MX-5 Miata Mazdaspeed 2004-05 (BP-ZET turbo, no VVT) → Link G4X MonsoonX (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 | 3: 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 | G4XMONSOONX-A-A17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W2 | OEM-4-R | G4XMONSOONX-A-A15 | 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
G4XMONSOONX-A
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A1 | Injector 4 | — | — | — | — | — | — | — | — |
| A10 | Ignition 4 | — | — | — | — | — | — | — | — |
| A11 | Ignition 3 | — | — | — | — | — | — | — | — |
| A12 | Ignition 2 | — | — | — | — | — | — | — | — |
| A13 | Ignition 1 | — | — | — | — | — | — | — | — |
| A14 | Analog Volt 4 | — | — | — | — | — | — | — | — |
| A15 | Analog Temp 1 | — | W2 | — | 0.5 | OEM-4-R | — | — | — |
| A16 | Analog Temp 2 | — | — | — | — | — | — | — | — |
| A17 | Analog Volt 1 | — | W1 | — | 0.5 | OEM-4-AE | — | — | — |
| A18 | Aux 4 | — | — | — | — | — | — | — | — |
| A19 | Aux 3 | — | — | — | — | — | — | — | — |
| A2 | Injector 3 | — | — | — | — | — | — | — | — |
| A20 | Aux 2 | — | — | — | — | — | — | — | — |
| A21 | Aux 1 | — | — | — | — | — | — | — | — |
| A22 | Analog Volt 2 | — | — | — | — | — | — | — | — |
| A23 | Digital Input 3 | — | — | — | — | — | — | — | — |
| A24 | Sensor Ground | — | — | — | — | — | — | — | — |
| A25 | System Ground | — | — | — | — | — | — | — | — |
| A26 | Aux 6 | — | — | — | — | — | — | — | — |
| A27 | Aux 5 | — | — | — | — | — | — | — | — |
| A28 | CAN H | — | — | — | — | — | — | — | — |
| A29 | CAN L | — | — | — | — | — | — | — | — |
| A3 | Injector 2 | — | — | — | — | — | — | — | — |
| A30 | Digital Input 1 | — | — | — | — | — | — | — | — |
| A31 | Digital Input 2 | — | — | — | — | — | — | — | — |
| A32 | +5V Out | — | — | — | — | — | — | — | — |
| A33 | Analog Volt 3 | — | — | — | — | — | — | — | — |
| A34 | System Ground | — | — | — | — | — | — | — | — |
| A4 | Injector 1 | — | — | — | — | — | — | — | — |
| A5 | +14V ECU Power | — | — | — | — | — | — | — | — |
| A6 | Knock 1 / Digital Input 4 | — | — | — | — | — | — | — | — |
| A7 | Shield Ground | — | — | — | — | — | — | — | — |
| A8 | Trigger 1 | — | — | — | — | — | — | — | — |
| A9 | Trigger 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 | G4XMONSOONX-A-A17 | — | — | — |
| D | Boost control solenoid (turbo) | — | — | — | — | — | — | — | — |
| E | Boost control solenoid (turbo) | — | — | — | — | — | — | — | — |
| R | Intake air temperature 2 (IAT2, turbo) | — | W2 | — | 0.5 | G4XMONSOONX-A-A15 | — | — | — |
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 | G4XMONSOONX-A-A17 | Analog Volt 1 | 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 | G4XMONSOONX-A-A15 | Analog Temp 1 | temp_in | VY | single_source |
Cut list
| Wire | From | To | Gauge (mm²) | Colour | Length | Signal | Ident |
|---|---|---|---|---|---|---|---|
| W1 | OEM-4-AE | G4XMONSOONX-A-A17 | 0.5 | no route | BARO/MAP sensor (turbo boost pressure) | — | |
| W2 | OEM-4-R | G4XMONSOONX-A-A15 | 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 (4)
| Severity | Code | Subject | Message |
|---|---|---|---|
| error | PHYS_REQUIRED_OPEN | G4XMONSOONX-A-A25 | G4XMONSOONX-A-A25 "System Ground" is required but not wired. |
| error | PHYS_REQUIRED_OPEN | G4XMONSOONX-A-A34 | G4XMONSOONX-A-A34 "System Ground" is required but not wired. |
| error | PHYS_REQUIRED_OPEN | G4XMONSOONX-A-A5 | G4XMONSOONX-A-A5 "+14V ECU Power" 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
Fit check: unconfirmed. Confirm these before building: - Trigger pattern for Mazda BP-ZET not found in the ECU's docs (Link's trigger-mode list is only inside PCLink, not online) 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 - G4XMONSOONX-A A25: System Ground: required by Link G4X MonsoonX but no stock pin feeds it; wire by hand - G4XMONSOONX-A A34: System Ground: required by Link G4X MonsoonX but no stock pin feeds it; wire by hand - G4XMONSOONX-A A5: +14V ECU Power: required by Link G4X MonsoonX 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 Link G4X MonsoonX - OEM-4 E: Boost control solenoid (turbo): no free high_side/ls_hs on Link G4X MonsoonX - OEM-4 AC: Data link connector (DLC TEN, turbo): no free k_line on Link G4X MonsoonX
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 | Link: G4X MonsoonX quickstart + RET 115-1000 | https://linkecu.com/documentation/MonsoonXQuickstartGuide.pdf | archive | 2026-10-05 | e8d432b273d6 |
| 3 | community_copy | YourSpec: Link G4X MonsoonX flying-lead harness wiring list | https://wpm.yourspec.com/projects/view/1469 | — | — | — |