← Back

MX-5 Miata NA8 1996-97 (BP-ZE, 1.8, OBD-II) → MaxxECU MaxxECU RACE REV9+ (auto)

MX-5 Miata NA8 1996-97 (BP-ZE, 1.8, OBD-II) — MaxxECU — MaxxECU RACE
⚠ NOT CHECKED. Don't build from this.
Drawn by Michael Gnankou · Rev 0 · draft · 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.

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 job45 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-4-BSP-14V-10.85☐☐☐☐☐☐☐
W2SP-14V-1MAXXECURACE-C1-M40.85☐☐☐☐☐☐☐
W3OEM-4-ASP-GND-10.85☐☐☐☐☐☐☐
W4OEM-4-CSP-GND-10.85☐☐☐☐☐☐☐
W5OEM-4-DSP-GND-10.85☐☐☐☐☐☐☐
W6OEM-4-KSP-GND-10.85☐☐☐☐☐☐☐
W7SP-GND-1MAXXECURACE-C1-L40.85☐☐☐☐☐☐☐
W8SP-GND-1MAXXECURACE-C2-G40.85☐☐☐☐☐☐☐
W9OEM-3-OSP-0V-10.5☐☐☐☐☐☐☐
W10OEM-4-HSP-0V-10.5☐☐☐☐☐☐☐
W11SP-0V-1MAXXECURACE-C1-H10.5☐☐☐☐☐☐☐
W12SP-0V-1MAXXECURACE-C1-H20.5☐☐☐☐☐☐☐
W13OEM-3-IMAXXECURACE-C1-G10.5☐☐☐☐☐☐☐
W14OEM-4-EMAXXECURACE-C1-H30.5☐☐☐☐☐☐☐
W15OEM-4-GMAXXECURACE-C1-H40.5☐☐☐☐☐☐☐
W16OEM-4-NMAXXECURACE-C1-A20.5☐☐☐☐☐☐☐
W17OEM-4-RMAXXECURACE-C1-A30.5☐☐☐☐☐☐☐
W18OEM-4-UMAXXECURACE-C1-K10.5☐☐☐☐☐☐☐
W19OEM-4-VMAXXECURACE-C1-K20.5☐☐☐☐☐☐☐
W20OEM-4-WMAXXECURACE-C1-M10.5☐☐☐☐☐☐☐
W21OEM-4-XMAXXECURACE-C1-M20.5☐☐☐☐☐☐☐
W22OEM-3-BMAXXECURACE-C1-J30.5☐☐☐☐☐☐☐
W23OEM-3-FMAXXECURACE-C1-G20.5☐☐☐☐☐☐☐
W24OEM-3-GMAXXECURACE-C1-F10.5☐☐☐☐☐☐☐
W25OEM-1-AMAXXECURACE-C1-B40.5☐☐☐☐☐☐☐
W26OEM-1-BMAXXECURACE-C1-C40.5☐☐☐☐☐☐☐
W27OEM-1-GMAXXECURACE-C1-D40.5☐☐☐☐☐☐☐
W28OEM-1-UMAXXECURACE-C1-E40.5☐☐☐☐☐☐☐
W29OEM-3-MMAXXECURACE-C1-D10.5☐☐☐☐☐☐☐
W30OEM-1-EMAXXECURACE-C1-A10.5☐☐☐☐☐☐☐
W31OEM-4-JMAXXECURACE-C1-B10.5☐☐☐☐☐☐☐
W32OEM-4-OMAXXECURACE-C1-C10.5☐☐☐☐☐☐☐
W33OEM-4-PMAXXECURACE-C1-A40.5☐☐☐☐☐☐☐
W34OEM-4-QMAXXECURACE-C1-M30.5☐☐☐☐☐☐☐
W35OEM-4-TMAXXECURACE-C1-L30.5☐☐☐☐☐☐☐
W36OEM-3-HMAXXECURACE-C1-J40.5☐☐☐☐☐☐☐
W37OEM-3-NMAXXECURACE-C2-G30.5☐☐☐☐☐☐☐
W38OEM-3-CMAXXECURACE-C2-E40.5☐☐☐☐☐☐☐
W39OEM-3-DMAXXECURACE-C2-F10.5☐☐☐☐☐☐☐
W40OEM-3-KMAXXECURACE-C1-F20.5☐☐☐☐☐☐☐
W41OEM-3-JMAXXECURACE-C2-F20.5☐☐☐☐☐☐☐
W42OEM-1-MMAXXECURACE-C1-K30.5☐☐☐☐☐☐☐
W43OEM-1-CMAXXECURACE-C1-K40.5☐☐☐☐☐☐☐
W44OEM-1-KMAXXECURACE-C2-F30.5☐☐☐☐☐☐☐
W45OEM-1-LMAXXECURACE-C2-F40.5☐☐☐☐☐☐☐

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
1MAXXECURACE-C1-G1MAXXECURACE-C1-H1open (OL)5 V sensor reference must not touch sensor ground
2MAXXECURACE-C1-G1MAXXECURACE-C1-L4open (OL)5 V sensor reference must not touch power ground
3MAXXECURACE-C1-G1MAXXECURACE-C1-M4open (OL)5 V sensor reference must not touch +12 V supply
4MAXXECURACE-C1-H1MAXXECURACE-C1-M4open (OL)sensor ground must not touch +12 V supply
5MAXXECURACE-C1-L4MAXXECURACE-C1-M4open (OL)power ground must not touch +12 V supply

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

Revisions

RevLabelByDate
No revisions yet.

Schematic

MAXXECURACE-C1MAXXECURACE-C2OEM-1OEM-3OEM-4SP-0VSP-14VSP-GND

Connectors

MAXXECURACE-C1

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
A1GPO 5—W30—0.5OEM-1-E———
A2IGN 1—W16—0.5OEM-4-N———
A3IGN 2—W17—0.5OEM-4-R———
A4GPO 8/TACHO—W33—0.5OEM-4-P———
B1GPO 6—W31—0.5OEM-4-J———
B2IGN 3————————
B3IGN 4————————
B4GPO 1—W25—0.5OEM-1-A———
C1GPO 7—W32—0.5OEM-4-O———
C2IGN 5————————
C3IGN 6————————
C4GPO 2—W26—0.5OEM-1-B———
D1WBO2 Heater-—W29—0.5OEM-3-M———
D2IGN 7————————
D3IGN 8————————
D4GPO 3—W27—0.5OEM-1-G———
E1CAN H————————
E2CAN L————————
E3GND Shield————————
E4GPO 4—W28—0.5OEM-1-U———
F1CLT—W24—0.5OEM-3-G———
F2IAT—W40—0.5OEM-3-K———
F3WBO2 VREF————————
F4WBO2 VS————————
G1+5V sensor supply—W13—0.5OEM-3-I———
G2TPS/AIN—W23—0.5OEM-3-F———
G3WBO2 IP————————
G4WBO2 RCAL————————
H1Sensor GND—W11—0.5SP-0V-1———
H2Trigger GND—W12—0.5SP-0V-1———
H3TRIGGER—W14—0.5OEM-4-E———
H4HOME—W15—0.5OEM-4-G———
J1AIN 1 (temperature)————————
J2AIN 2 (temperature)————————
J3AIN 3 (0-5V)—W22—0.5OEM-3-B———
J4AIN 4 (0-5V)—W36—0.5OEM-3-H———
K1INJ 1—W18—0.5OEM-4-U———
K2INJ 2—W19—0.5OEM-4-V———
K3DIN/VR 1—W42—0.5OEM-1-M———
K4DIN/VR 2—W43—0.5OEM-1-C———
L1INJ 8————————
L2INJ 7————————
L3INJ 6—W35—0.5OEM-4-T———
L4Engine GND—W7—0.85SP-GND-1———
M1INJ 3—W20—0.5OEM-4-W———
M2INJ 4—W21—0.5OEM-4-X———
M3INJ 5—W34—0.5OEM-4-Q———
M4+12V ECU power supply—W2—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————————
E3Knock 2————————
E4AIN 6 (0-5V)—W38—0.5OEM-3-C———
F1AIN 7 (0-5V)—W39—0.5OEM-3-D———
F2AIN 8 (0-5V)—W41—0.5OEM-3-J———
F3DIN/VR 4—W44—0.5OEM-1-K———
F4DIN/VR 5—W45—0.5OEM-1-L———
G1GPO 15 (+12V)————————
G2GPO 16 (+12V)————————
G3AIN 5 (0-5V)—W37—0.5OEM-3-N———
G4ENGINE GROUND—W8—0.85SP-GND-1———
H1MOTOR 2+————————
H2MOTOR 1-————————
H3MOTOR 2-————————
H4MOTOR 1+————————

OEM-1

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
ACooling fan relay (low-side)—W25—0.5MAXXECURACE-C1-B4———
BA/C condenser fan relay—W26—0.5MAXXECURACE-C1-C4———
CStarter input (12V while cranking)—W43—0.5MAXXECURACE-C1-K4———
ECheck engine light (MIL)—W30—0.5MAXXECURACE-C1-A1———
GA/C clutch relay—W27—0.5MAXXECURACE-C1-D4———
KA/C pressure switch (A/C request)—W44—0.5MAXXECURACE-C2-F3———
LClutch switch—W45—0.5MAXXECURACE-C2-F4———
MVehicle speed sensor (VSS)—W42—0.5MAXXECURACE-C1-K3———
QBrake switch————————
UFuel pump relay (low-side)—W28—0.5MAXXECURACE-C1-E4———

OEM-3

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
BMAF sensor input—W22—0.5MAXXECURACE-C1-J3———
CFront O2 sensor input—W38—0.5MAXXECURACE-C2-E4———
DRear O2 sensor input—W39—0.5MAXXECURACE-C2-F1———
FThrottle position (TPS)—W23—0.5MAXXECURACE-C1-G2———
GEngine coolant temp (CLT)—W24—0.5MAXXECURACE-C1-F1———
HEGR boost sensor—W36—0.5MAXXECURACE-C1-J4———
I+5V sensor reference—W13—0.5MAXXECURACE-C1-G1———
JEGR valve position sensor—W41—0.5MAXXECURACE-C2-F2———
KIntake air temp (IAT)—W40—0.5MAXXECURACE-C1-F2———
LIdle switch (closed throttle)————————
MFront O2 heater control—W29—0.5MAXXECURACE-C1-D1———
NEGR boost sensor (2nd channel)—W37—0.5MAXXECURACE-C2-G3———
OSensor ground—W9—0.5SP-0V-1———
PPower steering pressure switch————————

OEM-4

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
AChassis ground—W3—0.85SP-GND-1———
BECU power +12V (main relay)—W1—0.85SP-14V-1———
CChassis ground—W4—0.85SP-GND-1———
DChassis ground—W5—0.85SP-GND-1———
ECrank position (CKP) sensor—W14—0.5MAXXECURACE-C1-H3———
FCAS SGT (cam trigger)————————
GCAS SGC (cam sync)—W15—0.5MAXXECURACE-C1-H4———
HCrank pickup timing ground (CKP gnd)—W10—0.5SP-0V-1———
IPermanent +12V (battery)————————
JPRC solenoid (FPR control)—W31—0.5MAXXECURACE-C1-B1———
KChassis ground—W6—0.85SP-GND-1———
LTachometer output————————
NIgnition coil trigger (cyl 1&4)—W16—0.5MAXXECURACE-C1-A2———
OEGR vent solenoid—W32—0.5MAXXECURACE-C1-C1———
PEGR vacuum solenoid—W33—0.5MAXXECURACE-C1-A4———
QIdle air control (IAC) valve—W34—0.5MAXXECURACE-C1-M3———
RIgnition coil trigger (cyl 2&3)—W17—0.5MAXXECURACE-C1-A3———
TEVAP purge solenoid—W35—0.5MAXXECURACE-C1-L3———
UInjector 1 (cyl 1)—W18—0.5MAXXECURACE-C1-K1———
VInjector 2 (cyl 2)—W19—0.5MAXXECURACE-C1-K2———
WInjector 3 (cyl 3)—W20—0.5MAXXECURACE-C1-M1———
XInjector 4 (cyl 4)—W21—0.5MAXXECURACE-C1-M2———

SP-0V

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W9—0.5OEM-3-O———
1——W10—0.5OEM-4-H———
1——W11—0.5MAXXECURACE-C1-H1———
1——W12—0.5MAXXECURACE-C1-H2———

SP-14V

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W1—0.85OEM-4-B———
1——W2—0.85MAXXECURACE-C1-M4———

SP-GND

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W3—0.85OEM-4-A———
1——W4—0.85OEM-4-C———
1——W5—0.85OEM-4-D———
1——W6—0.85OEM-4-K———
1——W7—0.85MAXXECURACE-C1-L4———
1——W8—0.85MAXXECURACE-C2-G4———

Pin map

OEM pointOEM functionOEM familyTarget pointTarget functionTarget familyWire colourEvidence
OEM-1-ACooling fan relay (low-side)low_side_outMAXXECURACE-C1-B4GPO 1low_side_outcorroborated
OEM-1-BA/C condenser fan relaylow_side_outMAXXECURACE-C1-C4GPO 2low_side_outcorroborated
OEM-1-CStarter input (12V while cranking)digital_inMAXXECURACE-C1-K4DIN/VR 2digital_incorroborated
OEM-1-ECheck engine light (MIL)low_side_outMAXXECURACE-C1-A1GPO 5low_side_outcorroborated
OEM-1-GA/C clutch relaylow_side_outMAXXECURACE-C1-D4GPO 3low_side_outcorroborated
OEM-1-KA/C pressure switch (A/C request)digital_inMAXXECURACE-C2-F3DIN/VR 4digital_incorroborated
OEM-1-LClutch switchdigital_inMAXXECURACE-C2-F4DIN/VR 5digital_incorroborated
OEM-1-MVehicle speed sensor (VSS)digital_inMAXXECURACE-C1-K3DIN/VR 1digital_incorroborated
OEM-1-QBrake switchdigital_in———corroborated
OEM-1-UFuel pump relay (low-side)low_side_outMAXXECURACE-C1-E4GPO 4low_side_outcorroborated
OEM-3-BMAF sensor inputanalog_inMAXXECURACE-C1-J3AIN 3 (0-5V)analog_incorroborated
OEM-3-CFront O2 sensor inputlambda_nb_inMAXXECURACE-C2-E4AIN 6 (0-5V)analog_incorroborated
OEM-3-DRear O2 sensor inputlambda_nb_inMAXXECURACE-C2-F1AIN 7 (0-5V)analog_incorroborated
OEM-3-FThrottle position (TPS)analog_inMAXXECURACE-C1-G2TPS/AINanalog_incorroborated
OEM-3-GEngine coolant temp (CLT)temp_inMAXXECURACE-C1-F1CLTtemp_incorroborated
OEM-3-HEGR boost sensoranalog_inMAXXECURACE-C1-J4AIN 4 (0-5V)analog_incorroborated
OEM-3-I+5V sensor referencevrefMAXXECURACE-C1-G1+5V sensor supplyvrefcorroborated
OEM-3-JEGR valve position sensoranalog_inMAXXECURACE-C2-F2AIN 8 (0-5V)analog_incorroborated
OEM-3-KIntake air temp (IAT)temp_inMAXXECURACE-C1-F2IATtemp_incorroborated
OEM-3-LIdle switch (closed throttle)digital_in———corroborated
OEM-3-MFront O2 heater controllow_side_outMAXXECURACE-C1-D1WBO2 Heater-low_side_outcorroborated
OEM-3-NEGR boost sensor (2nd channel)analog_inMAXXECURACE-C2-G3AIN 5 (0-5V)analog_incorroborated
OEM-3-OSensor groundsensor_groundMAXXECURACE-C1-H1 + MAXXECURACE-C1-H2Sensor GND + Trigger GNDsensor_groundcorroborated
OEM-3-PPower steering pressure switchdigital_in———corroborated
OEM-4-AChassis groundgroundMAXXECURACE-C1-L4 + MAXXECURACE-C2-G4Engine GND + ENGINE GROUNDgroundcorroborated
OEM-4-BECU power +12V (main relay)power_inMAXXECURACE-C1-M4+12V ECU power supplypower_incorroborated
OEM-4-CChassis groundgroundMAXXECURACE-C1-L4 + MAXXECURACE-C2-G4Engine GND + ENGINE GROUNDgroundcorroborated
OEM-4-DChassis groundgroundMAXXECURACE-C1-L4 + MAXXECURACE-C2-G4Engine GND + ENGINE GROUNDgroundcorroborated
OEM-4-ECrank position (CKP) sensortrigger_inMAXXECURACE-C1-H3TRIGGERtrigger_incorroborated
OEM-4-FCAS SGT (cam trigger)trigger_in———corroborated
OEM-4-GCAS SGC (cam sync)trigger_inMAXXECURACE-C1-H4HOMEtrigger_incorroborated
OEM-4-HCrank pickup timing ground (CKP gnd)sensor_groundMAXXECURACE-C1-H1 + MAXXECURACE-C1-H2Sensor GND + Trigger GNDsensor_groundcorroborated
OEM-4-IPermanent +12V (battery)power_in———corroborated
OEM-4-JPRC solenoid (FPR control)low_side_outMAXXECURACE-C1-B1GPO 6low_side_outcorroborated
OEM-4-KChassis groundgroundMAXXECURACE-C1-L4 + MAXXECURACE-C2-G4Engine GND + ENGINE GROUNDgroundcorroborated
OEM-4-LTachometer outputtacho_out———corroborated
OEM-4-NIgnition coil trigger (cyl 1&4)ignition_outMAXXECURACE-C1-A2IGN 1ignition_outcorroborated
OEM-4-OEGR vent solenoidlow_side_outMAXXECURACE-C1-C1GPO 7low_side_outcorroborated
OEM-4-PEGR vacuum solenoidlow_side_outMAXXECURACE-C1-A4GPO 8/TACHOlow_side_outcorroborated
OEM-4-QIdle air control (IAC) valvelow_side_outMAXXECURACE-C1-M3INJ 5injector_outcorroborated
OEM-4-RIgnition coil trigger (cyl 2&3)ignition_outMAXXECURACE-C1-A3IGN 2ignition_outcorroborated
OEM-4-TEVAP purge solenoidlow_side_outMAXXECURACE-C1-L3INJ 6injector_outcorroborated
OEM-4-UInjector 1 (cyl 1)injector_outMAXXECURACE-C1-K1INJ 1injector_outcorroborated
OEM-4-VInjector 2 (cyl 2)injector_outMAXXECURACE-C1-K2INJ 2injector_outcorroborated
OEM-4-WInjector 3 (cyl 3)injector_outMAXXECURACE-C1-M1INJ 3injector_outcorroborated
OEM-4-XInjector 4 (cyl 4)injector_outMAXXECURACE-C1-M2INJ 4injector_outcorroborated

Cut list

WireFromToGauge (mm²)ColourLengthSignalIdent
W1OEM-4-BSP-14V-10.85no routeECU power +12V (main relay)—
W2SP-14V-1MAXXECURACE-C1-M40.85no route+12V ECU power supply—
W3OEM-4-ASP-GND-10.85no routeChassis ground—
W4OEM-4-CSP-GND-10.85no routeChassis ground—
W5OEM-4-DSP-GND-10.85no routeChassis ground—
W6OEM-4-KSP-GND-10.85no routeChassis ground—
W7SP-GND-1MAXXECURACE-C1-L40.85no routeEngine GND—
W8SP-GND-1MAXXECURACE-C2-G40.85no routeENGINE GROUND—
W9OEM-3-OSP-0V-10.5no routeSensor ground—
W10OEM-4-HSP-0V-10.5no routeCrank pickup timing ground (CKP gnd)—
W11SP-0V-1MAXXECURACE-C1-H10.5no routeSensor GND—
W12SP-0V-1MAXXECURACE-C1-H20.5no routeTrigger GND—
W13OEM-3-IMAXXECURACE-C1-G10.5no route+5V sensor reference—
W14OEM-4-EMAXXECURACE-C1-H30.5no routeCrank position (CKP) sensor—
W15OEM-4-GMAXXECURACE-C1-H40.5no routeCAS SGC (cam sync)—
W16OEM-4-NMAXXECURACE-C1-A20.5no routeIgnition coil trigger (cyl 1&4)—
W17OEM-4-RMAXXECURACE-C1-A30.5no routeIgnition coil trigger (cyl 2&3)—
W18OEM-4-UMAXXECURACE-C1-K10.5no routeInjector 1 (cyl 1)—
W19OEM-4-VMAXXECURACE-C1-K20.5no routeInjector 2 (cyl 2)—
W20OEM-4-WMAXXECURACE-C1-M10.5no routeInjector 3 (cyl 3)—
W21OEM-4-XMAXXECURACE-C1-M20.5no routeInjector 4 (cyl 4)—
W22OEM-3-BMAXXECURACE-C1-J30.5no routeMAF sensor input—
W23OEM-3-FMAXXECURACE-C1-G20.5no routeThrottle position (TPS)—
W24OEM-3-GMAXXECURACE-C1-F10.5no routeEngine coolant temp (CLT)—
W25OEM-1-AMAXXECURACE-C1-B40.5no routeCooling fan relay (low-side)—
W26OEM-1-BMAXXECURACE-C1-C40.5no routeA/C condenser fan relay—
W27OEM-1-GMAXXECURACE-C1-D40.5no routeA/C clutch relay—
W28OEM-1-UMAXXECURACE-C1-E40.5no routeFuel pump relay (low-side)—
W29OEM-3-MMAXXECURACE-C1-D10.5no routeFront O2 heater control—
W30OEM-1-EMAXXECURACE-C1-A10.5no routeCheck engine light (MIL)—
W31OEM-4-JMAXXECURACE-C1-B10.5no routePRC solenoid (FPR control)—
W32OEM-4-OMAXXECURACE-C1-C10.5no routeEGR vent solenoid—
W33OEM-4-PMAXXECURACE-C1-A40.5no routeEGR vacuum solenoid—
W34OEM-4-QMAXXECURACE-C1-M30.5no routeIdle air control (IAC) valve—
W35OEM-4-TMAXXECURACE-C1-L30.5no routeEVAP purge solenoid—
W36OEM-3-HMAXXECURACE-C1-J40.5no routeEGR boost sensor—
W37OEM-3-NMAXXECURACE-C2-G30.5no routeEGR boost sensor (2nd channel)—
W38OEM-3-CMAXXECURACE-C2-E40.5no routeFront O2 sensor input—
W39OEM-3-DMAXXECURACE-C2-F10.5no routeRear O2 sensor input—
W40OEM-3-KMAXXECURACE-C1-F20.5no routeIntake air temp (IAT)—
W41OEM-3-JMAXXECURACE-C2-F20.5no routeEGR valve position sensor—
W42OEM-1-MMAXXECURACE-C1-K30.5no routeVehicle speed sensor (VSS)—
W43OEM-1-CMAXXECURACE-C1-K40.5no routeStarter input (12V while cranking)—
W44OEM-1-KMAXXECURACE-C2-F30.5no routeA/C pressure switch (A/C request)—
W45OEM-1-LMAXXECURACE-C2-F40.5no routeClutch switch—

Bill of materials

CategoryPart numberManufacturerDescriptionQtyUnit

ECU setup sheet

RoleEngine refEngine signalSensorECU pointECU functionECU classSetup flag
No configured channels.

Findings

Open (8)

SeverityCodeSubjectMessage
errorREQUIRED_UNMAPPEDOEM-4-FRequired OEM function "CAS SGT (cam trigger)" (trigger_in) is not connected to the new ECU.
warnLOAD_UNKNOWNMAXXECURACE-C1-B4MAXXECURACE-C1-B4 "GPO 1" drives OEM-1-A Cooling fan relay (low-side) (load 0.2 A) but its current rating is unknown. Check the ECU manual.
warnLOAD_UNKNOWNMAXXECURACE-C1-C4MAXXECURACE-C1-C4 "GPO 2" drives OEM-1-B A/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-1-G 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-1-U Fuel pump relay (low-side) (load 0.2 A) but its current rating is unknown. Check the ECU manual.
infoNET_FAMILYOEM-4-Q ↔ MAXXECURACE-C1-M3OEM-4-Q "Idle air control (IAC) 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-4-T ↔ MAXXECURACE-C1-L3OEM-4-T "EVAP purge solenoid" [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.
infoUNMAPPEDOEM4 optional OEM pins are not mapped: OEM-1-Q Brake switch; OEM-3-L Idle switch (closed throttle); OEM-3-P Power steering pressure switch; OEM-4-L Tachometer output

Accepted (1)

CodeSubjectReasonBy
REQUIRED_UNMAPPEDOEM-4-IBattery-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. Open items: - OEM-4 F: CAS SGT (cam trigger): no free cam_hall/cam_vr/frequency_in input on MaxxECU MaxxECU RACE Not wired: - OEM-4 I: Permanent +12V (battery): MaxxECU MaxxECU RACE has no battery-constant input; not needed - OEM-4 L: Tachometer output: no free tacho/frequency_out/low_side/ls_hs on MaxxECU MaxxECU RACE - OEM-1 Q: Brake switch: no free switch_in/frequency_in/analog_0_5 on MaxxECU MaxxECU RACE - OEM-3 L: Idle switch (closed throttle): no free switch_in/frequency_in/analog_0_5 on MaxxECU MaxxECU RACE - OEM-3 P: Power steering pressure switch: no free switch_in/frequency_in/analog_0_5 on MaxxECU MaxxECU RACE

Sources

ReliabilityKindTitleURLArchiveCapturedSHA-256
4vendor_docAEM EMS 30-1720 Plug-and-Play adapter manual (1996-97 Miata)https://static.summitracing.com/global/images/instructions/avm-30-1720.pdf———
4vendor_docMaxxECU GEN1 pinout (MINI / STREET / SPORT / V1 / RACE / PRO)http://www.maxxecu.com/webhelp/wirings-maxxecu_pinout.htmlarchive2026-10-052e37b6814690
3community_copyMellens.net: 1996 Mazda Miata wiring diagrams (FSM-derived)http://www.mellens.net/mazda/mazda_miata_extra_manual/1996_wiring.pdf———