MX-5 Miata Mazdaspeed 2004-05 (BP-ZET turbo, no VVT) → FuelTech FT450 (auto)
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 | 2: read the Findings page before cutting any wire |
| Size of the job | 2 wires · 2 connectors · 0 part lines |
| Tools | Crimp and extraction tools for each terminal family (see Connectors) · wire strippers · multimeter · heat gun + heat-shrink |
| 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-AE | FT450-A-A23 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W2 | OEM-4-R | FT450-A-A26 | 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 |
|---|---|---|---|---|---|
| No supply/ground nets found to cross-check. | |||||
If any reading doesn't match, stop and get help before powering up.
Revisions
| Rev | Label | By | Date |
|---|---|---|---|
| No revisions yet. | |||
Schematic
Connectors
FT450-A
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A1 | Injector 1 (Bank A) | — | — | — | — | — | — | — | — |
| A10 | Ignition 3 | — | — | — | — | — | — | — | — |
| A11 | Ignition 4 | — | — | — | — | — | — | — | — |
| A12 | Signal ground | — | — | — | — | — | — | — | — |
| A13 | +12V switched | — | — | — | — | — | — | — | — |
| A14 | +5V sensor supply | — | — | — | — | — | — | — | — |
| A15 | CAN A LOW | — | — | — | — | — | — | — | — |
| A16 | CAN A HIGH | — | — | — | — | — | — | — | — |
| A17 | Phase input (cam) | — | — | — | — | — | — | — | — |
| A18 | RPM reference (crank -) | — | — | — | — | — | — | — | — |
| A19 | RPM signal (crank +) | — | — | — | — | — | — | — | — |
| A2 | Injector 2 (Bank A) | — | — | — | — | — | — | — | — |
| A20 | White input 1 | — | — | — | — | — | — | — | — |
| A21 | White input 2 | — | — | — | — | — | — | — | — |
| A22 | White input 3 (TPS) | — | — | — | — | — | — | — | — |
| A23 | White input 4 (oil pressure) | — | W1 | — | 0.5 | OEM-4-AE | — | — | — |
| A24 | White input 5 (water temp) | — | — | — | — | — | — | — | — |
| A25 | White input 6 (fuel pressure) | — | — | — | — | — | — | — | — |
| A26 | White input 7 (air temp) | — | W2 | — | 0.5 | OEM-4-R | — | — | — |
| A3 | Aux 1 | — | — | — | — | — | — | — | — |
| A4 | Aux 2 | — | — | — | — | — | — | — | — |
| A5 | Aux 3 | — | — | — | — | — | — | — | — |
| A6 | Aux 4 (fuel pump / relays) | — | — | — | — | — | — | — | — |
| A7 | Power ground | — | — | — | — | — | — | — | — |
| A8 | Ignition 1 | — | — | — | — | — | — | — | — |
| A9 | Ignition 2 | — | — | — | — | — | — | — | — |
OEM-4
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| AC | Data link connector (DLC TEN, turbo) | — | — | — | — | — | — | — | — |
| AE | BARO/MAP sensor (turbo boost pressure) | — | W1 | — | 0.5 | FT450-A-A23 | — | — | — |
| D | Boost control solenoid (turbo) | — | — | — | — | — | — | — | — |
| E | Boost control solenoid (turbo) | — | — | — | — | — | — | — | — |
| R | Intake air temperature 2 (IAT2, turbo) | — | W2 | — | 0.5 | FT450-A-A26 | — | — | — |
Pin map
| OEM point | OEM function | OEM family | Target point | Target function | Target family | Wire colour | Evidence |
|---|---|---|---|---|---|---|---|
| OEM-4-AC | Data link connector (DLC TEN, turbo) | serial | — | — | — | BrY | single_source |
| OEM-4-AE | BARO/MAP sensor (turbo boost pressure) | analog_in | FT450-A-A23 | White input 4 (oil pressure) | analog_in | LY | single_source |
| OEM-4-D | Boost control solenoid (turbo) | high_side_out | — | — | — | Y | single_source |
| OEM-4-E | Boost control solenoid (turbo) | high_side_out | — | — | — | Y | single_source |
| OEM-4-R | Intake air temperature 2 (IAT2, turbo) | temp_in | FT450-A-A26 | White input 7 (air temp) | temp_in | VY | single_source |
Cut list
| Wire | From | To | Gauge (mm²) | Colour | Length | Signal | Ident |
|---|---|---|---|---|---|---|---|
| W1 | OEM-4-AE | FT450-A-A23 | 0.5 | no route | BARO/MAP sensor (turbo boost pressure) | — | |
| W2 | OEM-4-R | FT450-A-A26 | 0.5 | no route | Intake air temperature 2 (IAT2, turbo) | — |
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 (3)
| Severity | Code | Subject | Message |
|---|---|---|---|
| error | PHYS_REQUIRED_OPEN | FT450-A-A13 | FT450-A-A13 "+12V switched" is required but not wired. |
| error | PHYS_REQUIRED_OPEN | FT450-A-A7 | FT450-A-A7 "Power ground" is required but not wired. |
| info | UNMAPPED | OEM | 3 optional OEM pins are not mapped: OEM-4-AC Data link connector (DLC TEN, turbo); OEM-4-D Boost control solenoid (turbo); OEM-4-E Boost control solenoid (turbo) |
Accepted (0)
| Code | Subject | Reason | By |
|---|
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: - Main-relay feed: no ecu_main_power pin on the stock or the new ECU - FT450-A A13: +12V switched: required by FuelTech FT450 but no stock pin feeds it; wire by hand - FT450-A A7: Power ground: required by FuelTech FT450 but no stock pin feeds it; wire by hand Not wired: - OEM-4 D: Boost control solenoid (turbo): no free high_side/ls_hs on FuelTech FT450 - OEM-4 E: Boost control solenoid (turbo): no free high_side/ls_hs on FuelTech FT450 - OEM-4 AC: Data link connector (DLC TEN, turbo): no free k_line on FuelTech FT450
Sources
| Reliability | Kind | Title | URL | Archive | Captured | SHA-256 |
|---|---|---|---|---|---|---|
| 4 | oem_manual | 2005 Mazda MX-5 Miata Engine Performance Control System (PCM terminal voltage reference, BP and BP WITH TC) | https://trull.org/alex/pubmirror/www.mellens.net/mazda/Mazda-Miata-2005/engine_control_system.pdf | — | — | — |
| 4 | vendor_doc | Adaptronic eSel039 Select Plugin ECU for Mazda MX5 / Miata NB8B/C (OEM ECU pinout) | https://www.miataturbo.net/attachments/ecus-tuning-54/04-msm-ecu-pinout-104032/nb8bc_oem_ecu_pinouts-224948d1602912806 | — | — | — |
| 4 | vendor_doc | FuelTech FT450/FT550 ready harness manual (4 & 6 cylinder) — FT450 Connector A pinout | http://ftmanager.fueltech.com.br/downloads/manual/Portugues/Chicote_pronto_FT450-FT550.pdf | — | — | — |