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VW Golf/Jetta Mk2 1.8 8v Digifant II → Link G4X StormX 108-4000 (auto)

VW Golf/Jetta Mk2 1.8 8v Digifant II — Link — G4X StormX
⚠ 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 job29 wires · 7 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-A-14SP-14V-10.85☐☐☐☐☐☐☐
W2SP-14V-1G4XSTORMX-A-A50.85☐☐☐☐☐☐☐
W3OEM-A-13SP-GND-10.85☐☐☐☐☐☐☐
W4OEM-A-19SP-GND-10.85☐☐☐☐☐☐☐
W5SP-GND-1G4XSTORMX-A-A250.85☐☐☐☐☐☐☐
W6SP-GND-1G4XSTORMX-A-A340.85☐☐☐☐☐☐☐
W7SP-GND-1G4XSTORMX-B-B250.85☐☐☐☐☐☐☐
W8SP-GND-1G4XSTORMX-B-B340.85☐☐☐☐☐☐☐
W9OEM-A-5SP-0V-10.5☐☐☐☐☐☐☐
W10OEM-A-6SP-0V-10.5☐☐☐☐☐☐☐
W11SP-0V-1G4XSTORMX-A-A240.5☐☐☐☐☐☐☐
W12SP-0V-1G4XSTORMX-B-B220.5☐☐☐☐☐☐☐
W13OEM-A-17G4XSTORMX-A-A320.5☐☐☐☐☐☐☐
W14OEM-A-18G4XSTORMX-A-A90.5☐☐☐☐☐☐☐
W15OEM-A-4G4XSTORMX-B-B90.5☐☐☐☐☐☐☐
W16OEM-A-25G4XSTORMX-A-A130.5☐☐☐☐☐☐☐
W17OEM-A-12G4XSTORMX-A-A40.5☐☐☐☐☐☐☐
W18OEM-A-7SP-SHD-10.5☐☐☐☐☐☐☐
W19SP-SHD-1G4XSTORMX-A-A70.5☐☐☐☐☐☐☐
W20OEM-A-3G4XSTORMX-A-A210.5☐☐☐☐☐☐☐
W21OEM-A-21G4XSTORMX-A-A170.5☐☐☐☐☐☐☐
W22OEM-A-10G4XSTORMX-A-A150.5☐☐☐☐☐☐☐
W23OEM-A-22G4XSTORMX-A-A200.5☐☐☐☐☐☐☐
W24OEM-A-23G4XSTORMX-A-A190.5☐☐☐☐☐☐☐
W25OEM-A-2G4XSTORMX-A-A220.5☐☐☐☐☐☐☐
W26OEM-A-9G4XSTORMX-A-A160.5☐☐☐☐☐☐☐
W27OEM-A-1G4XSTORMX-A-A300.5☐☐☐☐☐☐☐
W28OEM-A-11G4XSTORMX-A-A310.5☐☐☐☐☐☐☐
W29OEM-A-16G4XSTORMX-A-A230.5☐☐☐☐☐☐☐

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
1G4XSTORMX-A-A32G4XSTORMX-A-A24open (OL)5 V sensor reference must not touch sensor ground
2G4XSTORMX-A-A5G4XSTORMX-A-A24open (OL)+12 V supply must not touch sensor ground
3G4XSTORMX-A-A25G4XSTORMX-A-A32open (OL)power ground must not touch 5 V sensor reference
4G4XSTORMX-A-A25G4XSTORMX-A-A5open (OL)power ground must not touch +12 V supply
5G4XSTORMX-A-A5G4XSTORMX-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

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Schematic

G4XSTORMX-AG4XSTORMX-BOEM-ASP-0VSP-14VSP-GNDSP-SHD

Connectors

G4XSTORMX-A

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
A1Injector 4————————
A10Ignition 4————————
A11Ignition 3————————
A12Ignition 2————————
A13Ignition 1—W16—0.5OEM-A-25———
A14Analog Volt 4————————
A15Analog Temp 1—W22—0.5OEM-A-10———
A16Analog Temp 2—W26—0.5OEM-A-9———
A17Analog Volt 1—W21—0.5OEM-A-21———
A18Aux 4————————
A19Aux 3—W24—0.5OEM-A-23———
A2Injector 3————————
A20Aux 2—W23—0.5OEM-A-22———
A21Aux 1—W20—0.5OEM-A-3———
A22Analog Volt 2—W25—0.5OEM-A-2———
A23Digital Input 3—W29—0.5OEM-A-16———
A24Sensor Ground—W11—0.5SP-0V-1———
A25System Ground—W5—0.85SP-GND-1———
A26Aux 8————————
A27Aux 7————————
A28Aux 6————————
A29Aux 5————————
A3Injector 2————————
A30Digital Input 1—W27—0.5OEM-A-1———
A31Digital Input 2—W28—0.5OEM-A-11———
A32+5V Out—W13—0.5OEM-A-17———
A33Analog Volt 3————————
A34System Ground—W6—0.85SP-GND-1———
A4Injector 1—W17—0.5OEM-A-12———
A5+14V ECU Power—W2—0.85SP-14V-1———
A6+8V Out————————
A7Shield Ground—W19—0.5SP-SHD-1———
A8Trigger 1————————
A9Trigger 2—W14—0.5OEM-A-18———

G4XSTORMX-B

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
B1Injector 8————————
B10Ignition 8————————
B11Ignition 7————————
B12Ignition 6————————
B13Ignition 5————————
B15Analog Volt 6————————
B16Analog Volt 7————————
B17Shield Ground————————
B19Digital Input 6————————
B2Injector 7————————
B20Digital Input 5————————
B21Digital Input 4————————
B22Sensor Ground—W12—0.5SP-0V-1———
B23Analog Volt 8————————
B25System Ground—W7—0.85SP-GND-1———
B27CAN 2 H————————
B28CAN 2 L————————
B29Digital Input 8————————
B3Injector 6————————
B30Digital Input 7————————
B33Analog Volt 5————————
B34System Ground—W8—0.85SP-GND-1———
B4Injector 5————————
B6Analog Temp 3————————
B8Knock 2————————
B9Knock 1—W15—0.5OEM-A-4———

OEM-A

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1Starter signal (term 50)—W27—0.5G4XSTORMX-A-A30———
10Coolant temperature sensor—W22—0.5G4XSTORMX-A-A15———
11Idle/WOT throttle switch—W28—0.5G4XSTORMX-A-A31———
12Injector driver (batch, all 4)—W17—0.5G4XSTORMX-A-A4———
13Ground—W3—0.85SP-GND-1———
14ECU power (control-unit relay)—W1—0.85SP-14V-1———
16A/C compressor signal—W29—0.5G4XSTORMX-A-A23———
17AFM potentiometer supply—W13—0.5G4XSTORMX-A-A32———
18Hall sender signal (engine speed)—W14—0.5G4XSTORMX-A-A9———
19Ground—W4—0.85SP-GND-1———
2Oxygen (lambda) sensor signal—W25—0.5G4XSTORMX-A-A22———
21AFM signal—W21—0.5G4XSTORMX-A-A17———
22Idle stabilizer valve coil 1—W23—0.5G4XSTORMX-A-A20———
23Idle stabilizer valve coil 2—W24—0.5G4XSTORMX-A-A19———
25Ignition timing signal to TCI—W16—0.5G4XSTORMX-A-A13———
3Fuel pump relay control—W20—0.5G4XSTORMX-A-A21———
4Knock sensor signal—W15—0.5G4XSTORMX-B-B9———
5Knock sensor return—W9—0.5SP-0V-1———
6Sensor ground (CTS/Hall/AFM/throttle)—W10—0.5SP-0V-1———
7Knock sensor shield—W18—0.5SP-SHD-1———
8Hall sender supply (distributor)————————
9Intake air temperature sensor—W26—0.5G4XSTORMX-A-A16———

SP-0V

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W9—0.5OEM-A-5———
1——W10—0.5OEM-A-6———
1——W11—0.5G4XSTORMX-A-A24———
1——W12—0.5G4XSTORMX-B-B22———

SP-14V

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W1—0.85OEM-A-14———
1——W2—0.85G4XSTORMX-A-A5———

SP-GND

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W3—0.85OEM-A-13———
1——W4—0.85OEM-A-19———
1——W5—0.85G4XSTORMX-A-A25———
1——W6—0.85G4XSTORMX-A-A34———
1——W7—0.85G4XSTORMX-B-B25———
1——W8—0.85G4XSTORMX-B-B34———

SP-SHD

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W18—0.5OEM-A-7———
1——W19—0.5G4XSTORMX-A-A7———

Pin map

OEM pointOEM functionOEM familyTarget pointTarget functionTarget familyWire colourEvidence
OEM-A-1Starter signal (term 50)digital_inG4XSTORMX-A-A30Digital Input 1digital_incorroborated
OEM-A-10Coolant temperature sensortemp_inG4XSTORMX-A-A15Analog Temp 1temp_incorroborated
OEM-A-11Idle/WOT throttle switchdigital_inG4XSTORMX-A-A31Digital Input 2digital_incorroborated
OEM-A-12Injector driver (batch, all 4)injector_outG4XSTORMX-A-A4Injector 1injector_outcorroborated
OEM-A-13GroundgroundG4XSTORMX-A-A25 + G4XSTORMX-A-A34 + G4XSTORMX-B-B25 + G4XSTORMX-B-B34System Ground + System Ground + System Ground + System Groundgroundcorroborated
OEM-A-14ECU power (control-unit relay)power_inG4XSTORMX-A-A5+14V ECU Powerpower_incorroborated
OEM-A-16A/C compressor signaldigital_inG4XSTORMX-A-A23Digital Input 3digital_incorroborated
OEM-A-17AFM potentiometer supplyvrefG4XSTORMX-A-A32+5V Outvrefcorroborated
OEM-A-18Hall sender signal (engine speed)trigger_inG4XSTORMX-A-A9Trigger 2trigger_incorroborated
OEM-A-19GroundgroundG4XSTORMX-A-A25 + G4XSTORMX-A-A34 + G4XSTORMX-B-B25 + G4XSTORMX-B-B34System Ground + System Ground + System Ground + System Groundgroundcorroborated
OEM-A-2Oxygen (lambda) sensor signallambda_nb_inG4XSTORMX-A-A22Analog Volt 2analog_incorroborated
OEM-A-21AFM signalanalog_inG4XSTORMX-A-A17Analog Volt 1analog_incorroborated
OEM-A-22Idle stabilizer valve coil 1low_side_outG4XSTORMX-A-A20Aux 2low_side_outcorroborated
OEM-A-23Idle stabilizer valve coil 2low_side_outG4XSTORMX-A-A19Aux 3low_side_outcorroborated
OEM-A-25Ignition timing signal to TCIignition_outG4XSTORMX-A-A13Ignition 1ignition_outcorroborated
OEM-A-3Fuel pump relay controllow_side_outG4XSTORMX-A-A21Aux 1low_side_outcorroborated
OEM-A-4Knock sensor signalknock_inG4XSTORMX-B-B9Knock 1knock_incorroborated
OEM-A-5Knock sensor returnsensor_groundG4XSTORMX-A-A24 + G4XSTORMX-B-B22Sensor Ground + Sensor Groundsensor_groundcorroborated
OEM-A-6Sensor ground (CTS/Hall/AFM/throttle)sensor_groundG4XSTORMX-A-A24 + G4XSTORMX-B-B22Sensor Ground + Sensor Groundsensor_groundcorroborated
OEM-A-7Knock sensor shieldshieldG4XSTORMX-A-A7Shield Groundshieldcorroborated
OEM-A-8Hall sender supply (distributor)power_in———corroborated
OEM-A-9Intake air temperature sensortemp_inG4XSTORMX-A-A16Analog Temp 2temp_incorroborated

Cut list

WireFromToGauge (mm²)ColourLengthSignalIdent
W1OEM-A-14SP-14V-10.85no routeECU power (control-unit relay)—
W2SP-14V-1G4XSTORMX-A-A50.85no route+14V ECU Power—
W3OEM-A-13SP-GND-10.85no routeGround—
W4OEM-A-19SP-GND-10.85no routeGround—
W5SP-GND-1G4XSTORMX-A-A250.85no routeSystem Ground—
W6SP-GND-1G4XSTORMX-A-A340.85no routeSystem Ground—
W7SP-GND-1G4XSTORMX-B-B250.85no routeSystem Ground—
W8SP-GND-1G4XSTORMX-B-B340.85no routeSystem Ground—
W9OEM-A-5SP-0V-10.5no routeKnock sensor return—
W10OEM-A-6SP-0V-10.5no routeSensor ground (CTS/Hall/AFM/throttle)—
W11SP-0V-1G4XSTORMX-A-A240.5no routeSensor Ground—
W12SP-0V-1G4XSTORMX-B-B220.5no routeSensor Ground—
W13OEM-A-17G4XSTORMX-A-A320.5no routeAFM potentiometer supply—
W14OEM-A-18G4XSTORMX-A-A90.5no routeHall sender signal (engine speed)—
W15OEM-A-4G4XSTORMX-B-B90.5no routeKnock sensor signal—
W16OEM-A-25G4XSTORMX-A-A130.5no routeIgnition timing signal to TCI—
W17OEM-A-12G4XSTORMX-A-A40.5no routeInjector driver (batch, all 4)—
W18OEM-A-7SP-SHD-10.5no routeKnock sensor shield—
W19SP-SHD-1G4XSTORMX-A-A70.5no routeShield Ground—
W20OEM-A-3G4XSTORMX-A-A210.5no routeFuel pump relay control—
W21OEM-A-21G4XSTORMX-A-A170.5no routeAFM signal—
W22OEM-A-10G4XSTORMX-A-A150.5no routeCoolant temperature sensor—
W23OEM-A-22G4XSTORMX-A-A200.5no routeIdle stabilizer valve coil 1—
W24OEM-A-23G4XSTORMX-A-A190.5no routeIdle stabilizer valve coil 2—
W25OEM-A-2G4XSTORMX-A-A220.5no routeOxygen (lambda) sensor signal—
W26OEM-A-9G4XSTORMX-A-A160.5no routeIntake air temperature sensor—
W27OEM-A-1G4XSTORMX-A-A300.5no routeStarter signal (term 50)—
W28OEM-A-11G4XSTORMX-A-A310.5no routeIdle/WOT throttle switch—
W29OEM-A-16G4XSTORMX-A-A230.5no routeA/C compressor signal—

Bill of materials

CategoryPart numberManufacturerDescriptionQtyUnit

ECU setup sheet

RoleEngine refEngine signalSensorECU pointECU functionECU classSetup flag
No configured channels.

Findings

Open (2)

SeverityCodeSubjectMessage
errorREQUIRED_UNMAPPEDOEM-A-8Required OEM function "Hall sender supply (distributor)" (power_in) is not connected to the new ECU.
warnLOAD_UNKNOWNG4XSTORMX-A-A21G4XSTORMX-A-A21 "Aux 1" drives OEM-A-3 Fuel pump relay control (load 0.2 A) but its current rating is unknown. Check the ECU manual.

Accepted (0)

CodeSubjectReasonBy

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-A 8: Hall sender supply (distributor): no rule for class sensor_supply_in; wire by hand

Sources

ReliabilityKindTitleURLArchiveCapturedSHA-256
4vendor_docLink: G4X StormX quickstart guidehttps://linkecu.com/documentation/StormXQuickstartGuide.pdf———
3community_copyYourSpec: Link G4X StormX flying-lead harness wiring listhttps://wpm.yourspec.com/projects/view/1482———
2community_copya2resource: Digifant II engine controller pinout (VW Golf/Jetta Mk2 1.8 8v)http://www.a2resource.com/electrical/management/digifant2.html———
2community_copydrive2.ru: VW Golf Mk2 PF Digifant II ECU pinouthttps://www.drive2.ru/l/9886121———