MX-5 Miata NA8 1996-97 (BP-ZE, 1.8, OBD-II) → Emtron SL8 (auto)
MX-5 Miata NA8 1996-97 (BP-ZE, 1.8, OBD-II) — Emtron — SL8
⚠ NOT CHECKED. Don't build from this.
Drawn by Michael Gnankou · Rev 0 · draft · 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 | draft · not yet verified: nobody has reported building and running this harness |
|---|---|
| Open errors | 1: read the Findings page before cutting any wire |
| Size of the job | 50 wires · 8 connectors · 3 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-4-B | SP-14V-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W2 | SP-14V-1 | SL8-A-34 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W3 | SP-14V-1 | SL8-B-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W4 | OEM-4-A | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W5 | OEM-4-C | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W6 | OEM-4-D | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W7 | OEM-4-K | 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-O | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | OEM-4-H | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | SP-0V-1 | SL8-B-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | OEM-3-I | SL8-B-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | OEM-4-E | SL8-B-5 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | SP-0V-1 | SL8-B-6 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | OEM-4-G | SL8-B-7 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | SP-0V-1 | SL8-B-8 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-4-N | SL8-A-26 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-4-R | SL8-A-27 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-4-U | SL8-A-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-4-V | SL8-A-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-4-W | SL8-A-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-4-X | SL8-A-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-3-B | SL8-B-11 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-3-F | SL8-B-12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-3-G | SL8-B-13 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-1-A | SL8-B-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-1-B | SL8-A-14 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-1-G | SL8-A-15 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | OEM-1-U | SL8-A-16 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-3-M | SL8-A-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-1-E | SL8-A-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-4-J | SL8-A-11 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-4-O | SL8-A-12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W35 | OEM-4-P | SL8-A-13 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W36 | OEM-4-Q | SL8-A-5 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W37 | OEM-4-T | SL8-A-6 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W38 | OEM-3-H | SL8-B-14 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W39 | OEM-3-N | SL8-B-15 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W40 | OEM-3-C | SL8-B-19 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W41 | OEM-3-D | SL8-B-20 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W42 | OEM-3-K | SL8-B-21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W43 | OEM-3-J | SL8-B-22 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W44 | OEM-1-M | SL8-A-20 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W45 | OEM-1-C | SL8-A-21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W46 | OEM-1-K | SL8-A-22 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W47 | OEM-1-L | SL8-A-23 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W48 | OEM-1-Q | SL8-A-24 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W49 | OEM-3-L | SL8-A-25 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W50 | OEM-3-P | SL8-B-23 | 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-B-2 | SL8-B-10 | open (OL) | 5 V sensor reference must not touch sensor ground | |
| 2 | SL8-B-2 | SL8-B-18 | open (OL) | 5 V sensor reference must not touch power ground | |
| 3 | SL8-B-10 | SL8-A-34 | open (OL) | sensor ground must not touch +12 V supply | |
| 4 | SL8-B-18 | SL8-A-34 | open (OL) | power ground must not touch +12 V supply | |
| 5 | SL8-B-2 | SL8-A-34 | open (OL) | 5 V sensor reference 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
OEM-1
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A | Cooling fan relay (low-side) | — | W27 | — | 0.5 | SL8-B-3 | — | — | — |
| B | A/C condenser fan relay | — | W28 | — | 0.5 | SL8-A-14 | — | — | — |
| C | Starter input (12V while cranking) | — | W45 | — | 0.5 | SL8-A-21 | — | — | — |
| E | Check engine light (MIL) | — | W32 | — | 0.5 | SL8-A-10 | — | — | — |
| G | A/C clutch relay | — | W29 | — | 0.5 | SL8-A-15 | — | — | — |
| K | A/C pressure switch (A/C request) | — | W46 | — | 0.5 | SL8-A-22 | — | — | — |
| L | Clutch switch | — | W47 | — | 0.5 | SL8-A-23 | — | — | — |
| M | Vehicle speed sensor (VSS) | — | W44 | — | 0.5 | SL8-A-20 | — | — | — |
| Q | Brake switch | — | W48 | — | 0.5 | SL8-A-24 | — | — | — |
| U | Fuel pump relay (low-side) | — | W30 | — | 0.5 | SL8-A-16 | — | — | — |
OEM-3
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| B | MAF sensor input | — | W24 | — | 0.5 | SL8-B-11 | — | — | — |
| C | Front O2 sensor input | — | W40 | — | 0.5 | SL8-B-19 | — | — | — |
| D | Rear O2 sensor input | — | W41 | — | 0.5 | SL8-B-20 | — | — | — |
| F | Throttle position (TPS) | — | W25 | — | 0.5 | SL8-B-12 | — | — | — |
| G | Engine coolant temp (CLT) | — | W26 | — | 0.5 | SL8-B-13 | — | — | — |
| H | EGR boost sensor | — | W38 | — | 0.5 | SL8-B-14 | — | — | — |
| I | +5V sensor reference | — | W13 | — | 0.5 | SL8-B-2 | — | — | — |
| J | EGR valve position sensor | — | W43 | — | 0.5 | SL8-B-22 | — | — | — |
| K | Intake air temp (IAT) | — | W42 | — | 0.5 | SL8-B-21 | — | — | — |
| L | Idle switch (closed throttle) | — | W49 | — | 0.5 | SL8-A-25 | — | — | — |
| M | Front O2 heater control | — | W31 | — | 0.5 | SL8-A-17 | — | — | — |
| N | EGR boost sensor (2nd channel) | — | W39 | — | 0.5 | SL8-B-15 | — | — | — |
| O | Sensor ground | — | W10 | — | 0.5 | SP-0V-1 | — | — | — |
| P | Power steering pressure switch | — | W50 | — | 0.5 | SL8-B-23 | — | — | — |
OEM-4
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A | Chassis ground | — | W4 | — | 0.85 | SP-GND-1 | — | — | — |
| B | ECU power +12V (main relay) | — | W1 | — | 0.85 | SP-14V-1 | — | — | — |
| C | Chassis ground | — | W5 | — | 0.85 | SP-GND-1 | — | — | — |
| D | Chassis ground | — | W6 | — | 0.85 | SP-GND-1 | — | — | — |
| E | Crank position (CKP) sensor | — | W14 | — | 0.5 | SL8-B-5 | — | — | — |
| F | CAS SGT (cam trigger) | — | — | — | — | — | — | — | — |
| G | CAS SGC (cam sync) | — | W16 | — | 0.5 | SL8-B-7 | — | — | — |
| H | Crank pickup timing ground (CKP gnd) | — | W11 | — | 0.5 | SP-0V-1 | — | — | — |
| I | Permanent +12V (battery) | — | — | — | — | — | — | — | — |
| J | PRC solenoid (FPR control) | — | W33 | — | 0.5 | SL8-A-11 | — | — | — |
| K | Chassis ground | — | W7 | — | 0.85 | SP-GND-1 | — | — | — |
| L | Tachometer output | — | — | — | — | — | — | — | — |
| N | Ignition coil trigger (cyl 1&4) | — | W18 | — | 0.5 | SL8-A-26 | — | — | — |
| O | EGR vent solenoid | — | W34 | — | 0.5 | SL8-A-12 | — | — | — |
| P | EGR vacuum solenoid | — | W35 | — | 0.5 | SL8-A-13 | — | — | — |
| Q | Idle air control (IAC) valve | — | W36 | — | 0.5 | SL8-A-5 | — | — | — |
| R | Ignition coil trigger (cyl 2&3) | — | W19 | — | 0.5 | SL8-A-27 | — | — | — |
| T | EVAP purge solenoid | — | W37 | — | 0.5 | SL8-A-6 | — | — | — |
| U | Injector 1 (cyl 1) | — | W20 | — | 0.5 | SL8-A-1 | — | — | — |
| V | Injector 2 (cyl 2) | — | W21 | — | 0.5 | SL8-A-2 | — | — | — |
| W | Injector 3 (cyl 3) | — | W22 | — | 0.5 | SL8-A-3 | — | — | — |
| X | Injector 4 (cyl 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-4-U | — | — | — |
| 2 | Injection channel 2 | — | W21 | — | 0.5 | OEM-4-V | — | — | — |
| 3 | Injection channel 3 | — | W22 | — | 0.5 | OEM-4-W | — | — | — |
| 4 | Injection channel 4 | — | W23 | — | 0.5 | OEM-4-X | — | — | — |
| 5 | Injection channel 5 | — | W36 | — | 0.5 | OEM-4-Q | — | — | — |
| 6 | Injection channel 6 | — | W37 | — | 0.5 | OEM-4-T | — | — | — |
| 7 | Injection channel 7 | — | — | — | — | — | — | — | — |
| 8 | Injection channel 8 | — | — | — | — | — | — | — | — |
| 9 | Sensor supply 8V | — | — | — | — | — | — | — | — |
| 10 | Auxiliary output 1 | — | W32 | — | 0.5 | OEM-1-E | — | — | — |
| 11 | Auxiliary output 2 | — | W33 | — | 0.5 | OEM-4-J | — | — | — |
| 12 | Auxiliary output 3 | — | W34 | — | 0.5 | OEM-4-O | — | — | — |
| 13 | Auxiliary output 4 | — | W35 | — | 0.5 | OEM-4-P | — | — | — |
| 14 | Auxiliary output 5 | — | W28 | — | 0.5 | OEM-1-B | — | — | — |
| 15 | Auxiliary output 6 | — | W29 | — | 0.5 | OEM-1-G | — | — | — |
| 16 | Auxiliary output 7 | — | W30 | — | 0.5 | OEM-1-U | — | — | — |
| 17 | Auxiliary output 8 | — | W31 | — | 0.5 | OEM-3-M | — | — | — |
| 18 | Auxiliary output 9 | — | — | — | — | — | — | — | — |
| 19 | Auxiliary output 10 | — | — | — | — | — | — | — | — |
| 20 | Digital input 1 | — | W44 | — | 0.5 | OEM-1-M | — | — | — |
| 21 | Digital input 2 | — | W45 | — | 0.5 | OEM-1-C | — | — | — |
| 22 | Digital input 3 | — | W46 | — | 0.5 | OEM-1-K | — | — | — |
| 23 | Digital input 4 | — | W47 | — | 0.5 | OEM-1-L | — | — | — |
| 24 | Digital input 5 | — | W48 | — | 0.5 | OEM-1-Q | — | — | — |
| 25 | Digital input 6 | — | W49 | — | 0.5 | OEM-3-L | — | — | — |
| 26 | Ignition channel 1 | — | W18 | — | 0.5 | OEM-4-N | — | — | — |
| 27 | Ignition channel 2 | — | W19 | — | 0.5 | OEM-4-R | — | — | — |
| 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 | — | W2 | — | 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 | — | W3 | — | 0.85 | SP-14V-1 | — | — | — |
| 2 | Sensor supply Vref1 5.0V | — | W13 | — | 0.5 | OEM-3-I | — | — | — |
| 3 | EFI relay output (low side, 200 mA) | — | W27 | — | 0.5 | OEM-1-A | — | — | — |
| 4 | Ignition switch input | — | — | — | — | — | — | — | — |
| 5 | Crank index sensor + | — | W14 | — | 0.5 | OEM-4-E | — | — | — |
| 6 | Crank index sensor − | — | W15 | — | 0.5 | SP-0V-1 | — | — | — |
| 7 | Sync sensor + | — | W16 | — | 0.5 | OEM-4-G | — | — | — |
| 8 | Sync sensor − | — | W17 | — | 0.5 | SP-0V-1 | — | — | — |
| 9 | Shield (crank/sync/knock) | — | — | — | — | — | — | — | — |
| 10 | Analog sensor 0V reference | — | W12 | — | 0.5 | SP-0V-1 | — | — | — |
| 11 | Analog input 1 | — | W24 | — | 0.5 | OEM-3-B | — | — | — |
| 12 | Analog input 2 | — | W25 | — | 0.5 | OEM-3-F | — | — | — |
| 13 | Analog input 3 | — | W26 | — | 0.5 | OEM-3-G | — | — | — |
| 14 | Analog input 4 | — | W38 | — | 0.5 | OEM-3-H | — | — | — |
| 15 | Analog input 5 | — | W39 | — | 0.5 | OEM-3-N | — | — | — |
| 16 | Knock 1 + | — | — | — | — | — | — | — | — |
| 17 | Knock 1 − | — | — | — | — | — | — | — | — |
| 18 | ECU ground | — | W8 | — | 0.85 | SP-GND-1 | — | — | — |
| 19 | Analog input 6 | — | W40 | — | 0.5 | OEM-3-C | — | — | — |
| 20 | Analog input 7 (switchable 1k pull-up) | — | W41 | — | 0.5 | OEM-3-D | — | — | — |
| 21 | Analog input 8 (switchable 1k pull-up) | — | W42 | — | 0.5 | OEM-3-K | — | — | — |
| 22 | Analog input 9 (switchable 1k pull-up) | — | W43 | — | 0.5 | OEM-3-J | — | — | — |
| 23 | Analog input 10 (switchable 1k pull-up) | — | W50 | — | 0.5 | OEM-3-P | — | — | — |
| 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 | — | — | W17 | — | 0.5 | SL8-B-8 | — | — | — |
| 1 | — | — | W10 | — | 0.5 | OEM-3-O | — | — | — |
| 1 | — | — | W11 | — | 0.5 | OEM-4-H | — | — | — |
| 1 | — | — | W12 | — | 0.5 | SL8-B-10 | — | — | — |
| 1 | — | — | W15 | — | 0.5 | SL8-B-6 | — | — | — |
SP-14V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W1 | — | 0.85 | OEM-4-B | — | — | — |
| 1 | — | — | W2 | — | 0.85 | SL8-A-34 | — | — | — |
| 1 | — | — | W3 | — | 0.85 | SL8-B-1 | — | — | — |
SP-GND
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W4 | — | 0.85 | OEM-4-A | — | — | — |
| 1 | — | — | W5 | — | 0.85 | OEM-4-C | — | — | — |
| 1 | — | — | W6 | — | 0.85 | OEM-4-D | — | — | — |
| 1 | — | — | W7 | — | 0.85 | OEM-4-K | — | — | — |
| 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 | Cooling fan relay (low-side) | low_side_out | SL8-B-3 | EFI relay output (low side, 200 mA) | low_side_out | corroborated | |
| OEM-1-B | A/C condenser fan relay | low_side_out | SL8-A-14 | Auxiliary output 5 | switch_out | corroborated | |
| OEM-1-C | Starter input (12V while cranking) | digital_in | SL8-A-21 | Digital input 2 | digital_in | corroborated | |
| OEM-1-E | Check engine light (MIL) | low_side_out | SL8-A-10 | Auxiliary output 1 | switch_out | corroborated | |
| OEM-1-G | A/C clutch relay | low_side_out | SL8-A-15 | Auxiliary output 6 | switch_out | corroborated | |
| OEM-1-K | A/C pressure switch (A/C request) | digital_in | SL8-A-22 | Digital input 3 | digital_in | corroborated | |
| OEM-1-L | Clutch switch | digital_in | SL8-A-23 | Digital input 4 | digital_in | corroborated | |
| OEM-1-M | Vehicle speed sensor (VSS) | digital_in | SL8-A-20 | Digital input 1 | digital_in | corroborated | |
| OEM-1-Q | Brake switch | digital_in | SL8-A-24 | Digital input 5 | digital_in | corroborated | |
| OEM-1-U | Fuel pump relay (low-side) | low_side_out | SL8-A-16 | Auxiliary output 7 | switch_out | corroborated | |
| OEM-3-B | MAF sensor input | analog_in | SL8-B-11 | Analog input 1 | analog_in | corroborated | |
| OEM-3-C | Front O2 sensor input | lambda_nb_in | SL8-B-19 | Analog input 6 | analog_in | corroborated | |
| OEM-3-D | Rear O2 sensor input | lambda_nb_in | SL8-B-20 | Analog input 7 (switchable 1k pull-up) | analog_in | corroborated | |
| OEM-3-F | Throttle position (TPS) | analog_in | SL8-B-12 | Analog input 2 | analog_in | corroborated | |
| OEM-3-G | Engine coolant temp (CLT) | temp_in | SL8-B-13 | Analog input 3 | analog_in | corroborated | |
| OEM-3-H | EGR boost sensor | analog_in | SL8-B-14 | Analog input 4 | analog_in | corroborated | |
| OEM-3-I | +5V sensor reference | vref | SL8-B-2 | Sensor supply Vref1 5.0V | vref | corroborated | |
| OEM-3-J | EGR valve position sensor | analog_in | SL8-B-22 | Analog input 9 (switchable 1k pull-up) | analog_in | corroborated | |
| OEM-3-K | Intake air temp (IAT) | temp_in | SL8-B-21 | Analog input 8 (switchable 1k pull-up) | analog_in | corroborated | |
| OEM-3-L | Idle switch (closed throttle) | digital_in | SL8-A-25 | Digital input 6 | digital_in | corroborated | |
| OEM-3-M | Front O2 heater control | low_side_out | SL8-A-17 | Auxiliary output 8 | switch_out | corroborated | |
| OEM-3-N | EGR boost sensor (2nd channel) | analog_in | SL8-B-15 | Analog input 5 | analog_in | corroborated | |
| OEM-3-O | Sensor 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 | corroborated | |
| OEM-3-P | Power steering pressure switch | digital_in | SL8-B-23 | Analog input 10 (switchable 1k pull-up) | analog_in | corroborated | |
| OEM-4-A | Chassis ground | ground | SL8-B-18 + SL8-B-26 | ECU ground + ECU ground | ground | corroborated | |
| OEM-4-B | ECU power +12V (main relay) | power_in | SL8-A-34 + SL8-B-1 | Aux 9–10 14V supply + ECU 14V supply | power_in | corroborated | |
| OEM-4-C | Chassis ground | ground | SL8-B-18 + SL8-B-26 | ECU ground + ECU ground | ground | corroborated | |
| OEM-4-D | Chassis ground | ground | SL8-B-18 + SL8-B-26 | ECU ground + ECU ground | ground | corroborated | |
| OEM-4-E | Crank position (CKP) sensor | trigger_in | SL8-B-5 | Crank index sensor + | trigger_in | corroborated | |
| OEM-4-F | CAS SGT (cam trigger) | trigger_in | — | — | — | corroborated | |
| OEM-4-G | CAS SGC (cam sync) | trigger_in | SL8-B-7 | Sync sensor + | trigger_in | corroborated | |
| OEM-4-H | Crank pickup timing ground (CKP gnd) | sensor_ground | SL8-B-10 + SL8-B-6 + SL8-B-8 | Analog sensor 0V reference + Crank index sensor − + Sync sensor − | sensor_ground + trigger_in | corroborated | |
| OEM-4-I | Permanent +12V (battery) | power_in | — | — | — | corroborated | |
| OEM-4-J | PRC solenoid (FPR control) | low_side_out | SL8-A-11 | Auxiliary output 2 | switch_out | corroborated | |
| OEM-4-K | Chassis ground | ground | SL8-B-18 + SL8-B-26 | ECU ground + ECU ground | ground | corroborated | |
| OEM-4-L | Tachometer output | tacho_out | — | — | — | corroborated | |
| OEM-4-N | Ignition coil trigger (cyl 1&4) | ignition_out | SL8-A-26 | Ignition channel 1 | ignition_out | corroborated | |
| OEM-4-O | EGR vent solenoid | low_side_out | SL8-A-12 | Auxiliary output 3 | switch_out | corroborated | |
| OEM-4-P | EGR vacuum solenoid | low_side_out | SL8-A-13 | Auxiliary output 4 | switch_out | corroborated | |
| OEM-4-Q | Idle air control (IAC) valve | low_side_out | SL8-A-5 | Injection channel 5 | injector_out | corroborated | |
| OEM-4-R | Ignition coil trigger (cyl 2&3) | ignition_out | SL8-A-27 | Ignition channel 2 | ignition_out | corroborated | |
| OEM-4-T | EVAP purge solenoid | low_side_out | SL8-A-6 | Injection channel 6 | injector_out | corroborated | |
| OEM-4-U | Injector 1 (cyl 1) | injector_out | SL8-A-1 | Injection channel 1 | injector_out | corroborated | |
| OEM-4-V | Injector 2 (cyl 2) | injector_out | SL8-A-2 | Injection channel 2 | injector_out | corroborated | |
| OEM-4-W | Injector 3 (cyl 3) | injector_out | SL8-A-3 | Injection channel 3 | injector_out | corroborated | |
| OEM-4-X | Injector 4 (cyl 4) | injector_out | SL8-A-4 | Injection channel 4 | 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 | SL8-A-34 | 0.85 | no route | Aux 9–10 14V supply | — | |
| W3 | SP-14V-1 | SL8-B-1 | 0.85 | no route | ECU 14V supply | — | |
| W4 | OEM-4-A | SP-GND-1 | 0.85 | no route | Chassis ground | — | |
| W5 | OEM-4-C | SP-GND-1 | 0.85 | no route | Chassis ground | — | |
| W6 | OEM-4-D | SP-GND-1 | 0.85 | no route | Chassis ground | — | |
| W7 | OEM-4-K | SP-GND-1 | 0.85 | no route | Chassis 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-O | SP-0V-1 | 0.5 | no route | Sensor ground | — | |
| W11 | OEM-4-H | SP-0V-1 | 0.5 | no route | Crank pickup timing ground (CKP gnd) | — | |
| W12 | SP-0V-1 | SL8-B-10 | 0.5 | no route | Analog sensor 0V reference | — | |
| W13 | OEM-3-I | SL8-B-2 | 0.5 | no route | +5V sensor reference | — | |
| W14 | OEM-4-E | SL8-B-5 | 0.5 | no route | Crank position (CKP) sensor | — | |
| W15 | SP-0V-1 | SL8-B-6 | 0.5 | no route | Crank index sensor − | — | |
| W16 | OEM-4-G | SL8-B-7 | 0.5 | no route | CAS SGC (cam sync) | — | |
| W17 | SP-0V-1 | SL8-B-8 | 0.5 | no route | Sync sensor − | — | |
| W18 | OEM-4-N | SL8-A-26 | 0.5 | no route | Ignition coil trigger (cyl 1&4) | — | |
| W19 | OEM-4-R | SL8-A-27 | 0.5 | no route | Ignition coil trigger (cyl 2&3) | — | |
| W20 | OEM-4-U | SL8-A-1 | 0.5 | no route | Injector 1 (cyl 1) | — | |
| W21 | OEM-4-V | SL8-A-2 | 0.5 | no route | Injector 2 (cyl 2) | — | |
| W22 | OEM-4-W | SL8-A-3 | 0.5 | no route | Injector 3 (cyl 3) | — | |
| W23 | OEM-4-X | SL8-A-4 | 0.5 | no route | Injector 4 (cyl 4) | — | |
| W24 | OEM-3-B | SL8-B-11 | 0.5 | no route | MAF sensor input | — | |
| W25 | OEM-3-F | SL8-B-12 | 0.5 | no route | Throttle position (TPS) | — | |
| W26 | OEM-3-G | SL8-B-13 | 0.5 | no route | Engine coolant temp (CLT) | — | |
| W27 | OEM-1-A | SL8-B-3 | 0.5 | no route | Cooling fan relay (low-side) | — | |
| W28 | OEM-1-B | SL8-A-14 | 0.5 | no route | A/C condenser fan relay | — | |
| W29 | OEM-1-G | SL8-A-15 | 0.5 | no route | A/C clutch relay | — | |
| W30 | OEM-1-U | SL8-A-16 | 0.5 | no route | Fuel pump relay (low-side) | — | |
| W31 | OEM-3-M | SL8-A-17 | 0.5 | no route | Front O2 heater control | — | |
| W32 | OEM-1-E | SL8-A-10 | 0.5 | no route | Check engine light (MIL) | — | |
| W33 | OEM-4-J | SL8-A-11 | 0.5 | no route | PRC solenoid (FPR control) | — | |
| W34 | OEM-4-O | SL8-A-12 | 0.5 | no route | EGR vent solenoid | — | |
| W35 | OEM-4-P | SL8-A-13 | 0.5 | no route | EGR vacuum solenoid | — | |
| W36 | OEM-4-Q | SL8-A-5 | 0.5 | no route | Idle air control (IAC) valve | — | |
| W37 | OEM-4-T | SL8-A-6 | 0.5 | no route | EVAP purge solenoid | — | |
| W38 | OEM-3-H | SL8-B-14 | 0.5 | no route | EGR boost sensor | — | |
| W39 | OEM-3-N | SL8-B-15 | 0.5 | no route | EGR boost sensor (2nd channel) | — | |
| W40 | OEM-3-C | SL8-B-19 | 0.5 | no route | Front O2 sensor input | — | |
| W41 | OEM-3-D | SL8-B-20 | 0.5 | no route | Rear O2 sensor input | — | |
| W42 | OEM-3-K | SL8-B-21 | 0.5 | no route | Intake air temp (IAT) | — | |
| W43 | OEM-3-J | SL8-B-22 | 0.5 | no route | EGR valve position sensor | — | |
| W44 | OEM-1-M | SL8-A-20 | 0.5 | no route | Vehicle speed sensor (VSS) | — | |
| W45 | OEM-1-C | SL8-A-21 | 0.5 | no route | Starter input (12V while cranking) | — | |
| W46 | OEM-1-K | SL8-A-22 | 0.5 | no route | A/C pressure switch (A/C request) | — | |
| W47 | OEM-1-L | SL8-A-23 | 0.5 | no route | Clutch switch | — | |
| W48 | OEM-1-Q | SL8-A-24 | 0.5 | no route | Brake switch | — | |
| W49 | OEM-3-L | SL8-A-25 | 0.5 | no route | Idle switch (closed throttle) | — | |
| W50 | OEM-3-P | SL8-B-23 | 0.5 | no route | Power steering pressure switch | — |
Bill of materials
| Category | Part number | Manufacturer | Description | Qty | Unit |
|---|---|---|---|---|---|
| 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) | 43.000 | ea |
ECU setup sheet
| Role | Engine ref | Engine signal | Sensor | ECU point | ECU function | ECU class | Setup flag |
|---|---|---|---|---|---|---|---|
| No configured channels. | |||||||
Findings
Open (16)
| Severity | Code | Subject | Message |
|---|---|---|---|
| error | REQUIRED_UNMAPPED | OEM-4-F | Required OEM function "CAS SGT (cam trigger)" (trigger_in) is not connected to the new ECU. |
| warn | NET_FAMILY | OEM-3-P ↔ SL8-B-23 | OEM-3-P "Power steering pressure switch" [digital_in] is wired to SL8-B-23 "Analog input 10 (switchable 1k pull-up)" [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 | NET_FAMILY | OEM-1-B ↔ SL8-A-14 | OEM-1-B "A/C condenser 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-E ↔ SL8-A-10 | OEM-1-E "Check engine light (MIL)" [low_side_out] is wired to SL8-A-10 "Auxiliary output 1" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-1-G ↔ SL8-A-15 | OEM-1-G "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-16 | OEM-1-U "Fuel pump relay (low-side)" [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-G ↔ SL8-B-13 | OEM-3-G "Engine coolant temp (CLT)" [temp_in] is wired to SL8-B-13 "Analog input 3" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one. |
| info | NET_FAMILY | OEM-3-K ↔ SL8-B-21 | OEM-3-K "Intake air temp (IAT)" [temp_in] is wired to SL8-B-21 "Analog input 8 (switchable 1k pull-up)" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one. |
| info | NET_FAMILY | OEM-3-M ↔ SL8-A-17 | OEM-3-M "Front O2 heater control" [low_side_out] is wired to SL8-A-17 "Auxiliary output 8" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-4-J ↔ SL8-A-11 | OEM-4-J "PRC solenoid (FPR control)" [low_side_out] is wired to SL8-A-11 "Auxiliary output 2" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-4-O ↔ SL8-A-12 | OEM-4-O "EGR vent solenoid" [low_side_out] is wired to SL8-A-12 "Auxiliary output 3" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-4-P ↔ SL8-A-13 | OEM-4-P "EGR vacuum solenoid" [low_side_out] is wired to SL8-A-13 "Auxiliary output 4" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-4-Q ↔ SL8-A-5 | OEM-4-Q "Idle air control (IAC) valve" [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-4-T ↔ SL8-A-6 | OEM-4-T "EVAP purge solenoid" [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 | 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 | 1 optional OEM pins are not mapped: OEM-4-L Tachometer output |
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. Open items: - OEM-4 F: CAS SGT (cam trigger): no free cam_hall/cam_vr/frequency_in input on Emtron SL8 Not wired: - OEM-4 I: Permanent +12V (battery): Emtron SL8 has no battery-constant input; not needed - OEM-4 L: 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 | 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 | 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 |
| 3 | community_copy | Mellens.net: 1996 Mazda Miata wiring diagrams (FSM-derived) | http://www.mellens.net/mazda/mazda_miata_extra_manual/1996_wiring.pdf | — | — | — |