MX-5 Miata NA8 1994-97 (BP-ZE, 1.8) → Emtron KV8 (auto)
MX-5 Miata NA8 1994-97 (BP-ZE, 1.8) — Emtron — KV8
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 | 45 wires · 9 connectors · 7 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 | SP-14V-1 | KV8-D-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W3 | SP-14V-1 | KV8-D-2 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W4 | SP-14V-1 | KV8-D-20 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W5 | OEM-2-A | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W6 | OEM-2-B | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W7 | OEM-2-C | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | OEM-2-D | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | SP-GND-1 | KV8-B-34 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | SP-GND-1 | KV8-B-9 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | SP-GND-1 | KV8-C-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | SP-GND-1 | KV8-C-26 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | OEM-2-F | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | SP-0V-1 | KV8-C-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | SP-0V-1 | KV8-C-25 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | OEM-2-K | KV8-D-21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-2-E | KV8-D-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | SP-0V-1 | KV8-D-5 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-2-G | KV8-D-6 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | SP-0V-1 | KV8-D-7 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-1-G | KV8-B-26 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-1-H | KV8-B-27 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-2-U | KV8-B-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-2-V | KV8-B-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-2-Y | KV8-B-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-2-Z | KV8-B-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-1-J | KV8-D-9 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-1-R | KV8-B-14 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-2-S | KV8-B-15 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | OEM-2-T | KV8-B-16 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-2-W | KV8-B-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-1-E | KV8-B-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-2-R | KV8-B-11 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-2-X | KV8-B-12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W35 | OEM-2-I | KV8-B-13 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W36 | OEM-2-O | KV8-C-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W37 | OEM-2-M | KV8-C-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W38 | OEM-2-N | KV8-C-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W39 | OEM-2-Q | KV8-C-5 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W40 | OEM-2-P | KV8-C-6 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W41 | OEM-1-M | KV8-C-27 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W42 | OEM-1-C | KV8-C-28 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W43 | OEM-1-P | KV8-C-29 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W44 | OEM-1-Q | KV8-C-30 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W45 | OEM-1-V | KV8-C-31 | 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 | KV8-D-1 | KV8-B-34 | open (OL) | +12 V supply must not touch power ground | |
| 2 | KV8-D-1 | KV8-C-17 | open (OL) | +12 V supply must not touch sensor ground | |
| 3 | KV8-B-34 | KV8-D-21 | open (OL) | power ground must not touch 5 V sensor reference | |
| 4 | KV8-C-17 | KV8-D-21 | open (OL) | sensor ground must not touch 5 V sensor reference | |
| 5 | KV8-D-1 | KV8-D-21 | open (OL) | +12 V supply must not touch 5 V sensor reference |
Revisions
| Rev | Label | By | Date |
|---|---|---|---|
| No revisions yet. | |||
Schematic
Connectors
KV8-A
Mating face
Wire side
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | — | — | — | — | — | — | — |
| 2 | — | — | — | — | — | — | — | — | — |
| 3 | — | — | — | — | — | — | — | — | — |
| 4 | — | — | — | — | — | — | — | — | — |
| 5 | — | — | — | — | — | — | — | — | — |
| 6 | — | — | — | — | — | — | — | — | — |
| 7 | — | — | — | — | — | — | — | — | — |
| 8 | — | — | — | — | — | — | — | — | — |
| 9 | — | — | — | — | — | — | — | — | — |
| 10 | Lambda 1 heater − | — | — | — | — | — | — | — | — |
| 11 | Lambda 2 heater − | — | — | — | — | — | — | — | — |
| 12 | — | — | — | — | — | — | — | — | — |
| 13 | — | — | — | — | — | — | — | — | — |
| 14 | — | — | — | — | — | — | — | — | — |
| 15 | — | — | — | — | — | — | — | — | — |
| 16 | Lambda 1 heater + | — | — | — | — | — | — | — | — |
| 17 | Lambda 2 heater + | — | — | — | — | — | — | — | — |
| 18 | Lambda 1 Nernst cell (Vs) | — | — | — | — | — | — | — | — |
| 19 | — | — | — | — | — | — | — | — | — |
| 20 | Lambda 2 cal resistor | — | — | — | — | — | — | — | — |
| 21 | Lambda 2 Nernst cell (Vs) | — | — | — | — | — | — | — | — |
| 22 | Lambda 2 pump cell (Ip) | — | — | — | — | — | — | — | — |
| 23 | Lambda 2 virtual ground | — | — | — | — | — | — | — | — |
| 24 | Lambda 1 cal resistor | — | — | — | — | — | — | — | — |
| 25 | Lambda 1 pump cell (Ip) | — | — | — | — | — | — | — | — |
| 26 | Lambda 1 virtual ground | — | — | — | — | — | — | — | — |
KV8-B
Mating face
Wire side
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Injection 1 | — | W23 | — | 0.5 | OEM-2-U | — | — | — |
| 2 | Injection 2 | — | W24 | — | 0.5 | OEM-2-V | — | — | — |
| 3 | Injection 3 | — | W25 | — | 0.5 | OEM-2-Y | — | — | — |
| 4 | Injection 4 | — | W26 | — | 0.5 | OEM-2-Z | — | — | — |
| 5 | Injection 5 | — | — | — | — | — | — | — | — |
| 6 | Injection 6 | — | — | — | — | — | — | — | — |
| 7 | Injection 7 | — | — | — | — | — | — | — | — |
| 8 | Injection 8 | — | — | — | — | — | — | — | — |
| 9 | ECU ground | — | W10 | — | 0.85 | SP-GND-1 | — | — | — |
| 10 | Aux 1 | — | W32 | — | 0.5 | OEM-1-E | — | — | — |
| 11 | Aux 2 | — | W33 | — | 0.5 | OEM-2-R | — | — | — |
| 12 | Aux 3 | — | W34 | — | 0.5 | OEM-2-X | — | — | — |
| 13 | Aux 4 | — | W35 | — | 0.5 | OEM-2-I | — | — | — |
| 14 | Aux 5 | — | W28 | — | 0.5 | OEM-1-R | — | — | — |
| 15 | Aux 6 | — | W29 | — | 0.5 | OEM-2-S | — | — | — |
| 16 | Aux 7 | — | W30 | — | 0.5 | OEM-2-T | — | — | — |
| 17 | Aux 8 | — | W31 | — | 0.5 | OEM-2-W | — | — | — |
| 18 | Aux 9 | — | — | — | — | — | — | — | — |
| 19 | Aux 10 | — | — | — | — | — | — | — | — |
| 20 | Aux 11 | — | — | — | — | — | — | — | — |
| 21 | Aux 12 | — | — | — | — | — | — | — | — |
| 22 | Aux 13 | — | — | — | — | — | — | — | — |
| 23 | Aux 14 | — | — | — | — | — | — | — | — |
| 24 | Aux 15 | — | — | — | — | — | — | — | — |
| 25 | Aux 16 | — | — | — | — | — | — | — | — |
| 26 | Ignition 1 | — | W21 | — | 0.5 | OEM-1-G | — | — | — |
| 27 | Ignition 2 | — | W22 | — | 0.5 | OEM-1-H | — | — | — |
| 28 | Ignition 3 | — | — | — | — | — | — | — | — |
| 29 | Ignition 4 | — | — | — | — | — | — | — | — |
| 30 | Ignition 5 | — | — | — | — | — | — | — | — |
| 31 | Ignition 6 | — | — | — | — | — | — | — | — |
| 32 | Ignition 7 | — | — | — | — | — | — | — | — |
| 33 | Ignition 8 | — | — | — | — | — | — | — | — |
| 34 | ECU ground | — | W9 | — | 0.85 | SP-GND-1 | — | — | — |
KV8-C
Mating face
Wire side
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | ECU ground | — | W11 | — | 0.85 | SP-GND-1 | — | — | — |
| 2 | Analog in 1 | — | W36 | — | 0.5 | OEM-2-O | — | — | — |
| 3 | Analog in 2 | — | W37 | — | 0.5 | OEM-2-M | — | — | — |
| 4 | Analog in 3 | — | W38 | — | 0.5 | OEM-2-N | — | — | — |
| 5 | Analog in 4 | — | W39 | — | 0.5 | OEM-2-Q | — | — | — |
| 6 | Analog in 5 | — | W40 | — | 0.5 | OEM-2-P | — | — | — |
| 7 | Analog in 6 | — | — | — | — | — | — | — | — |
| 8 | Analog in 7 | — | — | — | — | — | — | — | — |
| 9 | Analog in 8 | — | — | — | — | — | — | — | — |
| 10 | Analog in 9 | — | — | — | — | — | — | — | — |
| 11 | Analog in 10 | — | — | — | — | — | — | — | — |
| 12 | Analog in 11 | — | — | — | — | — | — | — | — |
| 13 | Analog in 12 | — | — | — | — | — | — | — | — |
| 14 | Analog in 13 | — | — | — | — | — | — | — | — |
| 15 | Analog in 14 | — | — | — | — | — | — | — | — |
| 16 | Analog in 15 | — | — | — | — | — | — | — | — |
| 17 | Analog sensor 0V reference | — | W14 | — | 0.5 | SP-0V-1 | — | — | — |
| 18 | Digital in 9 | — | — | — | — | — | — | — | — |
| 19 | Digital in 10 | — | — | — | — | — | — | — | — |
| 20 | Digital in 11 | — | — | — | — | — | — | — | — |
| 21 | Digital in 12 | — | — | — | — | — | — | — | — |
| 22 | Digital in 13 | — | — | — | — | — | — | — | — |
| 23 | Digital in 14 | — | — | — | — | — | — | — | — |
| 24 | Analog in 16 | — | — | — | — | — | — | — | — |
| 25 | Analog sensor 0V reference | — | W15 | — | 0.5 | SP-0V-1 | — | — | — |
| 26 | ECU ground | — | W12 | — | 0.85 | SP-GND-1 | — | — | — |
| 27 | Digital in 1 | — | W41 | — | 0.5 | OEM-1-M | — | — | — |
| 28 | Digital in 2 | — | W42 | — | 0.5 | OEM-1-C | — | — | — |
| 29 | Digital in 3 | — | W43 | — | 0.5 | OEM-1-P | — | — | — |
| 30 | Digital in 4 | — | W44 | — | 0.5 | OEM-1-Q | — | — | — |
| 31 | Digital in 5 | — | W45 | — | 0.5 | OEM-1-V | — | — | — |
| 32 | Digital in 6 | — | — | — | — | — | — | — | — |
| 33 | Digital in 7 | — | — | — | — | — | — | — | — |
| 34 | Digital in 8 | — | — | — | — | — | — | — | — |
KV8-D
Mating face
Wire side
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | ECU 14V supply | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
| 2 | Aux 13–16 14V supply | — | W3 | — | 0.85 | SP-14V-1 | — | — | — |
| 3 | Sensor supply 8V | — | — | — | — | — | — | — | — |
| 4 | Crank index sensor + | — | W17 | — | 0.5 | OEM-2-E | — | — | — |
| 5 | Crank index sensor − | — | W18 | — | 0.5 | SP-0V-1 | — | — | — |
| 6 | Sync sensor + | — | W19 | — | 0.5 | OEM-2-G | — | — | — |
| 7 | Sync sensor − | — | W20 | — | 0.5 | SP-0V-1 | — | — | — |
| 8 | CAN 1 H | — | — | — | — | — | — | — | — |
| 9 | EFI relay output (low side, 200 mA) | — | W27 | — | 0.5 | OEM-1-J | — | — | — |
| 10 | CAN 2 H | — | — | — | — | — | — | — | — |
| 11 | Knock 1 + | — | — | — | — | — | — | — | — |
| 12 | Knock 1 − | — | — | — | — | — | — | — | — |
| 13 | Shield (crank/cam/knock) | — | — | — | — | — | — | — | — |
| 14 | CAN 1 L | — | — | — | — | — | — | — | — |
| 15 | Ignition switch input | — | — | — | — | — | — | — | — |
| 16 | CAN 2 L | — | — | — | — | — | — | — | — |
| 17 | Knock 2 + | — | — | — | — | — | — | — | — |
| 18 | Knock 2 − | — | — | — | — | — | — | — | — |
| 19 | Analog output 0–5V | — | — | — | — | — | — | — | — |
| 20 | Aux 9–12 14V supply | — | W4 | — | 0.85 | SP-14V-1 | — | — | — |
| 21 | Sensor supply Vref1 5.0V | — | W16 | — | 0.5 | OEM-2-K | — | — | — |
| 22 | Sensor supply Vref2 5.0V | — | — | — | — | — | — | — | — |
| 23 | Ethernet Tx+ | — | — | — | — | — | — | — | — |
| 24 | Ethernet Tx− | — | — | — | — | — | — | — | — |
| 25 | Ethernet Rx+ | — | — | — | — | — | — | — | — |
| 26 | Ethernet Rx− | — | — | — | — | — | — | — | — |
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 | — | W42 | — | 0.5 | KV8-C-28 | — | — | — |
| E | Malfunction indicator lamp (MIL) | — | W32 | — | 0.5 | KV8-B-10 | — | — | — |
| G | Ignition 1 (coils 1+4, wasted spark) | — | W21 | — | 0.5 | KV8-B-26 | — | — | — |
| H | Ignition 2 (coils 2+3, wasted spark) | — | W22 | — | 0.5 | KV8-B-27 | — | — | — |
| J | A/C relay | — | W27 | — | 0.5 | KV8-D-9 | — | — | — |
| M | Vehicle speed | — | W41 | — | 0.5 | KV8-C-27 | — | — | — |
| P | Power steering pressure switch | — | W43 | — | 0.5 | KV8-C-29 | — | — | — |
| Q | A/C request | — | W44 | — | 0.5 | KV8-C-30 | — | — | — |
| R | Cooling fan relay | — | W28 | — | 0.5 | KV8-B-14 | — | — | — |
| V | Neutral/clutch switch | — | W45 | — | 0.5 | KV8-C-31 | — | — | — |
OEM-2
| 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 | — | — | — |
| D | Power ground | — | W8 | — | 0.85 | SP-GND-1 | — | — | — |
| E | Crank position (CAS NE) | — | W17 | — | 0.5 | KV8-D-4 | — | — | — |
| F | MAF ground | — | W13 | — | 0.5 | SP-0V-1 | — | — | — |
| G | Cam position (CAS G) | — | W19 | — | 0.5 | KV8-D-6 | — | — | — |
| I | Tachometer output | — | W35 | — | 0.5 | KV8-B-13 | — | — | — |
| K | +5V sensor supply | — | W16 | — | 0.5 | KV8-D-21 | — | — | — |
| M | Throttle position (TPS) | — | W37 | — | 0.5 | KV8-C-3 | — | — | — |
| N | O2 sensor | — | W38 | — | 0.5 | KV8-C-4 | — | — | — |
| O | Mass air flow (MAF) | — | W36 | — | 0.5 | KV8-C-2 | — | — | — |
| P | Intake air temperature (IAT) | — | W40 | — | 0.5 | KV8-C-6 | — | — | — |
| Q | Coolant temperature (ECT) | — | W39 | — | 0.5 | KV8-C-5 | — | — | — |
| R | PRC solenoid (fuel pressure regulator) | — | W33 | — | 0.5 | KV8-B-11 | — | — | — |
| S | Condenser fan relay | — | W29 | — | 0.5 | KV8-B-15 | — | — | — |
| T | Fuel pump relay | — | W30 | — | 0.5 | KV8-B-16 | — | — | — |
| U | Injector 1 | — | W23 | — | 0.5 | KV8-B-1 | — | — | — |
| V | Injector 2 | — | W24 | — | 0.5 | KV8-B-2 | — | — | — |
| W | ISC solenoid | — | W31 | — | 0.5 | KV8-B-17 | — | — | — |
| X | Evap purge solenoid | — | W34 | — | 0.5 | KV8-B-12 | — | — | — |
| Y | Injector 3 | — | W25 | — | 0.5 | KV8-B-3 | — | — | — |
| Z | Injector 4 | — | W26 | — | 0.5 | KV8-B-4 | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W13 | — | 0.5 | OEM-2-F | — | — | — |
| 1 | — | — | W14 | — | 0.5 | KV8-C-17 | — | — | — |
| 1 | — | — | W15 | — | 0.5 | KV8-C-25 | — | — | — |
| 1 | — | — | W18 | — | 0.5 | KV8-D-5 | — | — | — |
| 1 | — | — | W20 | — | 0.5 | KV8-D-7 | — | — | — |
SP-14V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W1 | — | 0.85 | OEM-1-B | — | — | — |
| 1 | — | — | W2 | — | 0.85 | KV8-D-1 | — | — | — |
| 1 | — | — | W3 | — | 0.85 | KV8-D-2 | — | — | — |
| 1 | — | — | W4 | — | 0.85 | KV8-D-20 | — | — | — |
SP-GND
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W5 | — | 0.85 | OEM-2-A | — | — | — |
| 1 | — | — | W6 | — | 0.85 | OEM-2-B | — | — | — |
| 1 | — | — | W7 | — | 0.85 | OEM-2-C | — | — | — |
| 1 | — | — | W8 | — | 0.85 | OEM-2-D | — | — | — |
| 1 | — | — | W9 | — | 0.85 | KV8-B-34 | — | — | — |
| 1 | — | — | W10 | — | 0.85 | KV8-B-9 | — | — | — |
| 1 | — | — | W11 | — | 0.85 | KV8-C-1 | — | — | — |
| 1 | — | — | W12 | — | 0.85 | KV8-C-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 | KV8-D-1 + KV8-D-2 + KV8-D-20 | ECU 14V supply + Aux 13–16 14V supply + Aux 9–12 14V supply | power_in | single_source | |
| OEM-1-C | Start signal | digital_in | KV8-C-28 | Digital in 2 | digital_in | single_source | |
| OEM-1-E | Malfunction indicator lamp (MIL) | low_side_out | KV8-B-10 | Aux 1 | low_side_out | single_source | |
| OEM-1-G | Ignition 1 (coils 1+4, wasted spark) | ignition_out | KV8-B-26 | Ignition 1 | ignition_out | single_source | |
| OEM-1-H | Ignition 2 (coils 2+3, wasted spark) | ignition_out | KV8-B-27 | Ignition 2 | ignition_out | single_source | |
| OEM-1-J | A/C relay | low_side_out | KV8-D-9 | EFI relay output (low side, 200 mA) | low_side_out | single_source | |
| OEM-1-M | Vehicle speed | digital_in | KV8-C-27 | Digital in 1 | digital_in | single_source | |
| OEM-1-P | Power steering pressure switch | digital_in | KV8-C-29 | Digital in 3 | digital_in | single_source | |
| OEM-1-Q | A/C request | digital_in | KV8-C-30 | Digital in 4 | digital_in | single_source | |
| OEM-1-R | Cooling fan relay | low_side_out | KV8-B-14 | Aux 5 | low_side_out | single_source | |
| OEM-1-V | Neutral/clutch switch | digital_in | KV8-C-31 | Digital in 5 | digital_in | single_source | |
| OEM-2-A | Power ground | ground | KV8-B-34 + KV8-B-9 + KV8-C-1 + KV8-C-26 | ECU ground + ECU ground + ECU ground + ECU ground | ground | single_source | |
| OEM-2-B | Power ground | ground | KV8-B-34 + KV8-B-9 + KV8-C-1 + KV8-C-26 | ECU ground + ECU ground + ECU ground + ECU ground | ground | single_source | |
| OEM-2-C | Power ground | ground | KV8-B-34 + KV8-B-9 + KV8-C-1 + KV8-C-26 | ECU ground + ECU ground + ECU ground + ECU ground | ground | single_source | |
| OEM-2-D | Power ground | ground | KV8-B-34 + KV8-B-9 + KV8-C-1 + KV8-C-26 | ECU ground + ECU ground + ECU ground + ECU ground | ground | single_source | |
| OEM-2-E | Crank position (CAS NE) | trigger_in | KV8-D-4 | Crank index sensor + | trigger_in | single_source | |
| OEM-2-F | MAF ground | sensor_ground | KV8-C-17 + KV8-C-25 + KV8-D-5 + KV8-D-7 | Analog sensor 0V reference + Analog sensor 0V reference + Crank index sensor − + Sync sensor − | sensor_ground + trigger_in | single_source | |
| OEM-2-G | Cam position (CAS G) | trigger_in | KV8-D-6 | Sync sensor + | trigger_in | single_source | |
| OEM-2-I | Tachometer output | tacho_out | KV8-B-13 | Aux 4 | low_side_out | single_source | |
| OEM-2-K | +5V sensor supply | vref | KV8-D-21 | Sensor supply Vref1 5.0V | vref | single_source | |
| OEM-2-M | Throttle position (TPS) | analog_in | KV8-C-3 | Analog in 2 | analog_in | single_source | |
| OEM-2-N | O2 sensor | lambda_nb_in | KV8-C-4 | Analog in 3 | analog_in | single_source | |
| OEM-2-O | Mass air flow (MAF) | analog_in | KV8-C-2 | Analog in 1 | analog_in | single_source | |
| OEM-2-P | Intake air temperature (IAT) | temp_in | KV8-C-6 | Analog in 5 | analog_in | single_source | |
| OEM-2-Q | Coolant temperature (ECT) | temp_in | KV8-C-5 | Analog in 4 | analog_in | single_source | |
| OEM-2-R | PRC solenoid (fuel pressure regulator) | low_side_out | KV8-B-11 | Aux 2 | low_side_out | single_source | |
| OEM-2-S | Condenser fan relay | low_side_out | KV8-B-15 | Aux 6 | low_side_out | single_source | |
| OEM-2-T | Fuel pump relay | low_side_out | KV8-B-16 | Aux 7 | low_side_out | single_source | |
| OEM-2-U | Injector 1 | injector_out | KV8-B-1 | Injection 1 | injector_out | single_source | |
| OEM-2-V | Injector 2 | injector_out | KV8-B-2 | Injection 2 | injector_out | single_source | |
| OEM-2-W | ISC solenoid | low_side_out | KV8-B-17 | Aux 8 | low_side_out | single_source | |
| OEM-2-X | Evap purge solenoid | low_side_out | KV8-B-12 | Aux 3 | low_side_out | single_source | |
| OEM-2-Y | Injector 3 | injector_out | KV8-B-3 | Injection 3 | injector_out | single_source | |
| OEM-2-Z | Injector 4 | injector_out | KV8-B-4 | Injection 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 | KV8-D-1 | 0.85 | no route | ECU 14V supply | — | |
| W3 | SP-14V-1 | KV8-D-2 | 0.85 | no route | Aux 13–16 14V supply | — | |
| W4 | SP-14V-1 | KV8-D-20 | 0.85 | no route | Aux 9–12 14V supply | — | |
| W5 | OEM-2-A | SP-GND-1 | 0.85 | no route | Power ground | — | |
| W6 | OEM-2-B | SP-GND-1 | 0.85 | no route | Power ground | — | |
| W7 | OEM-2-C | SP-GND-1 | 0.85 | no route | Power ground | — | |
| W8 | OEM-2-D | SP-GND-1 | 0.85 | no route | Power ground | — | |
| W9 | SP-GND-1 | KV8-B-34 | 0.85 | no route | ECU ground | — | |
| W10 | SP-GND-1 | KV8-B-9 | 0.85 | no route | ECU ground | — | |
| W11 | SP-GND-1 | KV8-C-1 | 0.85 | no route | ECU ground | — | |
| W12 | SP-GND-1 | KV8-C-26 | 0.85 | no route | ECU ground | — | |
| W13 | OEM-2-F | SP-0V-1 | 0.5 | no route | MAF ground | — | |
| W14 | SP-0V-1 | KV8-C-17 | 0.5 | no route | Analog sensor 0V reference | — | |
| W15 | SP-0V-1 | KV8-C-25 | 0.5 | no route | Analog sensor 0V reference | — | |
| W16 | OEM-2-K | KV8-D-21 | 0.5 | no route | +5V sensor supply | — | |
| W17 | OEM-2-E | KV8-D-4 | 0.5 | no route | Crank position (CAS NE) | — | |
| W18 | SP-0V-1 | KV8-D-5 | 0.5 | no route | Crank index sensor − | — | |
| W19 | OEM-2-G | KV8-D-6 | 0.5 | no route | Cam position (CAS G) | — | |
| W20 | SP-0V-1 | KV8-D-7 | 0.5 | no route | Sync sensor − | — | |
| W21 | OEM-1-G | KV8-B-26 | 0.5 | no route | Ignition 1 (coils 1+4, wasted spark) | — | |
| W22 | OEM-1-H | KV8-B-27 | 0.5 | no route | Ignition 2 (coils 2+3, wasted spark) | — | |
| W23 | OEM-2-U | KV8-B-1 | 0.5 | no route | Injector 1 | — | |
| W24 | OEM-2-V | KV8-B-2 | 0.5 | no route | Injector 2 | — | |
| W25 | OEM-2-Y | KV8-B-3 | 0.5 | no route | Injector 3 | — | |
| W26 | OEM-2-Z | KV8-B-4 | 0.5 | no route | Injector 4 | — | |
| W27 | OEM-1-J | KV8-D-9 | 0.5 | no route | A/C relay | — | |
| W28 | OEM-1-R | KV8-B-14 | 0.5 | no route | Cooling fan relay | — | |
| W29 | OEM-2-S | KV8-B-15 | 0.5 | no route | Condenser fan relay | — | |
| W30 | OEM-2-T | KV8-B-16 | 0.5 | no route | Fuel pump relay | — | |
| W31 | OEM-2-W | KV8-B-17 | 0.5 | no route | ISC solenoid | — | |
| W32 | OEM-1-E | KV8-B-10 | 0.5 | no route | Malfunction indicator lamp (MIL) | — | |
| W33 | OEM-2-R | KV8-B-11 | 0.5 | no route | PRC solenoid (fuel pressure regulator) | — | |
| W34 | OEM-2-X | KV8-B-12 | 0.5 | no route | Evap purge solenoid | — | |
| W35 | OEM-2-I | KV8-B-13 | 0.5 | no route | Tachometer output | — | |
| W36 | OEM-2-O | KV8-C-2 | 0.5 | no route | Mass air flow (MAF) | — | |
| W37 | OEM-2-M | KV8-C-3 | 0.5 | no route | Throttle position (TPS) | — | |
| W38 | OEM-2-N | KV8-C-4 | 0.5 | no route | O2 sensor | — | |
| W39 | OEM-2-Q | KV8-C-5 | 0.5 | no route | Coolant temperature (ECT) | — | |
| W40 | OEM-2-P | KV8-C-6 | 0.5 | no route | Intake air temperature (IAT) | — | |
| W41 | OEM-1-M | KV8-C-27 | 0.5 | no route | Vehicle speed | — | |
| W42 | OEM-1-C | KV8-C-28 | 0.5 | no route | Start signal | — | |
| W43 | OEM-1-P | KV8-C-29 | 0.5 | no route | Power steering pressure switch | — | |
| W44 | OEM-1-Q | KV8-C-30 | 0.5 | no route | A/C request | — | |
| W45 | OEM-1-V | KV8-C-31 | 0.5 | no route | Neutral/clutch switch | — |
Bill of materials
| Category | Part number | Manufacturer | Description | Qty | Unit |
|---|---|---|---|---|---|
| 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 | 3-1437290-7 | TE | Superseal 1.0 26-way plug | 1.000 | ea |
| connector | 3-1437290-8 | TE | Superseal 1.0 26-way plug, Key 2 | 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) | 39.000 | ea |
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 |
|---|---|---|---|
| warn | DATASET_GAP | KV8 A | 14 of 26 cavities on KV8 A have no pin data (1,2,3,4,5,6,7,8,9,12,13,14,15,19). Anything there is invisible to these checks. |
| info | NET_FAMILY | OEM-2-F ↔ KV8-D-7 | OEM-2-F "MAF ground" [sensor_ground] is wired to KV8-D-7 "Sync sensor −" [trigger_in]. Trigger return tied to sensor/trigger ground: correct for single-ended trigger inputs. |
| info | NET_FAMILY | OEM-2-I ↔ KV8-B-13 | OEM-2-I "Tachometer output" [tacho_out] is wired to KV8-B-13 "Aux 4" [low_side_out]. Tacho as a low-side output: check the tach needs a pull-up. |
| info | NET_FAMILY | OEM-2-P ↔ KV8-C-6 | OEM-2-P "Intake air temperature (IAT)" [temp_in] is wired to KV8-C-6 "Analog in 5" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one. |
| info | NET_FAMILY | OEM-2-Q ↔ KV8-C-5 | OEM-2-Q "Coolant temperature (ECT)" [temp_in] is wired to KV8-C-5 "Analog in 4" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one. |
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 KV8 has no battery-constant input; not needed - KV8-D 15: 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 | Link G4X MX5X install manual (NA 1.6/1.8) | https://linkecu.com/documentation/MX5X.pdf | archive | 2026-10-05 | b7f730de9f6e |
| 2 | user_dataset | Subaru ECU Matcher dataset (hiubin), vehicleId=1 | — | — | — | — |