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MX-5 Miata Mazdaspeed 2004-05 (BP-ZET turbo, no VVT) → MaxxECU MaxxECU MINI REV10+ (auto)

MX-5 Miata Mazdaspeed 2004-05 (BP-ZET turbo, no VVT) — MaxxECU — MaxxECU MINI
⚠ NOT CHECKED. Don't build from this.
Drawn by Michael Gnankou · Rev 0 · draft · 2026-10-11

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.

Statusdraft · not yet verified: nobody has reported building and running this harness
Open errors2: read the Findings page before cutting any wire
Size of the job2 wires · 2 connectors · 0 part lines
ToolsCrimp and extraction tools for each terminal family (see Connectors) · wire strippers · multimeter · heat gun + heat-shrink
Order of work1. 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.

WireFromToGaugeColourCutLabelCrimp ACrimp BPin APin BContinuity
W1OEM-4-AEMAXXECUMINI-C1-C30.5☐☐☐☐☐☐☐
W2OEM-4-RMAXXECUMINI-C1-C10.5☐☐☐☐☐☐☐

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 AProbe BExpectWhyReading
No supply/ground nets found to cross-check.

If any reading doesn't match, stop and get help before powering up.

Revisions

RevLabelByDate
No revisions yet.

Schematic

MAXXECUMINI-C1OEM-2OEM-3OEM-4

Connectors

MAXXECUMINI-C1

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
A1TRIGGER————————
A2TRIGGER GND————————
B1DIN 1 (Hall only)————————
B2DIN 2 (Hall only)————————
B3SENSOR GND————————
B4SENSOR GND————————
C1CLT—W2—0.5OEM-4-R———
C2IAT————————
C3AIN 3 (0-5V)—W1—0.5OEM-4-AE———
C4AIN 4 (0-5V)————————
D1GPO 8/TACHO————————
D2TPS————————
D3GND Shield————————
D4SENSOR GND————————
E1GPO 3————————
E2+5V sensor supply————————
E3CAN L————————
E4CAN H————————
F1IGN 1————————
F2IGN 2————————
F3IGN 3————————
F4IGN 4————————
G1GPO 2————————
G2GPO 1————————
G3INJ 1————————
G4ENGINE GND————————
H1INJ 2————————
H2INJ 3————————
H3INJ 4————————
H4+12V (ECU power supply)————————

OEM-4

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
ACData link connector (DLC TEN, turbo)————————
AEBARO/MAP sensor (turbo boost pressure)—W1—0.5MAXXECUMINI-C1-C3———
DBoost control solenoid (turbo)————————
EBoost control solenoid (turbo)————————
RIntake air temperature 2 (IAT2, turbo)—W2—0.5MAXXECUMINI-C1-C1———

Pin map

OEM pointOEM functionOEM familyTarget pointTarget functionTarget familyWire colourEvidence
OEM-4-ACData link connector (DLC TEN, turbo)serial———BrYsingle_source
OEM-4-AEBARO/MAP sensor (turbo boost pressure)analog_inMAXXECUMINI-C1-C3AIN 3 (0-5V)analog_inLYsingle_source
OEM-4-DBoost control solenoid (turbo)high_side_out———Ysingle_source
OEM-4-EBoost control solenoid (turbo)high_side_out———Ysingle_source
OEM-4-RIntake air temperature 2 (IAT2, turbo)temp_inMAXXECUMINI-C1-C1CLTtemp_inVYsingle_source

Cut list

WireFromToGauge (mm²)ColourLengthSignalIdent
W1OEM-4-AEMAXXECUMINI-C1-C30.5no routeBARO/MAP sensor (turbo boost pressure)—
W2OEM-4-RMAXXECUMINI-C1-C10.5no routeIntake air temperature 2 (IAT2, turbo)—

Bill of materials

CategoryPart numberManufacturerDescriptionQtyUnit

ECU setup sheet

RoleEngine refEngine signalSensorECU pointECU functionECU classSetup flag
No configured channels.

Findings

Open (3)

SeverityCodeSubjectMessage
errorPHYS_REQUIRED_OPENMAXXECUMINI-C1-G4MAXXECUMINI-C1-G4 "ENGINE GND" is required but not wired.
errorPHYS_REQUIRED_OPENMAXXECUMINI-C1-H4MAXXECUMINI-C1-H4 "+12V (ECU power supply)" is required but not wired.
infoUNMAPPEDOEM3 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)

CodeSubjectReasonBy

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 - MAXXECUMINI-C1 G4: ENGINE GND: required by MaxxECU MaxxECU MINI but no stock pin feeds it; wire by hand - MAXXECUMINI-C1 H4: +12V (ECU power supply): required by MaxxECU MaxxECU MINI but no stock pin feeds it; wire by hand Not wired: - OEM-4 D: Boost control solenoid (turbo): no free high_side/ls_hs/hbridge on MaxxECU MaxxECU MINI - OEM-4 E: Boost control solenoid (turbo): no free high_side/ls_hs/hbridge on MaxxECU MaxxECU MINI - OEM-4 AC: Data link connector (DLC TEN, turbo): no free k_line on MaxxECU MaxxECU MINI

Sources

ReliabilityKindTitleURLArchiveCapturedSHA-256
4oem_manual2005 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———
4vendor_docAdaptronic 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———
4vendor_docMaxxECU GEN1 pinout (MINI / STREET / SPORT / V1 / RACE / PRO)http://www.maxxecu.com/webhelp/wirings-maxxecu_pinout.htmlarchive2026-10-052e37b6814690