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Mazda RX-7 FD 1992-2002 (13B-REW twin-turbo) → Speeduino Speeduino v0.4 (auto)

Mazda RX-7 FD 1992-2002 (13B-REW twin-turbo) — Speeduino — Speeduino
⚠ 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 job39 wires · 6 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-A-1AFSP-GND-10.85☐☐☐☐☐☐☐
W2OEM-A-1AJSP-GND-10.85☐☐☐☐☐☐☐
W3OEM-A-1LSP-GND-10.85☐☐☐☐☐☐☐
W4SP-GND-1SPEEDUINO-A-100.85☐☐☐☐☐☐☐
W5SP-GND-1SPEEDUINO-A-90.85☐☐☐☐☐☐☐
W6OEM-A-1ABSP-0V-10.5☐☐☐☐☐☐☐
W7OEM-A-1XSP-0V-10.5☐☐☐☐☐☐☐
W8OEM-C-3ABSP-0V-10.5☐☐☐☐☐☐☐
W9OEM-C-3SSP-0V-10.5☐☐☐☐☐☐☐
W10SP-0V-1SPEEDUINO-A-120.5☐☐☐☐☐☐☐
W11SP-0V-1SPEEDUINO-A-230.5☐☐☐☐☐☐☐
W12OEM-C-3ASPEEDUINO-A-130.5☐☐☐☐☐☐☐
W13OEM-C-3RSPEEDUINO-A-250.5☐☐☐☐☐☐☐
W14OEM-C-3USPEEDUINO-A-240.5☐☐☐☐☐☐☐
W15OEM-D-4AFSPEEDUINO-A-70.5☐☐☐☐☐☐☐
W16OEM-D-4AJSPEEDUINO-A-340.5☐☐☐☐☐☐☐
W17OEM-D-4ANSPEEDUINO-A-330.5☐☐☐☐☐☐☐
W18OEM-A-1QSPEEDUINO-A-10.5☐☐☐☐☐☐☐
W19OEM-A-1USPEEDUINO-A-20.5☐☐☐☐☐☐☐
W20OEM-A-1YSPEEDUINO-A-30.5☐☐☐☐☐☐☐
W21OEM-A-1ACSPEEDUINO-A-50.5☐☐☐☐☐☐☐
W22OEM-A-1AASPEEDUINO-A-310.5☐☐☐☐☐☐☐
W23OEM-A-1AESPEEDUINO-A-320.5☐☐☐☐☐☐☐
W24OEM-A-1SSPEEDUINO-A-290.5☐☐☐☐☐☐☐
W25OEM-A-1WSPEEDUINO-A-300.5☐☐☐☐☐☐☐
W26OEM-A-1HSPEEDUINO-A-160.5☐☐☐☐☐☐☐
W27OEM-D-4DSPEEDUINO-A-150.5☐☐☐☐☐☐☐
W28OEM-D-4FSPEEDUINO-A-360.5☐☐☐☐☐☐☐
W29OEM-D-4GSPEEDUINO-A-350.5☐☐☐☐☐☐☐
W30OEM-D-4ISPEEDUINO-A-370.5☐☐☐☐☐☐☐
W31OEM-D-4KSPEEDUINO-A-380.5☐☐☐☐☐☐☐
W32OEM-D-4MSPEEDUINO-A-170.5☐☐☐☐☐☐☐
W33OEM-D-4AHSPEEDUINO-A-110.5☐☐☐☐☐☐☐
W34OEM-C-3ISPEEDUINO-A-220.5☐☐☐☐☐☐☐
W35OEM-C-3DSPEEDUINO-A-210.5☐☐☐☐☐☐☐
W36OEM-C-3WSPEEDUINO-A-190.5☐☐☐☐☐☐☐
W37OEM-C-3TSPEEDUINO-A-200.5☐☐☐☐☐☐☐
W38OEM-D-4QSPEEDUINO-A-140.5☐☐☐☐☐☐☐
W39OEM-D-4AASPEEDUINO-A-180.5☐☐☐☐☐☐☐

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
1SPEEDUINO-A-10SPEEDUINO-A-13open (OL)power ground must not touch 5 V sensor reference
2SPEEDUINO-A-12SPEEDUINO-A-13open (OL)sensor ground must not touch 5 V sensor reference

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

Revisions

RevLabelByDate
No revisions yet.

Schematic

OEM-AOEM-BOEM-COEM-DSP-0VSP-GNDSPEEDUINO-A

Connectors

OEM-A

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1AAOMP stepper phase B1—W22—0.5SPEEDUINO-A-31———
1ABSensor ground—W6—0.5SP-0V-1———
1ACInjector 4 (rear secondary)—W21—0.5SPEEDUINO-A-5———
1AEOMP stepper phase A1—W23—0.5SPEEDUINO-A-32———
1AFPower ground—W1—0.85SP-GND-1———
1AJPower ground—W2—0.85SP-GND-1———
1CIdle speed control (ISC) solenoid————————
1ETurbo charge control solenoid————————
1GPurge solenoid————————
1HCooling fan relay (low speed)—W26—0.5SPEEDUINO-A-16———
1ITurbo charge relief solenoid————————
1KTurbo pre-control solenoid————————
1LPower ground—W3—0.85SP-GND-1———
1MTurbo control solenoid————————
1OBoost control solenoid————————
1QInjector 1 (front primary)—W18—0.5SPEEDUINO-A-1———
1SOMP stepper phase B2—W24—0.5SPEEDUINO-A-29———
1UInjector 2 (rear primary)—W19—0.5SPEEDUINO-A-2———
1WOMP stepper phase A2—W25—0.5SPEEDUINO-A-30———
1XSensor ground—W7—0.5SP-0V-1———
1YInjector 3 (front secondary)—W20—0.5SPEEDUINO-A-3———

OEM-C

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
3A+5V sensor supply—W12—0.5SPEEDUINO-A-13———
3ABSensor ground—W8—0.5SP-0V-1———
3DO2 sensor (narrowband)—W35—0.5SPEEDUINO-A-21———
3GFuel pressure regulator control (PRC) solenoid————————
3HOMP position sensor————————
3IThrottle position (TPS, full range)—W34—0.5SPEEDUINO-A-22———
3OKnock sensor————————
3RCrank position (CAS NE)—W13—0.5SPEEDUINO-A-25———
3SSensor ground (CAS)—W9—0.5SP-0V-1———
3TIntake air temperature (IAT)—W37—0.5SPEEDUINO-A-20———
3UHome position (CAS G)—W14—0.5SPEEDUINO-A-24———
3VFuel temperature————————
3WCoolant temperature (ECT)—W36—0.5SPEEDUINO-A-19———

OEM-D

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
4AECU main power (+12V via main relay/ECR)————————
4AABrake pedal switch—W39—0.5SPEEDUINO-A-18———
4AFIgnition front trailing—W15—0.5SPEEDUINO-A-7———
4AHMAP sensor (PIM)—W33—0.5SPEEDUINO-A-11———
4AJIgnition rear trailing—W16—0.5SPEEDUINO-A-34———
4ANIgnition leading (wasted spark)—W17—0.5SPEEDUINO-A-33———
4BBattery constant (+12V)————————
4CIgnition switch / start signal————————
4DAir pump clutch relay—W27—0.5SPEEDUINO-A-15———
4EECU main power (+12V via main relay/ECR)————————
4FFuel pump speed relay—W28—0.5SPEEDUINO-A-36———
4GFuel pump relay—W29—0.5SPEEDUINO-A-35———
4IA/C relay—W30—0.5SPEEDUINO-A-37———
4KCooling fan relay (low speed)—W31—0.5SPEEDUINO-A-38———
4LCooling fan relay (high speed)————————
4MTachometer output—W32—0.5SPEEDUINO-A-17———
4QVehicle speed sensor—W38—0.5SPEEDUINO-A-14———
4SClutch switch————————
4VA/C request————————
4WPower steering pressure switch————————

SP-0V

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W6—0.5OEM-A-1AB———
1——W7—0.5OEM-A-1X———
1——W8—0.5OEM-C-3AB———
1——W9—0.5OEM-C-3S———
1——W10—0.5SPEEDUINO-A-12———
1——W11—0.5SPEEDUINO-A-23———

SP-GND

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W1—0.85OEM-A-1AF———
1——W2—0.85OEM-A-1AJ———
1——W3—0.85OEM-A-1L———
1——W4—0.85SPEEDUINO-A-10———
1——W5—0.85SPEEDUINO-A-9———

SPEEDUINO-A

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1Injector 1—W18—0.5OEM-A-1Q———
10Ground—W4—0.85SP-GND-1———
11MAP sensor (0-5V)—W33—0.5OEM-D-4AH———
12Ground—W10—0.5SP-0V-1———
135V—W12—0.5OEM-C-3A———
14Proto area 1 (flex fuel)—W38—0.5OEM-D-4Q———
15Proto area 2 (fan)—W27—0.5OEM-D-4D———
16Proto area 3 (fuel pump)—W26—0.5OEM-A-1H———
17Proto area 4 (tachometer)—W32—0.5OEM-D-4M———
18Proto area 5 (clutch)—W39—0.5OEM-D-4AA———
19Coolant temp (CLT)—W36—0.5OEM-C-3W———
2Injector 2—W19—0.5OEM-A-1U———
20Inlet air temp (IAT)—W37—0.5OEM-C-3T———
21O2 sensor—W35—0.5OEM-C-3D———
22TPS input—W34—0.5OEM-C-3I———
23Ground—W11—0.5SP-0V-1———
24Cam input / VR2+—W14—0.5OEM-C-3U———
25Crank input / VR1+—W13—0.5OEM-C-3R———
26VR2-————————
27VR1-————————
285V————————
29Idle stepper 2B—W24—0.5OEM-A-1S———
3Injector 3—W20—0.5OEM-A-1Y———
30Idle stepper 2A—W25—0.5OEM-A-1W———
31Idle stepper 1A—W22—0.5OEM-A-1AA———
32Idle stepper 1B—W23—0.5OEM-A-1AE———
33Ignition 3—W17—0.5OEM-D-4AN———
34Ignition 2—W16—0.5OEM-D-4AJ———
35Boost—W29—0.5OEM-D-4G———
36Idle 2 (3-wire idle)—W28—0.5OEM-D-4F———
37PWM idle—W30—0.5OEM-D-4I———
38VVT—W31—0.5OEM-D-4K———
5Injector 4—W21—0.5OEM-A-1AC———
7Ignition 1—W15—0.5OEM-D-4AF———
8Ignition 4————————
9Ground—W5—0.85SP-GND-1———

Pin map

OEM pointOEM functionOEM familyTarget pointTarget functionTarget familyWire colourEvidence
OEM-A-1AAOMP stepper phase B1hbridge_outSPEEDUINO-A-31Idle stepper 1Ahbridge_outsingle_source
OEM-A-1ABSensor groundsensor_groundSPEEDUINO-A-12 + SPEEDUINO-A-23Ground + Groundsensor_groundsingle_source
OEM-A-1ACInjector 4 (rear secondary)injector_outSPEEDUINO-A-5Injector 4injector_outsingle_source
OEM-A-1AEOMP stepper phase A1hbridge_outSPEEDUINO-A-32Idle stepper 1Bhbridge_outsingle_source
OEM-A-1AFPower groundgroundSPEEDUINO-A-10 + SPEEDUINO-A-9Ground + Groundgroundsingle_source
OEM-A-1AJPower groundgroundSPEEDUINO-A-10 + SPEEDUINO-A-9Ground + Groundgroundsingle_source
OEM-A-1CIdle speed control (ISC) solenoidlow_side_out———single_source
OEM-A-1ETurbo charge control solenoidlow_side_out———single_source
OEM-A-1GPurge solenoidlow_side_out———single_source
OEM-A-1HCooling fan relay (low speed)low_side_outSPEEDUINO-A-16Proto area 3 (fuel pump)low_side_outsingle_source
OEM-A-1ITurbo charge relief solenoidlow_side_out———single_source
OEM-A-1KTurbo pre-control solenoidlow_side_out———single_source
OEM-A-1LPower groundgroundSPEEDUINO-A-10 + SPEEDUINO-A-9Ground + Groundgroundsingle_source
OEM-A-1MTurbo control solenoidlow_side_out———single_source
OEM-A-1OBoost control solenoidlow_side_out———single_source
OEM-A-1QInjector 1 (front primary)injector_outSPEEDUINO-A-1Injector 1injector_outsingle_source
OEM-A-1SOMP stepper phase B2hbridge_outSPEEDUINO-A-29Idle stepper 2Bhbridge_outsingle_source
OEM-A-1UInjector 2 (rear primary)injector_outSPEEDUINO-A-2Injector 2injector_outsingle_source
OEM-A-1WOMP stepper phase A2hbridge_outSPEEDUINO-A-30Idle stepper 2Ahbridge_outsingle_source
OEM-A-1XSensor groundsensor_groundSPEEDUINO-A-12 + SPEEDUINO-A-23Ground + Groundsensor_groundsingle_source
OEM-A-1YInjector 3 (front secondary)injector_outSPEEDUINO-A-3Injector 3injector_outsingle_source
OEM-C-3A+5V sensor supplyvrefSPEEDUINO-A-135Vvrefsingle_source
OEM-C-3ABSensor groundsensor_groundSPEEDUINO-A-12 + SPEEDUINO-A-23Ground + Groundsensor_groundsingle_source
OEM-C-3DO2 sensor (narrowband)lambda_nb_inSPEEDUINO-A-21O2 sensorlambda_nb_insingle_source
OEM-C-3GFuel pressure regulator control (PRC) solenoidlow_side_out———single_source
OEM-C-3HOMP position sensoranalog_in———single_source
OEM-C-3IThrottle position (TPS, full range)analog_inSPEEDUINO-A-22TPS inputanalog_insingle_source
OEM-C-3OKnock sensorknock_in———single_source
OEM-C-3RCrank position (CAS NE)trigger_inSPEEDUINO-A-25Crank input / VR1+trigger_insingle_source
OEM-C-3SSensor ground (CAS)sensor_groundSPEEDUINO-A-12 + SPEEDUINO-A-23Ground + Groundsensor_groundsingle_source
OEM-C-3TIntake air temperature (IAT)temp_inSPEEDUINO-A-20Inlet air temp (IAT)temp_insingle_source
OEM-C-3UHome position (CAS G)trigger_inSPEEDUINO-A-24Cam input / VR2+trigger_insingle_source
OEM-C-3VFuel temperaturetemp_in———single_source
OEM-C-3WCoolant temperature (ECT)temp_inSPEEDUINO-A-19Coolant temp (CLT)temp_insingle_source
OEM-D-4AECU main power (+12V via main relay/ECR)power_in———single_source
OEM-D-4AABrake pedal switchdigital_inSPEEDUINO-A-18Proto area 5 (clutch)digital_insingle_source
OEM-D-4AFIgnition front trailingignition_outSPEEDUINO-A-7Ignition 1ignition_outsingle_source
OEM-D-4AHMAP sensor (PIM)analog_inSPEEDUINO-A-11MAP sensor (0-5V)analog_insingle_source
OEM-D-4AJIgnition rear trailingignition_outSPEEDUINO-A-34Ignition 2ignition_outsingle_source
OEM-D-4ANIgnition leading (wasted spark)ignition_outSPEEDUINO-A-33Ignition 3ignition_outsingle_source
OEM-D-4BBattery constant (+12V)power_in———single_source
OEM-D-4CIgnition switch / start signaldigital_in———single_source
OEM-D-4DAir pump clutch relaylow_side_outSPEEDUINO-A-15Proto area 2 (fan)low_side_outsingle_source
OEM-D-4EECU main power (+12V via main relay/ECR)power_in———single_source
OEM-D-4FFuel pump speed relaylow_side_outSPEEDUINO-A-36Idle 2 (3-wire idle)low_side_outsingle_source
OEM-D-4GFuel pump relaylow_side_outSPEEDUINO-A-35Boostlow_side_outsingle_source
OEM-D-4IA/C relaylow_side_outSPEEDUINO-A-37PWM idlelow_side_outsingle_source
OEM-D-4KCooling fan relay (low speed)low_side_outSPEEDUINO-A-38VVTlow_side_outsingle_source
OEM-D-4LCooling fan relay (high speed)low_side_out———single_source
OEM-D-4MTachometer outputtacho_outSPEEDUINO-A-17Proto area 4 (tachometer)tacho_outsingle_source
OEM-D-4QVehicle speed sensordigital_inSPEEDUINO-A-14Proto area 1 (flex fuel)digital_insingle_source
OEM-D-4SClutch switchdigital_in———single_source
OEM-D-4VA/C requestdigital_in———single_source
OEM-D-4WPower steering pressure switchdigital_in———single_source

Cut list

WireFromToGauge (mm²)ColourLengthSignalIdent
W1OEM-A-1AFSP-GND-10.85no routePower ground—
W2OEM-A-1AJSP-GND-10.85no routePower ground—
W3OEM-A-1LSP-GND-10.85no routePower ground—
W4SP-GND-1SPEEDUINO-A-100.85no routeGround—
W5SP-GND-1SPEEDUINO-A-90.85no routeGround—
W6OEM-A-1ABSP-0V-10.5no routeSensor ground—
W7OEM-A-1XSP-0V-10.5no routeSensor ground—
W8OEM-C-3ABSP-0V-10.5no routeSensor ground—
W9OEM-C-3SSP-0V-10.5no routeSensor ground (CAS)—
W10SP-0V-1SPEEDUINO-A-120.5no routeGround—
W11SP-0V-1SPEEDUINO-A-230.5no routeGround—
W12OEM-C-3ASPEEDUINO-A-130.5no route+5V sensor supply—
W13OEM-C-3RSPEEDUINO-A-250.5no routeCrank position (CAS NE)—
W14OEM-C-3USPEEDUINO-A-240.5no routeHome position (CAS G)—
W15OEM-D-4AFSPEEDUINO-A-70.5no routeIgnition front trailing—
W16OEM-D-4AJSPEEDUINO-A-340.5no routeIgnition rear trailing—
W17OEM-D-4ANSPEEDUINO-A-330.5no routeIgnition leading (wasted spark)—
W18OEM-A-1QSPEEDUINO-A-10.5no routeInjector 1 (front primary)—
W19OEM-A-1USPEEDUINO-A-20.5no routeInjector 2 (rear primary)—
W20OEM-A-1YSPEEDUINO-A-30.5no routeInjector 3 (front secondary)—
W21OEM-A-1ACSPEEDUINO-A-50.5no routeInjector 4 (rear secondary)—
W22OEM-A-1AASPEEDUINO-A-310.5no routeOMP stepper phase B1—
W23OEM-A-1AESPEEDUINO-A-320.5no routeOMP stepper phase A1—
W24OEM-A-1SSPEEDUINO-A-290.5no routeOMP stepper phase B2—
W25OEM-A-1WSPEEDUINO-A-300.5no routeOMP stepper phase A2—
W26OEM-A-1HSPEEDUINO-A-160.5no routeCooling fan relay (low speed)—
W27OEM-D-4DSPEEDUINO-A-150.5no routeAir pump clutch relay—
W28OEM-D-4FSPEEDUINO-A-360.5no routeFuel pump speed relay—
W29OEM-D-4GSPEEDUINO-A-350.5no routeFuel pump relay—
W30OEM-D-4ISPEEDUINO-A-370.5no routeA/C relay—
W31OEM-D-4KSPEEDUINO-A-380.5no routeCooling fan relay (low speed)—
W32OEM-D-4MSPEEDUINO-A-170.5no routeTachometer output—
W33OEM-D-4AHSPEEDUINO-A-110.5no routeMAP sensor (PIM)—
W34OEM-C-3ISPEEDUINO-A-220.5no routeThrottle position (TPS, full range)—
W35OEM-C-3DSPEEDUINO-A-210.5no routeO2 sensor (narrowband)—
W36OEM-C-3WSPEEDUINO-A-190.5no routeCoolant temperature (ECT)—
W37OEM-C-3TSPEEDUINO-A-200.5no routeIntake air temperature (IAT)—
W38OEM-D-4QSPEEDUINO-A-140.5no routeVehicle speed sensor—
W39OEM-D-4AASPEEDUINO-A-180.5no routeBrake pedal switch—

Bill of materials

CategoryPart numberManufacturerDescriptionQtyUnit

ECU setup sheet

RoleEngine refEngine signalSensorECU pointECU functionECU classSetup flag
No configured channels.

Findings

Open (9)

SeverityCodeSubjectMessage
errorREQUIRED_UNMAPPEDOEM-D-4ARequired OEM function "ECU main power (+12V via main relay/ECR)" (power_in) is not connected to the new ECU.
errorREQUIRED_UNMAPPEDOEM-D-4ERequired OEM function "ECU main power (+12V via main relay/ECR)" (power_in) is not connected to the new ECU.
warnLOAD_UNKNOWNSPEEDUINO-A-15SPEEDUINO-A-15 "Proto area 2 (fan)" drives OEM-D-4D Air pump clutch relay (load 0.2 A) but its current rating is unknown. Check the ECU manual.
warnLOAD_UNKNOWNSPEEDUINO-A-16SPEEDUINO-A-16 "Proto area 3 (fuel pump)" drives OEM-A-1H Cooling fan relay (low speed) (load 0.2 A) but its current rating is unknown. Check the ECU manual.
warnLOAD_UNKNOWNSPEEDUINO-A-35SPEEDUINO-A-35 "Boost" drives OEM-D-4G Fuel pump relay (load 0.2 A) but its current rating is unknown. Check the ECU manual.
warnLOAD_UNKNOWNSPEEDUINO-A-36SPEEDUINO-A-36 "Idle 2 (3-wire idle)" drives OEM-D-4F Fuel pump speed relay (load 0.2 A) but its current rating is unknown. Check the ECU manual.
warnLOAD_UNKNOWNSPEEDUINO-A-37SPEEDUINO-A-37 "PWM idle" drives OEM-D-4I A/C relay (load 0.2 A) but its current rating is unknown. Check the ECU manual.
warnLOAD_UNKNOWNSPEEDUINO-A-38SPEEDUINO-A-38 "VVT" drives OEM-D-4K Cooling fan relay (low speed) (load 0.2 A) but its current rating is unknown. Check the ECU manual.
infoUNMAPPEDOEM16 optional OEM pins are not mapped: OEM-A-1C Idle speed control (ISC) solenoid; OEM-A-1E Turbo charge control solenoid; OEM-A-1G Purge solenoid; OEM-A-1I Turbo charge relief solenoid; OEM-A-1K Turbo pre-control solenoid; OEM-A-1M Turbo control solenoid; OEM-A-1O Boost control solenoid; OEM-C-3G Fuel pressure regulator control (PRC) solenoid; OEM-C-3H OMP position sensor; OEM-C-3O Knock sensor; OEM-C-3V Fuel temperature; OEM-D-4C Ignition switch / start signal; OEM-D-4L Cooling fan relay (high speed); OEM-D-4S Clutch switch; OEM-D-4V A/C request; OEM-D-4W Power steering pressure switch

Accepted (1)

CodeSubjectReasonBy
REQUIRED_UNMAPPEDOEM-D-4BBattery-constant (memory) feed of the stock ECU: the new ECU has no such input, so it is not needed.mapping-proposal

Notes

Fit check: needs add-on. Resolve these before building: - Oil metering pump stepper driver needed; not documented for this ECU - Sequential twin-turbo control needed; not documented for this ECU - No knock input; the stock knock sensor would be unused 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 - OEM-D 4A: ECU main power (+12V via main relay/ECR): no rule for class ecu_main_power; wire by hand - OEM-D 4E: ECU main power (+12V via main relay/ECR): no rule for class ecu_main_power; wire by hand Not wired: - OEM-D 4B: Battery constant (+12V): Speeduino Speeduino has no battery-constant input; not needed - OEM-C 3O: Knock sensor: no free knock input on Speeduino Speeduino - OEM-D 4C: Ignition switch / start signal: key-on 12 V sense — optional in a swap (the main relay is energized from keyed 12 V, not from this pin); Speeduino Speeduino has no dedicated key-on input - OEM-D 4L: Cooling fan relay (high speed): no free relay_control/low_side/ls_hs/injector/hbridge rated ≥ 0.2 A on Speeduino Speeduino - OEM-A 1C: Idle speed control (ISC) solenoid: no free low_side/ls_hs/injector/hbridge on Speeduino Speeduino - OEM-A 1E: Turbo charge control solenoid: no free low_side/ls_hs/injector/hbridge on Speeduino Speeduino - OEM-A 1G: Purge solenoid: no free low_side/ls_hs/injector/hbridge on Speeduino Speeduino - OEM-A 1I: Turbo charge relief solenoid: no free low_side/ls_hs/injector/hbridge on Speeduino Speeduino - OEM-A 1K: Turbo pre-control solenoid: no free low_side/ls_hs/injector/hbridge on Speeduino Speeduino - OEM-A 1M: Turbo control solenoid: no free low_side/ls_hs/injector/hbridge on Speeduino Speeduino - OEM-A 1O: Boost control solenoid: no free low_side/ls_hs/injector/hbridge on Speeduino Speeduino - OEM-C 3G: Fuel pressure regulator control (PRC) solenoid: no free low_side/ls_hs/injector/hbridge on Speeduino Speeduino - OEM-C 3V: Fuel temperature: no free thermistor/analog_0_5 on Speeduino Speeduino - OEM-C 3H: OMP position sensor: no free analog_0_5 on Speeduino Speeduino - OEM-D 4S: Clutch switch: no free switch_in/frequency_in/analog_0_5 on Speeduino Speeduino - OEM-D 4V: A/C request: no free switch_in/frequency_in/analog_0_5 on Speeduino Speeduino - OEM-D 4W: Power steering pressure switch: no free switch_in/frequency_in/analog_0_5 on Speeduino Speeduino

Sources

ReliabilityKindTitleURLArchiveCapturedSHA-256
4vendor_docHaltech: RX7 FD Series 7-8 Nexus PnP adapter pinout (HT-186338)https://www.haltech.com/wp-admin/admin-ajax.php?action=ht_get_file&id=681af8c0cc78f3b6860e615e&op=1———
4vendor_docSpeeduino Manual (08/04/25) — V0.4 board IDC40 pinout & featureshttps://speeduino.com/Speeduino_manual.pdfarchive2026-10-0521806bd29ef0
2forumdefreezemotorsport: MS3 FD3S 16-bit ECU pinouthttps://defreezemotorsport.ru/doku.php?id=ms3:fd3s162———