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MX-5 Miata Mazdaspeed 2004-05 (BP-ZET turbo, no VVT) → MaxxECU MaxxECU GEN2 TRACK (auto)

MX-5 Miata Mazdaspeed 2004-05 (BP-ZET turbo, no VVT) — MaxxECU — MaxxECU GEN2 TRACK
⚠ 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 errors5: read the Findings page before cutting any wire
Size of the job4 wires · 4 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-DMAXXECUGEN2T-MX3-140.5☐☐☐☐☐☐☐
W2OEM-4-EMAXXECUGEN2T-MX3-150.5☐☐☐☐☐☐☐
W3OEM-4-AEMAXXECUGEN2T-MX1-260.5☐☐☐☐☐☐☐
W4OEM-4-RMAXXECUGEN2T-MX1-270.5☐☐☐☐☐☐☐

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

MAXXECUGEN2T-MX1MAXXECUGEN2T-MX2MAXXECUGEN2T-MX3OEM-2OEM-3OEM-4

Connectors

MAXXECUGEN2T-MX1

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1Ignition 1————————
10Digital/VR 1 SIGNAL +————————
11Digital/VR 1 SIGNAL -————————
12Digital/VR 1 POWER SUPPLY————————
13Digital/VR 1 SHIELD————————
14SENSOR GND————————
15CAN L————————
16CAN H————————
17GP out 5 (GND)————————
18Digital/VR 2 SIGNAL +————————
19Digital/VR 2 SIGNAL -————————
2Ignition 2————————
20Digital/VR 2 POWER SUPPLY————————
21Digital/VR 2 SHIELD————————
225V power supply————————
23Digital/VR 3 SIGNAL +————————
24Digital/VR 4 SIGNAL +————————
2512V supply 1————————
26AIN 1—W3—0.5OEM-4-AE———
27AIN 2—W4—0.5OEM-4-R———
28AIN 3————————
29AIN 4————————
3Ignition 3————————
30AIN 5————————
31INJECTOR 1————————
32INJECTOR 2————————
33INJECTOR 3————————
34INJECTOR 4————————
4Ignition 4————————
5GP out 1 (GND)————————
6GP out 2 (GND)————————
7GP out 3 (GND)————————
8GP out 4 (GND)————————
9Engine gnd————————

MAXXECUGEN2T-MX2

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1Ignition 5————————
10WBO2 Sensor 1 VS————————
11WBO2 Sensor 1 COM/VREF————————
12GP OUT 7 / WBO2 Sensor 1 H-————————
13AIN 9————————
14AIN 10————————
15AIN 11————————
16AIN 12————————
17AIN 13————————
18WBO2 sensor 1 RCAL————————
19WBO2 sensor 1 IP————————
2Ignition 6————————
2012V WBO2 sensor 1 H+————————
21WBO2 sensor 1 SHIELD————————
22AIN 14————————
23AIN 15————————
2412V supply 3————————
2512V supply 2————————
26KNOCK1 SHIELD————————
27KNOCK 1-————————
28KNOCK 1+————————
29KNOCK 2 SHIELD————————
3GP out 6 (GND)————————
30KNOCK 2-————————
31KNOCK 2+————————
32AIN 16————————
33INJECTOR 5————————
34INJECTOR 6————————
4AIN 6————————
5AIN 7————————
6AIN 8————————
7GP out 13 (H-BRIDGE 1)————————
8GP out 14 (H-BRIDGE 1)————————
9Engine gnd————————

MAXXECUGEN2T-MX3

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1GP out 15 (H-BRIDGE 2)————————
10WBO2 sensor 2 VS————————
11WBO2 sensor 2 COM/VREF————————
12GP Out 8 (GND) / WBO2 Sensor 2 H-————————
14GP OUT 9 (12V)—W1—0.5OEM-4-D———
15GP OUT 10 (12V)—W2—0.5OEM-4-E———
16GP OUT 11 (12V)————————
17GP OUT 12 (12V)————————
18WBO2 sensor 2 RCAL————————
19WBO2 sensor 2 IP————————
2GP out 16 (H-BRIDGE 2)————————
2012V WBO2 sensor 2 (H+)————————
21Digital/VR 5 SIGNAL +————————
22Digital/VR 5 SIGNAL -————————
23Digital/VR 5 SHIELD————————
24CAN 2 L————————
25CAN 2 H————————
26Digital/VR 6 SIGNAL +————————
27Digital/VR 6 SIGNAL -————————
28Digital/VR 6 SHIELD————————
29INJECTOR 7————————
3Ignition 7————————
30INJECTOR 8————————
4Ignition 8————————
9Engine gnd————————

OEM-4

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
ACData link connector (DLC TEN, turbo)————————
AEBARO/MAP sensor (turbo boost pressure)—W3—0.5MAXXECUGEN2T-MX1-26———
DBoost control solenoid (turbo)—W1—0.5MAXXECUGEN2T-MX3-14———
EBoost control solenoid (turbo)—W2—0.5MAXXECUGEN2T-MX3-15———
RIntake air temperature 2 (IAT2, turbo)—W4—0.5MAXXECUGEN2T-MX1-27———

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_inMAXXECUGEN2T-MX1-26AIN 1analog_inLYsingle_source
OEM-4-DBoost control solenoid (turbo)high_side_outMAXXECUGEN2T-MX3-14GP OUT 9 (12V)high_side_outYsingle_source
OEM-4-EBoost control solenoid (turbo)high_side_outMAXXECUGEN2T-MX3-15GP OUT 10 (12V)high_side_outYsingle_source
OEM-4-RIntake air temperature 2 (IAT2, turbo)temp_inMAXXECUGEN2T-MX1-27AIN 2analog_inVYsingle_source

Cut list

WireFromToGauge (mm²)ColourLengthSignalIdent
W1OEM-4-DMAXXECUGEN2T-MX3-140.5no routeBoost control solenoid (turbo)—
W2OEM-4-EMAXXECUGEN2T-MX3-150.5no routeBoost control solenoid (turbo)—
W3OEM-4-AEMAXXECUGEN2T-MX1-260.5no routeBARO/MAP sensor (turbo boost pressure)—
W4OEM-4-RMAXXECUGEN2T-MX1-270.5no 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 (7)

SeverityCodeSubjectMessage
errorPHYS_REQUIRED_OPENMAXXECUGEN2T-MX1-25MAXXECUGEN2T-MX1-25 "12V supply 1" is required but not wired.
errorPHYS_REQUIRED_OPENMAXXECUGEN2T-MX1-9MAXXECUGEN2T-MX1-9 "Engine gnd" is required but not wired.
errorPHYS_REQUIRED_OPENMAXXECUGEN2T-MX2-25MAXXECUGEN2T-MX2-25 "12V supply 2" is required but not wired.
errorPHYS_REQUIRED_OPENMAXXECUGEN2T-MX2-9MAXXECUGEN2T-MX2-9 "Engine gnd" is required but not wired.
errorPHYS_REQUIRED_OPENMAXXECUGEN2T-MX3-9MAXXECUGEN2T-MX3-9 "Engine gnd" is required but not wired.
infoNET_FAMILYOEM-4-R ↔ MAXXECUGEN2T-MX1-27OEM-4-R "Intake air temperature 2 (IAT2, turbo)" [temp_in] is wired to MAXXECUGEN2T-MX1-27 "AIN 2" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one.
infoUNMAPPEDOEM1 optional OEM pins are not mapped: OEM-4-AC Data link connector (DLC TEN, 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 - MAXXECUGEN2T-MX1 25: 12V supply 1: required by MaxxECU MaxxECU GEN2 TRACK but no stock pin feeds it; wire by hand - MAXXECUGEN2T-MX1 9: Engine gnd: required by MaxxECU MaxxECU GEN2 TRACK but no stock pin feeds it; wire by hand - MAXXECUGEN2T-MX2 25: 12V supply 2: required by MaxxECU MaxxECU GEN2 TRACK but no stock pin feeds it; wire by hand - MAXXECUGEN2T-MX2 9: Engine gnd: required by MaxxECU MaxxECU GEN2 TRACK but no stock pin feeds it; wire by hand - MAXXECUGEN2T-MX3 9: Engine gnd: required by MaxxECU MaxxECU GEN2 TRACK but no stock pin feeds it; wire by hand Not wired: - OEM-4 AC: Data link connector (DLC TEN, turbo): no free k_line on MaxxECU MaxxECU GEN2 TRACK - MAXXECUGEN2T-MX2 24: 12V supply 3: not fed (the stock ECU has no ignition-sense pin); feed it from a switched-ignition source

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 GEN2 pinout (RACE MX1–MX4 / TRACK MX1–MX3)http://www.maxxecu.com/webhelp/wirings-maxxecu_gen2_pinout.htmlarchive2026-10-05f689b8b6b08f