BMW 3 Series E36 1990–2000 (M50/M52) → Link G4X AtomX 111-4000 (auto)
BMW 3 Series E36 1990–2000 (M50/M52) — Link — G4X AtomX
⚠ 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.
| Status | draft · not yet verified: nobody has reported building and running this harness |
|---|---|
| Open errors | 4: read the Findings page before cutting any wire |
| Size of the job | 40 wires · 6 connectors · 1 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-X-54 | SP-14V-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W2 | SP-14V-1 | G4XATOMX-A-A5 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W3 | OEM-X-15 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W4 | OEM-X-34 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W5 | OEM-X-55 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W6 | OEM-X-6 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W7 | SP-GND-1 | G4XATOMX-A-A25 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | SP-GND-1 | G4XATOMX-A-A34 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | OEM-X-28 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | OEM-X-40 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | OEM-X-43 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | OEM-X-44 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | OEM-X-71 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | SP-0V-1 | G4XATOMX-A-A24 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | OEM-X-59 | G4XATOMX-A-A32 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | OEM-X-16 | G4XATOMX-A-A8 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-X-17 | G4XATOMX-A-A9 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-X-70 | G4XATOMX-A-A6 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-X-50 | G4XATOMX-A-A13 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-X-51 | G4XATOMX-A-A12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-X-52 | G4XATOMX-A-A11 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-X-23 | G4XATOMX-A-A10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-X-33 | G4XATOMX-A-A4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-X-32 | G4XATOMX-A-A3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-X-31 | G4XATOMX-A-A2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-X-5 | G4XATOMX-A-A1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-X-3 | G4XATOMX-A-A4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-X-4 | G4XATOMX-A-A3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-X-45 | SP-SHD-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | SP-SHD-1 | G4XATOMX-A-A7 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-X-1 | G4XATOMX-A-A21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-X-27 | G4XATOMX-A-A20 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-X-38 | G4XATOMX-A-A19 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-X-2 | G4XATOMX-A-A18 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W35 | OEM-X-41 | G4XATOMX-A-A17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W36 | OEM-X-73 | G4XATOMX-A-A22 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W37 | OEM-X-13 | G4XATOMX-A-A33 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W38 | OEM-X-78 | G4XATOMX-A-A15 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W39 | OEM-X-77 | G4XATOMX-A-A16 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W40 | OEM-X-42 | G4XATOMX-A-A30 | 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 | G4XATOMX-A-A24 | G4XATOMX-A-A32 | open (OL) | sensor ground must not touch 5 V sensor reference | |
| 2 | G4XATOMX-A-A24 | G4XATOMX-A-A5 | open (OL) | sensor ground must not touch +12 V supply | |
| 3 | G4XATOMX-A-A25 | G4XATOMX-A-A32 | open (OL) | power ground must not touch 5 V sensor reference | |
| 4 | G4XATOMX-A-A25 | G4XATOMX-A-A5 | open (OL) | power ground must not touch +12 V supply | |
| 5 | G4XATOMX-A-A5 | G4XATOMX-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
G4XATOMX-A
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A1 | Injector 4 | — | W26 | — | 0.5 | OEM-X-5 | — | — | — |
| A10 | Ignition 4 | — | W22 | — | 0.5 | OEM-X-23 | — | — | — |
| A11 | Ignition 3 | — | W21 | — | 0.5 | OEM-X-52 | — | — | — |
| A12 | Ignition 2 | — | W20 | — | 0.5 | OEM-X-51 | — | — | — |
| A13 | Ignition 1 | — | W19 | — | 0.5 | OEM-X-50 | — | — | — |
| A15 | Analog Temp 1 | — | W38 | — | 0.5 | OEM-X-78 | — | — | — |
| A16 | Analog Temp 2 | — | W39 | — | 0.5 | OEM-X-77 | — | — | — |
| A17 | Analog Volt 1 | — | W35 | — | 0.5 | OEM-X-41 | — | — | — |
| A18 | Aux 4 | — | W34 | — | 0.5 | OEM-X-2 | — | — | — |
| A19 | Aux 3 | — | W33 | — | 0.5 | OEM-X-38 | — | — | — |
| A2 | Injector 3 | — | W25 | — | 0.5 | OEM-X-31 | — | — | — |
| A20 | Aux 2 | — | W32 | — | 0.5 | OEM-X-27 | — | — | — |
| A21 | Aux 1 | — | W31 | — | 0.5 | OEM-X-1 | — | — | — |
| A22 | Analog Volt 2 | — | W36 | — | 0.5 | OEM-X-73 | — | — | — |
| A24 | Sensor Ground | — | W14 | — | 0.5 | SP-0V-1 | — | — | — |
| A25 | System Ground | — | W7 | — | 0.85 | SP-GND-1 | — | — | — |
| A28 | CAN H | — | — | — | — | — | — | — | — |
| A29 | CAN L | — | — | — | — | — | — | — | — |
| A3 | Injector 2 | — | W24 | — | 0.5 | OEM-X-32 | — | — | — |
| A3 | Injector 2 | — | W28 | — | 0.5 | OEM-X-4 | — | — | — |
| A30 | Digital Input 1 | — | W40 | — | 0.5 | OEM-X-42 | — | — | — |
| A31 | Digital Input 2 | — | — | — | — | — | — | — | — |
| A32 | +5V Out | — | W15 | — | 0.5 | OEM-X-59 | — | — | — |
| A33 | Analog Volt 3 | — | W37 | — | 0.5 | OEM-X-13 | — | — | — |
| A34 | System Ground | — | W8 | — | 0.85 | SP-GND-1 | — | — | — |
| A4 | Injector 1 | — | W23 | — | 0.5 | OEM-X-33 | — | — | — |
| A4 | Injector 1 | — | W27 | — | 0.5 | OEM-X-3 | — | — | — |
| A5 | +14V ECU Power | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
| A6 | Knock 1 | — | W18 | — | 0.5 | OEM-X-70 | — | — | — |
| A7 | Shield Ground | — | W30 | — | 0.5 | SP-SHD-1 | — | — | — |
| A8 | Trigger 1 | — | W16 | — | 0.5 | OEM-X-16 | — | — | — |
| A9 | Trigger 2 | — | W17 | — | 0.5 | OEM-X-17 | — | — | — |
OEM-X
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Fuel pump relay control | — | W31 | — | 0.5 | G4XATOMX-A-A21 | — | — | — |
| 13 | O2 sensor signal | — | W37 | — | 0.5 | G4XATOMX-A-A33 | — | — | — |
| 15 | Ground | — | W3 | — | 0.85 | SP-GND-1 | — | — | — |
| 16 | Crank position sensor (+) | — | W16 | — | 0.5 | G4XATOMX-A-A8 | — | — | — |
| 17 | Camshaft position sensor (Hall) | — | W17 | — | 0.5 | G4XATOMX-A-A9 | — | — | — |
| 2 | Idle speed control valve (close winding) | — | W34 | — | 0.5 | G4XATOMX-A-A18 | — | — | — |
| 23 | Ignition coil cylinder 4 | — | W22 | — | 0.5 | G4XATOMX-A-A10 | — | — | — |
| 24 | Ignition coil cylinder 6 | — | — | — | — | — | — | — | — |
| 25 | Ignition coil cylinder 5 | — | — | — | — | — | — | — | — |
| 26 | Battery voltage (constant +12V) | — | — | — | — | — | — | — | — |
| 27 | Main relay control | — | W32 | — | 0.5 | G4XATOMX-A-A20 | — | — | — |
| 28 | Ground (electronics + sensor shielding) | — | W9 | — | 0.5 | SP-0V-1 | — | — | — |
| 29 | Idle speed control valve (open winding) | — | — | — | — | — | — | — | — |
| 3 | Injector cylinder 5 | — | W27 | — | 0.5 | G4XATOMX-A-A4 | — | — | — |
| 31 | Injector cylinder 3 | — | W25 | — | 0.5 | G4XATOMX-A-A2 | — | — | — |
| 32 | Injector cylinder 2 | — | W24 | — | 0.5 | G4XATOMX-A-A3 | — | — | — |
| 33 | Injector cylinder 1 | — | W23 | — | 0.5 | G4XATOMX-A-A4 | — | — | — |
| 34 | Ground (output stages) | — | W4 | — | 0.85 | SP-GND-1 | — | — | — |
| 36 | Evap purge solenoid | — | — | — | — | — | — | — | — |
| 38 | O2 sensor heater relay control | — | W33 | — | 0.5 | G4XATOMX-A-A19 | — | — | — |
| 4 | Injector cylinder 6 | — | W28 | — | 0.5 | G4XATOMX-A-A3 | — | — | — |
| 40 | O2 sensor signal ground | — | W10 | — | 0.5 | SP-0V-1 | — | — | — |
| 41 | Mass air flow (MAF) signal | — | W35 | — | 0.5 | G4XATOMX-A-A17 | — | — | — |
| 42 | Vehicle speed signal | — | W40 | — | 0.5 | G4XATOMX-A-A30 | — | — | — |
| 43 | Crank position sensor (-) | — | W11 | — | 0.5 | SP-0V-1 | — | — | — |
| 44 | Sensor ground (IAT/ECT/TPS) | — | W12 | — | 0.5 | SP-0V-1 | — | — | — |
| 45 | Shield ground | — | W29 | — | 0.5 | SP-SHD-1 | — | — | — |
| 47 | Tachometer output | — | — | — | — | — | — | — | — |
| 5 | Injector cylinder 4 | — | W26 | — | 0.5 | G4XATOMX-A-A1 | — | — | — |
| 50 | Ignition coil cylinder 1 | — | W19 | — | 0.5 | G4XATOMX-A-A13 | — | — | — |
| 51 | Ignition coil cylinder 2 | — | W20 | — | 0.5 | G4XATOMX-A-A12 | — | — | — |
| 52 | Ignition coil cylinder 3 | — | W21 | — | 0.5 | G4XATOMX-A-A11 | — | — | — |
| 54 | ECU power (+14V from main relay) | — | W1 | — | 0.85 | SP-14V-1 | — | — | — |
| 55 | Ground (ignition) | — | W5 | — | 0.85 | SP-GND-1 | — | — | — |
| 56 | Ignition switch (terminal 15) | — | — | — | — | — | — | — | — |
| 59 | +5V sensor supply | — | W15 | — | 0.5 | G4XATOMX-A-A32 | — | — | — |
| 6 | Ground (injector output stages) | — | W6 | — | 0.85 | SP-GND-1 | — | — | — |
| 69 | Knock sensor cylinders 4-6 | — | — | — | — | — | — | — | — |
| 7 | VANOS intake camshaft solenoid | — | — | — | — | — | — | — | — |
| 70 | Knock sensor cylinders 1-3 | — | W18 | — | 0.5 | G4XATOMX-A-A6 | — | — | — |
| 71 | Knock sensor ground/shield | — | W13 | — | 0.5 | SP-0V-1 | — | — | — |
| 73 | Throttle position (TPS) | — | W36 | — | 0.5 | G4XATOMX-A-A22 | — | — | — |
| 77 | Intake air temperature (IAT) | — | W39 | — | 0.5 | G4XATOMX-A-A16 | — | — | — |
| 78 | Engine coolant temperature (ECT) | — | W38 | — | 0.5 | G4XATOMX-A-A15 | — | — | — |
| 8 | Check engine light (MIL) | — | — | — | — | — | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W9 | — | 0.5 | OEM-X-28 | — | — | — |
| 1 | — | — | W10 | — | 0.5 | OEM-X-40 | — | — | — |
| 1 | — | — | W11 | — | 0.5 | OEM-X-43 | — | — | — |
| 1 | — | — | W12 | — | 0.5 | OEM-X-44 | — | — | — |
| 1 | — | — | W13 | — | 0.5 | OEM-X-71 | — | — | — |
| 1 | — | — | W14 | — | 0.5 | G4XATOMX-A-A24 | — | — | — |
SP-14V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W1 | — | 0.85 | OEM-X-54 | — | — | — |
| 1 | — | — | W2 | — | 0.85 | G4XATOMX-A-A5 | — | — | — |
SP-GND
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W3 | — | 0.85 | OEM-X-15 | — | — | — |
| 1 | — | — | W4 | — | 0.85 | OEM-X-34 | — | — | — |
| 1 | — | — | W5 | — | 0.85 | OEM-X-55 | — | — | — |
| 1 | — | — | W6 | — | 0.85 | OEM-X-6 | — | — | — |
| 1 | — | — | W7 | — | 0.85 | G4XATOMX-A-A25 | — | — | — |
| 1 | — | — | W8 | — | 0.85 | G4XATOMX-A-A34 | — | — | — |
SP-SHD
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W29 | — | 0.5 | OEM-X-45 | — | — | — |
| 1 | — | — | W30 | — | 0.5 | G4XATOMX-A-A7 | — | — | — |
Pin map
| OEM point | OEM function | OEM family | Target point | Target function | Target family | Wire colour | Evidence |
|---|---|---|---|---|---|---|---|
| OEM-X-1 | Fuel pump relay control | low_side_out | G4XATOMX-A-A21 | Aux 1 | low_side_out | corroborated | |
| OEM-X-13 | O2 sensor signal | lambda_nb_in | G4XATOMX-A-A33 | Analog Volt 3 | analog_in | corroborated | |
| OEM-X-15 | Ground | ground | G4XATOMX-A-A25 + G4XATOMX-A-A34 | System Ground + System Ground | ground | corroborated | |
| OEM-X-16 | Crank position sensor (+) | trigger_in | G4XATOMX-A-A8 | Trigger 1 | trigger_in | corroborated | |
| OEM-X-17 | Camshaft position sensor (Hall) | trigger_in | G4XATOMX-A-A9 | Trigger 2 | trigger_in | corroborated | |
| OEM-X-2 | Idle speed control valve (close winding) | low_side_out | G4XATOMX-A-A18 | Aux 4 | low_side_out | corroborated | |
| OEM-X-23 | Ignition coil cylinder 4 | ignition_out | G4XATOMX-A-A10 | Ignition 4 | ignition_out | corroborated | |
| OEM-X-24 | Ignition coil cylinder 6 | ignition_out | — | — | — | corroborated | |
| OEM-X-25 | Ignition coil cylinder 5 | ignition_out | — | — | — | corroborated | |
| OEM-X-26 | Battery voltage (constant +12V) | power_in | — | — | — | corroborated | |
| OEM-X-27 | Main relay control | low_side_out | G4XATOMX-A-A20 | Aux 2 | low_side_out | corroborated | |
| OEM-X-28 | Ground (electronics + sensor shielding) | sensor_ground | G4XATOMX-A-A24 | Sensor Ground | sensor_ground | corroborated | |
| OEM-X-29 | Idle speed control valve (open winding) | low_side_out | — | — | — | corroborated | |
| OEM-X-3 | Injector cylinder 5 | injector_out | G4XATOMX-A-A4 | Injector 1 | injector_out | corroborated | |
| OEM-X-31 | Injector cylinder 3 | injector_out | G4XATOMX-A-A2 | Injector 3 | injector_out | corroborated | |
| OEM-X-32 | Injector cylinder 2 | injector_out | G4XATOMX-A-A3 | Injector 2 | injector_out | corroborated | |
| OEM-X-33 | Injector cylinder 1 | injector_out | G4XATOMX-A-A4 | Injector 1 | injector_out | corroborated | |
| OEM-X-34 | Ground (output stages) | ground | G4XATOMX-A-A25 + G4XATOMX-A-A34 | System Ground + System Ground | ground | corroborated | |
| OEM-X-36 | Evap purge solenoid | low_side_out | — | — | — | corroborated | |
| OEM-X-38 | O2 sensor heater relay control | low_side_out | G4XATOMX-A-A19 | Aux 3 | low_side_out | corroborated | |
| OEM-X-4 | Injector cylinder 6 | injector_out | G4XATOMX-A-A3 | Injector 2 | injector_out | corroborated | |
| OEM-X-40 | O2 sensor signal ground | sensor_ground | G4XATOMX-A-A24 | Sensor Ground | sensor_ground | corroborated | |
| OEM-X-41 | Mass air flow (MAF) signal | analog_in | G4XATOMX-A-A17 | Analog Volt 1 | analog_in | corroborated | |
| OEM-X-42 | Vehicle speed signal | digital_in | G4XATOMX-A-A30 | Digital Input 1 | digital_in | corroborated | |
| OEM-X-43 | Crank position sensor (-) | sensor_ground | G4XATOMX-A-A24 | Sensor Ground | sensor_ground | corroborated | |
| OEM-X-44 | Sensor ground (IAT/ECT/TPS) | sensor_ground | G4XATOMX-A-A24 | Sensor Ground | sensor_ground | corroborated | |
| OEM-X-45 | Shield ground | shield | G4XATOMX-A-A7 | Shield Ground | shield | corroborated | |
| OEM-X-47 | Tachometer output | tacho_out | — | — | — | corroborated | |
| OEM-X-5 | Injector cylinder 4 | injector_out | G4XATOMX-A-A1 | Injector 4 | injector_out | corroborated | |
| OEM-X-50 | Ignition coil cylinder 1 | ignition_out | G4XATOMX-A-A13 | Ignition 1 | ignition_out | corroborated | |
| OEM-X-51 | Ignition coil cylinder 2 | ignition_out | G4XATOMX-A-A12 | Ignition 2 | ignition_out | corroborated | |
| OEM-X-52 | Ignition coil cylinder 3 | ignition_out | G4XATOMX-A-A11 | Ignition 3 | ignition_out | corroborated | |
| OEM-X-54 | ECU power (+14V from main relay) | power_in | G4XATOMX-A-A5 | +14V ECU Power | power_in | corroborated | |
| OEM-X-55 | Ground (ignition) | ground | G4XATOMX-A-A25 + G4XATOMX-A-A34 | System Ground + System Ground | ground | corroborated | |
| OEM-X-56 | Ignition switch (terminal 15) | digital_in | — | — | — | corroborated | |
| OEM-X-59 | +5V sensor supply | vref | G4XATOMX-A-A32 | +5V Out | vref | corroborated | |
| OEM-X-6 | Ground (injector output stages) | ground | G4XATOMX-A-A25 + G4XATOMX-A-A34 | System Ground + System Ground | ground | corroborated | |
| OEM-X-69 | Knock sensor cylinders 4-6 | knock_in | — | — | — | corroborated | |
| OEM-X-7 | VANOS intake camshaft solenoid | low_side_out | — | — | — | corroborated | |
| OEM-X-70 | Knock sensor cylinders 1-3 | knock_in | G4XATOMX-A-A6 | Knock 1 | knock_in | corroborated | |
| OEM-X-71 | Knock sensor ground/shield | sensor_ground | G4XATOMX-A-A24 | Sensor Ground | sensor_ground | corroborated | |
| OEM-X-73 | Throttle position (TPS) | analog_in | G4XATOMX-A-A22 | Analog Volt 2 | analog_in | corroborated | |
| OEM-X-77 | Intake air temperature (IAT) | temp_in | G4XATOMX-A-A16 | Analog Temp 2 | temp_in | corroborated | |
| OEM-X-78 | Engine coolant temperature (ECT) | temp_in | G4XATOMX-A-A15 | Analog Temp 1 | temp_in | corroborated | |
| OEM-X-8 | Check engine light (MIL) | low_side_out | — | — | — | corroborated |
Cut list
| Wire | From | To | Gauge (mm²) | Colour | Length | Signal | Ident |
|---|---|---|---|---|---|---|---|
| W1 | OEM-X-54 | SP-14V-1 | 0.85 | no route | ECU power (+14V from main relay) | — | |
| W2 | SP-14V-1 | G4XATOMX-A-A5 | 0.85 | no route | +14V ECU Power | — | |
| W3 | OEM-X-15 | SP-GND-1 | 0.85 | no route | Ground | — | |
| W4 | OEM-X-34 | SP-GND-1 | 0.85 | no route | Ground (output stages) | — | |
| W5 | OEM-X-55 | SP-GND-1 | 0.85 | no route | Ground (ignition) | — | |
| W6 | OEM-X-6 | SP-GND-1 | 0.85 | no route | Ground (injector output stages) | — | |
| W7 | SP-GND-1 | G4XATOMX-A-A25 | 0.85 | no route | System Ground | — | |
| W8 | SP-GND-1 | G4XATOMX-A-A34 | 0.85 | no route | System Ground | — | |
| W9 | OEM-X-28 | SP-0V-1 | 0.5 | no route | Ground (electronics + sensor shielding) | — | |
| W10 | OEM-X-40 | SP-0V-1 | 0.5 | no route | O2 sensor signal ground | — | |
| W11 | OEM-X-43 | SP-0V-1 | 0.5 | no route | Crank position sensor (-) | — | |
| W12 | OEM-X-44 | SP-0V-1 | 0.5 | no route | Sensor ground (IAT/ECT/TPS) | — | |
| W13 | OEM-X-71 | SP-0V-1 | 0.5 | no route | Knock sensor ground/shield | — | |
| W14 | SP-0V-1 | G4XATOMX-A-A24 | 0.5 | no route | Sensor Ground | — | |
| W15 | OEM-X-59 | G4XATOMX-A-A32 | 0.5 | no route | +5V sensor supply | — | |
| W16 | OEM-X-16 | G4XATOMX-A-A8 | 0.5 | no route | Crank position sensor (+) | — | |
| W17 | OEM-X-17 | G4XATOMX-A-A9 | 0.5 | no route | Camshaft position sensor (Hall) | — | |
| W18 | OEM-X-70 | G4XATOMX-A-A6 | 0.5 | no route | Knock sensor cylinders 1-3 | — | |
| W19 | OEM-X-50 | G4XATOMX-A-A13 | 0.5 | no route | Ignition coil cylinder 1 | — | |
| W20 | OEM-X-51 | G4XATOMX-A-A12 | 0.5 | no route | Ignition coil cylinder 2 | — | |
| W21 | OEM-X-52 | G4XATOMX-A-A11 | 0.5 | no route | Ignition coil cylinder 3 | — | |
| W22 | OEM-X-23 | G4XATOMX-A-A10 | 0.5 | no route | Ignition coil cylinder 4 | — | |
| W23 | OEM-X-33 | G4XATOMX-A-A4 | 0.5 | no route | Injector cylinder 1 | — | |
| W24 | OEM-X-32 | G4XATOMX-A-A3 | 0.5 | no route | Injector cylinder 2 | — | |
| W25 | OEM-X-31 | G4XATOMX-A-A2 | 0.5 | no route | Injector cylinder 3 | — | |
| W26 | OEM-X-5 | G4XATOMX-A-A1 | 0.5 | no route | Injector cylinder 4 | — | |
| W27 | OEM-X-3 | G4XATOMX-A-A4 | 0.5 | no route | Injector cylinder 5 | — | |
| W28 | OEM-X-4 | G4XATOMX-A-A3 | 0.5 | no route | Injector cylinder 6 | — | |
| W29 | OEM-X-45 | SP-SHD-1 | 0.5 | no route | Shield ground | — | |
| W30 | SP-SHD-1 | G4XATOMX-A-A7 | 0.5 | no route | Shield Ground | — | |
| W31 | OEM-X-1 | G4XATOMX-A-A21 | 0.5 | no route | Fuel pump relay control | — | |
| W32 | OEM-X-27 | G4XATOMX-A-A20 | 0.5 | no route | Main relay control | — | |
| W33 | OEM-X-38 | G4XATOMX-A-A19 | 0.5 | no route | O2 sensor heater relay control | — | |
| W34 | OEM-X-2 | G4XATOMX-A-A18 | 0.5 | no route | Idle speed control valve (close winding) | — | |
| W35 | OEM-X-41 | G4XATOMX-A-A17 | 0.5 | no route | Mass air flow (MAF) signal | — | |
| W36 | OEM-X-73 | G4XATOMX-A-A22 | 0.5 | no route | Throttle position (TPS) | — | |
| W37 | OEM-X-13 | G4XATOMX-A-A33 | 0.5 | no route | O2 sensor signal | — | |
| W38 | OEM-X-78 | G4XATOMX-A-A15 | 0.5 | no route | Engine coolant temperature (ECT) | — | |
| W39 | OEM-X-77 | G4XATOMX-A-A16 | 0.5 | no route | Intake air temperature (IAT) | — | |
| W40 | OEM-X-42 | G4XATOMX-A-A30 | 0.5 | no route | Vehicle speed signal | — |
Bill of materials
| Category | Part number | Manufacturer | Description | Qty | Unit |
|---|---|---|---|---|---|
| connector | BMW-E36-DME-CONN | BMW | E36 DME (M3.1/M3.3.1) harness connector | 1.000 | ea |
ECU setup sheet
| Role | Engine ref | Engine signal | Sensor | ECU point | ECU function | ECU class | Setup flag |
|---|---|---|---|---|---|---|---|
| No configured channels. | |||||||
Findings
Open (5)
| Severity | Code | Subject | Message |
|---|---|---|---|
| error | NET_MERGED | G4XATOMX-A-A3 + OEM-X-32 + OEM-X-4 | 2 different OEM functions share one net: OEM-X-32 Injector cylinder 2; OEM-X-4 Injector cylinder 6 |
| error | NET_MERGED | G4XATOMX-A-A4 + OEM-X-3 + OEM-X-33 | 2 different OEM functions share one net: OEM-X-3 Injector cylinder 5; OEM-X-33 Injector cylinder 1 |
| error | REQUIRED_UNMAPPED | OEM-X-24 | Required OEM function "Ignition coil cylinder 6" (ignition_out) is not connected to the new ECU. |
| error | REQUIRED_UNMAPPED | OEM-X-25 | Required OEM function "Ignition coil cylinder 5" (ignition_out) is not connected to the new ECU. |
| info | UNMAPPED | OEM | 7 optional OEM pins are not mapped: OEM-X-29 Idle speed control valve (open winding); OEM-X-36 Evap purge solenoid; OEM-X-47 Tachometer output; OEM-X-56 Ignition switch (terminal 15); OEM-X-69 Knock sensor cylinders 4-6; OEM-X-7 VANOS intake camshaft solenoid; OEM-X-8 Check engine light (MIL) |
Accepted (1)
| Code | Subject | Reason | By |
|---|---|---|---|
| REQUIRED_UNMAPPED | OEM-X-26 | Battery-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 2026-10-11. Review every wire against both manuals before building. Open items: - OEM-X 25: Ignition coil cylinder 5: no free ignition output on Link G4X AtomX - OEM-X 24: Ignition coil cylinder 6: no free ignition output on Link G4X AtomX Not wired: - OEM-X 26: Battery voltage (constant +12V): Link G4X AtomX has no battery-constant input; not needed - OEM-X 69: Knock sensor cylinders 4-6: no free knock input on Link G4X AtomX - OEM-X 56: Ignition switch (terminal 15): key-on 12 V sense — optional in a swap (the main relay is energized from keyed 12 V, not from this pin); Link G4X AtomX has no dedicated key-on input - OEM-X 29: Idle speed control valve (open winding): no free low_side/ls_hs/injector/hbridge on Link G4X AtomX - OEM-X 36: Evap purge solenoid: no free low_side/ls_hs/injector/hbridge on Link G4X AtomX - OEM-X 7: VANOS intake camshaft solenoid: no free low_side/ls_hs/injector/hbridge on Link G4X AtomX - OEM-X 8: Check engine light (MIL): no free low_side/ls_hs/injector/hbridge on Link G4X AtomX - OEM-X 47: Tachometer output: no free tacho/frequency_out/low_side/ls_hs on Link G4X AtomX
Sources
| Reliability | Kind | Title | URL | Archive | Captured | SHA-256 |
|---|---|---|---|---|---|---|
| 4 | vendor_doc | Link BMWLink E36X (G4X) plug-in install manual | https://linkecu.com/documentation/E36X.pdf | archive | 2026-10-05 | 010cda3acd08 |
| 4 | vendor_doc | Link: G4X AtomX quickstart | https://linkecu.com/documentation/AtomXQuickstartGuide.pdf | archive | 2026-10-05 | 5fa903ea7bdf |
| 3 | community_copy | YourSpec: Link G4X AtomX ECU flying-lead harness wiring list | https://wpm.yourspec.com/projects/view/1462 | — | — | — |
| 2 | community_copy | bimmer-service: Bosch Motronic M3.3.1 pinout (E36 M50) | https://www.bimmer-service.com/2025/11/17/bosch-motronic-m3-3-1-pinout-wiring-diagram/ | — | — | — |