← Back

MX-5 Miata NB2 2001-05 (BP-Z3, VVT; excludes Mazdaspeed) → Link G4X XtremeX 109-4000 (auto)

MX-5 Miata NB2 2001-05 (BP-Z3, VVT; excludes Mazdaspeed) — Link — G4X XtremeX
⚠ NOT CHECKED. Don't build from this.
Drawn by Michael Gnankou · Rev 0 · draft · 2026-10-11

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

Statusdraft · not yet verified: nobody has reported building and running this harness
Open errorsnone
Size of the job55 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-1G4XXTREMEX-A-A50.85☐☐☐☐☐☐☐
W5SP-14V-1G4XXTREMEX-B-B50.85☐☐☐☐☐☐☐
W6OEM-3-ASP-GND-10.85☐☐☐☐☐☐☐
W7OEM-3-BSP-GND-10.85☐☐☐☐☐☐☐
W8OEM-4-ASP-GND-10.85☐☐☐☐☐☐☐
W9SP-GND-1G4XXTREMEX-A-A250.85☐☐☐☐☐☐☐
W10SP-GND-1G4XXTREMEX-A-A340.85☐☐☐☐☐☐☐
W11SP-GND-1G4XXTREMEX-B-B250.85☐☐☐☐☐☐☐
W12SP-GND-1G4XXTREMEX-B-B340.85☐☐☐☐☐☐☐
W13OEM-4-OSP-0V-10.5☐☐☐☐☐☐☐
W14SP-0V-1G4XXTREMEX-A-A240.5☐☐☐☐☐☐☐
W15SP-0V-1G4XXTREMEX-B-B220.5☐☐☐☐☐☐☐
W16OEM-4-LG4XXTREMEX-A-A320.5☐☐☐☐☐☐☐
W17OEM-3-YG4XXTREMEX-A-A80.5☐☐☐☐☐☐☐
W18OEM-3-VG4XXTREMEX-A-A90.5☐☐☐☐☐☐☐
W19OEM-4-MG4XXTREMEX-B-B90.5☐☐☐☐☐☐☐
W20OEM-3-FG4XXTREMEX-A-A130.5☐☐☐☐☐☐☐
W21OEM-3-IG4XXTREMEX-A-A120.5☐☐☐☐☐☐☐
W22OEM-2-AG4XXTREMEX-A-A40.5☐☐☐☐☐☐☐
W23OEM-2-DG4XXTREMEX-A-A30.5☐☐☐☐☐☐☐
W24OEM-2-GG4XXTREMEX-A-A20.5☐☐☐☐☐☐☐
W25OEM-2-JG4XXTREMEX-A-A10.5☐☐☐☐☐☐☐
W26OEM-2-BG4XXTREMEX-A-A210.5☐☐☐☐☐☐☐
W27OEM-2-CG4XXTREMEX-A-A200.5☐☐☐☐☐☐☐
W28OEM-2-KG4XXTREMEX-A-A190.5☐☐☐☐☐☐☐
W29OEM-2-MG4XXTREMEX-A-A180.5☐☐☐☐☐☐☐
W30OEM-3-HG4XXTREMEX-A-A290.5☐☐☐☐☐☐☐
W31OEM-2-OG4XXTREMEX-A-A280.5☐☐☐☐☐☐☐
W32OEM-3-JG4XXTREMEX-A-A270.5☐☐☐☐☐☐☐
W33OEM-3-PG4XXTREMEX-A-A260.5☐☐☐☐☐☐☐
W34OEM-2-QG4XXTREMEX-B-B40.5☐☐☐☐☐☐☐
W35OEM-2-EG4XXTREMEX-B-B30.5☐☐☐☐☐☐☐
W36OEM-2-FG4XXTREMEX-B-B20.5☐☐☐☐☐☐☐
W37OEM-2-HG4XXTREMEX-B-B10.5☐☐☐☐☐☐☐
W38OEM-2-IG4XXTREMEX-B-B180.5☐☐☐☐☐☐☐
W39OEM-2-NG4XXTREMEX-B-B260.5☐☐☐☐☐☐☐
W40OEM-4-XG4XXTREMEX-A-A170.5☐☐☐☐☐☐☐
W41OEM-4-AEG4XXTREMEX-A-A220.5☐☐☐☐☐☐☐
W42OEM-4-VG4XXTREMEX-A-A330.5☐☐☐☐☐☐☐
W43OEM-4-AAG4XXTREMEX-A-A140.5☐☐☐☐☐☐☐
W44OEM-4-WG4XXTREMEX-B-B330.5☐☐☐☐☐☐☐
W45OEM-4-PG4XXTREMEX-A-A150.5☐☐☐☐☐☐☐
W46OEM-4-NG4XXTREMEX-A-A160.5☐☐☐☐☐☐☐
W47OEM-4-ADG4XXTREMEX-B-B150.5☐☐☐☐☐☐☐
W48OEM-3-TG4XXTREMEX-A-A300.5☐☐☐☐☐☐☐
W49OEM-3-SG4XXTREMEX-A-A310.5☐☐☐☐☐☐☐
W50OEM-4-BG4XXTREMEX-A-A230.5☐☐☐☐☐☐☐
W51OEM-4-CG4XXTREMEX-B-B210.5☐☐☐☐☐☐☐
W52OEM-4-FG4XXTREMEX-B-B200.5☐☐☐☐☐☐☐
W53OEM-4-HG4XXTREMEX-B-B190.5☐☐☐☐☐☐☐
W54OEM-4-IG4XXTREMEX-B-B300.5☐☐☐☐☐☐☐
W55OEM-4-JG4XXTREMEX-B-B290.5☐☐☐☐☐☐☐

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
1G4XXTREMEX-A-A32G4XXTREMEX-A-A24open (OL)5 V sensor reference must not touch sensor ground
2G4XXTREMEX-A-A5G4XXTREMEX-A-A24open (OL)+12 V supply must not touch sensor ground
3G4XXTREMEX-A-A5G4XXTREMEX-A-A25open (OL)+12 V supply must not touch power ground
4G4XXTREMEX-A-A25G4XXTREMEX-A-A32open (OL)power ground must not touch 5 V sensor reference
5G4XXTREMEX-A-A5G4XXTREMEX-A-A32open (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

G4XXTREMEX-AG4XXTREMEX-BOEM-2OEM-3OEM-4SP-0VSP-14VSP-GND

Connectors

G4XXTREMEX-A

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
A1Injector 4—W25—0.5OEM-2-J———
A10Ignition 4————————
A11Ignition 3————————
A12Ignition 2—W21—0.5OEM-3-I———
A13Ignition 1—W20—0.5OEM-3-F———
A14Analog Volt 4—W43—0.5OEM-4-AA———
A15Analog Temp 1—W45—0.5OEM-4-P———
A16Analog Temp 2—W46—0.5OEM-4-N———
A17Analog Volt 1—W40—0.5OEM-4-X———
A18Aux 4—W29—0.5OEM-2-M———
A19Aux 3—W28—0.5OEM-2-K———
A2Injector 3—W24—0.5OEM-2-G———
A20Aux 2—W27—0.5OEM-2-C———
A21Aux 1—W26—0.5OEM-2-B———
A22Analog Volt 2—W41—0.5OEM-4-AE———
A23Digital Input 3—W50—0.5OEM-4-B———
A24Sensor Ground—W14—0.5SP-0V-1———
A25System Ground—W9—0.85SP-GND-1———
A26Aux 8—W33—0.5OEM-3-P———
A27Aux 7—W32—0.5OEM-3-J———
A28Aux 6—W31—0.5OEM-2-O———
A29Aux 5—W30—0.5OEM-3-H———
A3Injector 2—W23—0.5OEM-2-D———
A30Digital Input 1—W48—0.5OEM-3-T———
A31Digital Input 2—W49—0.5OEM-3-S———
A32+5V Out—W16—0.5OEM-4-L———
A33Analog Volt 3—W42—0.5OEM-4-V———
A34System Ground—W10—0.85SP-GND-1———
A4Injector 1—W22—0.5OEM-2-A———
A5+14V ECU Power—W4—0.85SP-14V-1———
A6+8V Out————————
A7Shield Ground————————
A8Trigger 1—W17—0.5OEM-3-Y———
A9Trigger 2—W18—0.5OEM-3-V———

G4XXTREMEX-B

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
B1Injector 8—W37—0.5OEM-2-H———
B10Ignition 8————————
B11Ignition 7————————
B12Ignition 6————————
B13Ignition 5————————
B15Analog Volt 6—W47—0.5OEM-4-AD———
B16Analog Volt 7————————
B17Shield Ground————————
B18Aux 9—W38—0.5OEM-2-I———
B19Digital Input 6—W53—0.5OEM-4-H———
B2Injector 7—W36—0.5OEM-2-F———
B20Digital Input 5—W52—0.5OEM-4-F———
B21Digital Input 4—W51—0.5OEM-4-C———
B22Sensor Ground—W15—0.5SP-0V-1———
B23Analog Volt 8————————
B24Analog Volt 9————————
B25System Ground—W11—0.85SP-GND-1———
B26Aux 10—W39—0.5OEM-2-N———
B27CAN 2 H————————
B28CAN 2 L————————
B29Digital Input 8—W55—0.5OEM-4-J———
B3Injector 6—W35—0.5OEM-2-E———
B30Digital Input 7—W54—0.5OEM-4-I———
B31Analog Volt 10————————
B32Analog Volt 11————————
B33Analog Volt 5—W44—0.5OEM-4-W———
B34System Ground—W12—0.85SP-GND-1———
B4Injector 5—W34—0.5OEM-2-Q———
B5Aux 9/10 E-Throttle Supply—W5—0.85SP-14V-1———
B6Analog Temp 3————————
B7Analog Temp 4————————
B8Knock 2————————
B9Knock 1—W19—0.5OEM-4-M———

OEM-2

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
AInjector 1—W22—0.5G4XXTREMEX-A-A4———
BCooling fan relay—W26—0.5G4XXTREMEX-A-A21———
CCondenser fan relay—W27—0.5G4XXTREMEX-A-A20———
DInjector 2—W23—0.5G4XXTREMEX-A-A3———
EEGR valve—W35—0.5G4XXTREMEX-B-B3———
FEGR valve—W36—0.5G4XXTREMEX-B-B2———
GInjector 3—W24—0.5G4XXTREMEX-A-A2———
HEGR valve—W37—0.5G4XXTREMEX-B-B1———
IEGR valve—W38—0.5G4XXTREMEX-B-B18———
JInjector 4—W25—0.5G4XXTREMEX-A-A1———
KA/C clutch relay—W28—0.5G4XXTREMEX-A-A19———
LNC————————
MFuel pump relay—W29—0.5G4XXTREMEX-A-A18———
NVTCS solenoid (intake butterflies)—W39—0.5G4XXTREMEX-B-B26———
OFuel pump relay (non-immobiliser)—W31—0.5G4XXTREMEX-A-A28———
PISC valve +14V feed—W1—0.85SP-14V-1———
QISC valve low side—W34—0.5G4XXTREMEX-B-B4———
RMalfunction indicator lamp (MIL)————————

OEM-3

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
APower ground—W6—0.85SP-GND-1———
BPower ground—W7—0.85SP-GND-1———
CPurge solenoid valve————————
DEGR boost solenoid————————
ENC————————
FIgnition 1 (coils 1+4, wasted spark)—W20—0.5G4XXTREMEX-A-A13———
GNC————————
HMain relay—W30—0.5G4XXTREMEX-A-A29———
IIgnition 2 (coils 2+3, wasted spark)—W21—0.5G4XXTREMEX-A-A12———
JFront O2 heater—W32—0.5G4XXTREMEX-A-A27———
KEVAP leak detection pump————————
LNC————————
MAlternator control————————
NNC————————
OTachometer output————————
PRear O2 heater—W33—0.5G4XXTREMEX-A-A26———
QData link connector (K-line)————————
RNC————————
SImmobiliser—W49—0.5G4XXTREMEX-A-A31———
TVehicle speed—W48—0.5G4XXTREMEX-A-A30———
UCharge lamp————————
VCam position (CMP)—W18—0.5G4XXTREMEX-A-A9———
WNC————————
XNC————————
YCrank position (CKP)—W17—0.5G4XXTREMEX-A-A8———
ZNC————————

OEM-4

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
APower ground—W8—0.85SP-GND-1———
AARear O2 signal—W43—0.5G4XXTREMEX-A-A14———
ABNC————————
ACTCM (automatic only)————————
ADFuel level—W47—0.5G4XXTREMEX-B-B15———
AEPressure sensor (Mazda: EGR boost sensor)—W41—0.5G4XXTREMEX-A-A22———
AFECU power +14V (main relay)—W2—0.85SP-14V-1———
AGConstant +12V————————
AHEVAP leak detection pump solenoid valve————————
BBrake switch—W50—0.5G4XXTREMEX-A-A23———
CPower steering pressure switch—W51—0.5G4XXTREMEX-B-B21———
DVVT oil-control solenoid +12V feed—W3—0.85SP-14V-1———
EDiagnostic (DLC TEN) (NA)————————
FA/C request—W52—0.5G4XXTREMEX-B-B20———
GNC————————
HNeutral switch—W53—0.5G4XXTREMEX-B-B19———
IClutch switch—W54—0.5G4XXTREMEX-B-B30———
JVTCS vacuum switch—W55—0.5G4XXTREMEX-B-B29———
KNC————————
L+5V sensor supply—W16—0.5G4XXTREMEX-A-A32———
MKnock sensor—W19—0.5G4XXTREMEX-B-B9———
NIntake air temperature (IAT)—W46—0.5G4XXTREMEX-A-A16———
OSignal ground—W13—0.5SP-0V-1———
PCoolant temperature (ECT)—W45—0.5G4XXTREMEX-A-A15———
QNC————————
RVVT oil-control solenoid (low-side control)————————
SIgnition switch (IG1) sense————————
TGenerator output voltage (terminal P)————————
UNC————————
VThrottle position (TPS)—W42—0.5G4XXTREMEX-A-A33———
WFront O2 signal—W44—0.5G4XXTREMEX-B-B33———
XMass air flow (MAF)—W40—0.5G4XXTREMEX-A-A17———
YNC————————
ZTCM (automatic only)————————

SP-0V

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W13—0.5OEM-4-O———
1——W14—0.5G4XXTREMEX-A-A24———
1——W15—0.5G4XXTREMEX-B-B22———

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—0.85G4XXTREMEX-A-A5———
1——W5—0.85G4XXTREMEX-B-B5———

SP-GND

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W6—0.85OEM-3-A———
1——W7—0.85OEM-3-B———
1——W8—0.85OEM-4-A———
1——W9—0.85G4XXTREMEX-A-A25———
1——W10—0.85G4XXTREMEX-A-A34———
1——W11—0.85G4XXTREMEX-B-B25———
1——W12—0.85G4XXTREMEX-B-B34———

Pin map

OEM pointOEM functionOEM familyTarget pointTarget functionTarget familyWire colourEvidence
OEM-2-AInjector 1injector_outG4XXTREMEX-A-A4Injector 1injector_outYBsingle_source
OEM-2-BCooling fan relaylow_side_outG4XXTREMEX-A-A21Aux 1low_side_outRYsingle_source
OEM-2-CCondenser fan relaylow_side_outG4XXTREMEX-A-A20Aux 2low_side_outLWsingle_source
OEM-2-DInjector 2injector_outG4XXTREMEX-A-A3Injector 2injector_outVGsingle_source
OEM-2-EEGR valvelow_side_outG4XXTREMEX-B-B3Injector 6injector_outLgsingle_source
OEM-2-FEGR valvelow_side_outG4XXTREMEX-B-B2Injector 7injector_outWGsingle_source
OEM-2-GInjector 3injector_outG4XXTREMEX-A-A2Injector 3injector_outYRsingle_source
OEM-2-HEGR valvelow_side_outG4XXTREMEX-B-B1Injector 8injector_outPBsingle_source
OEM-2-IEGR valvelow_side_outG4XXTREMEX-B-B18Aux 9hbridge_outPsingle_source
OEM-2-JInjector 4injector_outG4XXTREMEX-A-A1Injector 4injector_outYGsingle_source
OEM-2-KA/C clutch relaylow_side_outG4XXTREMEX-A-A19Aux 3low_side_outLBsingle_source
OEM-2-LNC————unverified
OEM-2-MFuel pump relaylow_side_outG4XXTREMEX-A-A18Aux 4low_side_outRWsingle_source
OEM-2-NVTCS solenoid (intake butterflies)low_side_outG4XXTREMEX-B-B26Aux 10hbridge_outBWsingle_source
OEM-2-OFuel pump relay (non-immobiliser)low_side_outG4XXTREMEX-A-A28Aux 6switch_outRsingle_source
OEM-2-PISC valve +14V feedpower_inG4XXTREMEX-A-A5 + G4XXTREMEX-B-B5+14V ECU Power + Aux 9/10 E-Throttle Supplypower_inOrsingle_source
OEM-2-QISC valve low sidelow_side_outG4XXTREMEX-B-B4Injector 5injector_outVRsingle_source
OEM-2-RMalfunction indicator lamp (MIL)low_side_out———WLsingle_source
OEM-3-APower groundgroundG4XXTREMEX-A-A25 + G4XXTREMEX-A-A34 + G4XXTREMEX-B-B25 + G4XXTREMEX-B-B34System Ground + System Ground + System Ground + System GroundgroundBsingle_source
OEM-3-BPower groundgroundG4XXTREMEX-A-A25 + G4XXTREMEX-A-A34 + G4XXTREMEX-B-B25 + G4XXTREMEX-B-B34System Ground + System Ground + System Ground + System 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_outG4XXTREMEX-A-A13Ignition 1ignition_outBrWsingle_source
OEM-3-GNC————unverified
OEM-3-HMain relaylow_side_outG4XXTREMEX-A-A29Aux 5switch_outLOrsingle_source
OEM-3-IIgnition 2 (coils 2+3, wasted spark)ignition_outG4XXTREMEX-A-A12Ignition 2ignition_outBYsingle_source
OEM-3-JFront O2 heaterlow_side_outG4XXTREMEX-A-A27Aux 7switch_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_outG4XXTREMEX-A-A26Aux 8switch_outWBsingle_source
OEM-3-QData link connector (K-line)serial———GWsingle_source
OEM-3-RNC————unverified
OEM-3-SImmobiliserdigital_inG4XXTREMEX-A-A31Digital Input 2digital_inRBsingle_source
OEM-3-TVehicle speeddigital_inG4XXTREMEX-A-A30Digital Input 1digital_inGRsingle_source
OEM-3-UCharge lamplow_side_out———BrRsingle_source
OEM-3-VCam position (CMP)trigger_inG4XXTREMEX-A-A9Trigger 2trigger_inGyLsingle_source
OEM-3-WNC————unverified
OEM-3-XNC————unverified
OEM-3-YCrank position (CKP)trigger_inG4XXTREMEX-A-A8Trigger 1trigger_inVWsingle_source
OEM-3-ZNC————unverified
OEM-4-APower groundgroundG4XXTREMEX-A-A25 + G4XXTREMEX-A-A34 + G4XXTREMEX-B-B25 + G4XXTREMEX-B-B34System Ground + System Ground + System Ground + System GroundgroundBLsingle_source
OEM-4-AARear O2 signallambda_nb_inG4XXTREMEX-A-A14Analog Volt 4analog_inRsingle_source
OEM-4-ABNC————unverified
OEM-4-ACTCM (automatic only)————VGsingle_source
OEM-4-ADFuel levelanalog_inG4XXTREMEX-B-B15Analog Volt 6analog_inBrBsingle_source
OEM-4-AEPressure sensor (Mazda: EGR boost sensor)analog_inG4XXTREMEX-A-A22Analog Volt 2analog_inLYcorroborated
OEM-4-AFECU power +14V (main relay)power_inG4XXTREMEX-A-A5 + G4XXTREMEX-B-B5+14V ECU Power + Aux 9/10 E-Throttle 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_inG4XXTREMEX-A-A23Digital Input 3digital_inGsingle_source
OEM-4-CPower steering pressure switchdigital_inG4XXTREMEX-B-B21Digital Input 4digital_inBrsingle_source
OEM-4-DVVT oil-control solenoid +12V feedpower_inG4XXTREMEX-A-A5 + G4XXTREMEX-B-B5+14V ECU Power + Aux 9/10 E-Throttle Supplypower_inYsingle_source
OEM-4-EDiagnostic (DLC TEN) (NA)serial———LYsingle_source
OEM-4-FA/C requestdigital_inG4XXTREMEX-B-B20Digital Input 5digital_inLgBsingle_source
OEM-4-GNC————unverified
OEM-4-HNeutral switchdigital_inG4XXTREMEX-B-B19Digital Input 6digital_inVsingle_source
OEM-4-IClutch switchdigital_inG4XXTREMEX-B-B30Digital Input 7digital_inWGsingle_source
OEM-4-JVTCS vacuum switchdigital_inG4XXTREMEX-B-B29Digital Input 8digital_inOrsingle_source
OEM-4-KNC————unverified
OEM-4-L+5V sensor supplyvrefG4XXTREMEX-A-A32+5V OutvrefLgRsingle_source
OEM-4-MKnock sensorknock_inG4XXTREMEX-B-B9Knock 1knock_inWsingle_source
OEM-4-NIntake air temperature (IAT)temp_inG4XXTREMEX-A-A16Analog Temp 2temp_inPLsingle_source
OEM-4-OSignal groundsensor_groundG4XXTREMEX-A-A24 + G4XXTREMEX-B-B22Sensor Ground + Sensor Groundsensor_groundBRsingle_source
OEM-4-PCoolant temperature (ECT)temp_inG4XXTREMEX-A-A15Analog Temp 1temp_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_inG4XXTREMEX-A-A33Analog Volt 3analog_inGBsingle_source
OEM-4-WFront O2 signallambda_nb_inG4XXTREMEX-B-B33Analog Volt 5analog_inLsingle_source
OEM-4-XMass air flow (MAF)analog_inG4XXTREMEX-A-A17Analog Volt 1analog_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-1G4XXTREMEX-A-A50.85no route+14V ECU Power—
W5SP-14V-1G4XXTREMEX-B-B50.85no routeAux 9/10 E-Throttle Supply—
W6OEM-3-ASP-GND-10.85no routePower ground—
W7OEM-3-BSP-GND-10.85no routePower ground—
W8OEM-4-ASP-GND-10.85no routePower ground—
W9SP-GND-1G4XXTREMEX-A-A250.85no routeSystem Ground—
W10SP-GND-1G4XXTREMEX-A-A340.85no routeSystem Ground—
W11SP-GND-1G4XXTREMEX-B-B250.85no routeSystem Ground—
W12SP-GND-1G4XXTREMEX-B-B340.85no routeSystem Ground—
W13OEM-4-OSP-0V-10.5no routeSignal ground—
W14SP-0V-1G4XXTREMEX-A-A240.5no routeSensor Ground—
W15SP-0V-1G4XXTREMEX-B-B220.5no routeSensor Ground—
W16OEM-4-LG4XXTREMEX-A-A320.5no route+5V sensor supply—
W17OEM-3-YG4XXTREMEX-A-A80.5no routeCrank position (CKP)—
W18OEM-3-VG4XXTREMEX-A-A90.5no routeCam position (CMP)—
W19OEM-4-MG4XXTREMEX-B-B90.5no routeKnock sensor—
W20OEM-3-FG4XXTREMEX-A-A130.5no routeIgnition 1 (coils 1+4, wasted spark)—
W21OEM-3-IG4XXTREMEX-A-A120.5no routeIgnition 2 (coils 2+3, wasted spark)—
W22OEM-2-AG4XXTREMEX-A-A40.5no routeInjector 1—
W23OEM-2-DG4XXTREMEX-A-A30.5no routeInjector 2—
W24OEM-2-GG4XXTREMEX-A-A20.5no routeInjector 3—
W25OEM-2-JG4XXTREMEX-A-A10.5no routeInjector 4—
W26OEM-2-BG4XXTREMEX-A-A210.5no routeCooling fan relay—
W27OEM-2-CG4XXTREMEX-A-A200.5no routeCondenser fan relay—
W28OEM-2-KG4XXTREMEX-A-A190.5no routeA/C clutch relay—
W29OEM-2-MG4XXTREMEX-A-A180.5no routeFuel pump relay—
W30OEM-3-HG4XXTREMEX-A-A290.5no routeMain relay—
W31OEM-2-OG4XXTREMEX-A-A280.5no routeFuel pump relay (non-immobiliser)—
W32OEM-3-JG4XXTREMEX-A-A270.5no routeFront O2 heater—
W33OEM-3-PG4XXTREMEX-A-A260.5no routeRear O2 heater—
W34OEM-2-QG4XXTREMEX-B-B40.5no routeISC valve low side—
W35OEM-2-EG4XXTREMEX-B-B30.5no routeEGR valve—
W36OEM-2-FG4XXTREMEX-B-B20.5no routeEGR valve—
W37OEM-2-HG4XXTREMEX-B-B10.5no routeEGR valve—
W38OEM-2-IG4XXTREMEX-B-B180.5no routeEGR valve—
W39OEM-2-NG4XXTREMEX-B-B260.5no routeVTCS solenoid (intake butterflies)—
W40OEM-4-XG4XXTREMEX-A-A170.5no routeMass air flow (MAF)—
W41OEM-4-AEG4XXTREMEX-A-A220.5no routePressure sensor (Mazda: EGR boost sensor)—
W42OEM-4-VG4XXTREMEX-A-A330.5no routeThrottle position (TPS)—
W43OEM-4-AAG4XXTREMEX-A-A140.5no routeRear O2 signal—
W44OEM-4-WG4XXTREMEX-B-B330.5no routeFront O2 signal—
W45OEM-4-PG4XXTREMEX-A-A150.5no routeCoolant temperature (ECT)—
W46OEM-4-NG4XXTREMEX-A-A160.5no routeIntake air temperature (IAT)—
W47OEM-4-ADG4XXTREMEX-B-B150.5no routeFuel level—
W48OEM-3-TG4XXTREMEX-A-A300.5no routeVehicle speed—
W49OEM-3-SG4XXTREMEX-A-A310.5no routeImmobiliser—
W50OEM-4-BG4XXTREMEX-A-A230.5no routeBrake switch—
W51OEM-4-CG4XXTREMEX-B-B210.5no routePower steering pressure switch—
W52OEM-4-FG4XXTREMEX-B-B200.5no routeA/C request—
W53OEM-4-HG4XXTREMEX-B-B190.5no routeNeutral switch—
W54OEM-4-IG4XXTREMEX-B-B300.5no routeClutch switch—
W55OEM-4-JG4XXTREMEX-B-B290.5no routeVTCS vacuum switch—

Bill of materials

CategoryPart numberManufacturerDescriptionQtyUnit

ECU setup sheet

RoleEngine refEngine signalSensorECU pointECU functionECU classSetup flag
No configured channels.

Findings

Open (17)

SeverityCodeSubjectMessage
warnLOAD_UNKNOWNG4XXTREMEX-A-A18G4XXTREMEX-A-A18 "Aux 4" drives OEM-2-M 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-2-K 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-2-C Condenser 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-2-B Cooling fan relay (load 0.2 A) but its current rating is unknown. Check the ECU manual.
warnLOAD_UNKNOWNG4XXTREMEX-A-A29G4XXTREMEX-A-A29 "Aux 5" drives OEM-3-H Main relay (load 0.2 A) but its current rating is unknown. Check the ECU manual.
warnLOAD_UNKNOWNG4XXTREMEX-B-B4G4XXTREMEX-B-B4 "Injector 5" drives OEM-2-Q ISC valve low side (load 1.0 A) but its current rating is unknown. Check the ECU manual.
warnNET_FAMILYOEM-2-I ↔ G4XXTREMEX-B-B18OEM-2-I "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-N ↔ G4XXTREMEX-B-B26OEM-2-N "VTCS solenoid (intake butterflies)" [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-2-E ↔ G4XXTREMEX-B-B3OEM-2-E "EGR valve" [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-2-F ↔ G4XXTREMEX-B-B2OEM-2-F "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-H ↔ G4XXTREMEX-B-B1OEM-2-H "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-2-O ↔ G4XXTREMEX-A-A28OEM-2-O "Fuel pump relay (non-immobiliser)" [low_side_out] is wired to G4XXTREMEX-A-A28 "Aux 6" [switch_out]. Configure this output as low side.
infoNET_FAMILYOEM-2-Q ↔ G4XXTREMEX-B-B4OEM-2-Q "ISC valve low side" [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-3-H ↔ G4XXTREMEX-A-A29OEM-3-H "Main relay" [low_side_out] is wired to G4XXTREMEX-A-A29 "Aux 5" [switch_out]. Configure this output as low side.
infoNET_FAMILYOEM-3-J ↔ G4XXTREMEX-A-A27OEM-3-J "Front O2 heater" [low_side_out] is wired to G4XXTREMEX-A-A27 "Aux 7" [switch_out]. Configure this output as low side.
infoNET_FAMILYOEM-3-P ↔ G4XXTREMEX-A-A26OEM-3-P "Rear O2 heater" [low_side_out] is wired to G4XXTREMEX-A-A26 "Aux 8" [switch_out]. Configure this output as low side.
infoUNMAPPEDOEM15 optional OEM pins are not mapped: 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-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

Fit check: unconfirmed. Confirm these before building: - Trigger pattern for Mazda BP-Z3 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 2026-10-11. Review every wire against both manuals before building. Not wired: - OEM-4 AG: Constant +12V: Link G4X XtremeX 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); Link G4X XtremeX has no dedicated key-on input - OEM-2 R: Malfunction indicator lamp (MIL): no free low_side/ls_hs/injector/hbridge on Link G4X XtremeX - OEM-3 C: Purge solenoid valve: no free low_side/ls_hs/injector/hbridge on Link G4X XtremeX - OEM-3 K: EVAP leak detection pump: no free low_side/ls_hs/injector/hbridge on Link G4X XtremeX - OEM-3 M: Alternator control: no free low_side/ls_hs/injector/hbridge on Link G4X XtremeX - OEM-3 U: Charge lamp: no free low_side/ls_hs/injector/hbridge on Link G4X XtremeX - OEM-4 AH: EVAP leak detection pump solenoid valve: no free low_side/ls_hs/injector/hbridge on Link G4X XtremeX - OEM-4 R: VVT oil-control solenoid (low-side control): no free low_side/ls_hs/injector/hbridge on Link G4X XtremeX - OEM-3 O: Tachometer output: no free tacho/frequency_out/low_side/ls_hs on Link G4X XtremeX - OEM-3 Q: Data link connector (K-line): no free k_line on Link G4X XtremeX - OEM-4 E: Diagnostic (DLC TEN) (NA): no free k_line on Link G4X XtremeX - 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_docLink: G4X XtremeX quickstart guidehttps://linkecu.com/documentation/XtremeXQuickstartGuide.pdf———
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
3community_copyYourSpec: Link G4X XtremeX flying-lead harness wiring listhttps://wpm.yourspec.com/projects/view/1488———
2expert_reportJustin Barrera — Miata NA/NB wiring corrections————