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MX-5 Miata NB2 2001-05 (BP-Z3, VVT; excludes Mazdaspeed) → MaxxECU MaxxECU RACE REV9+ (auto)

MX-5 Miata NB2 2001-05 (BP-Z3, VVT; excludes Mazdaspeed) — MaxxECU — MaxxECU RACE
Drawn by Michael Gnankou · Rev 0 · proposal · 2026-10-12

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.

Install modifications

Steps on the car itself, outside the harness. Every harness for this car inherits them.

  • Re-route the pressure-sensor vacuum hose to the intake manifoldrequired

    Re-route the pressure sensor's (Mazda "EGR boost sensor", pin 4AE) vacuum hose directly to the intake manifold, bypassing the EGR boost solenoid. The stock ECU multiplexes baro + MAP through that solenoid: with it off the sensor reads atmosphere, with it energized it reads manifold. After re-routing the sensor reads MAP only, so the standalone needs its own barometric source — its onboard baro sensor if fitted, or a separate baro sensor on a spare analog input. (Alternative, not recommended: keep the hose stock and have the ECU energize the solenoid permanently via a low-side output switched with ignition; this costs an output.)

    Why: With the solenoid off (its default) the sensor reads atmospheric pressure, not manifold pressure, so a standalone that uses this sensor as its MAP input would read the wrong value.

    Where: EGR boost solenoid and the pressure sensor's vacuum hose (sensor signal 4AE).

    Source: Justin Barrera — Miata NA/NB wiring corrections

Statusproposal · not yet verified: nobody has reported building and running this harness
Open errorsnone
Size of the job48 wires · 8 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☐☐☐☐☐☐☐
W3OEM-4-DSP-14V-10.85☐☐☐☐☐☐☐
W4SP-14V-1MAXXECURACE-C1-M40.85☐☐☐☐☐☐☐
W5OEM-3-ASP-GND-10.85☐☐☐☐☐☐☐
W6OEM-3-BSP-GND-10.85☐☐☐☐☐☐☐
W7OEM-4-ASP-GND-10.85☐☐☐☐☐☐☐
W8SP-GND-1MAXXECURACE-C1-L40.85☐☐☐☐☐☐☐
W9SP-GND-1MAXXECURACE-C2-G40.85☐☐☐☐☐☐☐
W10OEM-4-OSP-0V-10.5☐☐☐☐☐☐☐
W11SP-0V-1MAXXECURACE-C1-H10.5☐☐☐☐☐☐☐
W12SP-0V-1MAXXECURACE-C1-H20.5☐☐☐☐☐☐☐
W13OEM-4-LMAXXECURACE-C1-G10.5☐☐☐☐☐☐☐
W14OEM-3-YMAXXECURACE-C1-H30.5☐☐☐☐☐☐☐
W15OEM-3-VMAXXECURACE-C1-H40.5☐☐☐☐☐☐☐
W16OEM-4-MMAXXECURACE-C2-E20.5☐☐☐☐☐☐☐
W17OEM-3-FMAXXECURACE-C1-A20.5☐☐☐☐☐☐☐
W18OEM-3-IMAXXECURACE-C1-A30.5☐☐☐☐☐☐☐
W19OEM-2-AMAXXECURACE-C1-K10.5☐☐☐☐☐☐☐
W20OEM-2-DMAXXECURACE-C1-K20.5☐☐☐☐☐☐☐
W21OEM-2-GMAXXECURACE-C1-M10.5☐☐☐☐☐☐☐
W22OEM-2-JMAXXECURACE-C1-M20.5☐☐☐☐☐☐☐
W23OEM-4-XMAXXECURACE-C1-J30.5☐☐☐☐☐☐☐
W24OEM-4-VMAXXECURACE-C1-G20.5☐☐☐☐☐☐☐
W25OEM-4-PMAXXECURACE-C1-F10.5☐☐☐☐☐☐☐
W26OEM-2-BMAXXECURACE-C1-B40.5☐☐☐☐☐☐☐
W27OEM-2-CMAXXECURACE-C1-C40.5☐☐☐☐☐☐☐
W28OEM-2-KMAXXECURACE-C1-D40.5☐☐☐☐☐☐☐
W29OEM-2-MMAXXECURACE-C1-E40.5☐☐☐☐☐☐☐
W30OEM-3-HMAXXECURACE-C1-A10.5☐☐☐☐☐☐☐
W31OEM-2-OMAXXECURACE-C1-B10.5☐☐☐☐☐☐☐
W32OEM-3-JMAXXECURACE-C1-D10.5☐☐☐☐☐☐☐
W33OEM-3-PMAXXECURACE-C1-C10.5☐☐☐☐☐☐☐
W34OEM-2-QMAXXECURACE-C1-A40.5☐☐☐☐☐☐☐
W35OEM-2-EMAXXECURACE-C1-M30.5☐☐☐☐☐☐☐
W36OEM-2-FMAXXECURACE-C1-L30.5☐☐☐☐☐☐☐
W37OEM-2-HMAXXECURACE-C1-L20.5☐☐☐☐☐☐☐
W38OEM-2-IMAXXECURACE-C1-L10.5☐☐☐☐☐☐☐
W39OEM-4-AEMAXXECURACE-C1-J40.5☐☐☐☐☐☐☐
W40OEM-4-AAMAXXECURACE-C2-G30.5☐☐☐☐☐☐☐
W41OEM-4-WMAXXECURACE-C2-E40.5☐☐☐☐☐☐☐
W42OEM-4-NMAXXECURACE-C1-F20.5☐☐☐☐☐☐☐
W43OEM-4-ADMAXXECURACE-C2-F10.5☐☐☐☐☐☐☐
W44OEM-3-TMAXXECURACE-C1-K30.5☐☐☐☐☐☐☐
W45OEM-3-SMAXXECURACE-C1-K40.5☐☐☐☐☐☐☐
W46OEM-4-BMAXXECURACE-C2-F30.5☐☐☐☐☐☐☐
W47OEM-4-CMAXXECURACE-C2-F40.5☐☐☐☐☐☐☐
W48OEM-4-FMAXXECURACE-C2-F20.5☐☐☐☐☐☐☐

Bench test (before first power-up)

Pre-power install steps (make these cuts/modifications on the car first, then verify the checks below): Re-route the pressure-sensor vacuum hose to the intake manifold.

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
1MAXXECURACE-C1-G1MAXXECURACE-C1-H1open (OL)5 V sensor reference must not touch sensor ground
2MAXXECURACE-C1-M4MAXXECURACE-C1-H1open (OL)+12 V supply must not touch sensor ground
3MAXXECURACE-C1-M4MAXXECURACE-C1-L4open (OL)+12 V supply must not touch power ground
4MAXXECURACE-C1-L4MAXXECURACE-C1-G1open (OL)power ground must not touch 5 V sensor reference
5MAXXECURACE-C1-M4MAXXECURACE-C1-G1open (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

MAXXECURACE-C1MAXXECURACE-C2OEM-2OEM-3OEM-4SP-0VSP-14VSP-GND

Connectors

MAXXECURACE-C1

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
A1GPO 5—W30—0.5OEM-3-H———
A2IGN 1—W17—0.5OEM-3-F———
A3IGN 2—W18—0.5OEM-3-I———
A4GPO 8/TACHO—W34—0.5OEM-2-Q———
B1GPO 6—W31—0.5OEM-2-O———
B2IGN 3————————
B3IGN 4————————
B4GPO 1—W26—0.5OEM-2-B———
C1GPO 7—W33—0.5OEM-3-P———
C2IGN 5————————
C3IGN 6————————
C4GPO 2—W27—0.5OEM-2-C———
D1WBO2 Heater-—W32—0.5OEM-3-J———
D2IGN 7————————
D3IGN 8————————
D4GPO 3—W28—0.5OEM-2-K———
E1CAN H————————
E2CAN L————————
E3GND Shield————————
E4GPO 4—W29—0.5OEM-2-M———
F1CLT—W25—0.5OEM-4-P———
F2IAT—W42—0.5OEM-4-N———
F3WBO2 VREF————————
F4WBO2 VS————————
G1+5V sensor supply—W13—0.5OEM-4-L———
G2TPS/AIN—W24—0.5OEM-4-V———
G3WBO2 IP————————
G4WBO2 RCAL————————
H1Sensor GND—W11—0.5SP-0V-1———
H2Trigger GND—W12—0.5SP-0V-1———
H3TRIGGER—W14—0.5OEM-3-Y———
H4HOME—W15—0.5OEM-3-V———
J1AIN 1 (temperature)————————
J2AIN 2 (temperature)————————
J3AIN 3 (0-5V)—W23—0.5OEM-4-X———
J4AIN 4 (0-5V)—W39—0.5OEM-4-AE———
K1INJ 1—W19—0.5OEM-2-A———
K2INJ 2—W20—0.5OEM-2-D———
K3DIN/VR 1—W44—0.5OEM-3-T———
K4DIN/VR 2—W45—0.5OEM-3-S———
L1INJ 8—W38—0.5OEM-2-I———
L2INJ 7—W37—0.5OEM-2-H———
L3INJ 6—W36—0.5OEM-2-F———
L4Engine GND—W8—0.85SP-GND-1———
M1INJ 3—W21—0.5OEM-2-G———
M2INJ 4—W22—0.5OEM-2-J———
M3INJ 5—W35—0.5OEM-2-E———
M4+12V ECU power supply—W4—0.85SP-14V-1———

MAXXECURACE-C2

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
A1EGT 5+————————
A2EGT 6+————————
A3EGT 7+————————
A4EGT 8+————————
B1EGT 5-————————
B2EGT 6-————————
B3EGT 7-————————
B4EGT 8-————————
C1EGT 1+————————
C2EGT 2+————————
C3EGT 3+————————
C4EGT 4+————————
D1EGT 1-————————
D2EGT 2-————————
D3EGT 3-————————
D4EGT 4-————————
E1KNOCK GND————————
E2Knock 1—W16—0.5OEM-4-M———
E3Knock 2————————
E4AIN 6 (0-5V)—W41—0.5OEM-4-W———
F1AIN 7 (0-5V)—W43—0.5OEM-4-AD———
F2AIN 8 (0-5V)—W48—0.5OEM-4-F———
F3DIN/VR 4—W46—0.5OEM-4-B———
F4DIN/VR 5—W47—0.5OEM-4-C———
G1GPO 15 (+12V)————————
G2GPO 16 (+12V)————————
G3AIN 5 (0-5V)—W40—0.5OEM-4-AA———
G4ENGINE GROUND—W9—0.85SP-GND-1———
H1MOTOR 2+————————
H2MOTOR 1-————————
H3MOTOR 2-————————
H4MOTOR 1+————————

OEM-2

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
AInjector 1—W19—0.5MAXXECURACE-C1-K1———
BCooling fan relay—W26—0.5MAXXECURACE-C1-B4———
CCondenser fan relay—W27—0.5MAXXECURACE-C1-C4———
DInjector 2—W20—0.5MAXXECURACE-C1-K2———
EEGR valve—W35—0.5MAXXECURACE-C1-M3———
FEGR valve—W36—0.5MAXXECURACE-C1-L3———
GInjector 3—W21—0.5MAXXECURACE-C1-M1———
HEGR valve—W37—0.5MAXXECURACE-C1-L2———
IEGR valve—W38—0.5MAXXECURACE-C1-L1———
JInjector 4—W22—0.5MAXXECURACE-C1-M2———
KA/C clutch relay—W28—0.5MAXXECURACE-C1-D4———
LNC————————
MFuel pump relay—W29—0.5MAXXECURACE-C1-E4———
NVTCS solenoid (intake butterflies)————————
OFuel pump relay (non-immobiliser)—W31—0.5MAXXECURACE-C1-B1———
PISC valve +14V feed—W1—0.85SP-14V-1———
QISC valve low side—W34—0.5MAXXECURACE-C1-A4———
RMalfunction indicator lamp (MIL)————————

OEM-3

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
APower ground—W5—0.85SP-GND-1———
BPower ground—W6—0.85SP-GND-1———
CPurge solenoid valve————————
DEGR boost solenoid————————
ENC————————
FIgnition 1 (coils 1+4, wasted spark)—W17—0.5MAXXECURACE-C1-A2———
GNC————————
HMain relay—W30—0.5MAXXECURACE-C1-A1———
IIgnition 2 (coils 2+3, wasted spark)—W18—0.5MAXXECURACE-C1-A3———
JFront O2 heater—W32—0.5MAXXECURACE-C1-D1———
KEVAP leak detection pump————————
LNC————————
MAlternator control————————
NNC————————
OTachometer output————————
PRear O2 heater—W33—0.5MAXXECURACE-C1-C1———
QData link connector (K-line)————————
RNC————————
SImmobiliser—W45—0.5MAXXECURACE-C1-K4———
TVehicle speed—W44—0.5MAXXECURACE-C1-K3———
UCharge lamp————————
VCam position (CMP)—W15—0.5MAXXECURACE-C1-H4———
WNC————————
XNC————————
YCrank position (CKP)—W14—0.5MAXXECURACE-C1-H3———
ZNC————————

OEM-4

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
APower ground—W7—0.85SP-GND-1———
AARear O2 signal—W40—0.5MAXXECURACE-C2-G3———
ABNC————————
ACTCM (automatic only)————————
ADFuel level—W43—0.5MAXXECURACE-C2-F1———
AEPressure sensor (Mazda: EGR boost sensor)—W39—0.5MAXXECURACE-C1-J4———
AFECU power +14V (main relay)—W2—0.85SP-14V-1———
AGConstant +12V————————
AHEVAP leak detection pump solenoid valve————————
BBrake switch—W46—0.5MAXXECURACE-C2-F3———
CPower steering pressure switch—W47—0.5MAXXECURACE-C2-F4———
DVVT oil-control solenoid +12V feed—W3—0.85SP-14V-1———
EDiagnostic (DLC TEN) (NA)————————
FA/C request—W48—0.5MAXXECURACE-C2-F2———
GNC————————
HNeutral switch————————
IClutch switch————————
JVTCS vacuum switch————————
KNC————————
L+5V sensor supply—W13—0.5MAXXECURACE-C1-G1———
MKnock sensor—W16—0.5MAXXECURACE-C2-E2———
NIntake air temperature (IAT)—W42—0.5MAXXECURACE-C1-F2———
OSignal ground—W10—0.5SP-0V-1———
PCoolant temperature (ECT)—W25—0.5MAXXECURACE-C1-F1———
QNC————————
RVVT oil-control solenoid (low-side control)————————
SIgnition switch (IG1) sense————————
TGenerator output voltage (terminal P)————————
UNC————————
VThrottle position (TPS)—W24—0.5MAXXECURACE-C1-G2———
WFront O2 signal—W41—0.5MAXXECURACE-C2-E4———
XMass air flow (MAF)—W23—0.5MAXXECURACE-C1-J3———
YNC————————
ZTCM (automatic only)————————

SP-0V

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W10—0.5OEM-4-O———
1——W11—0.5MAXXECURACE-C1-H1———
1——W12—0.5MAXXECURACE-C1-H2———

SP-14V

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W1—0.85OEM-2-P———
1——W2—0.85OEM-4-AF———
1——W3—0.85OEM-4-D———
1——W4—0.85MAXXECURACE-C1-M4———

SP-GND

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W5—0.85OEM-3-A———
1——W6—0.85OEM-3-B———
1——W7—0.85OEM-4-A———
1——W8—0.85MAXXECURACE-C1-L4———
1——W9—0.85MAXXECURACE-C2-G4———

Pin map

OEM pointOEM functionOEM familyTarget pointTarget functionTarget familyWire colourEvidence
OEM-2-AInjector 1injector_outMAXXECURACE-C1-K1INJ 1injector_outYBsingle_source
OEM-2-BCooling fan relaylow_side_outMAXXECURACE-C1-B4GPO 1low_side_outRYsingle_source
OEM-2-CCondenser fan relaylow_side_outMAXXECURACE-C1-C4GPO 2low_side_outLWsingle_source
OEM-2-DInjector 2injector_outMAXXECURACE-C1-K2INJ 2injector_outVGsingle_source
OEM-2-EEGR valvelow_side_outMAXXECURACE-C1-M3INJ 5injector_outLgsingle_source
OEM-2-FEGR valvelow_side_outMAXXECURACE-C1-L3INJ 6injector_outWGsingle_source
OEM-2-GInjector 3injector_outMAXXECURACE-C1-M1INJ 3injector_outYRsingle_source
OEM-2-HEGR valvelow_side_outMAXXECURACE-C1-L2INJ 7injector_outPBsingle_source
OEM-2-IEGR valvelow_side_outMAXXECURACE-C1-L1INJ 8injector_outPsingle_source
OEM-2-JInjector 4injector_outMAXXECURACE-C1-M2INJ 4injector_outYGsingle_source
OEM-2-KA/C clutch relaylow_side_outMAXXECURACE-C1-D4GPO 3low_side_outLBsingle_source
OEM-2-LNC————unverified
OEM-2-MFuel pump relaylow_side_outMAXXECURACE-C1-E4GPO 4low_side_outRWsingle_source
OEM-2-NVTCS solenoid (intake butterflies)low_side_out———BWsingle_source
OEM-2-OFuel pump relay (non-immobiliser)low_side_outMAXXECURACE-C1-B1GPO 6low_side_outRsingle_source
OEM-2-PISC valve +14V feedpower_inMAXXECURACE-C1-M4+12V ECU power supplypower_inOrsingle_source
OEM-2-QISC valve low sidelow_side_outMAXXECURACE-C1-A4GPO 8/TACHOlow_side_outVRsingle_source
OEM-2-RMalfunction indicator lamp (MIL)low_side_out———WLsingle_source
OEM-3-APower groundgroundMAXXECURACE-C1-L4 + MAXXECURACE-C2-G4Engine GND + ENGINE GROUNDgroundBsingle_source
OEM-3-BPower groundgroundMAXXECURACE-C1-L4 + MAXXECURACE-C2-G4Engine GND + ENGINE GROUNDgroundBRsingle_source
OEM-3-CPurge solenoid valvelow_side_out———GYsingle_source
OEM-3-DEGR boost solenoid————GyBsingle_source
OEM-3-ENC————unverified
OEM-3-FIgnition 1 (coils 1+4, wasted spark)ignition_outMAXXECURACE-C1-A2IGN 1ignition_outBrWsingle_source
OEM-3-GNC————unverified
OEM-3-HMain relaylow_side_outMAXXECURACE-C1-A1GPO 5low_side_outLOrsingle_source
OEM-3-IIgnition 2 (coils 2+3, wasted spark)ignition_outMAXXECURACE-C1-A3IGN 2ignition_outBYsingle_source
OEM-3-JFront O2 heaterlow_side_outMAXXECURACE-C1-D1WBO2 Heater-low_side_outBOrsingle_source
OEM-3-KEVAP leak detection pumplow_side_out———YBsingle_source
OEM-3-LNC————unverified
OEM-3-MAlternator controllow_side_out———GyRsingle_source
OEM-3-NNC————unverified
OEM-3-OTachometer outputtacho_out———GOrsingle_source
OEM-3-PRear O2 heaterlow_side_outMAXXECURACE-C1-C1GPO 7low_side_outWBsingle_source
OEM-3-QData link connector (K-line)serial———GWsingle_source
OEM-3-RNC————unverified
OEM-3-SImmobiliserdigital_inMAXXECURACE-C1-K4DIN/VR 2digital_inRBsingle_source
OEM-3-TVehicle speeddigital_inMAXXECURACE-C1-K3DIN/VR 1digital_inGRsingle_source
OEM-3-UCharge lamplow_side_out———BrRsingle_source
OEM-3-VCam position (CMP)trigger_inMAXXECURACE-C1-H4HOMEtrigger_inGyLsingle_source
OEM-3-WNC————unverified
OEM-3-XNC————unverified
OEM-3-YCrank position (CKP)trigger_inMAXXECURACE-C1-H3TRIGGERtrigger_inVWsingle_source
OEM-3-ZNC————unverified
OEM-4-APower groundgroundMAXXECURACE-C1-L4 + MAXXECURACE-C2-G4Engine GND + ENGINE GROUNDgroundBLsingle_source
OEM-4-AARear O2 signallambda_nb_inMAXXECURACE-C2-G3AIN 5 (0-5V)analog_inRsingle_source
OEM-4-ABNC————unverified
OEM-4-ACTCM (automatic only)————VGsingle_source
OEM-4-ADFuel levelanalog_inMAXXECURACE-C2-F1AIN 7 (0-5V)analog_inBrBsingle_source
OEM-4-AEPressure sensor (Mazda: EGR boost sensor)analog_inMAXXECURACE-C1-J4AIN 4 (0-5V)analog_inLYcorroborated
OEM-4-AFECU power +14V (main relay)power_inMAXXECURACE-C1-M4+12V ECU power supplypower_inWRsingle_source
OEM-4-AGConstant +12Vpower_in———LRsingle_source
OEM-4-AHEVAP leak detection pump solenoid valvelow_side_out———RGsingle_source
OEM-4-BBrake switchdigital_inMAXXECURACE-C2-F3DIN/VR 4digital_inGsingle_source
OEM-4-CPower steering pressure switchdigital_inMAXXECURACE-C2-F4DIN/VR 5digital_inBrsingle_source
OEM-4-DVVT oil-control solenoid +12V feedpower_inMAXXECURACE-C1-M4+12V ECU power supplypower_inYsingle_source
OEM-4-EDiagnostic (DLC TEN) (NA)serial———LYsingle_source
OEM-4-FA/C requestdigital_inMAXXECURACE-C2-F2AIN 8 (0-5V)analog_inLgBsingle_source
OEM-4-GNC————unverified
OEM-4-HNeutral switchdigital_in———Vsingle_source
OEM-4-IClutch switchdigital_in———WGsingle_source
OEM-4-JVTCS vacuum switchdigital_in———Orsingle_source
OEM-4-KNC————unverified
OEM-4-L+5V sensor supplyvrefMAXXECURACE-C1-G1+5V sensor supplyvrefLgRsingle_source
OEM-4-MKnock sensorknock_inMAXXECURACE-C2-E2Knock 1knock_inWsingle_source
OEM-4-NIntake air temperature (IAT)temp_inMAXXECURACE-C1-F2IATtemp_inPLsingle_source
OEM-4-OSignal groundsensor_groundMAXXECURACE-C1-H1 + MAXXECURACE-C1-H2Sensor GND + Trigger GNDsensor_groundBRsingle_source
OEM-4-PCoolant temperature (ECT)temp_inMAXXECURACE-C1-F1CLTtemp_inRLsingle_source
OEM-4-QNC————unverified
OEM-4-RVVT oil-control solenoid (low-side control)low_side_out———VYcorroborated
OEM-4-SIgnition switch (IG1) sensedigital_in———BWsingle_source
OEM-4-TGenerator output voltage (terminal P)————Gysingle_source
OEM-4-UNC————unverified
OEM-4-VThrottle position (TPS)analog_inMAXXECURACE-C1-G2TPS/AINanalog_inGBsingle_source
OEM-4-WFront O2 signallambda_nb_inMAXXECURACE-C2-E4AIN 6 (0-5V)analog_inLsingle_source
OEM-4-XMass air flow (MAF)analog_inMAXXECURACE-C1-J3AIN 3 (0-5V)analog_inPsingle_source
OEM-4-YNC————unverified
OEM-4-ZTCM (automatic only)————PBsingle_source

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)—
W3OEM-4-DSP-14V-10.85no routeVVT oil-control solenoid +12V feed—
W4SP-14V-1MAXXECURACE-C1-M40.85no route+12V ECU power supply—
W5OEM-3-ASP-GND-10.85no routePower ground—
W6OEM-3-BSP-GND-10.85no routePower ground—
W7OEM-4-ASP-GND-10.85no routePower ground—
W8SP-GND-1MAXXECURACE-C1-L40.85no routeEngine GND—
W9SP-GND-1MAXXECURACE-C2-G40.85no routeENGINE GROUND—
W10OEM-4-OSP-0V-10.5no routeSignal ground—
W11SP-0V-1MAXXECURACE-C1-H10.5no routeSensor GND—
W12SP-0V-1MAXXECURACE-C1-H20.5no routeTrigger GND—
W13OEM-4-LMAXXECURACE-C1-G10.5no route+5V sensor supply—
W14OEM-3-YMAXXECURACE-C1-H30.5no routeCrank position (CKP)—
W15OEM-3-VMAXXECURACE-C1-H40.5no routeCam position (CMP)—
W16OEM-4-MMAXXECURACE-C2-E20.5no routeKnock sensor—
W17OEM-3-FMAXXECURACE-C1-A20.5no routeIgnition 1 (coils 1+4, wasted spark)—
W18OEM-3-IMAXXECURACE-C1-A30.5no routeIgnition 2 (coils 2+3, wasted spark)—
W19OEM-2-AMAXXECURACE-C1-K10.5no routeInjector 1—
W20OEM-2-DMAXXECURACE-C1-K20.5no routeInjector 2—
W21OEM-2-GMAXXECURACE-C1-M10.5no routeInjector 3—
W22OEM-2-JMAXXECURACE-C1-M20.5no routeInjector 4—
W23OEM-4-XMAXXECURACE-C1-J30.5no routeMass air flow (MAF)—
W24OEM-4-VMAXXECURACE-C1-G20.5no routeThrottle position (TPS)—
W25OEM-4-PMAXXECURACE-C1-F10.5no routeCoolant temperature (ECT)—
W26OEM-2-BMAXXECURACE-C1-B40.5no routeCooling fan relay—
W27OEM-2-CMAXXECURACE-C1-C40.5no routeCondenser fan relay—
W28OEM-2-KMAXXECURACE-C1-D40.5no routeA/C clutch relay—
W29OEM-2-MMAXXECURACE-C1-E40.5no routeFuel pump relay—
W30OEM-3-HMAXXECURACE-C1-A10.5no routeMain relay—
W31OEM-2-OMAXXECURACE-C1-B10.5no routeFuel pump relay (non-immobiliser)—
W32OEM-3-JMAXXECURACE-C1-D10.5no routeFront O2 heater—
W33OEM-3-PMAXXECURACE-C1-C10.5no routeRear O2 heater—
W34OEM-2-QMAXXECURACE-C1-A40.5no routeISC valve low side—
W35OEM-2-EMAXXECURACE-C1-M30.5no routeEGR valve—
W36OEM-2-FMAXXECURACE-C1-L30.5no routeEGR valve—
W37OEM-2-HMAXXECURACE-C1-L20.5no routeEGR valve—
W38OEM-2-IMAXXECURACE-C1-L10.5no routeEGR valve—
W39OEM-4-AEMAXXECURACE-C1-J40.5no routePressure sensor (Mazda: EGR boost sensor)—
W40OEM-4-AAMAXXECURACE-C2-G30.5no routeRear O2 signal—
W41OEM-4-WMAXXECURACE-C2-E40.5no routeFront O2 signal—
W42OEM-4-NMAXXECURACE-C1-F20.5no routeIntake air temperature (IAT)—
W43OEM-4-ADMAXXECURACE-C2-F10.5no routeFuel level—
W44OEM-3-TMAXXECURACE-C1-K30.5no routeVehicle speed—
W45OEM-3-SMAXXECURACE-C1-K40.5no routeImmobiliser—
W46OEM-4-BMAXXECURACE-C2-F30.5no routeBrake switch—
W47OEM-4-CMAXXECURACE-C2-F40.5no routePower steering pressure switch—
W48OEM-4-FMAXXECURACE-C2-F20.5no routeA/C request—

Bill of materials

CategoryPart numberManufacturerDescriptionQtyUnit

ECU setup sheet

RoleEngine refEngine signalSensorECU pointECU functionECU classSetup flag
No configured channels.

Findings

Open (12)

SeverityCodeSubjectMessage
warnLOAD_UNKNOWNMAXXECURACE-C1-A1MAXXECURACE-C1-A1 "GPO 5" drives OEM-3-H Main relay (load 0.2 A) but its current rating is unknown. Check the ECU manual.
warnLOAD_UNKNOWNMAXXECURACE-C1-A4MAXXECURACE-C1-A4 "GPO 8/TACHO" drives OEM-2-Q ISC valve low side (load 1.0 A) but its current rating is unknown. Check the ECU manual.
warnLOAD_UNKNOWNMAXXECURACE-C1-B4MAXXECURACE-C1-B4 "GPO 1" drives OEM-2-B Cooling fan relay (load 0.2 A) but its current rating is unknown. Check the ECU manual.
warnLOAD_UNKNOWNMAXXECURACE-C1-C4MAXXECURACE-C1-C4 "GPO 2" drives OEM-2-C Condenser fan relay (load 0.2 A) but its current rating is unknown. Check the ECU manual.
warnLOAD_UNKNOWNMAXXECURACE-C1-D4MAXXECURACE-C1-D4 "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_UNKNOWNMAXXECURACE-C1-E4MAXXECURACE-C1-E4 "GPO 4" drives OEM-2-M Fuel pump relay (load 0.2 A) but its current rating is unknown. Check the ECU manual.
warnNET_FAMILYOEM-4-F ↔ MAXXECURACE-C2-F2OEM-4-F "A/C request" [digital_in] is wired to MAXXECURACE-C2-F2 "AIN 8 (0-5V)" [analog_in]. Analog and digital on one net. A switch on an analog input works with a pull-up and a threshold; an analog sensor on a digital input loses its value.
infoNET_FAMILYOEM-2-E ↔ MAXXECURACE-C1-M3OEM-2-E "EGR valve" [low_side_out] is wired to MAXXECURACE-C1-M3 "INJ 5" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency.
infoNET_FAMILYOEM-2-F ↔ MAXXECURACE-C1-L3OEM-2-F "EGR valve" [low_side_out] is wired to MAXXECURACE-C1-L3 "INJ 6" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency.
infoNET_FAMILYOEM-2-H ↔ MAXXECURACE-C1-L2OEM-2-H "EGR valve" [low_side_out] is wired to MAXXECURACE-C1-L2 "INJ 7" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency.
infoNET_FAMILYOEM-2-I ↔ MAXXECURACE-C1-L1OEM-2-I "EGR valve" [low_side_out] is wired to MAXXECURACE-C1-L1 "INJ 8" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency.
infoUNMAPPEDOEM19 optional OEM pins are not mapped: OEM-2-N VTCS solenoid (intake butterflies); OEM-2-R Malfunction indicator lamp (MIL); OEM-3-C Purge solenoid valve; OEM-3-D EGR boost solenoid; OEM-3-K EVAP leak detection pump; OEM-3-M Alternator control; OEM-3-O Tachometer output; OEM-3-Q Data link connector (K-line); OEM-3-U Charge lamp; OEM-4-AC TCM (automatic only); OEM-4-AH EVAP leak detection pump solenoid valve; OEM-4-E Diagnostic (DLC TEN) (NA); OEM-4-H Neutral switch; OEM-4-I Clutch switch; OEM-4-J VTCS vacuum switch; OEM-4-R VVT oil-control solenoid (low-side control); OEM-4-S Ignition switch (IG1) sense; OEM-4-T Generator output voltage (terminal P); 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 2026-10-11. Review every wire against both manuals before building. Not wired: - OEM-4 AG: Constant +12V: MaxxECU MaxxECU RACE has no battery-constant input; not needed - 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 RACE has no dedicated key-on input - OEM-2 N: VTCS solenoid (intake butterflies): no free low_side/relay_control/heater_low_side/ls_hs/injector on MaxxECU MaxxECU RACE - OEM-2 R: Malfunction indicator lamp (MIL): no free low_side/relay_control/heater_low_side/ls_hs/injector on MaxxECU MaxxECU RACE - OEM-3 C: Purge solenoid valve: no free low_side/relay_control/heater_low_side/ls_hs/injector on MaxxECU MaxxECU RACE - OEM-3 K: EVAP leak detection pump: no free low_side/relay_control/heater_low_side/ls_hs/injector on MaxxECU MaxxECU RACE - OEM-3 M: Alternator control: no free low_side/relay_control/heater_low_side/ls_hs/injector on MaxxECU MaxxECU RACE - OEM-3 U: Charge lamp: no free low_side/relay_control/heater_low_side/ls_hs/injector on MaxxECU MaxxECU RACE - OEM-4 AH: EVAP leak detection pump solenoid valve: no free low_side/relay_control/heater_low_side/ls_hs/injector on MaxxECU MaxxECU RACE - OEM-4 R: VVT oil-control solenoid (low-side control): no free low_side/relay_control/heater_low_side/ls_hs/injector on MaxxECU MaxxECU RACE - OEM-3 O: Tachometer output: no free tacho/frequency_out/low_side/ls_hs on MaxxECU MaxxECU RACE - OEM-4 H: Neutral switch: no free switch_in/frequency_in/analog_0_5 on MaxxECU MaxxECU RACE - OEM-4 I: Clutch switch: no free switch_in/frequency_in/analog_0_5 on MaxxECU MaxxECU RACE - OEM-4 J: VTCS vacuum switch: no free switch_in/frequency_in/analog_0_5 on MaxxECU MaxxECU RACE - OEM-3 Q: Data link connector (K-line): no free k_line on MaxxECU MaxxECU RACE - OEM-4 E: Diagnostic (DLC TEN) (NA): no free k_line on MaxxECU MaxxECU RACE - OEM-3 D: EGR boost solenoid: not classified in the library; wire by hand - OEM-4 AC: TCM (automatic only): 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
4oem_manualMazda MX-5 NB2 (2003) wiring diagram — engine / starting / charginghttps://web.archive.org/web/20191104195207/http://mellens.net/mazda/mazda_miata_extra_manual/2003_wiring.pdf—2026-10-055ee0777f12c1
2expert_reportJustin Barrera — Miata NA/NB wiring corrections————