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MX-5 Miata Mazdaspeed 2004-05 (BP-ZET turbo, no VVT) → DTAFast T2i (auto)

MX-5 Miata Mazdaspeed 2004-05 (BP-ZET turbo, no VVT) — DTAFast — T2i
⚠ 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 errors4: read the Findings page before cutting any wire
Size of the job2 wires · 2 connectors · 2 part lines
ToolsCrimp and extraction tools for each terminal family (see Connectors) · wire strippers · multimeter · heat gun + heat-shrink
Terminals3-1447221-4
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-AET2I-C1-200.5☐☐☐☐☐☐☐
W2OEM-4-RT2I-C1-240.5☐☐☐☐☐☐☐

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

OEM-2OEM-3OEM-4T2I-C1

Connectors

OEM-4

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
ACData link connector (DLC TEN, turbo)————————
AEBARO/MAP sensor (turbo boost pressure)—W1—0.5T2I-C1-20———
DBoost control solenoid (turbo)————————
EBoost control solenoid (turbo)————————
RIntake air temperature 2 (IAT2, turbo)—W2—0.5T2I-C1-24———

T2I-C1

Mating face
T2I-C1-1 · PWM 11T2I-C1-2 · Lambda Nernst Voltage2T2I-C1-3 · Coil 13T2I-C1-4 · Lambda VGND4T2I-C1-5 · Lambda Pump Current5T2I-C1-6 · Coil 26T2I-C1-7 · Lambda Trim Resistor7T2I-C1-88T2I-C1-99T2I-C1-10 · PWM 210T2I-C1-11 · Digital 111T2I-C1-12 · Wheel 112T2I-C1-13 · Power Ground 113T2I-C1-14 · Power Ground 214T2I-C1-15 · Lambda Heater Negative15T2I-C1-16 · CAN High16T2I-C1-17 · CAN Low17T2I-C1-18 · PWM 318T2I-C1-19 · Crank19T2I-C1-20 · Analogue 120T2I-C1-21 · Permanent 12v21T2I-C1-22 · Analogue 222T2I-C1-23 · Analogue 323T2I-C1-24 · Thermistor 124T2I-C1-25 · Analogue 425T2I-C1-26 · PWM 426T2I-C1-27 · 5v Output27T2I-C1-28 · Sensor Ground28T2I-C1-29 · Sensor Ground29T2I-C1-30 · Digital 230T2I-C1-31 · Ignition 12v In31T2I-C1-32 · Thermistor 232T2I-C1-33 · Analogue 533T2I-C1-34 · Analogue 634
Wire side
T2I-C1-1 · PWM 11T2I-C1-2 · Lambda Nernst Voltage2T2I-C1-3 · Coil 13T2I-C1-4 · Lambda VGND4T2I-C1-5 · Lambda Pump Current5T2I-C1-6 · Coil 26T2I-C1-7 · Lambda Trim Resistor7T2I-C1-88T2I-C1-99T2I-C1-10 · PWM 210T2I-C1-11 · Digital 111T2I-C1-12 · Wheel 112T2I-C1-13 · Power Ground 113T2I-C1-14 · Power Ground 214T2I-C1-15 · Lambda Heater Negative15T2I-C1-16 · CAN High16T2I-C1-17 · CAN Low17T2I-C1-18 · PWM 318T2I-C1-19 · Crank19T2I-C1-20 · Analogue 120T2I-C1-21 · Permanent 12v21T2I-C1-22 · Analogue 222T2I-C1-23 · Analogue 323T2I-C1-24 · Thermistor 124T2I-C1-25 · Analogue 425T2I-C1-26 · PWM 426T2I-C1-27 · 5v Output27T2I-C1-28 · Sensor Ground28T2I-C1-29 · Sensor Ground29T2I-C1-30 · Digital 230T2I-C1-31 · Ignition 12v In31T2I-C1-32 · Thermistor 232T2I-C1-33 · Analogue 533T2I-C1-34 · Analogue 634
CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1PWM 1————————
2Lambda Nernst Voltage————————
3Coil 1————————
4Lambda VGND————————
5Lambda Pump Current————————
6Coil 2————————
7Lambda Trim Resistor————————
8—————————
9—————————
10PWM 2————————
11Digital 1————————
12Wheel 1————————
13Power Ground 1————————
14Power Ground 2————————
15Lambda Heater Negative————————
16CAN High————————
17CAN Low————————
18PWM 3————————
19Crank————————
20Analogue 1—W1—0.5OEM-4-AE———
21Permanent 12v————————
22Analogue 2————————
23Analogue 3————————
24Thermistor 1—W2—0.5OEM-4-R———
25Analogue 4————————
26PWM 4————————
275v Output————————
28Sensor Ground————————
29Sensor Ground————————
30Digital 2————————
31Ignition 12v In————————
32Thermistor 2————————
33Analogue 5————————
34Analogue 6————————

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_inT2I-C1-20Analogue 1analog_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_inT2I-C1-24Thermistor 1temp_inVYsingle_source

Cut list

WireFromToGauge (mm²)ColourLengthSignalIdent
W1OEM-4-AET2I-C1-200.5no routeBARO/MAP sensor (turbo boost pressure)—
W2OEM-4-RT2I-C1-240.5no routeIntake air temperature 2 (IAT2, turbo)—

Bill of materials

CategoryPart numberManufacturerDescriptionQtyUnit
connector4-1437290-0TESuperseal 1.0 34-way plug, Key 11.000ea
terminal3-1447221-4TESuperseal 1.0 socket terminal, 20 AWG (0.5 sq mm)2.000ea

ECU setup sheet

RoleEngine refEngine signalSensorECU pointECU functionECU classSetup flag
No configured channels.

Findings

Open (6)

SeverityCodeSubjectMessage
errorPHYS_REQUIRED_OPENT2I-C1-13T2I-C1-13 "Power Ground 1" is required but not wired.
errorPHYS_REQUIRED_OPENT2I-C1-14T2I-C1-14 "Power Ground 2" is required but not wired.
errorPHYS_REQUIRED_OPENT2I-C1-21T2I-C1-21 "Permanent 12v" is required but not wired.
errorPHYS_REQUIRED_OPENT2I-C1-31T2I-C1-31 "Ignition 12v In" is required but not wired.
warnDATASET_GAPT2i C12 of 34 cavities on T2i C1 have no pin data (8,9). Anything there is invisible to these checks.
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 - T2I-C1 13: Power Ground 1: required by DTAFast T2i but no stock pin feeds it; wire by hand - T2I-C1 14: Power Ground 2: required by DTAFast T2i but no stock pin feeds it; wire by hand - T2I-C1 21: Permanent 12v: required by DTAFast T2i but no stock pin feeds it; wire by hand - T2I-C1 31: Ignition 12v In: required by DTAFast T2i 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 DTAFast T2i - OEM-4 E: Boost control solenoid (turbo): no free high_side/ls_hs/hbridge on DTAFast T2i - OEM-4 AC: Data link connector (DLC TEN, turbo): no free k_line on DTAFast T2i

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_docDTAFast T2i ECU wiring diagramhttps://cdn.shopify.com/s/files/1/0848/7508/4108/files/T2i_Wiring-Diagram.pdf?v=1728571341———