VW Golf/Jetta Mk2 1.8 8v Digifant II → Link G4X MonsoonX (auto)
VW Golf/Jetta Mk2 1.8 8v Digifant II — Link — G4X MonsoonX
⚠ 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.
| Status | draft · not yet verified: nobody has reported building and running this harness |
|---|---|
| Open errors | 1: read the Findings page before cutting any wire |
| Size of the job | 26 wires · 6 connectors · 0 part lines |
| Tools | Crimp and extraction tools for each terminal family (see Connectors) · wire strippers · multimeter · heat gun + heat-shrink |
| Order of work | 1. 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.
| Wire | From | To | Gauge | Colour | Cut | Label | Crimp A | Crimp B | Pin A | Pin B | Continuity |
|---|---|---|---|---|---|---|---|---|---|---|---|
| W1 | OEM-A-14 | SP-14V-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W2 | SP-14V-1 | G4XMONSOONX-A-A5 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W3 | OEM-A-13 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W4 | OEM-A-19 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W5 | SP-GND-1 | G4XMONSOONX-A-A25 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W6 | SP-GND-1 | G4XMONSOONX-A-A34 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W7 | OEM-A-5 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | OEM-A-6 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | SP-0V-1 | G4XMONSOONX-A-A24 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | OEM-A-17 | G4XMONSOONX-A-A32 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | OEM-A-18 | G4XMONSOONX-A-A9 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | OEM-A-4 | G4XMONSOONX-A-A6 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | OEM-A-25 | G4XMONSOONX-A-A13 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | OEM-A-12 | G4XMONSOONX-A-A4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | OEM-A-7 | SP-SHD-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | SP-SHD-1 | G4XMONSOONX-A-A7 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-A-3 | G4XMONSOONX-A-A21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-A-21 | G4XMONSOONX-A-A17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-A-10 | G4XMONSOONX-A-A15 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-A-22 | G4XMONSOONX-A-A20 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-A-23 | G4XMONSOONX-A-A19 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-A-2 | G4XMONSOONX-A-A22 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-A-9 | G4XMONSOONX-A-A16 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-A-1 | G4XMONSOONX-A-A30 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-A-11 | G4XMONSOONX-A-A31 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-A-16 | G4XMONSOONX-A-A23 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ |
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 A | Probe B | Expect | Why | Reading |
|---|---|---|---|---|---|
| 1 | G4XMONSOONX-A-A32 | G4XMONSOONX-A-A24 | open (OL) | 5 V sensor reference must not touch sensor ground | |
| 2 | G4XMONSOONX-A-A5 | G4XMONSOONX-A-A24 | open (OL) | +12 V supply must not touch sensor ground | |
| 3 | G4XMONSOONX-A-A25 | G4XMONSOONX-A-A32 | open (OL) | power ground must not touch 5 V sensor reference | |
| 4 | G4XMONSOONX-A-A25 | G4XMONSOONX-A-A5 | open (OL) | power ground must not touch +12 V supply | |
| 5 | G4XMONSOONX-A-A5 | G4XMONSOONX-A-A32 | open (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
| Rev | Label | By | Date |
|---|---|---|---|
| No revisions yet. | |||
Schematic
Connectors
G4XMONSOONX-A
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A1 | Injector 4 | — | — | — | — | — | — | — | — |
| A10 | Ignition 4 | — | — | — | — | — | — | — | — |
| A11 | Ignition 3 | — | — | — | — | — | — | — | — |
| A12 | Ignition 2 | — | — | — | — | — | — | — | — |
| A13 | Ignition 1 | — | W13 | — | 0.5 | OEM-A-25 | — | — | — |
| A14 | Analog Volt 4 | — | — | — | — | — | — | — | — |
| A15 | Analog Temp 1 | — | W19 | — | 0.5 | OEM-A-10 | — | — | — |
| A16 | Analog Temp 2 | — | W23 | — | 0.5 | OEM-A-9 | — | — | — |
| A17 | Analog Volt 1 | — | W18 | — | 0.5 | OEM-A-21 | — | — | — |
| A18 | Aux 4 | — | — | — | — | — | — | — | — |
| A19 | Aux 3 | — | W21 | — | 0.5 | OEM-A-23 | — | — | — |
| A2 | Injector 3 | — | — | — | — | — | — | — | — |
| A20 | Aux 2 | — | W20 | — | 0.5 | OEM-A-22 | — | — | — |
| A21 | Aux 1 | — | W17 | — | 0.5 | OEM-A-3 | — | — | — |
| A22 | Analog Volt 2 | — | W22 | — | 0.5 | OEM-A-2 | — | — | — |
| A23 | Digital Input 3 | — | W26 | — | 0.5 | OEM-A-16 | — | — | — |
| A24 | Sensor Ground | — | W9 | — | 0.5 | SP-0V-1 | — | — | — |
| A25 | System Ground | — | W5 | — | 0.85 | SP-GND-1 | — | — | — |
| A26 | Aux 6 | — | — | — | — | — | — | — | — |
| A27 | Aux 5 | — | — | — | — | — | — | — | — |
| A28 | CAN H | — | — | — | — | — | — | — | — |
| A29 | CAN L | — | — | — | — | — | — | — | — |
| A3 | Injector 2 | — | — | — | — | — | — | — | — |
| A30 | Digital Input 1 | — | W24 | — | 0.5 | OEM-A-1 | — | — | — |
| A31 | Digital Input 2 | — | W25 | — | 0.5 | OEM-A-11 | — | — | — |
| A32 | +5V Out | — | W10 | — | 0.5 | OEM-A-17 | — | — | — |
| A33 | Analog Volt 3 | — | — | — | — | — | — | — | — |
| A34 | System Ground | — | W6 | — | 0.85 | SP-GND-1 | — | — | — |
| A4 | Injector 1 | — | W14 | — | 0.5 | OEM-A-12 | — | — | — |
| A5 | +14V ECU Power | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
| A6 | Knock 1 / Digital Input 4 | — | W12 | — | 0.5 | OEM-A-4 | — | — | — |
| A7 | Shield Ground | — | W16 | — | 0.5 | SP-SHD-1 | — | — | — |
| A8 | Trigger 1 | — | — | — | — | — | — | — | — |
| A9 | Trigger 2 | — | W11 | — | 0.5 | OEM-A-18 | — | — | — |
OEM-A
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Starter signal (term 50) | — | W24 | — | 0.5 | G4XMONSOONX-A-A30 | — | — | — |
| 10 | Coolant temperature sensor | — | W19 | — | 0.5 | G4XMONSOONX-A-A15 | — | — | — |
| 11 | Idle/WOT throttle switch | — | W25 | — | 0.5 | G4XMONSOONX-A-A31 | — | — | — |
| 12 | Injector driver (batch, all 4) | — | W14 | — | 0.5 | G4XMONSOONX-A-A4 | — | — | — |
| 13 | Ground | — | W3 | — | 0.85 | SP-GND-1 | — | — | — |
| 14 | ECU power (control-unit relay) | — | W1 | — | 0.85 | SP-14V-1 | — | — | — |
| 16 | A/C compressor signal | — | W26 | — | 0.5 | G4XMONSOONX-A-A23 | — | — | — |
| 17 | AFM potentiometer supply | — | W10 | — | 0.5 | G4XMONSOONX-A-A32 | — | — | — |
| 18 | Hall sender signal (engine speed) | — | W11 | — | 0.5 | G4XMONSOONX-A-A9 | — | — | — |
| 19 | Ground | — | W4 | — | 0.85 | SP-GND-1 | — | — | — |
| 2 | Oxygen (lambda) sensor signal | — | W22 | — | 0.5 | G4XMONSOONX-A-A22 | — | — | — |
| 21 | AFM signal | — | W18 | — | 0.5 | G4XMONSOONX-A-A17 | — | — | — |
| 22 | Idle stabilizer valve coil 1 | — | W20 | — | 0.5 | G4XMONSOONX-A-A20 | — | — | — |
| 23 | Idle stabilizer valve coil 2 | — | W21 | — | 0.5 | G4XMONSOONX-A-A19 | — | — | — |
| 25 | Ignition timing signal to TCI | — | W13 | — | 0.5 | G4XMONSOONX-A-A13 | — | — | — |
| 3 | Fuel pump relay control | — | W17 | — | 0.5 | G4XMONSOONX-A-A21 | — | — | — |
| 4 | Knock sensor signal | — | W12 | — | 0.5 | G4XMONSOONX-A-A6 | — | — | — |
| 5 | Knock sensor return | — | W7 | — | 0.5 | SP-0V-1 | — | — | — |
| 6 | Sensor ground (CTS/Hall/AFM/throttle) | — | W8 | — | 0.5 | SP-0V-1 | — | — | — |
| 7 | Knock sensor shield | — | W15 | — | 0.5 | SP-SHD-1 | — | — | — |
| 8 | Hall sender supply (distributor) | — | — | — | — | — | — | — | — |
| 9 | Intake air temperature sensor | — | W23 | — | 0.5 | G4XMONSOONX-A-A16 | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W7 | — | 0.5 | OEM-A-5 | — | — | — |
| 1 | — | — | W8 | — | 0.5 | OEM-A-6 | — | — | — |
| 1 | — | — | W9 | — | 0.5 | G4XMONSOONX-A-A24 | — | — | — |
SP-14V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W1 | — | 0.85 | OEM-A-14 | — | — | — |
| 1 | — | — | W2 | — | 0.85 | G4XMONSOONX-A-A5 | — | — | — |
SP-GND
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W3 | — | 0.85 | OEM-A-13 | — | — | — |
| 1 | — | — | W4 | — | 0.85 | OEM-A-19 | — | — | — |
| 1 | — | — | W5 | — | 0.85 | G4XMONSOONX-A-A25 | — | — | — |
| 1 | — | — | W6 | — | 0.85 | G4XMONSOONX-A-A34 | — | — | — |
SP-SHD
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W15 | — | 0.5 | OEM-A-7 | — | — | — |
| 1 | — | — | W16 | — | 0.5 | G4XMONSOONX-A-A7 | — | — | — |
Pin map
| OEM point | OEM function | OEM family | Target point | Target function | Target family | Wire colour | Evidence |
|---|---|---|---|---|---|---|---|
| OEM-A-1 | Starter signal (term 50) | digital_in | G4XMONSOONX-A-A30 | Digital Input 1 | digital_in | corroborated | |
| OEM-A-10 | Coolant temperature sensor | temp_in | G4XMONSOONX-A-A15 | Analog Temp 1 | temp_in | corroborated | |
| OEM-A-11 | Idle/WOT throttle switch | digital_in | G4XMONSOONX-A-A31 | Digital Input 2 | digital_in | corroborated | |
| OEM-A-12 | Injector driver (batch, all 4) | injector_out | G4XMONSOONX-A-A4 | Injector 1 | injector_out | corroborated | |
| OEM-A-13 | Ground | ground | G4XMONSOONX-A-A25 + G4XMONSOONX-A-A34 | System Ground + System Ground | ground | corroborated | |
| OEM-A-14 | ECU power (control-unit relay) | power_in | G4XMONSOONX-A-A5 | +14V ECU Power | power_in | corroborated | |
| OEM-A-16 | A/C compressor signal | digital_in | G4XMONSOONX-A-A23 | Digital Input 3 | digital_in | corroborated | |
| OEM-A-17 | AFM potentiometer supply | vref | G4XMONSOONX-A-A32 | +5V Out | vref | corroborated | |
| OEM-A-18 | Hall sender signal (engine speed) | trigger_in | G4XMONSOONX-A-A9 | Trigger 2 | trigger_in | corroborated | |
| OEM-A-19 | Ground | ground | G4XMONSOONX-A-A25 + G4XMONSOONX-A-A34 | System Ground + System Ground | ground | corroborated | |
| OEM-A-2 | Oxygen (lambda) sensor signal | lambda_nb_in | G4XMONSOONX-A-A22 | Analog Volt 2 | analog_in | corroborated | |
| OEM-A-21 | AFM signal | analog_in | G4XMONSOONX-A-A17 | Analog Volt 1 | analog_in | corroborated | |
| OEM-A-22 | Idle stabilizer valve coil 1 | low_side_out | G4XMONSOONX-A-A20 | Aux 2 | low_side_out | corroborated | |
| OEM-A-23 | Idle stabilizer valve coil 2 | low_side_out | G4XMONSOONX-A-A19 | Aux 3 | low_side_out | corroborated | |
| OEM-A-25 | Ignition timing signal to TCI | ignition_out | G4XMONSOONX-A-A13 | Ignition 1 | ignition_out | corroborated | |
| OEM-A-3 | Fuel pump relay control | low_side_out | G4XMONSOONX-A-A21 | Aux 1 | low_side_out | corroborated | |
| OEM-A-4 | Knock sensor signal | knock_in | G4XMONSOONX-A-A6 | Knock 1 / Digital Input 4 | knock_in | corroborated | |
| OEM-A-5 | Knock sensor return | sensor_ground | G4XMONSOONX-A-A24 | Sensor Ground | sensor_ground | corroborated | |
| OEM-A-6 | Sensor ground (CTS/Hall/AFM/throttle) | sensor_ground | G4XMONSOONX-A-A24 | Sensor Ground | sensor_ground | corroborated | |
| OEM-A-7 | Knock sensor shield | shield | G4XMONSOONX-A-A7 | Shield Ground | shield | corroborated | |
| OEM-A-8 | Hall sender supply (distributor) | power_in | — | — | — | corroborated | |
| OEM-A-9 | Intake air temperature sensor | temp_in | G4XMONSOONX-A-A16 | Analog Temp 2 | temp_in | corroborated |
Cut list
| Wire | From | To | Gauge (mm²) | Colour | Length | Signal | Ident |
|---|---|---|---|---|---|---|---|
| W1 | OEM-A-14 | SP-14V-1 | 0.85 | no route | ECU power (control-unit relay) | — | |
| W2 | SP-14V-1 | G4XMONSOONX-A-A5 | 0.85 | no route | +14V ECU Power | — | |
| W3 | OEM-A-13 | SP-GND-1 | 0.85 | no route | Ground | — | |
| W4 | OEM-A-19 | SP-GND-1 | 0.85 | no route | Ground | — | |
| W5 | SP-GND-1 | G4XMONSOONX-A-A25 | 0.85 | no route | System Ground | — | |
| W6 | SP-GND-1 | G4XMONSOONX-A-A34 | 0.85 | no route | System Ground | — | |
| W7 | OEM-A-5 | SP-0V-1 | 0.5 | no route | Knock sensor return | — | |
| W8 | OEM-A-6 | SP-0V-1 | 0.5 | no route | Sensor ground (CTS/Hall/AFM/throttle) | — | |
| W9 | SP-0V-1 | G4XMONSOONX-A-A24 | 0.5 | no route | Sensor Ground | — | |
| W10 | OEM-A-17 | G4XMONSOONX-A-A32 | 0.5 | no route | AFM potentiometer supply | — | |
| W11 | OEM-A-18 | G4XMONSOONX-A-A9 | 0.5 | no route | Hall sender signal (engine speed) | — | |
| W12 | OEM-A-4 | G4XMONSOONX-A-A6 | 0.5 | no route | Knock sensor signal | — | |
| W13 | OEM-A-25 | G4XMONSOONX-A-A13 | 0.5 | no route | Ignition timing signal to TCI | — | |
| W14 | OEM-A-12 | G4XMONSOONX-A-A4 | 0.5 | no route | Injector driver (batch, all 4) | — | |
| W15 | OEM-A-7 | SP-SHD-1 | 0.5 | no route | Knock sensor shield | — | |
| W16 | SP-SHD-1 | G4XMONSOONX-A-A7 | 0.5 | no route | Shield Ground | — | |
| W17 | OEM-A-3 | G4XMONSOONX-A-A21 | 0.5 | no route | Fuel pump relay control | — | |
| W18 | OEM-A-21 | G4XMONSOONX-A-A17 | 0.5 | no route | AFM signal | — | |
| W19 | OEM-A-10 | G4XMONSOONX-A-A15 | 0.5 | no route | Coolant temperature sensor | — | |
| W20 | OEM-A-22 | G4XMONSOONX-A-A20 | 0.5 | no route | Idle stabilizer valve coil 1 | — | |
| W21 | OEM-A-23 | G4XMONSOONX-A-A19 | 0.5 | no route | Idle stabilizer valve coil 2 | — | |
| W22 | OEM-A-2 | G4XMONSOONX-A-A22 | 0.5 | no route | Oxygen (lambda) sensor signal | — | |
| W23 | OEM-A-9 | G4XMONSOONX-A-A16 | 0.5 | no route | Intake air temperature sensor | — | |
| W24 | OEM-A-1 | G4XMONSOONX-A-A30 | 0.5 | no route | Starter signal (term 50) | — | |
| W25 | OEM-A-11 | G4XMONSOONX-A-A31 | 0.5 | no route | Idle/WOT throttle switch | — | |
| W26 | OEM-A-16 | G4XMONSOONX-A-A23 | 0.5 | no route | A/C compressor signal | — |
Bill of materials
| Category | Part number | Manufacturer | Description | Qty | Unit |
|---|
ECU setup sheet
| Role | Engine ref | Engine signal | Sensor | ECU point | ECU function | ECU class | Setup flag |
|---|---|---|---|---|---|---|---|
| No configured channels. | |||||||
Findings
Open (2)
| Severity | Code | Subject | Message |
|---|---|---|---|
| error | REQUIRED_UNMAPPED | OEM-A-8 | Required OEM function "Hall sender supply (distributor)" (power_in) is not connected to the new ECU. |
| warn | LOAD_UNKNOWN | G4XMONSOONX-A-A21 | G4XMONSOONX-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)
| Code | Subject | Reason | By |
|---|
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
| Reliability | Kind | Title | URL | Archive | Captured | SHA-256 |
|---|---|---|---|---|---|---|
| 4 | vendor_doc | Link: G4X MonsoonX quickstart + RET 115-1000 | https://linkecu.com/documentation/MonsoonXQuickstartGuide.pdf | archive | 2026-10-05 | e8d432b273d6 |
| 3 | community_copy | YourSpec: Link G4X MonsoonX flying-lead harness wiring list | https://wpm.yourspec.com/projects/view/1469 | — | — | — |
| 2 | community_copy | a2resource: Digifant II engine controller pinout (VW Golf/Jetta Mk2 1.8 8v) | http://www.a2resource.com/electrical/management/digifant2.html | — | — | — |
| 2 | community_copy | drive2.ru: VW Golf Mk2 PF Digifant II ECU pinout | https://www.drive2.ru/l/9886121 | — | — | — |