VW Corrado VR6 12v (AAA) Motronic M2.9 OBD1 → Motorsport Electronics ME221 (auto)
VW Corrado VR6 12v (AAA) Motronic M2.9 OBD1 — Motorsport Electronics — ME221
⚠ 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 | 3: read the Findings page before cutting any wire |
| Size of the job | 46 wires · 5 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-23 | SP-14V-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W2 | SP-14V-1 | ME221-C1-15 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W3 | SP-14V-1 | ME221-C1-64 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W4 | OEM-A-1 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W5 | OEM-A-10 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W6 | OEM-A-55 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W7 | OEM-A-56 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | OEM-A-7 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | SP-GND-1 | ME221-C1-10 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | SP-GND-1 | ME221-C1-61 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | SP-GND-1 | ME221-C1-89 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | SP-GND-1 | ME221-C1-90 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | OEM-A-16 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | OEM-A-33 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | OEM-A-67 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | SP-0V-1 | ME221-C1-52 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | SP-0V-1 | ME221-C1-84 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-A-41 | ME221-C1-45 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-A-68 | ME221-C1-80 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-A-44 | ME221-C1-22 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-A-34 | ME221-C1-53 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-A-8 | ME221-C1-32 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-A-60 | ME221-C1-31 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-A-52 | ME221-C1-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-A-24 | ME221-C1-63 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-A-3 | ME221-C1-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-A-26 | ME221-C1-33 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-A-4 | ME221-C1-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-A-25 | ME221-C1-63 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | OEM-A-2 | ME221-C1-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-A-17 | ME221-C1-26 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-A-40 | ME221-C1-56 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-A-14 | ME221-C1-86 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-A-49 | ME221-C1-73 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W35 | OEM-A-6 | ME221-C1-12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W36 | OEM-A-9 | ME221-C1-74 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W37 | OEM-A-27 | ME221-C1-44 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W38 | OEM-A-31 | ME221-C1-69 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W39 | OEM-A-5 | ME221-C1-39 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W40 | OEM-A-53 | ME221-C1-37 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W41 | OEM-A-22 | ME221-C1-79 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W42 | OEM-A-20 | ME221-C1-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W43 | OEM-A-15 | ME221-C1-57 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W44 | OEM-A-36 | ME221-C1-18 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W45 | OEM-A-65 | ME221-C1-6 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W46 | OEM-A-37 | ME221-C1-7 | 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 | ME221-C1-10 | ME221-C1-15 | open (OL) | power ground must not touch +12 V supply | |
| 2 | ME221-C1-10 | ME221-C1-45 | open (OL) | power ground must not touch 5 V sensor reference | |
| 3 | ME221-C1-15 | ME221-C1-45 | open (OL) | +12 V supply must not touch 5 V sensor reference | |
| 4 | ME221-C1-52 | ME221-C1-15 | open (OL) | sensor ground must not touch +12 V supply | |
| 5 | ME221-C1-52 | ME221-C1-45 | open (OL) | sensor 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
ME221-C1
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | COIL 4 | — | — | — | — | — | — | — | — |
| 10 | GROUND CHASSIS | — | W9 | — | 0.85 | SP-GND-1 | — | — | — |
| 12 | LOW SIDE 2 | — | W35 | — | 0.5 | OEM-A-6 | — | — | — |
| 14 | LSU +12V | — | — | — | — | — | — | — | — |
| 15 | IGN +12V | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
| 16 | LSU HEATER -VE | — | — | — | — | — | — | — | — |
| 17 | ANA VOLT 3 | — | W42 | — | 0.5 | OEM-A-20 | — | — | — |
| 18 | ANA VOLT 4 | — | W44 | — | 0.5 | OEM-A-36 | — | — | — |
| 19 | LSU UN | — | — | — | — | — | — | — | — |
| 2 | COIL 3 | — | W24 | — | 0.5 | OEM-A-52 | — | — | — |
| 20 | LSU VM | — | — | — | — | — | — | — | — |
| 21 | CAN 1 HIGH | — | — | — | — | — | — | — | — |
| 22 | CAM A VR+ | — | W20 | — | 0.5 | OEM-A-44 | — | — | — |
| 23 | CAM A VR- | — | — | — | — | — | — | — | — |
| 24 | SERIAL 1 GROUND | — | — | — | — | — | — | — | — |
| 25 | SERIAL 1 TX | — | — | — | — | — | — | — | — |
| 26 | ANA VOLT 1 | — | W31 | — | 0.5 | OEM-A-17 | — | — | — |
| 3 | INJECTOR 4 | — | W28 | — | 0.5 | OEM-A-4 | — | — | — |
| 31 | COIL 2 | — | W23 | — | 0.5 | OEM-A-60 | — | — | — |
| 32 | COIL 1 | — | W22 | — | 0.5 | OEM-A-8 | — | — | — |
| 33 | INJECTOR 3 | — | W27 | — | 0.5 | OEM-A-26 | — | — | — |
| 35 | USB D+ | — | — | — | — | — | — | — | — |
| 36 | USB D- | — | — | — | — | — | — | — | — |
| 37 | LOW SIDE RELAY 11 | — | W40 | — | 0.5 | OEM-A-53 | — | — | — |
| 38 | USB VBUS | — | — | — | — | — | — | — | — |
| 39 | LOW SIDE 6 | — | W39 | — | 0.5 | OEM-A-5 | — | — | — |
| 4 | INJECTOR 2 | — | W26 | — | 0.5 | OEM-A-3 | — | — | — |
| 4 | INJECTOR 2 | — | W30 | — | 0.5 | OEM-A-2 | — | — | — |
| 41 | USB GROUND | — | — | — | — | — | — | — | — |
| 42 | LOW SIDE RELAY 12 | — | — | — | — | — | — | — | — |
| 43 | LOW SIDE RELAY 14 | — | — | — | — | — | — | — | — |
| 44 | LOW SIDE 4 | — | W37 | — | 0.5 | OEM-A-27 | — | — | — |
| 45 | 5V REF | — | W18 | — | 0.5 | OEM-A-41 | — | — | — |
| 46 | 5V REF | — | — | — | — | — | — | — | — |
| 49 | LSU IA | — | — | — | — | — | — | — | — |
| 50 | LSU IP | — | — | — | — | — | — | — | — |
| 51 | CAN 1 LOW | — | — | — | — | — | — | — | — |
| 52 | SENSORS GROUND | — | W16 | — | 0.5 | SP-0V-1 | — | — | — |
| 53 | KNOCK 1 SIGNAL | — | W21 | — | 0.5 | OEM-A-34 | — | — | — |
| 55 | SERIAL 1 RX | — | — | — | — | — | — | — | — |
| 56 | ANA VOLT 2 | — | W32 | — | 0.5 | OEM-A-40 | — | — | — |
| 57 | ANA TEMP 2 | — | W43 | — | 0.5 | OEM-A-15 | — | — | — |
| 6 | DIG_IN 1 | — | W45 | — | 0.5 | OEM-A-65 | — | — | — |
| 61 | GROUND | — | W10 | — | 0.85 | SP-GND-1 | — | — | — |
| 63 | INJECTOR 1 | — | W25 | — | 0.5 | OEM-A-24 | — | — | — |
| 63 | INJECTOR 1 | — | W29 | — | 0.5 | OEM-A-25 | — | — | — |
| 64 | VBAT | — | W3 | — | 0.85 | SP-14V-1 | — | — | — |
| 67 | Stepper 1 / A1 | — | — | — | — | — | — | — | — |
| 68 | Stepper 2 / A2 | — | — | — | — | — | — | — | — |
| 69 | LOW SIDE 5 | — | W38 | — | 0.5 | OEM-A-31 | — | — | — |
| 7 | DIG_IN 2 | — | W46 | — | 0.5 | OEM-A-37 | — | — | — |
| 70 | Stepper 3 / B1 | — | — | — | — | — | — | — | — |
| 71 | Stepper 4 / B2 | — | — | — | — | — | — | — | — |
| 72 | LOW SIDE RELAY 13 | — | — | — | — | — | — | — | — |
| 73 | LOW SIDE 1 | — | W34 | — | 0.5 | OEM-A-49 | — | — | — |
| 74 | LOW SIDE 3 | — | W36 | — | 0.5 | OEM-A-9 | — | — | — |
| 76 | 5V REF | — | — | — | — | — | — | — | — |
| 79 | TACHOMETER | — | W41 | — | 0.5 | OEM-A-22 | — | — | — |
| 80 | CRANK VR+ | — | W19 | — | 0.5 | OEM-A-68 | — | — | — |
| 81 | CRANK VR- | — | — | — | — | — | — | — | — |
| 84 | Sensor Ground | — | W17 | — | 0.5 | SP-0V-1 | — | — | — |
| 86 | ANA TEMP 1 | — | W33 | — | 0.5 | OEM-A-14 | — | — | — |
| 89 | GROUND | — | W11 | — | 0.85 | SP-GND-1 | — | — | — |
| 90 | GROUND | — | W12 | — | 0.85 | SP-GND-1 | — | — | — |
OEM-A
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Ground (E-1) | — | W4 | — | 0.85 | SP-GND-1 | — | — | — |
| 10 | Ground (OBD1 EGR enable) | — | W5 | — | 0.85 | SP-GND-1 | — | — | — |
| 14 | Coolant temperature (CLT) | — | W33 | — | 0.5 | ME221-C1-86 | — | — | — |
| 15 | EGR temperature sensor | — | W43 | — | 0.5 | ME221-C1-57 | — | — | — |
| 16 | MAF ground | — | W13 | — | 0.5 | SP-0V-1 | — | — | — |
| 17 | MAF signal | — | W31 | — | 0.5 | ME221-C1-26 | — | — | — |
| 2 | Injector 6 (cyl 6) | — | W30 | — | 0.5 | ME221-C1-4 | — | — | — |
| 20 | O2 sensor 1 (primary) | — | W42 | — | 0.5 | ME221-C1-17 | — | — | — |
| 21 | Diagnostic L-line | — | — | — | — | — | — | — | — |
| 22 | Tachometer output | — | W41 | — | 0.5 | ME221-C1-79 | — | — | — |
| 23 | ECU main power (from engine-electronics relay) | — | W1 | — | 0.85 | SP-14V-1 | — | — | — |
| 24 | Injector 1 (cyl 1) | — | W25 | — | 0.5 | ME221-C1-63 | — | — | — |
| 25 | Injector 5 (cyl 5) | — | W29 | — | 0.5 | ME221-C1-63 | — | — | — |
| 26 | Injector 3 (cyl 3) | — | W27 | — | 0.5 | ME221-C1-33 | — | — | — |
| 27 | Idle air control valve | — | W37 | — | 0.5 | ME221-C1-44 | — | — | — |
| 3 | Injector 2 (cyl 2) | — | W26 | — | 0.5 | ME221-C1-4 | — | — | — |
| 31 | EVAP canister purge valve | — | W38 | — | 0.5 | ME221-C1-69 | — | — | — |
| 33 | Sensor ground bus | — | W14 | — | 0.5 | SP-0V-1 | — | — | — |
| 34 | Knock sensor 1 | — | W21 | — | 0.5 | ME221-C1-53 | — | — | — |
| 36 | Intake air temperature (IAT) | — | W44 | — | 0.5 | ME221-C1-18 | — | — | — |
| 37 | A/C compressor switch | — | W46 | — | 0.5 | ME221-C1-7 | — | — | — |
| 38 | Ignition switch (run/start) | — | — | — | — | — | — | — | — |
| 39 | A/C switch (cabin) | — | — | — | — | — | — | — | — |
| 4 | Injector 4 (cyl 4) | — | W28 | — | 0.5 | ME221-C1-3 | — | — | — |
| 40 | Throttle position sensor 1 | — | W32 | — | 0.5 | ME221-C1-56 | — | — | — |
| 41 | TPS power (+5V) | — | W18 | — | 0.5 | ME221-C1-45 | — | — | — |
| 43 | Diagnostic K-line | — | — | — | — | — | — | — | — |
| 44 | Camshaft position sensor (G40) | — | W20 | — | 0.5 | ME221-C1-22 | — | — | — |
| 49 | Secondary air injection relay control | — | W34 | — | 0.5 | ME221-C1-73 | — | — | — |
| 5 | Check engine light (MIL) | — | W39 | — | 0.5 | ME221-C1-39 | — | — | — |
| 51 | MFA fuel-consumption signal | — | — | — | — | — | — | — | — |
| 52 | Ignition coil 4 (coil pack pin 4) | — | W24 | — | 0.5 | ME221-C1-2 | — | — | — |
| 53 | Idle air control valve (2nd) | — | W40 | — | 0.5 | ME221-C1-37 | — | — | — |
| 54 | Battery constant (+12V) | — | — | — | — | — | — | — | — |
| 55 | Ground (E-3) | — | W6 | — | 0.85 | SP-GND-1 | — | — | — |
| 56 | Ground (E-4) | — | W7 | — | 0.85 | SP-GND-1 | — | — | — |
| 59 | Mass airflow sensor (5th terminal) | — | — | — | — | — | — | — | — |
| 6 | Fuel pump relay control | — | W35 | — | 0.5 | ME221-C1-12 | — | — | — |
| 60 | Ignition coil 3 (coil pack pin 3) | — | W23 | — | 0.5 | ME221-C1-31 | — | — | — |
| 65 | Vehicle speed sensor (VSS) | — | W45 | — | 0.5 | ME221-C1-6 | — | — | — |
| 67 | Crank sensor return (VR-) | — | W15 | — | 0.5 | SP-0V-1 | — | — | — |
| 68 | Crank position sensor (G28, VR+) | — | W19 | — | 0.5 | ME221-C1-80 | — | — | — |
| 7 | Ground (E-2) | — | W8 | — | 0.85 | SP-GND-1 | — | — | — |
| 8 | Ignition coil 2 (coil pack pin 2) | — | W22 | — | 0.5 | ME221-C1-32 | — | — | — |
| 9 | Engine electronics relay control | — | W36 | — | 0.5 | ME221-C1-74 | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W13 | — | 0.5 | OEM-A-16 | — | — | — |
| 1 | — | — | W14 | — | 0.5 | OEM-A-33 | — | — | — |
| 1 | — | — | W15 | — | 0.5 | OEM-A-67 | — | — | — |
| 1 | — | — | W16 | — | 0.5 | ME221-C1-52 | — | — | — |
| 1 | — | — | W17 | — | 0.5 | ME221-C1-84 | — | — | — |
SP-14V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W1 | — | 0.85 | OEM-A-23 | — | — | — |
| 1 | — | — | W2 | — | 0.85 | ME221-C1-15 | — | — | — |
| 1 | — | — | W3 | — | 0.85 | ME221-C1-64 | — | — | — |
SP-GND
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W4 | — | 0.85 | OEM-A-1 | — | — | — |
| 1 | — | — | W5 | — | 0.85 | OEM-A-10 | — | — | — |
| 1 | — | — | W6 | — | 0.85 | OEM-A-55 | — | — | — |
| 1 | — | — | W7 | — | 0.85 | OEM-A-56 | — | — | — |
| 1 | — | — | W8 | — | 0.85 | OEM-A-7 | — | — | — |
| 1 | — | — | W9 | — | 0.85 | ME221-C1-10 | — | — | — |
| 1 | — | — | W10 | — | 0.85 | ME221-C1-61 | — | — | — |
| 1 | — | — | W11 | — | 0.85 | ME221-C1-89 | — | — | — |
| 1 | — | — | W12 | — | 0.85 | ME221-C1-90 | — | — | — |
Pin map
| OEM point | OEM function | OEM family | Target point | Target function | Target family | Wire colour | Evidence |
|---|---|---|---|---|---|---|---|
| OEM-A-1 | Ground (E-1) | ground | ME221-C1-10 + ME221-C1-61 + ME221-C1-89 + ME221-C1-90 | GROUND CHASSIS + GROUND + GROUND + GROUND | ground | single_source | |
| OEM-A-10 | Ground (OBD1 EGR enable) | ground | ME221-C1-10 + ME221-C1-61 + ME221-C1-89 + ME221-C1-90 | GROUND CHASSIS + GROUND + GROUND + GROUND | ground | single_source | |
| OEM-A-14 | Coolant temperature (CLT) | temp_in | ME221-C1-86 | ANA TEMP 1 | temp_in | single_source | |
| OEM-A-15 | EGR temperature sensor | temp_in | ME221-C1-57 | ANA TEMP 2 | temp_in | single_source | |
| OEM-A-16 | MAF ground | sensor_ground | ME221-C1-52 + ME221-C1-84 | SENSORS GROUND + Sensor Ground | sensor_ground | single_source | |
| OEM-A-17 | MAF signal | analog_in | ME221-C1-26 | ANA VOLT 1 | analog_in | single_source | |
| OEM-A-2 | Injector 6 (cyl 6) | injector_out | ME221-C1-4 | INJECTOR 2 | injector_out | single_source | |
| OEM-A-20 | O2 sensor 1 (primary) | lambda_nb_in | ME221-C1-17 | ANA VOLT 3 | analog_in | single_source | |
| OEM-A-21 | Diagnostic L-line | serial | — | — | — | single_source | |
| OEM-A-22 | Tachometer output | tacho_out | ME221-C1-79 | TACHOMETER | tacho_out | single_source | |
| OEM-A-23 | ECU main power (from engine-electronics relay) | power_in | ME221-C1-15 + ME221-C1-64 | IGN +12V + VBAT | power_in | single_source | |
| OEM-A-24 | Injector 1 (cyl 1) | injector_out | ME221-C1-63 | INJECTOR 1 | injector_out | single_source | |
| OEM-A-25 | Injector 5 (cyl 5) | injector_out | ME221-C1-63 | INJECTOR 1 | injector_out | single_source | |
| OEM-A-26 | Injector 3 (cyl 3) | injector_out | ME221-C1-33 | INJECTOR 3 | injector_out | single_source | |
| OEM-A-27 | Idle air control valve | low_side_out | ME221-C1-44 | LOW SIDE 4 | low_side_out | single_source | |
| OEM-A-3 | Injector 2 (cyl 2) | injector_out | ME221-C1-4 | INJECTOR 2 | injector_out | single_source | |
| OEM-A-31 | EVAP canister purge valve | low_side_out | ME221-C1-69 | LOW SIDE 5 | low_side_out | single_source | |
| OEM-A-33 | Sensor ground bus | sensor_ground | ME221-C1-52 + ME221-C1-84 | SENSORS GROUND + Sensor Ground | sensor_ground | single_source | |
| OEM-A-34 | Knock sensor 1 | knock_in | ME221-C1-53 | KNOCK 1 SIGNAL | knock_in | single_source | |
| OEM-A-36 | Intake air temperature (IAT) | temp_in | ME221-C1-18 | ANA VOLT 4 | analog_in | single_source | |
| OEM-A-37 | A/C compressor switch | digital_in | ME221-C1-7 | DIG_IN 2 | digital_in | single_source | |
| OEM-A-38 | Ignition switch (run/start) | digital_in | — | — | — | single_source | |
| OEM-A-39 | A/C switch (cabin) | digital_in | — | — | — | single_source | |
| OEM-A-4 | Injector 4 (cyl 4) | injector_out | ME221-C1-3 | INJECTOR 4 | injector_out | single_source | |
| OEM-A-40 | Throttle position sensor 1 | analog_in | ME221-C1-56 | ANA VOLT 2 | analog_in | single_source | |
| OEM-A-41 | TPS power (+5V) | vref | ME221-C1-45 | 5V REF | vref | single_source | |
| OEM-A-43 | Diagnostic K-line | serial | — | — | — | single_source | |
| OEM-A-44 | Camshaft position sensor (G40) | trigger_in | ME221-C1-22 | CAM A VR+ | trigger_in | single_source | |
| OEM-A-49 | Secondary air injection relay control | low_side_out | ME221-C1-73 | LOW SIDE 1 | low_side_out | single_source | |
| OEM-A-5 | Check engine light (MIL) | low_side_out | ME221-C1-39 | LOW SIDE 6 | low_side_out | single_source | |
| OEM-A-51 | MFA fuel-consumption signal | tacho_out | — | — | — | single_source | |
| OEM-A-52 | Ignition coil 4 (coil pack pin 4) | ignition_out | ME221-C1-2 | COIL 3 | ignition_out | single_source | |
| OEM-A-53 | Idle air control valve (2nd) | low_side_out | ME221-C1-37 | LOW SIDE RELAY 11 | low_side_out | single_source | |
| OEM-A-54 | Battery constant (+12V) | power_in | — | — | — | single_source | |
| OEM-A-55 | Ground (E-3) | ground | ME221-C1-10 + ME221-C1-61 + ME221-C1-89 + ME221-C1-90 | GROUND CHASSIS + GROUND + GROUND + GROUND | ground | single_source | |
| OEM-A-56 | Ground (E-4) | ground | ME221-C1-10 + ME221-C1-61 + ME221-C1-89 + ME221-C1-90 | GROUND CHASSIS + GROUND + GROUND + GROUND | ground | single_source | |
| OEM-A-59 | Mass airflow sensor (5th terminal) | sensor_out | — | — | — | single_source | |
| OEM-A-6 | Fuel pump relay control | low_side_out | ME221-C1-12 | LOW SIDE 2 | low_side_out | single_source | |
| OEM-A-60 | Ignition coil 3 (coil pack pin 3) | ignition_out | ME221-C1-31 | COIL 2 | ignition_out | single_source | |
| OEM-A-65 | Vehicle speed sensor (VSS) | digital_in | ME221-C1-6 | DIG_IN 1 | digital_in | single_source | |
| OEM-A-67 | Crank sensor return (VR-) | sensor_ground | ME221-C1-52 + ME221-C1-84 | SENSORS GROUND + Sensor Ground | sensor_ground | single_source | |
| OEM-A-68 | Crank position sensor (G28, VR+) | trigger_in | ME221-C1-80 | CRANK VR+ | trigger_in | single_source | |
| OEM-A-7 | Ground (E-2) | ground | ME221-C1-10 + ME221-C1-61 + ME221-C1-89 + ME221-C1-90 | GROUND CHASSIS + GROUND + GROUND + GROUND | ground | single_source | |
| OEM-A-8 | Ignition coil 2 (coil pack pin 2) | ignition_out | ME221-C1-32 | COIL 1 | ignition_out | single_source | |
| OEM-A-9 | Engine electronics relay control | low_side_out | ME221-C1-74 | LOW SIDE 3 | low_side_out | single_source |
Cut list
| Wire | From | To | Gauge (mm²) | Colour | Length | Signal | Ident |
|---|---|---|---|---|---|---|---|
| W1 | OEM-A-23 | SP-14V-1 | 0.85 | no route | ECU main power (from engine-electronics relay) | — | |
| W2 | SP-14V-1 | ME221-C1-15 | 0.85 | no route | IGN +12V | — | |
| W3 | SP-14V-1 | ME221-C1-64 | 0.85 | no route | VBAT | — | |
| W4 | OEM-A-1 | SP-GND-1 | 0.85 | no route | Ground (E-1) | — | |
| W5 | OEM-A-10 | SP-GND-1 | 0.85 | no route | Ground (OBD1 EGR enable) | — | |
| W6 | OEM-A-55 | SP-GND-1 | 0.85 | no route | Ground (E-3) | — | |
| W7 | OEM-A-56 | SP-GND-1 | 0.85 | no route | Ground (E-4) | — | |
| W8 | OEM-A-7 | SP-GND-1 | 0.85 | no route | Ground (E-2) | — | |
| W9 | SP-GND-1 | ME221-C1-10 | 0.85 | no route | GROUND CHASSIS | — | |
| W10 | SP-GND-1 | ME221-C1-61 | 0.85 | no route | GROUND | — | |
| W11 | SP-GND-1 | ME221-C1-89 | 0.85 | no route | GROUND | — | |
| W12 | SP-GND-1 | ME221-C1-90 | 0.85 | no route | GROUND | — | |
| W13 | OEM-A-16 | SP-0V-1 | 0.5 | no route | MAF ground | — | |
| W14 | OEM-A-33 | SP-0V-1 | 0.5 | no route | Sensor ground bus | — | |
| W15 | OEM-A-67 | SP-0V-1 | 0.5 | no route | Crank sensor return (VR-) | — | |
| W16 | SP-0V-1 | ME221-C1-52 | 0.5 | no route | SENSORS GROUND | — | |
| W17 | SP-0V-1 | ME221-C1-84 | 0.5 | no route | Sensor Ground | — | |
| W18 | OEM-A-41 | ME221-C1-45 | 0.5 | no route | TPS power (+5V) | — | |
| W19 | OEM-A-68 | ME221-C1-80 | 0.5 | no route | Crank position sensor (G28, VR+) | — | |
| W20 | OEM-A-44 | ME221-C1-22 | 0.5 | no route | Camshaft position sensor (G40) | — | |
| W21 | OEM-A-34 | ME221-C1-53 | 0.5 | no route | Knock sensor 1 | — | |
| W22 | OEM-A-8 | ME221-C1-32 | 0.5 | no route | Ignition coil 2 (coil pack pin 2) | — | |
| W23 | OEM-A-60 | ME221-C1-31 | 0.5 | no route | Ignition coil 3 (coil pack pin 3) | — | |
| W24 | OEM-A-52 | ME221-C1-2 | 0.5 | no route | Ignition coil 4 (coil pack pin 4) | — | |
| W25 | OEM-A-24 | ME221-C1-63 | 0.5 | no route | Injector 1 (cyl 1) | — | |
| W26 | OEM-A-3 | ME221-C1-4 | 0.5 | no route | Injector 2 (cyl 2) | — | |
| W27 | OEM-A-26 | ME221-C1-33 | 0.5 | no route | Injector 3 (cyl 3) | — | |
| W28 | OEM-A-4 | ME221-C1-3 | 0.5 | no route | Injector 4 (cyl 4) | — | |
| W29 | OEM-A-25 | ME221-C1-63 | 0.5 | no route | Injector 5 (cyl 5) | — | |
| W30 | OEM-A-2 | ME221-C1-4 | 0.5 | no route | Injector 6 (cyl 6) | — | |
| W31 | OEM-A-17 | ME221-C1-26 | 0.5 | no route | MAF signal | — | |
| W32 | OEM-A-40 | ME221-C1-56 | 0.5 | no route | Throttle position sensor 1 | — | |
| W33 | OEM-A-14 | ME221-C1-86 | 0.5 | no route | Coolant temperature (CLT) | — | |
| W34 | OEM-A-49 | ME221-C1-73 | 0.5 | no route | Secondary air injection relay control | — | |
| W35 | OEM-A-6 | ME221-C1-12 | 0.5 | no route | Fuel pump relay control | — | |
| W36 | OEM-A-9 | ME221-C1-74 | 0.5 | no route | Engine electronics relay control | — | |
| W37 | OEM-A-27 | ME221-C1-44 | 0.5 | no route | Idle air control valve | — | |
| W38 | OEM-A-31 | ME221-C1-69 | 0.5 | no route | EVAP canister purge valve | — | |
| W39 | OEM-A-5 | ME221-C1-39 | 0.5 | no route | Check engine light (MIL) | — | |
| W40 | OEM-A-53 | ME221-C1-37 | 0.5 | no route | Idle air control valve (2nd) | — | |
| W41 | OEM-A-22 | ME221-C1-79 | 0.5 | no route | Tachometer output | — | |
| W42 | OEM-A-20 | ME221-C1-17 | 0.5 | no route | O2 sensor 1 (primary) | — | |
| W43 | OEM-A-15 | ME221-C1-57 | 0.5 | no route | EGR temperature sensor | — | |
| W44 | OEM-A-36 | ME221-C1-18 | 0.5 | no route | Intake air temperature (IAT) | — | |
| W45 | OEM-A-65 | ME221-C1-6 | 0.5 | no route | Vehicle speed sensor (VSS) | — | |
| W46 | OEM-A-37 | ME221-C1-7 | 0.5 | no route | A/C compressor switch | — |
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 (5)
| Severity | Code | Subject | Message |
|---|---|---|---|
| error | NET_MERGED | ME221-C1-4 + OEM-A-2 + OEM-A-3 | 2 different OEM functions share one net: OEM-A-2 Injector 6 (cyl 6); OEM-A-3 Injector 2 (cyl 2) |
| error | NET_MERGED | ME221-C1-63 + OEM-A-24 + OEM-A-25 | 2 different OEM functions share one net: OEM-A-24 Injector 1 (cyl 1); OEM-A-25 Injector 5 (cyl 5) |
| error | REQUIRED_UNMAPPED | OEM-A-38 | Required OEM function "Ignition switch (run/start)" (digital_in) is not connected to the new ECU. |
| info | NET_FAMILY | OEM-A-36 ↔ ME221-C1-18 | OEM-A-36 "Intake air temperature (IAT)" [temp_in] is wired to ME221-C1-18 "ANA VOLT 4" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one. |
| info | UNMAPPED | OEM | 5 optional OEM pins are not mapped: OEM-A-21 Diagnostic L-line; OEM-A-39 A/C switch (cabin); OEM-A-43 Diagnostic K-line; OEM-A-51 MFA fuel-consumption signal; OEM-A-59 Mass airflow sensor (5th terminal) |
Accepted (1)
| Code | Subject | Reason | By |
|---|---|---|---|
| REQUIRED_UNMAPPED | OEM-A-54 | 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-A 38: Ignition switch (run/start): key-on 12 V sense — optional in a swap (the main relay is energized from keyed 12 V, not from this pin); Motorsport Electronics ME221 has no dedicated key-on input Not wired: - OEM-A 54: Battery constant (+12V): Motorsport Electronics ME221 has no battery-constant input; not needed - OEM-A 51: MFA fuel-consumption signal: no free tacho/frequency_out/low_side/ls_hs on Motorsport Electronics ME221 - OEM-A 39: A/C switch (cabin): no free switch_in/frequency_in/analog_0_5 on Motorsport Electronics ME221 - OEM-A 21: Diagnostic L-line: no free k_line on Motorsport Electronics ME221 - OEM-A 43: Diagnostic K-line: no free k_line on Motorsport Electronics ME221 - OEM-A 59: Mass airflow sensor (5th terminal): no rule for class sensor_signal; wire by hand
Sources
| Reliability | Kind | Title | URL | Archive | Captured | SHA-256 |
|---|---|---|---|---|---|---|
| 4 | vendor_doc | Motorsport Electronics GEN2 ME221/ME360/ME442 wire-in pinout | https://motorsport-electronics.co.uk/onlinehelp/html/ME442ME360ME221GEN2Wire-InPinout.html | — | — | — |
| 2 | community_copy | a2resource: VR6/ABA Motronic M2.9 (OBD1) engine control unit pinout | http://www.a2resource.com/electrical/management/motronicvr6aba.html | — | — | — |