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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 · 2026-10-17

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 errors1: read the Findings page before cutting any wire
Size of the job31 wires · 7 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-2-PSP-14V-10.85☐☐☐☐☐☐☐
W2OEM-4-AFSP-14V-10.85☐☐☐☐☐☐☐
W3SP-14V-1MAXXECUMINI-C1-H40.85☐☐☐☐☐☐☐
W4OEM-3-ASP-GND-10.85☐☐☐☐☐☐☐
W5OEM-3-BSP-GND-10.85☐☐☐☐☐☐☐
W6OEM-4-ASP-GND-10.85☐☐☐☐☐☐☐
W7SP-GND-1MAXXECUMINI-C1-G40.85☐☐☐☐☐☐☐
W8OEM-4-OSP-0V-10.5☐☐☐☐☐☐☐
W9SP-0V-1MAXXECUMINI-C1-A20.5☐☐☐☐☐☐☐
W10SP-0V-1MAXXECUMINI-C1-B30.5☐☐☐☐☐☐☐
W11SP-0V-1MAXXECUMINI-C1-B40.5☐☐☐☐☐☐☐
W12SP-0V-1MAXXECUMINI-C1-D40.5☐☐☐☐☐☐☐
W13OEM-4-LMAXXECUMINI-C1-E20.5☐☐☐☐☐☐☐
W14OEM-3-YMAXXECUMINI-C1-A10.5☐☐☐☐☐☐☐
W15OEM-3-FMAXXECUMINI-C1-F10.5☐☐☐☐☐☐☐
W16OEM-3-IMAXXECUMINI-C1-F20.5☐☐☐☐☐☐☐
W17OEM-2-AMAXXECUMINI-C1-G30.5☐☐☐☐☐☐☐
W18OEM-2-DMAXXECUMINI-C1-H10.5☐☐☐☐☐☐☐
W19OEM-2-GMAXXECUMINI-C1-H20.5☐☐☐☐☐☐☐
W20OEM-2-JMAXXECUMINI-C1-H30.5☐☐☐☐☐☐☐
W21OEM-4-XMAXXECUMINI-C1-C30.5☐☐☐☐☐☐☐
W22OEM-4-VMAXXECUMINI-C1-D20.5☐☐☐☐☐☐☐
W23OEM-4-PMAXXECUMINI-C1-C10.5☐☐☐☐☐☐☐
W24OEM-2-BMAXXECUMINI-C1-G20.5☐☐☐☐☐☐☐
W25OEM-2-CMAXXECUMINI-C1-G10.5☐☐☐☐☐☐☐
W26OEM-2-KMAXXECUMINI-C1-E10.5☐☐☐☐☐☐☐
W27OEM-2-MMAXXECUMINI-C1-D10.5☐☐☐☐☐☐☐
W28OEM-4-AEMAXXECUMINI-C1-C40.5☐☐☐☐☐☐☐
W29OEM-4-RMAXXECUMINI-C1-C20.5☐☐☐☐☐☐☐
W30OEM-3-TMAXXECUMINI-C1-B10.5☐☐☐☐☐☐☐
W31OEM-3-SMAXXECUMINI-C1-B20.5☐☐☐☐☐☐☐

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
1MAXXECUMINI-C1-E2MAXXECUMINI-C1-A2open (OL)5 V sensor reference must not touch sensor ground
2MAXXECUMINI-C1-H4MAXXECUMINI-C1-A2open (OL)+12 V supply must not touch sensor ground
3MAXXECUMINI-C1-H4MAXXECUMINI-C1-G4open (OL)+12 V supply must not touch power ground
4MAXXECUMINI-C1-G4MAXXECUMINI-C1-E2open (OL)power ground must not touch 5 V sensor reference
5MAXXECUMINI-C1-H4MAXXECUMINI-C1-E2open (OL)+12 V supply 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

MAXXECUMINI-C1OEM-2OEM-3OEM-4SP-0VSP-14VSP-GND

Connectors

MAXXECUMINI-C1

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
A1TRIGGER—W14—0.5OEM-3-Y———
A2TRIGGER GND—W9—0.5SP-0V-1———
B1DIN 1 (Hall only)—W30—0.5OEM-3-T———
B2DIN 2 (Hall only)—W31—0.5OEM-3-S———
B3SENSOR GND—W10—0.5SP-0V-1———
B4SENSOR GND—W11—0.5SP-0V-1———
C1CLT—W23—0.5OEM-4-P———
C2IAT—W29—0.5OEM-4-R———
C3AIN 3 (0-5V)—W21—0.5OEM-4-X———
C4AIN 4 (0-5V)—W28—0.5OEM-4-AE———
D1GPO 8/TACHO—W27—0.5OEM-2-M———
D2TPS—W22—0.5OEM-4-V———
D3GND Shield————————
D4SENSOR GND—W12—0.5SP-0V-1———
E1GPO 3—W26—0.5OEM-2-K———
E2+5V sensor supply—W13—0.5OEM-4-L———
E3CAN L————————
E4CAN H————————
F1IGN 1—W15—0.5OEM-3-F———
F2IGN 2—W16—0.5OEM-3-I———
F3IGN 3————————
F4IGN 4————————
G1GPO 2—W25—0.5OEM-2-C———
G2GPO 1—W24—0.5OEM-2-B———
G3INJ 1—W17—0.5OEM-2-A———
G4ENGINE GND—W7—0.85SP-GND-1———
H1INJ 2—W18—0.5OEM-2-D———
H2INJ 3—W19—0.5OEM-2-G———
H3INJ 4—W20—0.5OEM-2-J———
H4+12V (ECU power supply)—W3—0.85SP-14V-1———

OEM-2

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
AInjector 1—W17—0.5MAXXECUMINI-C1-G3———
BCooling fan relay—W24—0.5MAXXECUMINI-C1-G2———
CCondenser fan relay—W25—0.5MAXXECUMINI-C1-G1———
DInjector 2—W18—0.5MAXXECUMINI-C1-H1———
EEGR valve————————
FEGR valve————————
GInjector 3—W19—0.5MAXXECUMINI-C1-H2———
HEGR valve————————
IEGR valve————————
JInjector 4—W20—0.5MAXXECUMINI-C1-H3———
KA/C clutch relay—W26—0.5MAXXECUMINI-C1-E1———
LNC————————
MFuel pump relay—W27—0.5MAXXECUMINI-C1-D1———
NVTCS solenoid (intake butterflies)————————
OFuel pump relay (non-immobiliser)————————
PISC valve +14V feed—W1—0.85SP-14V-1———
QISC valve low side————————
RMalfunction indicator lamp (MIL)————————

OEM-3

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
APower ground—W4—0.85SP-GND-1———
BPower ground—W5—0.85SP-GND-1———
CPurge solenoid valve————————
DEGR boost solenoid————————
ENC————————
FIgnition 1 (coils 1+4, wasted spark)—W15—0.5MAXXECUMINI-C1-F1———
GNC————————
HMain relay————————
IIgnition 2 (coils 2+3, wasted spark)—W16—0.5MAXXECUMINI-C1-F2———
JFront O2 heater————————
KEVAP leak detection pump————————
LNC————————
MAlternator control————————
NNC————————
OTachometer output————————
PRear O2 heater————————
QData link connector (K-line)————————
RNC————————
SImmobiliser—W31—0.5MAXXECUMINI-C1-B2———
TVehicle speed—W30—0.5MAXXECUMINI-C1-B1———
UCharge lamp————————
VCam position (CMP)————————
WNC————————
XNC————————
YCrank position (CKP)—W14—0.5MAXXECUMINI-C1-A1———
ZNC————————

OEM-4

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
APower ground—W6—0.85SP-GND-1———
AARear O2 signal————————
ABNC————————
ACData link connector (DLC TEN, turbo)————————
ADFuel level————————
AEBARO/MAP sensor (turbo boost pressure)—W28—0.5MAXXECUMINI-C1-C4———
AFECU power +14V (main relay)—W2—0.85SP-14V-1———
AGConstant +12V————————
AHEVAP leak detection pump solenoid valve————————
BBrake switch————————
CPower steering pressure switch————————
DBoost control solenoid (turbo)————————
EBoost control solenoid (turbo)————————
FA/C request————————
GNC————————
HNeutral switch————————
IClutch switch————————
JVTCS vacuum switch————————
KNC————————
L+5V sensor supply—W13—0.5MAXXECUMINI-C1-E2———
MKnock sensor————————
NIntake air temperature (IAT)————————
OSignal ground—W8—0.5SP-0V-1———
PCoolant temperature (ECT)—W23—0.5MAXXECUMINI-C1-C1———
QNC————————
RIntake air temperature 2 (IAT2, turbo)—W29—0.5MAXXECUMINI-C1-C2———
SIgnition switch (IG1) sense————————
TGenerator output voltage (terminal P)————————
UNC————————
VThrottle position (TPS)—W22—0.5MAXXECUMINI-C1-D2———
WFront O2 signal————————
XMass air flow (MAF)—W21—0.5MAXXECUMINI-C1-C3———
YNC————————
ZTCM (automatic only)————————

SP-0V

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W8—0.5OEM-4-O———
1——W9—0.5MAXXECUMINI-C1-A2———
1——W10—0.5MAXXECUMINI-C1-B3———
1——W11—0.5MAXXECUMINI-C1-B4———
1——W12—0.5MAXXECUMINI-C1-D4———

SP-14V

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W1—0.85OEM-2-P———
1——W2—0.85OEM-4-AF———
1——W3—0.85MAXXECUMINI-C1-H4———

SP-GND

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W4—0.85OEM-3-A———
1——W5—0.85OEM-3-B———
1——W6—0.85OEM-4-A———
1——W7—0.85MAXXECUMINI-C1-G4———

Pin map

OEM pointOEM functionOEM familyTarget pointTarget functionTarget familyWire colourEvidence
OEM-2-AInjector 1injector_outMAXXECUMINI-C1-G3INJ 1injector_outcorroborated
OEM-2-BCooling fan relaylow_side_outMAXXECUMINI-C1-G2GPO 1low_side_outcorroborated
OEM-2-CCondenser fan relaylow_side_outMAXXECUMINI-C1-G1GPO 2low_side_outcorroborated
OEM-2-DInjector 2injector_outMAXXECUMINI-C1-H1INJ 2injector_outcorroborated
OEM-2-EEGR valvelow_side_out———corroborated
OEM-2-FEGR valvelow_side_out———corroborated
OEM-2-GInjector 3injector_outMAXXECUMINI-C1-H2INJ 3injector_outcorroborated
OEM-2-HEGR valvelow_side_out———corroborated
OEM-2-IEGR valvelow_side_out———corroborated
OEM-2-JInjector 4injector_outMAXXECUMINI-C1-H3INJ 4injector_outcorroborated
OEM-2-KA/C clutch relaylow_side_outMAXXECUMINI-C1-E1GPO 3low_side_outcorroborated
OEM-2-LNC————single_source
OEM-2-MFuel pump relaylow_side_outMAXXECUMINI-C1-D1GPO 8/TACHOlow_side_outcorroborated
OEM-2-NVTCS solenoid (intake butterflies)low_side_out———corroborated
OEM-2-OFuel pump relay (non-immobiliser)low_side_out———corroborated
OEM-2-PISC valve +14V feedpower_inMAXXECUMINI-C1-H4+12V (ECU power supply)power_incorroborated
OEM-2-QISC valve low sidelow_side_out———corroborated
OEM-2-RMalfunction indicator lamp (MIL)low_side_out———corroborated
OEM-3-APower groundgroundMAXXECUMINI-C1-G4ENGINE GNDgroundcorroborated
OEM-3-BPower groundgroundMAXXECUMINI-C1-G4ENGINE GNDgroundcorroborated
OEM-3-CPurge solenoid valvelow_side_out———corroborated
OEM-3-DEGR boost solenoid————conflict
OEM-3-ENC————single_source
OEM-3-FIgnition 1 (coils 1+4, wasted spark)ignition_outMAXXECUMINI-C1-F1IGN 1ignition_outcorroborated
OEM-3-GNC————single_source
OEM-3-HMain relaylow_side_out———corroborated
OEM-3-IIgnition 2 (coils 2+3, wasted spark)ignition_outMAXXECUMINI-C1-F2IGN 2ignition_outcorroborated
OEM-3-JFront O2 heaterlow_side_out———corroborated
OEM-3-KEVAP leak detection pumplow_side_out———corroborated
OEM-3-LNC————single_source
OEM-3-MAlternator controllow_side_out———corroborated
OEM-3-NNC————single_source
OEM-3-OTachometer outputtacho_out———corroborated
OEM-3-PRear O2 heaterlow_side_out———corroborated
OEM-3-QData link connector (K-line)serial———corroborated
OEM-3-RNC————single_source
OEM-3-SImmobiliserdigital_inMAXXECUMINI-C1-B2DIN 2 (Hall only)digital_incorroborated
OEM-3-TVehicle speeddigital_inMAXXECUMINI-C1-B1DIN 1 (Hall only)digital_incorroborated
OEM-3-UCharge lamplow_side_out———corroborated
OEM-3-VCam position (CMP)trigger_in———corroborated
OEM-3-WNC————single_source
OEM-3-XNC————single_source
OEM-3-YCrank position (CKP)trigger_inMAXXECUMINI-C1-A1TRIGGERtrigger_incorroborated
OEM-3-ZNC————single_source
OEM-4-APower groundgroundMAXXECUMINI-C1-G4ENGINE GNDgroundcorroborated
OEM-4-AARear O2 signallambda_nb_in———corroborated
OEM-4-ABNC————single_source
OEM-4-ACData link connector (DLC TEN, turbo)serial———BrYsingle_source
OEM-4-ADFuel levelanalog_in———corroborated
OEM-4-AEBARO/MAP sensor (turbo boost pressure)analog_inMAXXECUMINI-C1-C4AIN 4 (0-5V)analog_inLYsingle_source
OEM-4-AFECU power +14V (main relay)power_inMAXXECUMINI-C1-H4+12V (ECU power supply)power_incorroborated
OEM-4-AGConstant +12Vpower_in———corroborated
OEM-4-AHEVAP leak detection pump solenoid valvelow_side_out———corroborated
OEM-4-BBrake switchdigital_in———corroborated
OEM-4-CPower steering pressure switchdigital_in———corroborated
OEM-4-DBoost control solenoid (turbo)high_side_out———Ysingle_source
OEM-4-EBoost control solenoid (turbo)high_side_out———Ysingle_source
OEM-4-FA/C requestdigital_in———corroborated
OEM-4-GNC————single_source
OEM-4-HNeutral switchdigital_in———corroborated
OEM-4-IClutch switchdigital_in———corroborated
OEM-4-JVTCS vacuum switchdigital_in———corroborated
OEM-4-KNC————single_source
OEM-4-L+5V sensor supplyvrefMAXXECUMINI-C1-E2+5V sensor supplyvrefcorroborated
OEM-4-MKnock sensorknock_in———corroborated
OEM-4-NIntake air temperature (IAT)temp_in———corroborated
OEM-4-OSignal groundsensor_groundMAXXECUMINI-C1-A2 + MAXXECUMINI-C1-B3 + MAXXECUMINI-C1-B4 + MAXXECUMINI-C1-D4TRIGGER GND + SENSOR GND + SENSOR GND + SENSOR GNDsensor_groundcorroborated
OEM-4-PCoolant temperature (ECT)temp_inMAXXECUMINI-C1-C1CLTtemp_incorroborated
OEM-4-QNC————single_source
OEM-4-RIntake air temperature 2 (IAT2, turbo)temp_inMAXXECUMINI-C1-C2IATtemp_inVYsingle_source
OEM-4-SIgnition switch (IG1) sensedigital_in———corroborated
OEM-4-TGenerator output voltage (terminal P)————corroborated
OEM-4-UNC————single_source
OEM-4-VThrottle position (TPS)analog_inMAXXECUMINI-C1-D2TPSanalog_incorroborated
OEM-4-WFront O2 signallambda_nb_in———corroborated
OEM-4-XMass air flow (MAF)analog_inMAXXECUMINI-C1-C3AIN 3 (0-5V)analog_incorroborated
OEM-4-YNC————single_source
OEM-4-ZTCM (automatic only)————corroborated

Cut list

WireFromToGauge (mm²)ColourLengthSignalIdent
W1OEM-2-PSP-14V-10.85no routeISC valve +14V feed—
W2OEM-4-AFSP-14V-10.85no routeECU power +14V (main relay)—
W3SP-14V-1MAXXECUMINI-C1-H40.85no route+12V (ECU power supply)—
W4OEM-3-ASP-GND-10.85no routePower ground—
W5OEM-3-BSP-GND-10.85no routePower ground—
W6OEM-4-ASP-GND-10.85no routePower ground—
W7SP-GND-1MAXXECUMINI-C1-G40.85no routeENGINE GND—
W8OEM-4-OSP-0V-10.5no routeSignal ground—
W9SP-0V-1MAXXECUMINI-C1-A20.5no routeTRIGGER GND—
W10SP-0V-1MAXXECUMINI-C1-B30.5no routeSENSOR GND—
W11SP-0V-1MAXXECUMINI-C1-B40.5no routeSENSOR GND—
W12SP-0V-1MAXXECUMINI-C1-D40.5no routeSENSOR GND—
W13OEM-4-LMAXXECUMINI-C1-E20.5no route+5V sensor supply—
W14OEM-3-YMAXXECUMINI-C1-A10.5no routeCrank position (CKP)—
W15OEM-3-FMAXXECUMINI-C1-F10.5no routeIgnition 1 (coils 1+4, wasted spark)—
W16OEM-3-IMAXXECUMINI-C1-F20.5no routeIgnition 2 (coils 2+3, wasted spark)—
W17OEM-2-AMAXXECUMINI-C1-G30.5no routeInjector 1—
W18OEM-2-DMAXXECUMINI-C1-H10.5no routeInjector 2—
W19OEM-2-GMAXXECUMINI-C1-H20.5no routeInjector 3—
W20OEM-2-JMAXXECUMINI-C1-H30.5no routeInjector 4—
W21OEM-4-XMAXXECUMINI-C1-C30.5no routeMass air flow (MAF)—
W22OEM-4-VMAXXECUMINI-C1-D20.5no routeThrottle position (TPS)—
W23OEM-4-PMAXXECUMINI-C1-C10.5no routeCoolant temperature (ECT)—
W24OEM-2-BMAXXECUMINI-C1-G20.5no routeCooling fan relay—
W25OEM-2-CMAXXECUMINI-C1-G10.5no routeCondenser fan relay—
W26OEM-2-KMAXXECUMINI-C1-E10.5no routeA/C clutch relay—
W27OEM-2-MMAXXECUMINI-C1-D10.5no routeFuel pump relay—
W28OEM-4-AEMAXXECUMINI-C1-C40.5no routeBARO/MAP sensor (turbo boost pressure)—
W29OEM-4-RMAXXECUMINI-C1-C20.5no routeIntake air temperature 2 (IAT2, turbo)—
W30OEM-3-TMAXXECUMINI-C1-B10.5no routeVehicle speed—
W31OEM-3-SMAXXECUMINI-C1-B20.5no routeImmobiliser—

Bill of materials

CategoryPart numberManufacturerDescriptionQtyUnit

ECU setup sheet

RoleEngine refEngine signalSensorECU pointECU functionECU classSetup flag
No configured channels.

Findings

Open (6)

SeverityCodeSubjectMessage
errorREQUIRED_UNMAPPEDOEM-3-VRequired OEM function "Cam position (CMP)" (trigger_in) is not connected to the new ECU.
warnLOAD_UNKNOWNMAXXECUMINI-C1-D1MAXXECUMINI-C1-D1 "GPO 8/TACHO" drives OEM-2-M Fuel pump relay (load 0.2 A) but its current rating is unknown. Check the ECU manual.
warnLOAD_UNKNOWNMAXXECUMINI-C1-E1MAXXECUMINI-C1-E1 "GPO 3" drives OEM-2-K A/C clutch relay (load 0.2 A) but its current rating is unknown. Check the ECU manual.
warnLOAD_UNKNOWNMAXXECUMINI-C1-G1MAXXECUMINI-C1-G1 "GPO 2" drives OEM-2-C Condenser fan relay (load 0.2 A) but its current rating is unknown. Check the ECU manual.
warnLOAD_UNKNOWNMAXXECUMINI-C1-G2MAXXECUMINI-C1-G2 "GPO 1" drives OEM-2-B Cooling fan relay (load 0.2 A) but its current rating is unknown. Check the ECU manual.
infoUNMAPPEDOEM36 optional OEM pins are not mapped: OEM-2-E EGR valve; OEM-2-F EGR valve; OEM-2-H EGR valve; OEM-2-I EGR valve; OEM-2-N VTCS solenoid (intake butterflies); OEM-2-O Fuel pump relay (non-immobiliser); OEM-2-Q ISC valve low side; OEM-2-R Malfunction indicator lamp (MIL); OEM-3-C Purge solenoid valve; OEM-3-D EGR boost solenoid; OEM-3-H Main relay; OEM-3-J Front O2 heater; OEM-3-K EVAP leak detection pump; OEM-3-M Alternator control; OEM-3-O Tachometer output; OEM-3-P Rear O2 heater; OEM-3-Q Data link connector (K-line); OEM-3-U Charge lamp; OEM-4-AA Rear O2 signal; OEM-4-AC Data link connector (DLC TEN, turbo); OEM-4-AD Fuel level; OEM-4-AH EVAP leak detection pump solenoid valve; OEM-4-B Brake switch; OEM-4-C Power steering pressure switch; OEM-4-D Boost control solenoid (turbo); OEM-4-E Boost control solenoid (turbo); OEM-4-F A/C request; OEM-4-H Neutral switch; OEM-4-I Clutch switch; OEM-4-J VTCS vacuum switch; OEM-4-M Knock sensor; OEM-4-N Intake air temperature (IAT); OEM-4-S Ignition switch (IG1) sense; OEM-4-T Generator output voltage (terminal P); OEM-4-W Front O2 signal; OEM-4-Z TCM (automatic only)

Accepted (1)

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

Notes

Auto-mapped by auto_map() from the library pin data on 2026-10-17. Review every wire against both manuals before building. Open items: - OEM-3 V: Cam position (CMP): no free cam_hall/cam_vr/frequency_in input on MaxxECU MaxxECU MINI Not wired: - OEM-4 AG: Constant +12V: MaxxECU MaxxECU MINI has no battery-constant input; not needed - OEM-4 M: Knock sensor: no free knock input on MaxxECU MaxxECU MINI - OEM-4 S: Ignition switch (IG1) sense: key-on 12 V sense — optional in a swap (the main relay is energized from keyed 12 V, not from this pin); MaxxECU MaxxECU MINI has no dedicated key-on input - OEM-3 H: Main relay: no free relay_control/low_side/heater_low_side/ls_hs/injector rated ≥ 0.2 A on MaxxECU MaxxECU MINI - OEM-2 O: Fuel pump relay (non-immobiliser): no free relay_control/low_side/heater_low_side/ls_hs/injector on MaxxECU MaxxECU MINI - OEM-4 D: Boost control solenoid (turbo): no free high_side/ls_hs on MaxxECU MaxxECU MINI - OEM-4 E: Boost control solenoid (turbo): no free high_side/ls_hs on MaxxECU MaxxECU MINI - OEM-3 J: Front O2 heater: no free heater_low_side/low_side/relay_control/ls_hs/injector on MaxxECU MaxxECU MINI - OEM-3 P: Rear O2 heater: no free heater_low_side/low_side/relay_control/ls_hs/injector on MaxxECU MaxxECU MINI - OEM-2 Q: ISC valve low side: no free low_side/relay_control/heater_low_side/ls_hs/injector rated ≥ 1.0 A on MaxxECU MaxxECU MINI - OEM-2 E: EGR valve: no free low_side/relay_control/heater_low_side/ls_hs/injector on MaxxECU MaxxECU MINI - OEM-2 F: EGR valve: no free low_side/relay_control/heater_low_side/ls_hs/injector on MaxxECU MaxxECU MINI - OEM-2 H: EGR valve: no free low_side/relay_control/heater_low_side/ls_hs/injector on MaxxECU MaxxECU MINI - OEM-2 I: EGR valve: no free low_side/relay_control/heater_low_side/ls_hs/injector on MaxxECU MaxxECU MINI - OEM-2 N: VTCS solenoid (intake butterflies): no free low_side/relay_control/heater_low_side/ls_hs/injector on MaxxECU MaxxECU MINI - OEM-2 R: Malfunction indicator lamp (MIL): no free low_side/relay_control/heater_low_side/ls_hs/injector on MaxxECU MaxxECU MINI - OEM-3 C: Purge solenoid valve: no free low_side/relay_control/heater_low_side/ls_hs/injector on MaxxECU MaxxECU MINI - OEM-3 K: EVAP leak detection pump: no free low_side/relay_control/heater_low_side/ls_hs/injector on MaxxECU MaxxECU MINI - OEM-3 M: Alternator control: no free low_side/relay_control/heater_low_side/ls_hs/injector on MaxxECU MaxxECU MINI - OEM-3 U: Charge lamp: no free low_side/relay_control/heater_low_side/ls_hs/injector on MaxxECU MaxxECU MINI - OEM-4 AH: EVAP leak detection pump solenoid valve: no free low_side/relay_control/heater_low_side/ls_hs/injector on MaxxECU MaxxECU MINI - OEM-3 O: Tachometer output: no free tacho/frequency_out/low_side/ls_hs on MaxxECU MaxxECU MINI - OEM-4 AA: Rear O2 signal: no free o2_narrowband/analog_0_5 on MaxxECU MaxxECU MINI - OEM-4 W: Front O2 signal: no free o2_narrowband/analog_0_5 on MaxxECU MaxxECU MINI - OEM-4 N: Intake air temperature (IAT): no free thermistor/analog_0_5 on MaxxECU MaxxECU MINI - OEM-4 AD: Fuel level: no free analog_0_5 on MaxxECU MaxxECU MINI - OEM-4 B: Brake switch: no free switch_in/frequency_in/analog_0_5 on MaxxECU MaxxECU MINI - OEM-4 C: Power steering pressure switch: no free switch_in/frequency_in/analog_0_5 on MaxxECU MaxxECU MINI - OEM-4 F: A/C request: no free switch_in/frequency_in/analog_0_5 on MaxxECU MaxxECU MINI - OEM-4 H: Neutral switch: no free switch_in/frequency_in/analog_0_5 on MaxxECU MaxxECU MINI - OEM-4 I: Clutch switch: no free switch_in/frequency_in/analog_0_5 on MaxxECU MaxxECU MINI - OEM-4 J: VTCS vacuum switch: no free switch_in/frequency_in/analog_0_5 on MaxxECU MaxxECU MINI - OEM-3 Q: Data link connector (K-line): no free k_line on MaxxECU MaxxECU MINI - OEM-4 AC: Data link connector (DLC TEN, turbo): no free k_line on MaxxECU MaxxECU MINI - OEM-3 D: EGR boost solenoid: not classified in the library; wire by hand - OEM-4 T: Generator output voltage (terminal P): not classified in the library; wire by hand - OEM-4 Z: TCM (automatic only): not classified in the library; wire by hand

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_docLink G4X MX5NB2X install manual (NB2 2001-05)https://linkecu.com/documentation/MX5XNB2.pdfarchive2026-10-05741efdd9f2c8
4vendor_docMaxxECU GEN1 pinout (MINI / STREET / SPORT / V1 / RACE / PRO)http://www.maxxecu.com/webhelp/wirings-maxxecu_pinout.htmlarchive2026-10-052e37b6814690