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MX-5 Miata NB1 1999-00 (BP-4W) → MaxxECU MaxxECU MINI REV10+ (auto)

MX-5 Miata NB1 1999-00 (BP-4W) — MaxxECU — MaxxECU MINI
⚠ NOT CHECKED. Don't build from this.
Drawn by Michael Gnankou · Rev 0 · draft · 2026-10-04

Revisions

RevLabelByDate
No revisions yet.

Schematic

MAXXECUMINI-C1OEM-1OEM-2OEM-3SP-0VSP-14VSP-GND

Connectors

MAXXECUMINI-C1

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

OEM-1

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
AConstant +12V————————
BECU power +14V (main relay)—W1—0.85SP-14V-1———
EMalfunction indicator lamp (MIL)————————
FBrake switch—W31—0.5MAXXECUMINI-C1-B2———
GPower steering pressure switch————————
ICondenser fan relay—W21—0.5MAXXECUMINI-C1-G2———
OAlternator control————————
PA/C request————————
QCharge lamp————————
RCooling fan relay—W22—0.5MAXXECUMINI-C1-G1———
SA/C clutch relay—W23—0.5MAXXECUMINI-C1-E1———
UFront O2 heater————————
VNeutral switch————————

OEM-2

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
AFuel tank pressure————————
BIntake air temperature (IAT)—W29—0.5MAXXECUMINI-C1-C2———
CFront O2 signal—W27—0.5MAXXECUMINI-C1-C4———
DVehicle speed—W30—0.5MAXXECUMINI-C1-B1———
ECoolant temperature (ECT)—W28—0.5MAXXECUMINI-C1-C1———
FKnock sensor————————
HCam position (CMP)————————
I+5V sensor supply—W13—0.5MAXXECUMINI-C1-E2———
JCrank position (CKP)—W14—0.5MAXXECUMINI-C1-A1———
KTachometer output————————
LMass air flow (MAF)—W25—0.5MAXXECUMINI-C1-C3———
MEGR valve————————
NEGR valve————————
OEGR valve————————
PEGR valve————————

OEM-3

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
APower ground—W4—0.85SP-GND-1———
BPower ground—W5—0.85SP-GND-1———
CPower ground—W6—0.85SP-GND-1———
EThrottle position (TPS)—W26—0.5MAXXECUMINI-C1-D2———
FSignal ground—W8—0.5SP-0V-1———
GIgnition 1 (coils 1+4, wasted spark)—W15—0.5MAXXECUMINI-C1-F1———
HIgnition 2 (coils 2+3, wasted spark)—W16—0.5MAXXECUMINI-C1-F2———
IClutch switch————————
JRear O2 signal————————
KFuel level————————
LEvap purge solenoid————————
MISC valve +14V feed—W2—0.85SP-14V-1———
NFuel pump relay—W24—0.5MAXXECUMINI-C1-D1———
OISC valve low side————————
QVICS solenoid (intake butterflies)————————
SEGR boost sensor————————
TEGR boost solenoid————————
UCanister drain cut valve (CDCV)————————
VRear O2 heater————————
WInjector 1—W17—0.5MAXXECUMINI-C1-G3———
XInjector 2—W18—0.5MAXXECUMINI-C1-H1———
YInjector 3—W19—0.5MAXXECUMINI-C1-H2———
ZInjector 4—W20—0.5MAXXECUMINI-C1-H3———

SP-0V

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W8—0.5OEM-3-F———
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-1-B———
1——W2—0.85OEM-3-M———
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-3-C———
1——W7—0.85MAXXECUMINI-C1-G4———

Pin map

OEM pointOEM functionOEM familyTarget pointTarget functionTarget familyWire colourEvidence
OEM-1-AConstant +12Vpower_in———single_source
OEM-1-BECU power +14V (main relay)power_inMAXXECUMINI-C1-H4+12V (ECU power supply)power_insingle_source
OEM-1-EMalfunction indicator lamp (MIL)low_side_out———single_source
OEM-1-FBrake switchdigital_inMAXXECUMINI-C1-B2DIN 2 (Hall only)digital_insingle_source
OEM-1-GPower steering pressure switchdigital_in———single_source
OEM-1-ICondenser fan relaylow_side_outMAXXECUMINI-C1-G2GPO 1low_side_outsingle_source
OEM-1-OAlternator controllow_side_out———single_source
OEM-1-PA/C requestdigital_in———single_source
OEM-1-QCharge lamplow_side_out———single_source
OEM-1-RCooling fan relaylow_side_outMAXXECUMINI-C1-G1GPO 2low_side_outsingle_source
OEM-1-SA/C clutch relaylow_side_outMAXXECUMINI-C1-E1GPO 3low_side_outsingle_source
OEM-1-UFront O2 heaterlow_side_out———single_source
OEM-1-VNeutral switchdigital_in———single_source
OEM-2-AFuel tank pressureanalog_in———single_source
OEM-2-BIntake air temperature (IAT)temp_inMAXXECUMINI-C1-C2IATtemp_insingle_source
OEM-2-CFront O2 signallambda_nb_inMAXXECUMINI-C1-C4AIN 4 (0-5V)analog_insingle_source
OEM-2-DVehicle speeddigital_inMAXXECUMINI-C1-B1DIN 1 (Hall only)digital_insingle_source
OEM-2-ECoolant temperature (ECT)temp_inMAXXECUMINI-C1-C1CLTtemp_insingle_source
OEM-2-FKnock sensorknock_in———single_source
OEM-2-HCam position (CMP)trigger_in———single_source
OEM-2-I+5V sensor supplyvrefMAXXECUMINI-C1-E2+5V sensor supplyvrefsingle_source
OEM-2-JCrank position (CKP)trigger_inMAXXECUMINI-C1-A1TRIGGERtrigger_insingle_source
OEM-2-KTachometer outputtacho_out———single_source
OEM-2-LMass air flow (MAF)analog_inMAXXECUMINI-C1-C3AIN 3 (0-5V)analog_insingle_source
OEM-2-MEGR valvelow_side_out———single_source
OEM-2-NEGR valvelow_side_out———single_source
OEM-2-OEGR valvelow_side_out———single_source
OEM-2-PEGR valvelow_side_out———single_source
OEM-3-APower groundgroundMAXXECUMINI-C1-G4ENGINE GNDgroundsingle_source
OEM-3-BPower groundgroundMAXXECUMINI-C1-G4ENGINE GNDgroundsingle_source
OEM-3-CPower groundgroundMAXXECUMINI-C1-G4ENGINE GNDgroundsingle_source
OEM-3-EThrottle position (TPS)analog_inMAXXECUMINI-C1-D2TPSanalog_insingle_source
OEM-3-FSignal groundsensor_groundMAXXECUMINI-C1-A2 + MAXXECUMINI-C1-B3 + MAXXECUMINI-C1-B4 + MAXXECUMINI-C1-D4TRIGGER GND + SENSOR GND + SENSOR GND + SENSOR GNDsensor_groundsingle_source
OEM-3-GIgnition 1 (coils 1+4, wasted spark)ignition_outMAXXECUMINI-C1-F1IGN 1ignition_outsingle_source
OEM-3-HIgnition 2 (coils 2+3, wasted spark)ignition_outMAXXECUMINI-C1-F2IGN 2ignition_outsingle_source
OEM-3-IClutch switchdigital_in———single_source
OEM-3-JRear O2 signallambda_nb_in———single_source
OEM-3-KFuel levelanalog_in———single_source
OEM-3-LEvap purge solenoidlow_side_out———single_source
OEM-3-MISC valve +14V feedpower_inMAXXECUMINI-C1-H4+12V (ECU power supply)power_insingle_source
OEM-3-NFuel pump relaylow_side_outMAXXECUMINI-C1-D1GPO 8/TACHOlow_side_outsingle_source
OEM-3-OISC valve low sidelow_side_out———single_source
OEM-3-QVICS solenoid (intake butterflies)low_side_out———single_source
OEM-3-SEGR boost sensoranalog_in———single_source
OEM-3-TEGR boost solenoidlow_side_out———single_source
OEM-3-UCanister drain cut valve (CDCV)low_side_out———single_source
OEM-3-VRear O2 heaterlow_side_out———single_source
OEM-3-WInjector 1injector_outMAXXECUMINI-C1-G3INJ 1injector_outsingle_source
OEM-3-XInjector 2injector_outMAXXECUMINI-C1-H1INJ 2injector_outsingle_source
OEM-3-YInjector 3injector_outMAXXECUMINI-C1-H2INJ 3injector_outsingle_source
OEM-3-ZInjector 4injector_outMAXXECUMINI-C1-H3INJ 4injector_outsingle_source

Cut list

WireFromToGauge (mm²)ColourLengthSignalIdent
W1OEM-1-BSP-14V-10.85no routeECU power +14V (main relay)—
W2OEM-3-MSP-14V-10.85no routeISC valve +14V feed—
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-3-CSP-GND-10.85no routePower ground—
W7SP-GND-1MAXXECUMINI-C1-G40.85no routeENGINE GND—
W8OEM-3-FSP-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-2-IMAXXECUMINI-C1-E20.5no route+5V sensor supply—
W14OEM-2-JMAXXECUMINI-C1-A10.5no routeCrank position (CKP)—
W15OEM-3-GMAXXECUMINI-C1-F10.5no routeIgnition 1 (coils 1+4, wasted spark)—
W16OEM-3-HMAXXECUMINI-C1-F20.5no routeIgnition 2 (coils 2+3, wasted spark)—
W17OEM-3-WMAXXECUMINI-C1-G30.5no routeInjector 1—
W18OEM-3-XMAXXECUMINI-C1-H10.5no routeInjector 2—
W19OEM-3-YMAXXECUMINI-C1-H20.5no routeInjector 3—
W20OEM-3-ZMAXXECUMINI-C1-H30.5no routeInjector 4—
W21OEM-1-IMAXXECUMINI-C1-G20.5no routeCondenser fan relay—
W22OEM-1-RMAXXECUMINI-C1-G10.5no routeCooling fan relay—
W23OEM-1-SMAXXECUMINI-C1-E10.5no routeA/C clutch relay—
W24OEM-3-NMAXXECUMINI-C1-D10.5no routeFuel pump relay—
W25OEM-2-LMAXXECUMINI-C1-C30.5no routeMass air flow (MAF)—
W26OEM-3-EMAXXECUMINI-C1-D20.5no routeThrottle position (TPS)—
W27OEM-2-CMAXXECUMINI-C1-C40.5no routeFront O2 signal—
W28OEM-2-EMAXXECUMINI-C1-C10.5no routeCoolant temperature (ECT)—
W29OEM-2-BMAXXECUMINI-C1-C20.5no routeIntake air temperature (IAT)—
W30OEM-2-DMAXXECUMINI-C1-B10.5no routeVehicle speed—
W31OEM-1-FMAXXECUMINI-C1-B20.5no routeBrake switch—

Bill of materials

CategoryPart numberManufacturerDescriptionQtyUnit

ECU setup sheet

RoleEngine refEngine signalSensorECU pointECU functionECU classSetup flag
No configured channels.

Findings

Open (6)

SeverityCodeSubjectMessage
errorREQUIRED_UNMAPPEDOEM-2-HRequired 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-3-N 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-1-S 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-1-R Cooling 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-1-I Condenser fan relay (load 0.2 A) but its current rating is unknown. Check the ECU manual.
infoUNMAPPEDOEM24 optional OEM pins are not mapped: OEM-1-E Malfunction indicator lamp (MIL); OEM-1-G Power steering pressure switch; OEM-1-O Alternator control; OEM-1-P A/C request; OEM-1-Q Charge lamp; OEM-1-U Front O2 heater; OEM-1-V Neutral switch; OEM-2-A Fuel tank pressure; OEM-2-F Knock sensor; OEM-2-K Tachometer output; OEM-2-M EGR valve; OEM-2-N EGR valve; OEM-2-O EGR valve; OEM-2-P EGR valve; OEM-3-I Clutch switch; OEM-3-J Rear O2 signal; OEM-3-K Fuel level; OEM-3-L Evap purge solenoid; OEM-3-O ISC valve low side; OEM-3-Q VICS solenoid (intake butterflies); OEM-3-S EGR boost sensor; OEM-3-T EGR boost solenoid; OEM-3-U Canister drain cut valve (CDCV); OEM-3-V Rear O2 heater

Accepted (1)

CodeSubjectReasonBy
REQUIRED_UNMAPPEDOEM-1-ABattery-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 2026-10-04. Review every wire against both manuals before building. Open items: - OEM-2 H: Cam position (CMP): no free cam_hall/cam_vr/frequency_in input on MaxxECU MaxxECU MINI Not wired: - OEM-1 A: Constant +12V: MaxxECU MaxxECU MINI has no battery-constant input; not needed - OEM-2 F: Knock sensor: no free knock input on MaxxECU MaxxECU MINI - OEM-1 U: Front O2 heater: no free heater_low_side/low_side/ls_hs/hbridge on MaxxECU MaxxECU MINI - OEM-3 V: Rear O2 heater: no free heater_low_side/low_side/ls_hs/hbridge on MaxxECU MaxxECU MINI - OEM-3 O: ISC valve low side: no free low_side/ls_hs/injector/hbridge rated ≥ 1.0 A on MaxxECU MaxxECU MINI - OEM-1 E: Malfunction indicator lamp (MIL): no free low_side/ls_hs/injector/hbridge on MaxxECU MaxxECU MINI - OEM-1 O: Alternator control: no free low_side/ls_hs/injector/hbridge on MaxxECU MaxxECU MINI - OEM-1 Q: Charge lamp: no free low_side/ls_hs/injector/hbridge on MaxxECU MaxxECU MINI - OEM-2 M: EGR valve: no free low_side/ls_hs/injector/hbridge on MaxxECU MaxxECU MINI - OEM-2 N: EGR valve: no free low_side/ls_hs/injector/hbridge on MaxxECU MaxxECU MINI - OEM-2 O: EGR valve: no free low_side/ls_hs/injector/hbridge on MaxxECU MaxxECU MINI - OEM-2 P: EGR valve: no free low_side/ls_hs/injector/hbridge on MaxxECU MaxxECU MINI - OEM-3 L: Evap purge solenoid: no free low_side/ls_hs/injector/hbridge on MaxxECU MaxxECU MINI - OEM-3 Q: VICS solenoid (intake butterflies): no free low_side/ls_hs/injector/hbridge on MaxxECU MaxxECU MINI - OEM-3 T: EGR boost solenoid: no free low_side/ls_hs/injector/hbridge on MaxxECU MaxxECU MINI - OEM-3 U: Canister drain cut valve (CDCV): no free low_side/ls_hs/injector/hbridge on MaxxECU MaxxECU MINI - OEM-2 K: Tachometer output: no free tacho/frequency_out/low_side/ls_hs on MaxxECU MaxxECU MINI - OEM-3 J: Rear O2 signal: no free o2_narrowband/analog_0_5 on MaxxECU MaxxECU MINI - OEM-2 A: Fuel tank pressure: no free analog_0_5 on MaxxECU MaxxECU MINI - OEM-3 K: Fuel level: no free analog_0_5 on MaxxECU MaxxECU MINI - OEM-3 S: EGR boost sensor: no free analog_0_5 on MaxxECU MaxxECU MINI - OEM-1 G: Power steering pressure switch: no free switch_in/frequency_in/analog_0_5 on MaxxECU MaxxECU MINI - OEM-1 P: A/C request: no free switch_in/frequency_in/analog_0_5 on MaxxECU MaxxECU MINI - OEM-1 V: Neutral switch: no free switch_in/frequency_in/analog_0_5 on MaxxECU MaxxECU MINI - OEM-3 I: Clutch switch: no free switch_in/frequency_in/analog_0_5 on MaxxECU MaxxECU MINI

Sources

ReliabilityKindTitleURL
4vendor_docLink G4X MX5NB1X install manual (NB1 1999-00)https://linkecu.com/documentation/MX5XNB1.pdf
4vendor_docMaxxECU GEN1 pinout (MINI / STREET / SPORT / V1 / RACE / PRO)http://www.maxxecu.com/webhelp/wirings-maxxecu_pinout.html