ SL8-B-15 | OEM-2-E "Coolant temperature (ECT)" [temp_in] is wired to SL8-B-15 "Analog input 5" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one. |
| info | NET_FAMILY | OEM-2-M ↔ SL8-A-6 | OEM-2-M "EGR valve" [low_side_out] is wired to SL8-A-6 "Injection channel 6" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-2-N ↔ SL8-A-7 | OEM-2-N "EGR valve" [low_side_out] is wired to SL8-A-7 "Injection channel 7" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-2-O ↔ SL8-A-8 | OEM-2-O "EGR valve" [low_side_out] is wired to SL8-A-8 "Injection channel 8" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-3-N ↔ SL8-A-16 | OEM-3-N "Fuel pump relay" [low_side_out] is wired to SL8-A-16 "Auxiliary output 7" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-3-O ↔ SL8-A-11 | OEM-3-O "ISC valve low side" [low_side_out] is wired to SL8-A-11 "Auxiliary output 2" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-3-V ↔ SL8-A-10 | OEM-3-V "Rear O2 heater" [low_side_out] is wired to SL8-A-10 "Auxiliary output 1" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | SL8-B-8 ↔ SL8-B-10 | SL8-B-8 "Sync sensor −" [trigger_in] is wired to SL8-B-10 "Analog sensor 0V reference" [sensor_ground]. Trigger return tied to sensor/trigger ground: correct for single-ended trigger inputs. |
| info | UNMAPPED | OEM | 4 optional OEM pins are not mapped: OEM-2-K Tachometer output; OEM-3-Q VICS solenoid (intake butterflies); 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
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: Emtron SL8 has no battery-constant input; not needed - SL8-B 17: Knock 1 − left open: the stock knock sensor has one ECU wire; check the ECU manual for single-wire knock sensors - OEM-3 Q: VICS solenoid (intake butterflies): no free low_side/ls_hs/injector/hbridge on Emtron SL8 - OEM-3 T: EGR boost solenoid: no free low_side/ls_hs/injector/hbridge on Emtron SL8 - OEM-3 U: Canister drain cut valve (CDCV): no free low_side/ls_hs/injector/hbridge on Emtron SL8 - OEM-2 K: Tachometer output: no free tacho/frequency_out/low_side/ls_hs on Emtron SL8 - SL8-B 4: Ignition switch input: not fed (the stock ECU has no ignition-sense pin); feed it from a switched-ignition source
Sources
| Reliability | Kind | Title | URL | Archive | Captured | SHA-256 |
|---|---|---|---|---|---|---|
| 4 | vendor_doc | Emtron SL4/SL6/SL8 ECU datasheets | https://docs.emtronaustralia.com.au/engine-management/datasheets/index.html | archive | 2026-10-05 | 1e22846cec94 |
| 4 | vendor_doc | Emtron SL4/SL6/SL8 pinout pages | https://docs.emtronaustralia.com.au/engine-management/wiring/index.html | archive | 2026-10-05 | e52b3da9996a |
| 4 | vendor_doc | Link G4X MX5NB1X install manual (NB1 1999-00) | https://linkecu.com/documentation/MX5XNB1.pdf | archive | 2026-10-05 | 2e36c91270cc |