BMW 3 Series E36 1990–2000 (M50/M52) → AMP EFI MS3Pro Mini (auto)
BMW 3 Series E36 1990–2000 (M50/M52) — AMP EFI — MS3Pro 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 | 2: read the Findings page before cutting any wire |
| Size of the job | 37 wires · 5 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 | MS3PROMINI-A-1 | 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 | MS3PROMINI-A-22 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | SP-GND-1 | MS3PROMINI-A-23 | 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 | MS3PROMINI-A-21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | OEM-X-59 | MS3PROMINI-A-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | OEM-X-16 | MS3PROMINI-A-30 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-X-17 | MS3PROMINI-A-32 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-X-50 | MS3PROMINI-A-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-X-51 | MS3PROMINI-A-18 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-X-52 | MS3PROMINI-A-19 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-X-23 | MS3PROMINI-A-20 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-X-33 | MS3PROMINI-A-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-X-32 | MS3PROMINI-A-11 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-X-31 | MS3PROMINI-A-12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-X-5 | MS3PROMINI-A-5 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-X-3 | MS3PROMINI-A-6 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-X-4 | MS3PROMINI-A-7 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-X-1 | MS3PROMINI-A-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-X-27 | MS3PROMINI-A-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | OEM-X-41 | MS3PROMINI-A-13 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-X-73 | MS3PROMINI-A-28 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-X-78 | MS3PROMINI-A-26 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-X-38 | MS3PROMINI-A-8 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-X-2 | MS3PROMINI-A-9 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W35 | OEM-X-13 | MS3PROMINI-A-14 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W36 | OEM-X-77 | MS3PROMINI-A-27 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W37 | OEM-X-42 | MS3PROMINI-A-34 | 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 | MS3PROMINI-A-1 | MS3PROMINI-A-2 | open (OL) | +12 V supply must not touch 5 V sensor reference | |
| 2 | MS3PROMINI-A-21 | MS3PROMINI-A-1 | open (OL) | sensor ground must not touch +12 V supply | |
| 3 | MS3PROMINI-A-21 | MS3PROMINI-A-2 | open (OL) | sensor ground must not touch 5 V sensor reference | |
| 4 | MS3PROMINI-A-22 | MS3PROMINI-A-1 | open (OL) | power ground must not touch +12 V supply | |
| 5 | MS3PROMINI-A-22 | MS3PROMINI-A-2 | open (OL) | power ground 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
MS3PROMINI-A
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | 12V+ switched power in | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
| 10 | Injector out F | — | W22 | — | 0.5 | OEM-X-33 | — | — | — |
| 11 | Injector out G | — | W23 | — | 0.5 | OEM-X-32 | — | — | — |
| 12 | Injector out H | — | W24 | — | 0.5 | OEM-X-31 | — | — | — |
| 13 | Analog in 1 | — | W30 | — | 0.5 | OEM-X-41 | — | — | — |
| 14 | Analog in 2 | — | W35 | — | 0.5 | OEM-X-13 | — | — | — |
| 15 | Analog in 3 | — | — | — | — | — | — | — | — |
| 16 | Analog in 4 | — | — | — | — | — | — | — | — |
| 17 | Spark out A | — | W18 | — | 0.5 | OEM-X-50 | — | — | — |
| 18 | Spark out B | — | W19 | — | 0.5 | OEM-X-51 | — | — | — |
| 19 | Spark out C | — | W20 | — | 0.5 | OEM-X-52 | — | — | — |
| 2 | +5V VREF out | — | W15 | — | 0.5 | OEM-X-59 | — | — | — |
| 20 | Spark out D | — | W21 | — | 0.5 | OEM-X-23 | — | — | — |
| 21 | Sensor ground | — | W14 | — | 0.5 | SP-0V-1 | — | — | — |
| 22 | Power ground | — | W7 | — | 0.85 | SP-GND-1 | — | — | — |
| 23 | Power ground | — | W8 | — | 0.85 | SP-GND-1 | — | — | — |
| 24 | CAN Low | — | — | — | — | — | — | — | — |
| 25 | CAN High | — | — | — | — | — | — | — | — |
| 26 | CLT in | — | W32 | — | 0.5 | OEM-X-78 | — | — | — |
| 27 | IAT in | — | W36 | — | 0.5 | OEM-X-77 | — | — | — |
| 28 | TPS in | — | W31 | — | 0.5 | OEM-X-73 | — | — | — |
| 29 | Digital switched in 1 / Flex fuel | — | — | — | — | — | — | — | — |
| 3 | PWM out 1 / Idle | — | W29 | — | 0.5 | OEM-X-27 | — | — | — |
| 30 | CKP+ | — | W16 | — | 0.5 | OEM-X-16 | — | — | — |
| 31 | CKP- | — | — | — | — | — | — | — | — |
| 32 | CMP+ | — | W17 | — | 0.5 | OEM-X-17 | — | — | — |
| 33 | CMP- | — | — | — | — | — | — | — | — |
| 34 | Digital frequency in 1 (Hall) | — | W37 | — | 0.5 | OEM-X-42 | — | — | — |
| 35 | Digital frequency in 2 (Hall) | — | — | — | — | — | — | — | — |
| 4 | Fuel pump out | — | W28 | — | 0.5 | OEM-X-1 | — | — | — |
| 5 | Injector out A | — | W25 | — | 0.5 | OEM-X-5 | — | — | — |
| 6 | Injector out B | — | W26 | — | 0.5 | OEM-X-3 | — | — | — |
| 7 | Injector out C | — | W27 | — | 0.5 | OEM-X-4 | — | — | — |
| 8 | Injector out D | — | W33 | — | 0.5 | OEM-X-38 | — | — | — |
| 9 | Injector out E | — | W34 | — | 0.5 | OEM-X-2 | — | — | — |
OEM-X
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Fuel pump relay control | — | W28 | — | 0.5 | MS3PROMINI-A-4 | — | — | — |
| 13 | O2 sensor signal | — | W35 | — | 0.5 | MS3PROMINI-A-14 | — | — | — |
| 15 | Ground | — | W3 | — | 0.85 | SP-GND-1 | — | — | — |
| 16 | Crank position sensor (+) | — | W16 | — | 0.5 | MS3PROMINI-A-30 | — | — | — |
| 17 | Camshaft position sensor (Hall) | — | W17 | — | 0.5 | MS3PROMINI-A-32 | — | — | — |
| 2 | Idle speed control valve (close winding) | — | W34 | — | 0.5 | MS3PROMINI-A-9 | — | — | — |
| 23 | Ignition coil cylinder 4 | — | W21 | — | 0.5 | MS3PROMINI-A-20 | — | — | — |
| 24 | Ignition coil cylinder 6 | — | — | — | — | — | — | — | — |
| 25 | Ignition coil cylinder 5 | — | — | — | — | — | — | — | — |
| 26 | Battery voltage (constant +12V) | — | — | — | — | — | — | — | — |
| 27 | Main relay control | — | W29 | — | 0.5 | MS3PROMINI-A-3 | — | — | — |
| 28 | Ground (electronics + sensor shielding) | — | W9 | — | 0.5 | SP-0V-1 | — | — | — |
| 29 | Idle speed control valve (open winding) | — | — | — | — | — | — | — | — |
| 3 | Injector cylinder 5 | — | W26 | — | 0.5 | MS3PROMINI-A-6 | — | — | — |
| 31 | Injector cylinder 3 | — | W24 | — | 0.5 | MS3PROMINI-A-12 | — | — | — |
| 32 | Injector cylinder 2 | — | W23 | — | 0.5 | MS3PROMINI-A-11 | — | — | — |
| 33 | Injector cylinder 1 | — | W22 | — | 0.5 | MS3PROMINI-A-10 | — | — | — |
| 34 | Ground (output stages) | — | W4 | — | 0.85 | SP-GND-1 | — | — | — |
| 36 | Evap purge solenoid | — | — | — | — | — | — | — | — |
| 38 | O2 sensor heater relay control | — | W33 | — | 0.5 | MS3PROMINI-A-8 | — | — | — |
| 4 | Injector cylinder 6 | — | W27 | — | 0.5 | MS3PROMINI-A-7 | — | — | — |
| 40 | O2 sensor signal ground | — | W10 | — | 0.5 | SP-0V-1 | — | — | — |
| 41 | Mass air flow (MAF) signal | — | W30 | — | 0.5 | MS3PROMINI-A-13 | — | — | — |
| 42 | Vehicle speed signal | — | W37 | — | 0.5 | MS3PROMINI-A-34 | — | — | — |
| 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 | — | — | — | — | — | — | — | — |
| 47 | Tachometer output | — | — | — | — | — | — | — | — |
| 5 | Injector cylinder 4 | — | W25 | — | 0.5 | MS3PROMINI-A-5 | — | — | — |
| 50 | Ignition coil cylinder 1 | — | W18 | — | 0.5 | MS3PROMINI-A-17 | — | — | — |
| 51 | Ignition coil cylinder 2 | — | W19 | — | 0.5 | MS3PROMINI-A-18 | — | — | — |
| 52 | Ignition coil cylinder 3 | — | W20 | — | 0.5 | MS3PROMINI-A-19 | — | — | — |
| 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 | MS3PROMINI-A-2 | — | — | — |
| 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 | — | W13 | — | 0.5 | SP-0V-1 | — | — | — |
| 73 | Throttle position (TPS) | — | W31 | — | 0.5 | MS3PROMINI-A-28 | — | — | — |
| 77 | Intake air temperature (IAT) | — | W36 | — | 0.5 | MS3PROMINI-A-27 | — | — | — |
| 78 | Engine coolant temperature (ECT) | — | W32 | — | 0.5 | MS3PROMINI-A-26 | — | — | — |
| 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 | MS3PROMINI-A-21 | — | — | — |
SP-14V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W1 | — | 0.85 | OEM-X-54 | — | — | — |
| 1 | — | — | W2 | — | 0.85 | MS3PROMINI-A-1 | — | — | — |
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 | MS3PROMINI-A-22 | — | — | — |
| 1 | — | — | W8 | — | 0.85 | MS3PROMINI-A-23 | — | — | — |
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 | MS3PROMINI-A-4 | Fuel pump out | low_side_out | corroborated | |
| OEM-X-13 | O2 sensor signal | lambda_nb_in | MS3PROMINI-A-14 | Analog in 2 | analog_in | corroborated | |
| OEM-X-15 | Ground | ground | MS3PROMINI-A-22 + MS3PROMINI-A-23 | Power ground + Power ground | ground | corroborated | |
| OEM-X-16 | Crank position sensor (+) | trigger_in | MS3PROMINI-A-30 | CKP+ | trigger_in | corroborated | |
| OEM-X-17 | Camshaft position sensor (Hall) | trigger_in | MS3PROMINI-A-32 | CMP+ | trigger_in | corroborated | |
| OEM-X-2 | Idle speed control valve (close winding) | low_side_out | MS3PROMINI-A-9 | Injector out E | injector_out | corroborated | |
| OEM-X-23 | Ignition coil cylinder 4 | ignition_out | MS3PROMINI-A-20 | Spark out D | 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 | MS3PROMINI-A-3 | PWM out 1 / Idle | low_side_out | corroborated | |
| OEM-X-28 | Ground (electronics + sensor shielding) | sensor_ground | MS3PROMINI-A-21 | 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 | MS3PROMINI-A-6 | Injector out B | injector_out | corroborated | |
| OEM-X-31 | Injector cylinder 3 | injector_out | MS3PROMINI-A-12 | Injector out H | injector_out | corroborated | |
| OEM-X-32 | Injector cylinder 2 | injector_out | MS3PROMINI-A-11 | Injector out G | injector_out | corroborated | |
| OEM-X-33 | Injector cylinder 1 | injector_out | MS3PROMINI-A-10 | Injector out F | injector_out | corroborated | |
| OEM-X-34 | Ground (output stages) | ground | MS3PROMINI-A-22 + MS3PROMINI-A-23 | Power ground + Power ground | ground | corroborated | |
| OEM-X-36 | Evap purge solenoid | low_side_out | — | — | — | corroborated | |
| OEM-X-38 | O2 sensor heater relay control | low_side_out | MS3PROMINI-A-8 | Injector out D | injector_out | corroborated | |
| OEM-X-4 | Injector cylinder 6 | injector_out | MS3PROMINI-A-7 | Injector out C | injector_out | corroborated | |
| OEM-X-40 | O2 sensor signal ground | sensor_ground | MS3PROMINI-A-21 | Sensor ground | sensor_ground | corroborated | |
| OEM-X-41 | Mass air flow (MAF) signal | analog_in | MS3PROMINI-A-13 | Analog in 1 | analog_in | corroborated | |
| OEM-X-42 | Vehicle speed signal | digital_in | MS3PROMINI-A-34 | Digital frequency in 1 (Hall) | digital_in | corroborated | |
| OEM-X-43 | Crank position sensor (-) | sensor_ground | MS3PROMINI-A-21 | Sensor ground | sensor_ground | corroborated | |
| OEM-X-44 | Sensor ground (IAT/ECT/TPS) | sensor_ground | MS3PROMINI-A-21 | Sensor ground | sensor_ground | corroborated | |
| OEM-X-45 | Shield ground | shield | — | — | — | corroborated | |
| OEM-X-47 | Tachometer output | tacho_out | — | — | — | corroborated | |
| OEM-X-5 | Injector cylinder 4 | injector_out | MS3PROMINI-A-5 | Injector out A | injector_out | corroborated | |
| OEM-X-50 | Ignition coil cylinder 1 | ignition_out | MS3PROMINI-A-17 | Spark out A | ignition_out | corroborated | |
| OEM-X-51 | Ignition coil cylinder 2 | ignition_out | MS3PROMINI-A-18 | Spark out B | ignition_out | corroborated | |
| OEM-X-52 | Ignition coil cylinder 3 | ignition_out | MS3PROMINI-A-19 | Spark out C | ignition_out | corroborated | |
| OEM-X-54 | ECU power (+14V from main relay) | power_in | MS3PROMINI-A-1 | 12V+ switched power in | power_in | corroborated | |
| OEM-X-55 | Ground (ignition) | ground | MS3PROMINI-A-22 + MS3PROMINI-A-23 | Power ground + Power ground | ground | corroborated | |
| OEM-X-56 | Ignition switch (terminal 15) | digital_in | — | — | — | corroborated | |
| OEM-X-59 | +5V sensor supply | vref | MS3PROMINI-A-2 | +5V VREF out | vref | corroborated | |
| OEM-X-6 | Ground (injector output stages) | ground | MS3PROMINI-A-22 + MS3PROMINI-A-23 | Power ground + Power 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 | — | — | — | corroborated | |
| OEM-X-71 | Knock sensor ground/shield | sensor_ground | MS3PROMINI-A-21 | Sensor ground | sensor_ground | corroborated | |
| OEM-X-73 | Throttle position (TPS) | analog_in | MS3PROMINI-A-28 | TPS in | analog_in | corroborated | |
| OEM-X-77 | Intake air temperature (IAT) | temp_in | MS3PROMINI-A-27 | IAT in | temp_in | corroborated | |
| OEM-X-78 | Engine coolant temperature (ECT) | temp_in | MS3PROMINI-A-26 | CLT in | 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 | MS3PROMINI-A-1 | 0.85 | no route | 12V+ switched power in | — | |
| 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 | MS3PROMINI-A-22 | 0.85 | no route | Power ground | — | |
| W8 | SP-GND-1 | MS3PROMINI-A-23 | 0.85 | no route | Power 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 | MS3PROMINI-A-21 | 0.5 | no route | Sensor ground | — | |
| W15 | OEM-X-59 | MS3PROMINI-A-2 | 0.5 | no route | +5V sensor supply | — | |
| W16 | OEM-X-16 | MS3PROMINI-A-30 | 0.5 | no route | Crank position sensor (+) | — | |
| W17 | OEM-X-17 | MS3PROMINI-A-32 | 0.5 | no route | Camshaft position sensor (Hall) | — | |
| W18 | OEM-X-50 | MS3PROMINI-A-17 | 0.5 | no route | Ignition coil cylinder 1 | — | |
| W19 | OEM-X-51 | MS3PROMINI-A-18 | 0.5 | no route | Ignition coil cylinder 2 | — | |
| W20 | OEM-X-52 | MS3PROMINI-A-19 | 0.5 | no route | Ignition coil cylinder 3 | — | |
| W21 | OEM-X-23 | MS3PROMINI-A-20 | 0.5 | no route | Ignition coil cylinder 4 | — | |
| W22 | OEM-X-33 | MS3PROMINI-A-10 | 0.5 | no route | Injector cylinder 1 | — | |
| W23 | OEM-X-32 | MS3PROMINI-A-11 | 0.5 | no route | Injector cylinder 2 | — | |
| W24 | OEM-X-31 | MS3PROMINI-A-12 | 0.5 | no route | Injector cylinder 3 | — | |
| W25 | OEM-X-5 | MS3PROMINI-A-5 | 0.5 | no route | Injector cylinder 4 | — | |
| W26 | OEM-X-3 | MS3PROMINI-A-6 | 0.5 | no route | Injector cylinder 5 | — | |
| W27 | OEM-X-4 | MS3PROMINI-A-7 | 0.5 | no route | Injector cylinder 6 | — | |
| W28 | OEM-X-1 | MS3PROMINI-A-4 | 0.5 | no route | Fuel pump relay control | — | |
| W29 | OEM-X-27 | MS3PROMINI-A-3 | 0.5 | no route | Main relay control | — | |
| W30 | OEM-X-41 | MS3PROMINI-A-13 | 0.5 | no route | Mass air flow (MAF) signal | — | |
| W31 | OEM-X-73 | MS3PROMINI-A-28 | 0.5 | no route | Throttle position (TPS) | — | |
| W32 | OEM-X-78 | MS3PROMINI-A-26 | 0.5 | no route | Engine coolant temperature (ECT) | — | |
| W33 | OEM-X-38 | MS3PROMINI-A-8 | 0.5 | no route | O2 sensor heater relay control | — | |
| W34 | OEM-X-2 | MS3PROMINI-A-9 | 0.5 | no route | Idle speed control valve (close winding) | — | |
| W35 | OEM-X-13 | MS3PROMINI-A-14 | 0.5 | no route | O2 sensor signal | — | |
| W36 | OEM-X-77 | MS3PROMINI-A-27 | 0.5 | no route | Intake air temperature (IAT) | — | |
| W37 | OEM-X-42 | MS3PROMINI-A-34 | 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 | 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 | NET_FAMILY | OEM-X-2 ↔ MS3PROMINI-A-9 | OEM-X-2 "Idle speed control valve (close winding)" [low_side_out] is wired to MS3PROMINI-A-9 "Injector out E" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-X-38 ↔ MS3PROMINI-A-8 | OEM-X-38 "O2 sensor heater relay control" [low_side_out] is wired to MS3PROMINI-A-8 "Injector out D" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | UNMAPPED | OEM | 9 optional OEM pins are not mapped: OEM-X-29 Idle speed control valve (open winding); OEM-X-36 Evap purge solenoid; OEM-X-45 Shield ground; 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 25: Ignition coil cylinder 5: no free ignition output on AMP EFI MS3Pro Mini - OEM-X 24: Ignition coil cylinder 6: no free ignition output on AMP EFI MS3Pro Mini Not wired: - OEM-X 26: Battery voltage (constant +12V): AMP EFI MS3Pro Mini has no battery-constant input; not needed - OEM-X 70: Knock sensor cylinders 1-3: no free knock input on AMP EFI MS3Pro Mini - OEM-X 69: Knock sensor cylinders 4-6: no free knock input on AMP EFI MS3Pro Mini - OEM-X 45: Shield ground: no shield pin on AMP EFI MS3Pro 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); AMP EFI MS3Pro 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 AMP EFI MS3Pro Mini - OEM-X 36: Evap purge solenoid: no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI MS3Pro Mini - OEM-X 7: VANOS intake camshaft solenoid: no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI MS3Pro Mini - OEM-X 8: Check engine light (MIL): no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI MS3Pro Mini - OEM-X 47: Tachometer output: no free tacho/frequency_out/low_side/ls_hs on AMP EFI MS3Pro Mini
Sources
| Reliability | Kind | Title | URL | Archive | Captured | SHA-256 |
|---|---|---|---|---|---|---|
| 4 | vendor_doc | AMP EFI: MS3Pro Mini manual (fw 1.6.1) pinout & output ratings | https://cdn.shopify.com/s/files/1/0960/0014/7754/files/MS3Pro_User_Manual_Firmware_1.6.1_Mini.pdf?v=1760643335 | archive | 2026-10-05 | bed7d8ae8408 |
| 4 | vendor_doc | Link BMWLink E36X (G4X) plug-in install manual | https://linkecu.com/documentation/E36X.pdf | archive | 2026-10-05 | 010cda3acd08 |
| 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/ | — | — | — |