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MX-5 Miata NB1 1999-00 (BP-4W) → Link G4X XtremeX 109-4000 (auto)

MX-5 Miata NB1 1999-00 (BP-4W) — Link — G4X XtremeX
⚠ NOT CHECKED. Don't build from this.
Drawn by Michael Gnankou · Rev 0 · draft · 2026-10-08

Before you start

Statusdraft · not yet verified: nobody has reported building and running this harness
Open errorsnone
Size of the job53 wires · 8 connectors · 3 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-1-BSP-14V-10.85☐☐☐☐☐☐☐
W2OEM-3-MSP-14V-10.85☐☐☐☐☐☐☐
W3SP-14V-1G4XXTREMEX-A-A50.85☐☐☐☐☐☐☐
W4SP-14V-1G4XXTREMEX-B-B50.85☐☐☐☐☐☐☐
W5OEM-3-ASP-GND-10.85☐☐☐☐☐☐☐
W6OEM-3-BSP-GND-10.85☐☐☐☐☐☐☐
W7OEM-3-CSP-GND-10.85☐☐☐☐☐☐☐
W8SP-GND-1G4XXTREMEX-A-A250.85☐☐☐☐☐☐☐
W9SP-GND-1G4XXTREMEX-A-A340.85☐☐☐☐☐☐☐
W10SP-GND-1G4XXTREMEX-B-B250.85☐☐☐☐☐☐☐
W11SP-GND-1G4XXTREMEX-B-B340.85☐☐☐☐☐☐☐
W12OEM-3-FSP-0V-10.5☐☐☐☐☐☐☐
W13SP-0V-1G4XXTREMEX-A-A240.5☐☐☐☐☐☐☐
W14SP-0V-1G4XXTREMEX-B-B220.5☐☐☐☐☐☐☐
W15OEM-2-IG4XXTREMEX-A-A320.5☐☐☐☐☐☐☐
W16OEM-2-JG4XXTREMEX-A-A80.5☐☐☐☐☐☐☐
W17OEM-2-HG4XXTREMEX-A-A90.5☐☐☐☐☐☐☐
W18OEM-2-FG4XXTREMEX-B-B90.5☐☐☐☐☐☐☐
W19OEM-3-GG4XXTREMEX-A-A130.5☐☐☐☐☐☐☐
W20OEM-3-HG4XXTREMEX-A-A120.5☐☐☐☐☐☐☐
W21OEM-3-WG4XXTREMEX-A-A40.5☐☐☐☐☐☐☐
W22OEM-3-XG4XXTREMEX-A-A30.5☐☐☐☐☐☐☐
W23OEM-3-YG4XXTREMEX-A-A20.5☐☐☐☐☐☐☐
W24OEM-3-ZG4XXTREMEX-A-A10.5☐☐☐☐☐☐☐
W25OEM-1-IG4XXTREMEX-A-A210.5☐☐☐☐☐☐☐
W26OEM-1-RG4XXTREMEX-A-A200.5☐☐☐☐☐☐☐
W27OEM-1-SG4XXTREMEX-A-A190.5☐☐☐☐☐☐☐
W28OEM-3-NG4XXTREMEX-A-A180.5☐☐☐☐☐☐☐
W29OEM-1-UG4XXTREMEX-A-A290.5☐☐☐☐☐☐☐
W30OEM-3-VG4XXTREMEX-A-A280.5☐☐☐☐☐☐☐
W31OEM-3-OG4XXTREMEX-A-A270.5☐☐☐☐☐☐☐
W32OEM-1-EG4XXTREMEX-A-A260.5☐☐☐☐☐☐☐
W33OEM-1-OG4XXTREMEX-B-B40.5☐☐☐☐☐☐☐
W34OEM-1-QG4XXTREMEX-B-B30.5☐☐☐☐☐☐☐
W35OEM-2-MG4XXTREMEX-B-B20.5☐☐☐☐☐☐☐
W36OEM-2-NG4XXTREMEX-B-B10.5☐☐☐☐☐☐☐
W37OEM-2-OG4XXTREMEX-B-B180.5☐☐☐☐☐☐☐
W38OEM-2-PG4XXTREMEX-B-B260.5☐☐☐☐☐☐☐
W39OEM-2-LG4XXTREMEX-A-A170.5☐☐☐☐☐☐☐
W40OEM-3-EG4XXTREMEX-A-A220.5☐☐☐☐☐☐☐
W41OEM-2-CG4XXTREMEX-A-A330.5☐☐☐☐☐☐☐
W42OEM-3-JG4XXTREMEX-A-A140.5☐☐☐☐☐☐☐
W43OEM-2-EG4XXTREMEX-A-A150.5☐☐☐☐☐☐☐
W44OEM-2-BG4XXTREMEX-A-A160.5☐☐☐☐☐☐☐
W45OEM-2-AG4XXTREMEX-B-B330.5☐☐☐☐☐☐☐
W46OEM-3-KG4XXTREMEX-B-B150.5☐☐☐☐☐☐☐
W47OEM-3-SG4XXTREMEX-B-B160.5☐☐☐☐☐☐☐
W48OEM-2-DG4XXTREMEX-A-A300.5☐☐☐☐☐☐☐
W49OEM-1-FG4XXTREMEX-A-A310.5☐☐☐☐☐☐☐
W50OEM-1-GG4XXTREMEX-A-A230.5☐☐☐☐☐☐☐
W51OEM-1-PG4XXTREMEX-B-B210.5☐☐☐☐☐☐☐
W52OEM-1-VG4XXTREMEX-B-B200.5☐☐☐☐☐☐☐
W53OEM-3-IG4XXTREMEX-B-B190.5☐☐☐☐☐☐☐

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
1G4XXTREMEX-A-A32G4XXTREMEX-A-A24open (OL)5 V sensor reference must not touch sensor ground
2G4XXTREMEX-A-A32G4XXTREMEX-A-A25open (OL)5 V sensor reference must not touch power ground
3G4XXTREMEX-A-A5G4XXTREMEX-A-A24open (OL)+12 V supply must not touch sensor ground
4G4XXTREMEX-A-A5G4XXTREMEX-A-A25open (OL)+12 V supply must not touch power ground
5G4XXTREMEX-A-A5G4XXTREMEX-A-A32open (OL)+12 V supply must not touch 5 V sensor reference

Revisions

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No revisions yet.

Schematic

G4XXTREMEX-AG4XXTREMEX-BOEM-1OEM-2OEM-3SP-0VSP-14VSP-GND

Connectors

G4XXTREMEX-A

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
A1Injector 4—W24—0.5OEM-3-Z———
A10Ignition 4————————
A11Ignition 3————————
A12Ignition 2—W20—0.5OEM-3-H———
A13Ignition 1—W19—0.5OEM-3-G———
A14Analog Volt 4—W42—0.5OEM-3-J———
A15Analog Temp 1—W43—0.5OEM-2-E———
A16Analog Temp 2—W44—0.5OEM-2-B———
A17Analog Volt 1—W39—0.5OEM-2-L———
A18Aux 4—W28—0.5OEM-3-N———
A19Aux 3—W27—0.5OEM-1-S———
A2Injector 3—W23—0.5OEM-3-Y———
A20Aux 2—W26—0.5OEM-1-R———
A21Aux 1—W25—0.5OEM-1-I———
A22Analog Volt 2—W40—0.5OEM-3-E———
A23Digital Input 3—W50—0.5OEM-1-G———
A24Sensor Ground—W13—0.5SP-0V-1———
A25System Ground—W8—0.85SP-GND-1———
A26Aux 8—W32—0.5OEM-1-E———
A27Aux 7—W31—0.5OEM-3-O———
A28Aux 6—W30—0.5OEM-3-V———
A29Aux 5—W29—0.5OEM-1-U———
A3Injector 2—W22—0.5OEM-3-X———
A30Digital Input 1—W48—0.5OEM-2-D———
A31Digital Input 2—W49—0.5OEM-1-F———
A32+5V Out—W15—0.5OEM-2-I———
A33Analog Volt 3—W41—0.5OEM-2-C———
A34System Ground—W9—0.85SP-GND-1———
A4Injector 1—W21—0.5OEM-3-W———
A5+14V ECU Power—W3—0.85SP-14V-1———
A6+8V Out————————
A7Shield Ground————————
A8Trigger 1—W16—0.5OEM-2-J———
A9Trigger 2—W17—0.5OEM-2-H———

G4XXTREMEX-B

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
B1Injector 8—W36—0.5OEM-2-N———
B10Ignition 8————————
B11Ignition 7————————
B12Ignition 6————————
B13Ignition 5————————
B15Analog Volt 6—W46—0.5OEM-3-K———
B16Analog Volt 7—W47—0.5OEM-3-S———
B17Shield Ground————————
B18Aux 9—W37—0.5OEM-2-O———
B19Digital Input 6—W53—0.5OEM-3-I———
B2Injector 7—W35—0.5OEM-2-M———
B20Digital Input 5—W52—0.5OEM-1-V———
B21Digital Input 4—W51—0.5OEM-1-P———
B22Sensor Ground—W14—0.5SP-0V-1———
B23Analog Volt 8————————
B24Analog Volt 9————————
B25System Ground—W10—0.85SP-GND-1———
B26Aux 10—W38—0.5OEM-2-P———
B27CAN 2 H————————
B28CAN 2 L————————
B29Digital Input 8————————
B3Injector 6—W34—0.5OEM-1-Q———
B30Digital Input 7————————
B31Analog Volt 10————————
B32Analog Volt 11————————
B33Analog Volt 5—W45—0.5OEM-2-A———
B34System Ground—W11—0.85SP-GND-1———
B4Injector 5—W33—0.5OEM-1-O———
B5Aux 9/10 E-Throttle Supply—W4—0.85SP-14V-1———
B6Analog Temp 3————————
B7Analog Temp 4————————
B8Knock 2————————
B9Knock 1—W18—0.5OEM-2-F———

OEM-1

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
AConstant +12V————————
BECU power +14V (main relay)—W1—0.85SP-14V-1———
EMalfunction indicator lamp (MIL)—W32—0.5G4XXTREMEX-A-A26———
FBrake switch—W49—0.5G4XXTREMEX-A-A31———
GPower steering pressure switch—W50—0.5G4XXTREMEX-A-A23———
ICondenser fan relay—W25—0.5G4XXTREMEX-A-A21———
OAlternator control—W33—0.5G4XXTREMEX-B-B4———
PA/C request—W51—0.5G4XXTREMEX-B-B21———
QCharge lamp—W34—0.5G4XXTREMEX-B-B3———
RCooling fan relay—W26—0.5G4XXTREMEX-A-A20———
SA/C clutch relay—W27—0.5G4XXTREMEX-A-A19———
UFront O2 heater—W29—0.5G4XXTREMEX-A-A29———
VNeutral switch—W52—0.5G4XXTREMEX-B-B20———

OEM-2

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
AFuel tank pressure—W45—0.5G4XXTREMEX-B-B33———
BIntake air temperature (IAT)—W44—0.5G4XXTREMEX-A-A16———
CFront O2 signal—W41—0.5G4XXTREMEX-A-A33———
DVehicle speed—W48—0.5G4XXTREMEX-A-A30———
ECoolant temperature (ECT)—W43—0.5G4XXTREMEX-A-A15———
FKnock sensor—W18—0.5G4XXTREMEX-B-B9———
HCam position (CMP)—W17—0.5G4XXTREMEX-A-A9———
I+5V sensor supply—W15—0.5G4XXTREMEX-A-A32———
JCrank position (CKP)—W16—0.5G4XXTREMEX-A-A8———
KTachometer output————————
LMass air flow (MAF)—W39—0.5G4XXTREMEX-A-A17———
MEGR valve—W35—0.5G4XXTREMEX-B-B2———
NEGR valve—W36—0.5G4XXTREMEX-B-B1———
OEGR valve—W37—0.5G4XXTREMEX-B-B18———
PEGR valve—W38—0.5G4XXTREMEX-B-B26———

OEM-3

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
APower ground—W5—0.85SP-GND-1———
BPower ground—W6—0.85SP-GND-1———
CPower ground—W7—0.85SP-GND-1———
EThrottle position (TPS)—W40—0.5G4XXTREMEX-A-A22———
FSignal ground—W12—0.5SP-0V-1———
GIgnition 1 (coils 1+4, wasted spark)—W19—0.5G4XXTREMEX-A-A13———
HIgnition 2 (coils 2+3, wasted spark)—W20—0.5G4XXTREMEX-A-A12———
IClutch switch—W53—0.5G4XXTREMEX-B-B19———
JRear O2 signal—W42—0.5G4XXTREMEX-A-A14———
KFuel level—W46—0.5G4XXTREMEX-B-B15———
LEvap purge solenoid————————
MISC valve +14V feed—W2—0.85SP-14V-1———
NFuel pump relay—W28—0.5G4XXTREMEX-A-A18———
OISC valve low side—W31—0.5G4XXTREMEX-A-A27———
QVICS solenoid (intake butterflies)————————
SEGR boost sensor—W47—0.5G4XXTREMEX-B-B16———
TEGR boost solenoid————————
UCanister drain cut valve (CDCV)————————
VRear O2 heater—W30—0.5G4XXTREMEX-A-A28———
WInjector 1—W21—0.5G4XXTREMEX-A-A4———
XInjector 2—W22—0.5G4XXTREMEX-A-A3———
YInjector 3—W23—0.5G4XXTREMEX-A-A2———
ZInjector 4—W24—0.5G4XXTREMEX-A-A1———

SP-0V

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W12—0.5OEM-3-F———
1——W13—0.5G4XXTREMEX-A-A24———
1——W14—0.5G4XXTREMEX-B-B22———

SP-14V

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W1—0.85OEM-1-B———
1——W2—0.85OEM-3-M———
1——W3—0.85G4XXTREMEX-A-A5———
1——W4—0.85G4XXTREMEX-B-B5———

SP-GND

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W5—0.85OEM-3-A———
1——W6—0.85OEM-3-B———
1——W7—0.85OEM-3-C———
1——W8—0.85G4XXTREMEX-A-A25———
1——W9—0.85G4XXTREMEX-A-A34———
1——W10—0.85G4XXTREMEX-B-B25———
1——W11—0.85G4XXTREMEX-B-B34———

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_inG4XXTREMEX-A-A5 + G4XXTREMEX-B-B5+14V ECU Power + Aux 9/10 E-Throttle Supplypower_insingle_source
OEM-1-EMalfunction indicator lamp (MIL)low_side_outG4XXTREMEX-A-A26Aux 8switch_outsingle_source
OEM-1-FBrake switchdigital_inG4XXTREMEX-A-A31Digital Input 2digital_insingle_source
OEM-1-GPower steering pressure switchdigital_inG4XXTREMEX-A-A23Digital Input 3digital_insingle_source
OEM-1-ICondenser fan relaylow_side_outG4XXTREMEX-A-A21Aux 1low_side_outsingle_source
OEM-1-OAlternator controllow_side_outG4XXTREMEX-B-B4Injector 5injector_outsingle_source
OEM-1-PA/C requestdigital_inG4XXTREMEX-B-B21Digital Input 4digital_insingle_source
OEM-1-QCharge lamplow_side_outG4XXTREMEX-B-B3Injector 6injector_outsingle_source
OEM-1-RCooling fan relaylow_side_outG4XXTREMEX-A-A20Aux 2low_side_outsingle_source
OEM-1-SA/C clutch relaylow_side_outG4XXTREMEX-A-A19Aux 3low_side_outsingle_source
OEM-1-UFront O2 heaterlow_side_outG4XXTREMEX-A-A29Aux 5switch_outsingle_source
OEM-1-VNeutral switchdigital_inG4XXTREMEX-B-B20Digital Input 5digital_insingle_source
OEM-2-AFuel tank pressureanalog_inG4XXTREMEX-B-B33Analog Volt 5analog_insingle_source
OEM-2-BIntake air temperature (IAT)temp_inG4XXTREMEX-A-A16Analog Temp 2temp_insingle_source
OEM-2-CFront O2 signallambda_nb_inG4XXTREMEX-A-A33Analog Volt 3analog_insingle_source
OEM-2-DVehicle speeddigital_inG4XXTREMEX-A-A30Digital Input 1digital_insingle_source
OEM-2-ECoolant temperature (ECT)temp_inG4XXTREMEX-A-A15Analog Temp 1temp_insingle_source
OEM-2-FKnock sensorknock_inG4XXTREMEX-B-B9Knock 1knock_insingle_source
OEM-2-HCam position (CMP)trigger_inG4XXTREMEX-A-A9Trigger 2trigger_insingle_source
OEM-2-I+5V sensor supplyvrefG4XXTREMEX-A-A32+5V Outvrefsingle_source
OEM-2-JCrank position (CKP)trigger_inG4XXTREMEX-A-A8Trigger 1trigger_insingle_source
OEM-2-KTachometer outputtacho_out———single_source
OEM-2-LMass air flow (MAF)analog_inG4XXTREMEX-A-A17Analog Volt 1analog_insingle_source
OEM-2-MEGR valvelow_side_outG4XXTREMEX-B-B2Injector 7injector_outsingle_source
OEM-2-NEGR valvelow_side_outG4XXTREMEX-B-B1Injector 8injector_outsingle_source
OEM-2-OEGR valvelow_side_outG4XXTREMEX-B-B18Aux 9hbridge_outsingle_source
OEM-2-PEGR valvelow_side_outG4XXTREMEX-B-B26Aux 10hbridge_outsingle_source
OEM-3-APower groundgroundG4XXTREMEX-A-A25 + G4XXTREMEX-A-A34 + G4XXTREMEX-B-B25 + G4XXTREMEX-B-B34System Ground + System Ground + System Ground + System Groundgroundsingle_source
OEM-3-BPower groundgroundG4XXTREMEX-A-A25 + G4XXTREMEX-A-A34 + G4XXTREMEX-B-B25 + G4XXTREMEX-B-B34System Ground + System Ground + System Ground + System Groundgroundsingle_source
OEM-3-CPower groundgroundG4XXTREMEX-A-A25 + G4XXTREMEX-A-A34 + G4XXTREMEX-B-B25 + G4XXTREMEX-B-B34System Ground + System Ground + System Ground + System Groundgroundsingle_source
OEM-3-EThrottle position (TPS)analog_inG4XXTREMEX-A-A22Analog Volt 2analog_insingle_source
OEM-3-FSignal groundsensor_groundG4XXTREMEX-A-A24 + G4XXTREMEX-B-B22Sensor Ground + Sensor Groundsensor_groundsingle_source
OEM-3-GIgnition 1 (coils 1+4, wasted spark)ignition_outG4XXTREMEX-A-A13Ignition 1ignition_outsingle_source
OEM-3-HIgnition 2 (coils 2+3, wasted spark)ignition_outG4XXTREMEX-A-A12Ignition 2ignition_outsingle_source
OEM-3-IClutch switchdigital_inG4XXTREMEX-B-B19Digital Input 6digital_insingle_source
OEM-3-JRear O2 signallambda_nb_inG4XXTREMEX-A-A14Analog Volt 4analog_insingle_source
OEM-3-KFuel levelanalog_inG4XXTREMEX-B-B15Analog Volt 6analog_insingle_source
OEM-3-LEvap purge solenoidlow_side_out———single_source
OEM-3-MISC valve +14V feedpower_inG4XXTREMEX-A-A5 + G4XXTREMEX-B-B5+14V ECU Power + Aux 9/10 E-Throttle Supplypower_insingle_source
OEM-3-NFuel pump relaylow_side_outG4XXTREMEX-A-A18Aux 4low_side_outsingle_source
OEM-3-OISC valve low sidelow_side_outG4XXTREMEX-A-A27Aux 7switch_outsingle_source
OEM-3-QVICS solenoid (intake butterflies)low_side_out———single_source
OEM-3-SEGR boost sensoranalog_inG4XXTREMEX-B-B16Analog Volt 7analog_insingle_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_outG4XXTREMEX-A-A28Aux 6switch_outsingle_source
OEM-3-WInjector 1injector_outG4XXTREMEX-A-A4Injector 1injector_outsingle_source
OEM-3-XInjector 2injector_outG4XXTREMEX-A-A3Injector 2injector_outsingle_source
OEM-3-YInjector 3injector_outG4XXTREMEX-A-A2Injector 3injector_outsingle_source
OEM-3-ZInjector 4injector_outG4XXTREMEX-A-A1Injector 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-1G4XXTREMEX-A-A50.85no route+14V ECU Power—
W4SP-14V-1G4XXTREMEX-B-B50.85no routeAux 9/10 E-Throttle Supply—
W5OEM-3-ASP-GND-10.85no routePower ground—
W6OEM-3-BSP-GND-10.85no routePower ground—
W7OEM-3-CSP-GND-10.85no routePower ground—
W8SP-GND-1G4XXTREMEX-A-A250.85no routeSystem Ground—
W9SP-GND-1G4XXTREMEX-A-A340.85no routeSystem Ground—
W10SP-GND-1G4XXTREMEX-B-B250.85no routeSystem Ground—
W11SP-GND-1G4XXTREMEX-B-B340.85no routeSystem Ground—
W12OEM-3-FSP-0V-10.5no routeSignal ground—
W13SP-0V-1G4XXTREMEX-A-A240.5no routeSensor Ground—
W14SP-0V-1G4XXTREMEX-B-B220.5no routeSensor Ground—
W15OEM-2-IG4XXTREMEX-A-A320.5no route+5V sensor supply—
W16OEM-2-JG4XXTREMEX-A-A80.5no routeCrank position (CKP)—
W17OEM-2-HG4XXTREMEX-A-A90.5no routeCam position (CMP)—
W18OEM-2-FG4XXTREMEX-B-B90.5no routeKnock sensor—
W19OEM-3-GG4XXTREMEX-A-A130.5no routeIgnition 1 (coils 1+4, wasted spark)—
W20OEM-3-HG4XXTREMEX-A-A120.5no routeIgnition 2 (coils 2+3, wasted spark)—
W21OEM-3-WG4XXTREMEX-A-A40.5no routeInjector 1—
W22OEM-3-XG4XXTREMEX-A-A30.5no routeInjector 2—
W23OEM-3-YG4XXTREMEX-A-A20.5no routeInjector 3—
W24OEM-3-ZG4XXTREMEX-A-A10.5no routeInjector 4—
W25OEM-1-IG4XXTREMEX-A-A210.5no routeCondenser fan relay—
W26OEM-1-RG4XXTREMEX-A-A200.5no routeCooling fan relay—
W27OEM-1-SG4XXTREMEX-A-A190.5no routeA/C clutch relay—
W28OEM-3-NG4XXTREMEX-A-A180.5no routeFuel pump relay—
W29OEM-1-UG4XXTREMEX-A-A290.5no routeFront O2 heater—
W30OEM-3-VG4XXTREMEX-A-A280.5no routeRear O2 heater—
W31OEM-3-OG4XXTREMEX-A-A270.5no routeISC valve low side—
W32OEM-1-EG4XXTREMEX-A-A260.5no routeMalfunction indicator lamp (MIL)—
W33OEM-1-OG4XXTREMEX-B-B40.5no routeAlternator control—
W34OEM-1-QG4XXTREMEX-B-B30.5no routeCharge lamp—
W35OEM-2-MG4XXTREMEX-B-B20.5no routeEGR valve—
W36OEM-2-NG4XXTREMEX-B-B10.5no routeEGR valve—
W37OEM-2-OG4XXTREMEX-B-B180.5no routeEGR valve—
W38OEM-2-PG4XXTREMEX-B-B260.5no routeEGR valve—
W39OEM-2-LG4XXTREMEX-A-A170.5no routeMass air flow (MAF)—
W40OEM-3-EG4XXTREMEX-A-A220.5no routeThrottle position (TPS)—
W41OEM-2-CG4XXTREMEX-A-A330.5no routeFront O2 signal—
W42OEM-3-JG4XXTREMEX-A-A140.5no routeRear O2 signal—
W43OEM-2-EG4XXTREMEX-A-A150.5no routeCoolant temperature (ECT)—
W44OEM-2-BG4XXTREMEX-A-A160.5no routeIntake air temperature (IAT)—
W45OEM-2-AG4XXTREMEX-B-B330.5no routeFuel tank pressure—
W46OEM-3-KG4XXTREMEX-B-B150.5no routeFuel level—
W47OEM-3-SG4XXTREMEX-B-B160.5no routeEGR boost sensor—
W48OEM-2-DG4XXTREMEX-A-A300.5no routeVehicle speed—
W49OEM-1-FG4XXTREMEX-A-A310.5no routeBrake switch—
W50OEM-1-GG4XXTREMEX-A-A230.5no routePower steering pressure switch—
W51OEM-1-PG4XXTREMEX-B-B210.5no routeA/C request—
W52OEM-1-VG4XXTREMEX-B-B200.5no routeNeutral switch—
W53OEM-3-IG4XXTREMEX-B-B190.5no routeClutch switch—

Bill of materials

CategoryPart numberManufacturerDescriptionQtyUnit
connector174514-6TEAMP Multilock .040/.070 hybrid 16-pin female harness plug (Miata NB1 ECU)1.000ea
connector174515-6TEAMP Multilock .040/.070 hybrid 22-pin female harness plug (Miata NA/NB ECU)1.000ea
connector174516-6TEAMP Multilock .040/.070 hybrid 26-pin female harness plug (Miata NA/NB ECU)1.000ea

ECU setup sheet

RoleEngine refEngine signalSensorECU pointECU functionECU classSetup flag
No configured channels.

Findings

Open (16)

SeverityCodeSubjectMessage
warnLOAD_UNKNOWNG4XXTREMEX-A-A18G4XXTREMEX-A-A18 "Aux 4" drives OEM-3-N Fuel pump relay (load 0.2 A) but its current rating is unknown. Check the ECU manual.
warnLOAD_UNKNOWNG4XXTREMEX-A-A19G4XXTREMEX-A-A19 "Aux 3" drives OEM-1-S A/C clutch relay (load 0.2 A) but its current rating is unknown. Check the ECU manual.
warnLOAD_UNKNOWNG4XXTREMEX-A-A20G4XXTREMEX-A-A20 "Aux 2" drives OEM-1-R Cooling fan relay (load 0.2 A) but its current rating is unknown. Check the ECU manual.
warnLOAD_UNKNOWNG4XXTREMEX-A-A21G4XXTREMEX-A-A21 "Aux 1" drives OEM-1-I Condenser fan relay (load 0.2 A) but its current rating is unknown. Check the ECU manual.
warnLOAD_UNKNOWNG4XXTREMEX-A-A27G4XXTREMEX-A-A27 "Aux 7" drives OEM-3-O ISC valve low side (load 1.0 A) but its current rating is unknown. Check the ECU manual.
warnNET_FAMILYOEM-2-O ↔ G4XXTREMEX-B-B18OEM-2-O "EGR valve" [low_side_out] is wired to G4XXTREMEX-B-B18 "Aux 9" [hbridge_out]. A half-bridge can act as a low-side switch only if configured that way.
warnNET_FAMILYOEM-2-P ↔ G4XXTREMEX-B-B26OEM-2-P "EGR valve" [low_side_out] is wired to G4XXTREMEX-B-B26 "Aux 10" [hbridge_out]. A half-bridge can act as a low-side switch only if configured that way.
infoNET_FAMILYOEM-1-E ↔ G4XXTREMEX-A-A26OEM-1-E "Malfunction indicator lamp (MIL)" [low_side_out] is wired to G4XXTREMEX-A-A26 "Aux 8" [switch_out]. Configure this output as low side.
infoNET_FAMILYOEM-1-O ↔ G4XXTREMEX-B-B4OEM-1-O "Alternator control" [low_side_out] is wired to G4XXTREMEX-B-B4 "Injector 5" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency.
infoNET_FAMILYOEM-1-Q ↔ G4XXTREMEX-B-B3OEM-1-Q "Charge lamp" [low_side_out] is wired to G4XXTREMEX-B-B3 "Injector 6" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency.
infoNET_FAMILYOEM-1-U ↔ G4XXTREMEX-A-A29OEM-1-U "Front O2 heater" [low_side_out] is wired to G4XXTREMEX-A-A29 "Aux 5" [switch_out]. Configure this output as low side.
infoNET_FAMILYOEM-2-M ↔ G4XXTREMEX-B-B2OEM-2-M "EGR valve" [low_side_out] is wired to G4XXTREMEX-B-B2 "Injector 7" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency.
infoNET_FAMILYOEM-2-N ↔ G4XXTREMEX-B-B1OEM-2-N "EGR valve" [low_side_out] is wired to G4XXTREMEX-B-B1 "Injector 8" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency.
infoNET_FAMILYOEM-3-O ↔ G4XXTREMEX-A-A27OEM-3-O "ISC valve low side" [low_side_out] is wired to G4XXTREMEX-A-A27 "Aux 7" [switch_out]. Configure this output as low side.
infoNET_FAMILYOEM-3-V ↔ G4XXTREMEX-A-A28OEM-3-V "Rear O2 heater" [low_side_out] is wired to G4XXTREMEX-A-A28 "Aux 6" [switch_out]. Configure this output as low side.
infoUNMAPPEDOEM5 optional OEM pins are not mapped: OEM-2-K Tachometer output; OEM-3-L Evap purge solenoid; OEM-3-Q VICS solenoid (intake butterflies); OEM-3-T EGR boost solenoid; OEM-3-U Canister drain cut valve (CDCV)

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

Fit check: unconfirmed. Confirm these before building: - Trigger pattern for Mazda BP-4W not found in the ECU's docs (Link's trigger-mode list is only inside PCLink, not online) Auto-mapped by auto_map() from the library pin data on 2026-10-06. Review every wire against both manuals before building. Not wired: - OEM-1 A: Constant +12V: Link G4X XtremeX has no battery-constant input; not needed - OEM-3 L: Evap purge solenoid: no free low_side/ls_hs/injector/hbridge on Link G4X XtremeX - OEM-3 Q: VICS solenoid (intake butterflies): no free low_side/ls_hs/injector/hbridge on Link G4X XtremeX - OEM-3 T: EGR boost solenoid: no free low_side/ls_hs/injector/hbridge on Link G4X XtremeX - OEM-3 U: Canister drain cut valve (CDCV): no free low_side/ls_hs/injector/hbridge on Link G4X XtremeX - OEM-2 K: Tachometer output: no free tacho/frequency_out/low_side/ls_hs on Link G4X XtremeX

Sources

ReliabilityKindTitleURLArchiveCapturedSHA-256
4vendor_docLink G4X MX5NB1X install manual (NB1 1999-00)https://linkecu.com/documentation/MX5XNB1.pdfarchive2026-10-052e36c91270cc
4vendor_docLink: G4X XtremeX quickstart guidehttps://linkecu.com/documentation/XtremeXQuickstartGuide.pdf———
3community_copyYourSpec: Link G4X XtremeX flying-lead harness wiring listhttps://wpm.yourspec.com/projects/view/1488———