BMW 3 Series E36 1990–2000 (M50/M52) → MaxxECU MaxxECU MINI REV10+ (auto)
BMW 3 Series E36 1990–2000 (M50/M52) — MaxxECU — MaxxECU MINI
⚠ 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 | 5: 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 | MAXXECUMINI-C1-H4 | 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 | MAXXECUMINI-C1-G4 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | OEM-X-28 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | OEM-X-40 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | OEM-X-43 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | OEM-X-44 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | OEM-X-71 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | SP-0V-1 | MAXXECUMINI-C1-A2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | SP-0V-1 | MAXXECUMINI-C1-B3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | SP-0V-1 | MAXXECUMINI-C1-B4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | SP-0V-1 | MAXXECUMINI-C1-D4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-X-59 | MAXXECUMINI-C1-E2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-X-16 | MAXXECUMINI-C1-A1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-X-50 | MAXXECUMINI-C1-F1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-X-51 | MAXXECUMINI-C1-F2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-X-52 | MAXXECUMINI-C1-F3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-X-23 | MAXXECUMINI-C1-F4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-X-33 | MAXXECUMINI-C1-G3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-X-32 | MAXXECUMINI-C1-H1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-X-31 | MAXXECUMINI-C1-H2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-X-5 | MAXXECUMINI-C1-H3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-X-3 | MAXXECUMINI-C1-G3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-X-4 | MAXXECUMINI-C1-H1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-X-45 | SP-SHD-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | SP-SHD-1 | MAXXECUMINI-C1-D3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-X-1 | MAXXECUMINI-C1-G2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-X-27 | MAXXECUMINI-C1-G1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-X-41 | MAXXECUMINI-C1-C3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-X-73 | MAXXECUMINI-C1-D2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W35 | OEM-X-78 | MAXXECUMINI-C1-C1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W36 | OEM-X-38 | MAXXECUMINI-C1-E1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W37 | OEM-X-2 | MAXXECUMINI-C1-D1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W38 | OEM-X-13 | MAXXECUMINI-C1-C4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W39 | OEM-X-77 | MAXXECUMINI-C1-C2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W40 | OEM-X-42 | MAXXECUMINI-C1-B1 | 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 | MAXXECUMINI-C1-A2 | MAXXECUMINI-C1-E2 | open (OL) | sensor ground must not touch 5 V sensor reference | |
| 2 | MAXXECUMINI-C1-A2 | MAXXECUMINI-C1-H4 | open (OL) | sensor ground must not touch +12 V supply | |
| 3 | MAXXECUMINI-C1-G4 | MAXXECUMINI-C1-E2 | open (OL) | power ground must not touch 5 V sensor reference | |
| 4 | MAXXECUMINI-C1-G4 | MAXXECUMINI-C1-H4 | open (OL) | power ground must not touch +12 V supply | |
| 5 | MAXXECUMINI-C1-H4 | MAXXECUMINI-C1-E2 | 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
MAXXECUMINI-C1
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A1 | TRIGGER | — | W18 | — | 0.5 | OEM-X-16 | — | — | — |
| A2 | TRIGGER GND | — | W13 | — | 0.5 | SP-0V-1 | — | — | — |
| B1 | DIN 1 (Hall only) | — | W40 | — | 0.5 | OEM-X-42 | — | — | — |
| B2 | DIN 2 (Hall only) | — | — | — | — | — | — | — | — |
| B3 | SENSOR GND | — | W14 | — | 0.5 | SP-0V-1 | — | — | — |
| B4 | SENSOR GND | — | W15 | — | 0.5 | SP-0V-1 | — | — | — |
| C1 | CLT | — | W35 | — | 0.5 | OEM-X-78 | — | — | — |
| C2 | IAT | — | W39 | — | 0.5 | OEM-X-77 | — | — | — |
| C3 | AIN 3 (0-5V) | — | W33 | — | 0.5 | OEM-X-41 | — | — | — |
| C4 | AIN 4 (0-5V) | — | W38 | — | 0.5 | OEM-X-13 | — | — | — |
| D1 | GPO 8/TACHO | — | W37 | — | 0.5 | OEM-X-2 | — | — | — |
| D2 | TPS | — | W34 | — | 0.5 | OEM-X-73 | — | — | — |
| D3 | GND Shield | — | W30 | — | 0.5 | SP-SHD-1 | — | — | — |
| D4 | SENSOR GND | — | W16 | — | 0.5 | SP-0V-1 | — | — | — |
| E1 | GPO 3 | — | W36 | — | 0.5 | OEM-X-38 | — | — | — |
| E2 | +5V sensor supply | — | W17 | — | 0.5 | OEM-X-59 | — | — | — |
| E3 | CAN L | — | — | — | — | — | — | — | — |
| E4 | CAN H | — | — | — | — | — | — | — | — |
| F1 | IGN 1 | — | W19 | — | 0.5 | OEM-X-50 | — | — | — |
| F2 | IGN 2 | — | W20 | — | 0.5 | OEM-X-51 | — | — | — |
| F3 | IGN 3 | — | W21 | — | 0.5 | OEM-X-52 | — | — | — |
| F4 | IGN 4 | — | W22 | — | 0.5 | OEM-X-23 | — | — | — |
| G1 | GPO 2 | — | W32 | — | 0.5 | OEM-X-27 | — | — | — |
| G2 | GPO 1 | — | W31 | — | 0.5 | OEM-X-1 | — | — | — |
| G3 | INJ 1 | — | W23 | — | 0.5 | OEM-X-33 | — | — | — |
| G3 | INJ 1 | — | W27 | — | 0.5 | OEM-X-3 | — | — | — |
| G4 | ENGINE GND | — | W7 | — | 0.85 | SP-GND-1 | — | — | — |
| H1 | INJ 2 | — | W24 | — | 0.5 | OEM-X-32 | — | — | — |
| H1 | INJ 2 | — | W28 | — | 0.5 | OEM-X-4 | — | — | — |
| H2 | INJ 3 | — | W25 | — | 0.5 | OEM-X-31 | — | — | — |
| H3 | INJ 4 | — | W26 | — | 0.5 | OEM-X-5 | — | — | — |
| H4 | +12V (ECU power supply) | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
OEM-X
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Fuel pump relay control | — | W31 | — | 0.5 | MAXXECUMINI-C1-G2 | — | — | — |
| 13 | O2 sensor signal | — | W38 | — | 0.5 | MAXXECUMINI-C1-C4 | — | — | — |
| 15 | Ground | — | W3 | — | 0.85 | SP-GND-1 | — | — | — |
| 16 | Crank position sensor (+) | — | W18 | — | 0.5 | MAXXECUMINI-C1-A1 | — | — | — |
| 17 | Camshaft position sensor (Hall) | — | — | — | — | — | — | — | — |
| 2 | Idle speed control valve (close winding) | — | W37 | — | 0.5 | MAXXECUMINI-C1-D1 | — | — | — |
| 23 | Ignition coil cylinder 4 | — | W22 | — | 0.5 | MAXXECUMINI-C1-F4 | — | — | — |
| 24 | Ignition coil cylinder 6 | — | — | — | — | — | — | — | — |
| 25 | Ignition coil cylinder 5 | — | — | — | — | — | — | — | — |
| 26 | Battery voltage (constant +12V) | — | — | — | — | — | — | — | — |
| 27 | Main relay control | — | W32 | — | 0.5 | MAXXECUMINI-C1-G1 | — | — | — |
| 28 | Ground (electronics + sensor shielding) | — | W8 | — | 0.5 | SP-0V-1 | — | — | — |
| 29 | Idle speed control valve (open winding) | — | — | — | — | — | — | — | — |
| 3 | Injector cylinder 5 | — | W27 | — | 0.5 | MAXXECUMINI-C1-G3 | — | — | — |
| 31 | Injector cylinder 3 | — | W25 | — | 0.5 | MAXXECUMINI-C1-H2 | — | — | — |
| 32 | Injector cylinder 2 | — | W24 | — | 0.5 | MAXXECUMINI-C1-H1 | — | — | — |
| 33 | Injector cylinder 1 | — | W23 | — | 0.5 | MAXXECUMINI-C1-G3 | — | — | — |
| 34 | Ground (output stages) | — | W4 | — | 0.85 | SP-GND-1 | — | — | — |
| 36 | Evap purge solenoid | — | — | — | — | — | — | — | — |
| 38 | O2 sensor heater relay control | — | W36 | — | 0.5 | MAXXECUMINI-C1-E1 | — | — | — |
| 4 | Injector cylinder 6 | — | W28 | — | 0.5 | MAXXECUMINI-C1-H1 | — | — | — |
| 40 | O2 sensor signal ground | — | W9 | — | 0.5 | SP-0V-1 | — | — | — |
| 41 | Mass air flow (MAF) signal | — | W33 | — | 0.5 | MAXXECUMINI-C1-C3 | — | — | — |
| 42 | Vehicle speed signal | — | W40 | — | 0.5 | MAXXECUMINI-C1-B1 | — | — | — |
| 43 | Crank position sensor (-) | — | W10 | — | 0.5 | SP-0V-1 | — | — | — |
| 44 | Sensor ground (IAT/ECT/TPS) | — | W11 | — | 0.5 | SP-0V-1 | — | — | — |
| 45 | Shield ground | — | W29 | — | 0.5 | SP-SHD-1 | — | — | — |
| 47 | Tachometer output | — | — | — | — | — | — | — | — |
| 5 | Injector cylinder 4 | — | W26 | — | 0.5 | MAXXECUMINI-C1-H3 | — | — | — |
| 50 | Ignition coil cylinder 1 | — | W19 | — | 0.5 | MAXXECUMINI-C1-F1 | — | — | — |
| 51 | Ignition coil cylinder 2 | — | W20 | — | 0.5 | MAXXECUMINI-C1-F2 | — | — | — |
| 52 | Ignition coil cylinder 3 | — | W21 | — | 0.5 | MAXXECUMINI-C1-F3 | — | — | — |
| 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 | — | W17 | — | 0.5 | MAXXECUMINI-C1-E2 | — | — | — |
| 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 | — | — | — | — | — | — | — | — |
| 71 | Knock sensor ground/shield | — | W12 | — | 0.5 | SP-0V-1 | — | — | — |
| 73 | Throttle position (TPS) | — | W34 | — | 0.5 | MAXXECUMINI-C1-D2 | — | — | — |
| 77 | Intake air temperature (IAT) | — | W39 | — | 0.5 | MAXXECUMINI-C1-C2 | — | — | — |
| 78 | Engine coolant temperature (ECT) | — | W35 | — | 0.5 | MAXXECUMINI-C1-C1 | — | — | — |
| 8 | Check engine light (MIL) | — | — | — | — | — | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W8 | — | 0.5 | OEM-X-28 | — | — | — |
| 1 | — | — | W9 | — | 0.5 | OEM-X-40 | — | — | — |
| 1 | — | — | W10 | — | 0.5 | OEM-X-43 | — | — | — |
| 1 | — | — | W11 | — | 0.5 | OEM-X-44 | — | — | — |
| 1 | — | — | W12 | — | 0.5 | OEM-X-71 | — | — | — |
| 1 | — | — | W13 | — | 0.5 | MAXXECUMINI-C1-A2 | — | — | — |
| 1 | — | — | W14 | — | 0.5 | MAXXECUMINI-C1-B3 | — | — | — |
| 1 | — | — | W15 | — | 0.5 | MAXXECUMINI-C1-B4 | — | — | — |
| 1 | — | — | W16 | — | 0.5 | MAXXECUMINI-C1-D4 | — | — | — |
SP-14V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W1 | — | 0.85 | OEM-X-54 | — | — | — |
| 1 | — | — | W2 | — | 0.85 | MAXXECUMINI-C1-H4 | — | — | — |
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 | MAXXECUMINI-C1-G4 | — | — | — |
SP-SHD
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W29 | — | 0.5 | OEM-X-45 | — | — | — |
| 1 | — | — | W30 | — | 0.5 | MAXXECUMINI-C1-D3 | — | — | — |
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 | MAXXECUMINI-C1-G2 | GPO 1 | low_side_out | corroborated | |
| OEM-X-13 | O2 sensor signal | lambda_nb_in | MAXXECUMINI-C1-C4 | AIN 4 (0-5V) | analog_in | corroborated | |
| OEM-X-15 | Ground | ground | MAXXECUMINI-C1-G4 | ENGINE GND | ground | corroborated | |
| OEM-X-16 | Crank position sensor (+) | trigger_in | MAXXECUMINI-C1-A1 | TRIGGER | trigger_in | corroborated | |
| OEM-X-17 | Camshaft position sensor (Hall) | trigger_in | — | — | — | corroborated | |
| OEM-X-2 | Idle speed control valve (close winding) | low_side_out | MAXXECUMINI-C1-D1 | GPO 8/TACHO | low_side_out | corroborated | |
| OEM-X-23 | Ignition coil cylinder 4 | ignition_out | MAXXECUMINI-C1-F4 | IGN 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 | MAXXECUMINI-C1-G1 | GPO 2 | low_side_out | corroborated | |
| OEM-X-28 | Ground (electronics + sensor shielding) | sensor_ground | MAXXECUMINI-C1-A2 + MAXXECUMINI-C1-B3 + MAXXECUMINI-C1-B4 + MAXXECUMINI-C1-D4 | TRIGGER GND + SENSOR GND + SENSOR GND + SENSOR GND | sensor_ground | corroborated | |
| OEM-X-29 | Idle speed control valve (open winding) | low_side_out | — | — | — | corroborated | |
| OEM-X-3 | Injector cylinder 5 | injector_out | MAXXECUMINI-C1-G3 | INJ 1 | injector_out | corroborated | |
| OEM-X-31 | Injector cylinder 3 | injector_out | MAXXECUMINI-C1-H2 | INJ 3 | injector_out | corroborated | |
| OEM-X-32 | Injector cylinder 2 | injector_out | MAXXECUMINI-C1-H1 | INJ 2 | injector_out | corroborated | |
| OEM-X-33 | Injector cylinder 1 | injector_out | MAXXECUMINI-C1-G3 | INJ 1 | injector_out | corroborated | |
| OEM-X-34 | Ground (output stages) | ground | MAXXECUMINI-C1-G4 | ENGINE GND | ground | corroborated | |
| OEM-X-36 | Evap purge solenoid | low_side_out | — | — | — | corroborated | |
| OEM-X-38 | O2 sensor heater relay control | low_side_out | MAXXECUMINI-C1-E1 | GPO 3 | low_side_out | corroborated | |
| OEM-X-4 | Injector cylinder 6 | injector_out | MAXXECUMINI-C1-H1 | INJ 2 | injector_out | corroborated | |
| OEM-X-40 | O2 sensor signal ground | sensor_ground | MAXXECUMINI-C1-A2 + MAXXECUMINI-C1-B3 + MAXXECUMINI-C1-B4 + MAXXECUMINI-C1-D4 | TRIGGER GND + SENSOR GND + SENSOR GND + SENSOR GND | sensor_ground | corroborated | |
| OEM-X-41 | Mass air flow (MAF) signal | analog_in | MAXXECUMINI-C1-C3 | AIN 3 (0-5V) | analog_in | corroborated | |
| OEM-X-42 | Vehicle speed signal | digital_in | MAXXECUMINI-C1-B1 | DIN 1 (Hall only) | digital_in | corroborated | |
| OEM-X-43 | Crank position sensor (-) | sensor_ground | MAXXECUMINI-C1-A2 + MAXXECUMINI-C1-B3 + MAXXECUMINI-C1-B4 + MAXXECUMINI-C1-D4 | TRIGGER GND + SENSOR GND + SENSOR GND + SENSOR GND | sensor_ground | corroborated | |
| OEM-X-44 | Sensor ground (IAT/ECT/TPS) | sensor_ground | MAXXECUMINI-C1-A2 + MAXXECUMINI-C1-B3 + MAXXECUMINI-C1-B4 + MAXXECUMINI-C1-D4 | TRIGGER GND + SENSOR GND + SENSOR GND + SENSOR GND | sensor_ground | corroborated | |
| OEM-X-45 | Shield ground | shield | MAXXECUMINI-C1-D3 | GND Shield | shield | corroborated | |
| OEM-X-47 | Tachometer output | tacho_out | — | — | — | corroborated | |
| OEM-X-5 | Injector cylinder 4 | injector_out | MAXXECUMINI-C1-H3 | INJ 4 | injector_out | corroborated | |
| OEM-X-50 | Ignition coil cylinder 1 | ignition_out | MAXXECUMINI-C1-F1 | IGN 1 | ignition_out | corroborated | |
| OEM-X-51 | Ignition coil cylinder 2 | ignition_out | MAXXECUMINI-C1-F2 | IGN 2 | ignition_out | corroborated | |
| OEM-X-52 | Ignition coil cylinder 3 | ignition_out | MAXXECUMINI-C1-F3 | IGN 3 | ignition_out | corroborated | |
| OEM-X-54 | ECU power (+14V from main relay) | power_in | MAXXECUMINI-C1-H4 | +12V (ECU power supply) | power_in | corroborated | |
| OEM-X-55 | Ground (ignition) | ground | MAXXECUMINI-C1-G4 | ENGINE GND | ground | corroborated | |
| OEM-X-56 | Ignition switch (terminal 15) | digital_in | — | — | — | corroborated | |
| OEM-X-59 | +5V sensor supply | vref | MAXXECUMINI-C1-E2 | +5V sensor supply | vref | corroborated | |
| OEM-X-6 | Ground (injector output stages) | ground | MAXXECUMINI-C1-G4 | ENGINE GND | 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 | — | — | — | corroborated | |
| OEM-X-71 | Knock sensor ground/shield | sensor_ground | MAXXECUMINI-C1-A2 + MAXXECUMINI-C1-B3 + MAXXECUMINI-C1-B4 + MAXXECUMINI-C1-D4 | TRIGGER GND + SENSOR GND + SENSOR GND + SENSOR GND | sensor_ground | corroborated | |
| OEM-X-73 | Throttle position (TPS) | analog_in | MAXXECUMINI-C1-D2 | TPS | analog_in | corroborated | |
| OEM-X-77 | Intake air temperature (IAT) | temp_in | MAXXECUMINI-C1-C2 | IAT | temp_in | corroborated | |
| OEM-X-78 | Engine coolant temperature (ECT) | temp_in | MAXXECUMINI-C1-C1 | CLT | 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 | MAXXECUMINI-C1-H4 | 0.85 | no route | +12V (ECU power supply) | — | |
| 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 | MAXXECUMINI-C1-G4 | 0.85 | no route | ENGINE GND | — | |
| W8 | OEM-X-28 | SP-0V-1 | 0.5 | no route | Ground (electronics + sensor shielding) | — | |
| W9 | OEM-X-40 | SP-0V-1 | 0.5 | no route | O2 sensor signal ground | — | |
| W10 | OEM-X-43 | SP-0V-1 | 0.5 | no route | Crank position sensor (-) | — | |
| W11 | OEM-X-44 | SP-0V-1 | 0.5 | no route | Sensor ground (IAT/ECT/TPS) | — | |
| W12 | OEM-X-71 | SP-0V-1 | 0.5 | no route | Knock sensor ground/shield | — | |
| W13 | SP-0V-1 | MAXXECUMINI-C1-A2 | 0.5 | no route | TRIGGER GND | — | |
| W14 | SP-0V-1 | MAXXECUMINI-C1-B3 | 0.5 | no route | SENSOR GND | — | |
| W15 | SP-0V-1 | MAXXECUMINI-C1-B4 | 0.5 | no route | SENSOR GND | — | |
| W16 | SP-0V-1 | MAXXECUMINI-C1-D4 | 0.5 | no route | SENSOR GND | — | |
| W17 | OEM-X-59 | MAXXECUMINI-C1-E2 | 0.5 | no route | +5V sensor supply | — | |
| W18 | OEM-X-16 | MAXXECUMINI-C1-A1 | 0.5 | no route | Crank position sensor (+) | — | |
| W19 | OEM-X-50 | MAXXECUMINI-C1-F1 | 0.5 | no route | Ignition coil cylinder 1 | — | |
| W20 | OEM-X-51 | MAXXECUMINI-C1-F2 | 0.5 | no route | Ignition coil cylinder 2 | — | |
| W21 | OEM-X-52 | MAXXECUMINI-C1-F3 | 0.5 | no route | Ignition coil cylinder 3 | — | |
| W22 | OEM-X-23 | MAXXECUMINI-C1-F4 | 0.5 | no route | Ignition coil cylinder 4 | — | |
| W23 | OEM-X-33 | MAXXECUMINI-C1-G3 | 0.5 | no route | Injector cylinder 1 | — | |
| W24 | OEM-X-32 | MAXXECUMINI-C1-H1 | 0.5 | no route | Injector cylinder 2 | — | |
| W25 | OEM-X-31 | MAXXECUMINI-C1-H2 | 0.5 | no route | Injector cylinder 3 | — | |
| W26 | OEM-X-5 | MAXXECUMINI-C1-H3 | 0.5 | no route | Injector cylinder 4 | — | |
| W27 | OEM-X-3 | MAXXECUMINI-C1-G3 | 0.5 | no route | Injector cylinder 5 | — | |
| W28 | OEM-X-4 | MAXXECUMINI-C1-H1 | 0.5 | no route | Injector cylinder 6 | — | |
| W29 | OEM-X-45 | SP-SHD-1 | 0.5 | no route | Shield ground | — | |
| W30 | SP-SHD-1 | MAXXECUMINI-C1-D3 | 0.5 | no route | GND Shield | — | |
| W31 | OEM-X-1 | MAXXECUMINI-C1-G2 | 0.5 | no route | Fuel pump relay control | — | |
| W32 | OEM-X-27 | MAXXECUMINI-C1-G1 | 0.5 | no route | Main relay control | — | |
| W33 | OEM-X-41 | MAXXECUMINI-C1-C3 | 0.5 | no route | Mass air flow (MAF) signal | — | |
| W34 | OEM-X-73 | MAXXECUMINI-C1-D2 | 0.5 | no route | Throttle position (TPS) | — | |
| W35 | OEM-X-78 | MAXXECUMINI-C1-C1 | 0.5 | no route | Engine coolant temperature (ECT) | — | |
| W36 | OEM-X-38 | MAXXECUMINI-C1-E1 | 0.5 | no route | O2 sensor heater relay control | — | |
| W37 | OEM-X-2 | MAXXECUMINI-C1-D1 | 0.5 | no route | Idle speed control valve (close winding) | — | |
| W38 | OEM-X-13 | MAXXECUMINI-C1-C4 | 0.5 | no route | O2 sensor signal | — | |
| W39 | OEM-X-77 | MAXXECUMINI-C1-C2 | 0.5 | no route | Intake air temperature (IAT) | — | |
| W40 | OEM-X-42 | MAXXECUMINI-C1-B1 | 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 (6)
| Severity | Code | Subject | Message |
|---|---|---|---|
| error | NET_MERGED | MAXXECUMINI-C1-G3 + 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 | NET_MERGED | MAXXECUMINI-C1-H1 + 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 | REQUIRED_UNMAPPED | OEM-X-17 | Required OEM function "Camshaft position sensor (Hall)" (trigger_in) is not connected to the new ECU. |
| 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 | 8 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-70 Knock sensor cylinders 1-3; 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 17: Camshaft position sensor (Hall): no free cam_hall/cam_vr/frequency_in input on MaxxECU MaxxECU MINI - OEM-X 25: Ignition coil cylinder 5: no free ignition output on MaxxECU MaxxECU MINI - OEM-X 24: Ignition coil cylinder 6: no free ignition output on MaxxECU MaxxECU MINI Not wired: - OEM-X 26: Battery voltage (constant +12V): MaxxECU MaxxECU MINI has no battery-constant input; not needed - OEM-X 70: Knock sensor cylinders 1-3: no free knock input on MaxxECU MaxxECU MINI - OEM-X 69: Knock sensor cylinders 4-6: no free knock input on MaxxECU MaxxECU MINI - 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); MaxxECU MaxxECU MINI has no dedicated key-on input - OEM-X 29: Idle speed control valve (open winding): no free low_side/relay_control/heater_low_side/ls_hs/injector on MaxxECU MaxxECU MINI - OEM-X 36: Evap purge solenoid: no free low_side/relay_control/heater_low_side/ls_hs/injector on MaxxECU MaxxECU MINI - OEM-X 7: VANOS intake camshaft solenoid: no free low_side/relay_control/heater_low_side/ls_hs/injector on MaxxECU MaxxECU MINI - OEM-X 8: Check engine light (MIL): no free low_side/relay_control/heater_low_side/ls_hs/injector on MaxxECU MaxxECU MINI - OEM-X 47: Tachometer output: no free tacho/frequency_out/low_side/ls_hs on MaxxECU MaxxECU MINI
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 | MaxxECU GEN1 pinout (MINI / STREET / SPORT / V1 / RACE / PRO) | http://www.maxxecu.com/webhelp/wirings-maxxecu_pinout.html | archive | 2026-10-05 | 2e37b6814690 |
| 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/ | — | — | — |