VW Golf Mk4 1.8T 20v (AUM, Bosch ME7.5) DBW → Motorsport Electronics ME221 (auto)
VW Golf Mk4 1.8T 20v (AUM, Bosch ME7.5) DBW — Motorsport Electronics — ME221
⚠ NOT CHECKED. Don't build from this.
Drawn by Michael Gnankou · Rev 0 · draft · 2026-10-23
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 | 62 wires · 7 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-T121-121 | SP-14V-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W2 | OEM-T121-21 | SP-14V-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W3 | SP-14V-1 | ME221-C1-15 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W4 | SP-14V-1 | ME221-C1-64 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W5 | OEM-T121-1 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W6 | OEM-T121-2 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W7 | SP-GND-1 | ME221-C1-10 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | SP-GND-1 | ME221-C1-61 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | SP-GND-1 | ME221-C1-89 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | SP-GND-1 | ME221-C1-90 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | OEM-T121-108 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | OEM-T121-29 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | OEM-T121-34 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | OEM-T121-36 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | OEM-T121-90 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | OEM-T121-91 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | SP-0V-1 | ME221-C1-52 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | SP-0V-1 | ME221-C1-84 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-T121-72 | SP-5V1-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-T121-98 | SP-5V1-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | SP-5V1-1 | ME221-C1-45 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-T121-73 | SP-5V2-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-T121-99 | SP-5V2-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | SP-5V2-1 | ME221-C1-46 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-T121-83 | ME221-C1-76 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-T121-82 | ME221-C1-80 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-T121-86 | ME221-C1-22 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-T121-106 | ME221-C1-53 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-T121-102 | ME221-C1-32 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | OEM-T121-95 | ME221-C1-31 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-T121-103 | ME221-C1-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-T121-94 | ME221-C1-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-T121-96 | ME221-C1-63 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-T121-89 | ME221-C1-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W35 | OEM-T121-97 | ME221-C1-33 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W36 | OEM-T121-88 | ME221-C1-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W37 | OEM-T121-118 | ME221-C1-68 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W38 | OEM-T121-117 | ME221-C1-67 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W39 | OEM-T121-53 | ME221-C1-26 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W40 | OEM-T121-101 | ME221-C1-56 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W41 | OEM-T121-33 | ME221-C1-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W42 | OEM-T121-84 | ME221-C1-18 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W43 | OEM-T121-93 | ME221-C1-86 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W44 | OEM-T121-65 | ME221-C1-73 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W45 | OEM-T121-66 | ME221-C1-12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W46 | OEM-T121-5 | ME221-C1-16 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W47 | OEM-T121-63 | ME221-C1-74 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W48 | OEM-T121-25 | ME221-C1-44 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W49 | OEM-T121-80 | ME221-C1-69 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W50 | OEM-T121-104 | ME221-C1-39 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W51 | OEM-T121-105 | ME221-C1-37 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W52 | OEM-T121-115 | ME221-C1-42 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W53 | OEM-T121-22 | ME221-C1-72 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W54 | OEM-T121-47 | ME221-C1-43 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W55 | OEM-T121-37 | ME221-C1-79 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W56 | OEM-T121-51 | ME221-C1-50 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W57 | OEM-T121-70 | ME221-C1-19 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W58 | OEM-T121-85 | ME221-C1-57 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W59 | OEM-T121-54 | ME221-C1-6 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W60 | OEM-T121-28 | ME221-C1-7 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W61 | OEM-T121-60 | ME221-C1-21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W62 | OEM-T121-58 | ME221-C1-51 | 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-C1-10 | ME221-C1-46 | open (OL) | power ground must not touch 5 V sensor reference | |
| 4 | ME221-C1-10 | ME221-C1-76 | open (OL) | power ground must not touch 5 V sensor reference | |
| 5 | ME221-C1-15 | ME221-C1-45 | open (OL) | +12 V supply must not touch 5 V sensor reference | |
| 6 | ME221-C1-15 | ME221-C1-46 | open (OL) | +12 V supply must not touch 5 V sensor reference | |
| 7 | ME221-C1-15 | ME221-C1-76 | open (OL) | +12 V supply must not touch 5 V sensor reference | |
| 8 | ME221-C1-52 | ME221-C1-15 | open (OL) | sensor ground must not touch +12 V supply | |
| 9 | ME221-C1-52 | ME221-C1-45 | open (OL) | sensor ground must not touch 5 V sensor reference | |
| 10 | ME221-C1-52 | ME221-C1-46 | open (OL) | sensor ground must not touch 5 V sensor reference | |
| 11 | ME221-C1-52 | ME221-C1-76 | 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 | — | W32 | — | 0.5 | OEM-T121-94 | — | — | — |
| 10 | GROUND CHASSIS | — | W7 | — | 0.85 | SP-GND-1 | — | — | — |
| 12 | LOW SIDE 2 | — | W45 | — | 0.5 | OEM-T121-66 | — | — | — |
| 14 | LSU +12V | — | — | — | — | — | — | — | — |
| 15 | IGN +12V | — | W3 | — | 0.85 | SP-14V-1 | — | — | — |
| 16 | LSU HEATER -VE | — | W46 | — | 0.5 | OEM-T121-5 | — | — | — |
| 17 | ANA VOLT 3 | — | W41 | — | 0.5 | OEM-T121-33 | — | — | — |
| 18 | ANA VOLT 4 | — | W42 | — | 0.5 | OEM-T121-84 | — | — | — |
| 19 | LSU UN | — | W57 | — | 0.5 | OEM-T121-70 | — | — | — |
| 2 | COIL 3 | — | W31 | — | 0.5 | OEM-T121-103 | — | — | — |
| 20 | LSU VM | — | — | — | — | — | — | — | — |
| 21 | CAN 1 HIGH | — | W61 | — | 0.5 | OEM-T121-60 | — | — | — |
| 22 | CAM A VR+ | — | W27 | — | 0.5 | OEM-T121-86 | — | — | — |
| 23 | CAM A VR- | — | — | — | — | — | — | — | — |
| 24 | SERIAL 1 GROUND | — | — | — | — | — | — | — | — |
| 25 | SERIAL 1 TX | — | — | — | — | — | — | — | — |
| 26 | ANA VOLT 1 | — | W39 | — | 0.5 | OEM-T121-53 | — | — | — |
| 3 | INJECTOR 4 | — | W36 | — | 0.5 | OEM-T121-88 | — | — | — |
| 31 | COIL 2 | — | W30 | — | 0.5 | OEM-T121-95 | — | — | — |
| 32 | COIL 1 | — | W29 | — | 0.5 | OEM-T121-102 | — | — | — |
| 33 | INJECTOR 3 | — | W35 | — | 0.5 | OEM-T121-97 | — | — | — |
| 35 | USB D+ | — | — | — | — | — | — | — | — |
| 36 | USB D- | — | — | — | — | — | — | — | — |
| 37 | LOW SIDE RELAY 11 | — | W51 | — | 0.5 | OEM-T121-105 | — | — | — |
| 38 | USB VBUS | — | — | — | — | — | — | — | — |
| 39 | LOW SIDE 6 | — | W50 | — | 0.5 | OEM-T121-104 | — | — | — |
| 4 | INJECTOR 2 | — | W34 | — | 0.5 | OEM-T121-89 | — | — | — |
| 41 | USB GROUND | — | — | — | — | — | — | — | — |
| 42 | LOW SIDE RELAY 12 | — | W52 | — | 0.5 | OEM-T121-115 | — | — | — |
| 43 | LOW SIDE RELAY 14 | — | W54 | — | 0.5 | OEM-T121-47 | — | — | — |
| 44 | LOW SIDE 4 | — | W48 | — | 0.5 | OEM-T121-25 | — | — | — |
| 45 | 5V REF | — | W21 | — | 0.5 | SP-5V1-1 | — | — | — |
| 46 | 5V REF | — | W24 | — | 0.5 | SP-5V2-1 | — | — | — |
| 49 | LSU IA | — | — | — | — | — | — | — | — |
| 50 | LSU IP | — | W56 | — | 0.5 | OEM-T121-51 | — | — | — |
| 51 | CAN 1 LOW | — | W62 | — | 0.5 | OEM-T121-58 | — | — | — |
| 52 | SENSORS GROUND | — | W17 | — | 0.5 | SP-0V-1 | — | — | — |
| 53 | KNOCK 1 SIGNAL | — | W28 | — | 0.5 | OEM-T121-106 | — | — | — |
| 55 | SERIAL 1 RX | — | — | — | — | — | — | — | — |
| 56 | ANA VOLT 2 | — | W40 | — | 0.5 | OEM-T121-101 | — | — | — |
| 57 | ANA TEMP 2 | — | W58 | — | 0.5 | OEM-T121-85 | — | — | — |
| 6 | DIG_IN 1 | — | W59 | — | 0.5 | OEM-T121-54 | — | — | — |
| 61 | GROUND | — | W8 | — | 0.85 | SP-GND-1 | — | — | — |
| 63 | INJECTOR 1 | — | W33 | — | 0.5 | OEM-T121-96 | — | — | — |
| 64 | VBAT | — | W4 | — | 0.85 | SP-14V-1 | — | — | — |
| 67 | Stepper 1 / A1 | — | W38 | — | 0.5 | OEM-T121-117 | — | — | — |
| 68 | Stepper 2 / A2 | — | W37 | — | 0.5 | OEM-T121-118 | — | — | — |
| 69 | LOW SIDE 5 | — | W49 | — | 0.5 | OEM-T121-80 | — | — | — |
| 7 | DIG_IN 2 | — | W60 | — | 0.5 | OEM-T121-28 | — | — | — |
| 70 | Stepper 3 / B1 | — | — | — | — | — | — | — | — |
| 71 | Stepper 4 / B2 | — | — | — | — | — | — | — | — |
| 72 | LOW SIDE RELAY 13 | — | W53 | — | 0.5 | OEM-T121-22 | — | — | — |
| 73 | LOW SIDE 1 | — | W44 | — | 0.5 | OEM-T121-65 | — | — | — |
| 74 | LOW SIDE 3 | — | W47 | — | 0.5 | OEM-T121-63 | — | — | — |
| 76 | 5V REF | — | W25 | — | 0.5 | OEM-T121-83 | — | — | — |
| 79 | TACHOMETER | — | W55 | — | 0.5 | OEM-T121-37 | — | — | — |
| 80 | CRANK VR+ | — | W26 | — | 0.5 | OEM-T121-82 | — | — | — |
| 81 | CRANK VR- | — | — | — | — | — | — | — | — |
| 84 | Sensor Ground | — | W18 | — | 0.5 | SP-0V-1 | — | — | — |
| 86 | ANA TEMP 1 | — | W43 | — | 0.5 | OEM-T121-93 | — | — | — |
| 89 | GROUND | — | W9 | — | 0.85 | SP-GND-1 | — | — | — |
| 90 | GROUND | — | W10 | — | 0.85 | SP-GND-1 | — | — | — |
OEM-T121
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | ECU ground | — | W5 | — | 0.85 | SP-GND-1 | — | — | — |
| 101 | Boost pressure sensor (G31) | — | W40 | — | 0.5 | ME221-C1-56 | — | — | — |
| 102 | Ignition coil 1 (N127) | — | W29 | — | 0.5 | ME221-C1-32 | — | — | — |
| 103 | Ignition coil 3 (N158) | — | W31 | — | 0.5 | ME221-C1-2 | — | — | — |
| 104 | Boost control solenoid (N75) | — | W50 | — | 0.5 | ME221-C1-39 | — | — | — |
| 105 | Diverter valve (N249) | — | W51 | — | 0.5 | ME221-C1-37 | — | — | — |
| 106 | Knock sensor 1 (G61) | — | W28 | — | 0.5 | ME221-C1-53 | — | — | — |
| 107 | Knock sensor 2 (G66) | — | — | — | — | — | — | — | — |
| 108 | Sensor ground | — | W11 | — | 0.5 | SP-0V-1 | — | — | — |
| 115 | VVT camshaft adjustment valve (N205) | — | W52 | — | 0.5 | ME221-C1-42 | — | — | — |
| 117 | Throttle motor G186 (+) | — | W38 | — | 0.5 | ME221-C1-67 | — | — | — |
| 118 | Throttle motor G186 (−) | — | W37 | — | 0.5 | ME221-C1-68 | — | — | — |
| 121 | ECM + coil power (J271 relay feed) | — | W1 | — | 0.85 | SP-14V-1 | — | — | — |
| 2 | ECU ground | — | W6 | — | 0.85 | SP-GND-1 | — | — | — |
| 21 | ECM power (J271 relay feed) | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
| 22 | Brake vacuum pump (V192) | — | W53 | — | 0.5 | ME221-C1-72 | — | — | — |
| 25 | V144 Evaporative diagnostic pump (Pin 2) | — | W48 | — | 0.5 | ME221-C1-44 | — | — | — |
| 27 | MAF sensor supply (G70) | — | — | — | — | — | — | — | — |
| 28 | Alternator DF terminal (charge warning) | — | W60 | — | 0.5 | ME221-C1-7 | — | — | — |
| 29 | MAF sensor ground (G70) | — | W12 | — | 0.5 | SP-0V-1 | — | — | — |
| 3 | Ignition switch +12V (term 15) | — | — | — | — | — | — | — | — |
| 33 | Accelerator pedal position 1 (G79) | — | W41 | — | 0.5 | ME221-C1-17 | — | — | — |
| 34 | Accelerator pedal position 1 ground (G79) | — | W13 | — | 0.5 | SP-0V-1 | — | — | — |
| 35 | Accelerator pedal position 2 (G185) | — | — | — | — | — | — | — | — |
| 36 | Accelerator pedal position 2 ground (G185) | — | W14 | — | 0.5 | SP-0V-1 | — | — | — |
| 37 | Engine speed signal (tacho to cluster) | — | W55 | — | 0.5 | ME221-C1-79 | — | — | — |
| 38 | Cruise control switch (E45) | — | — | — | — | — | — | — | — |
| 39 | Clutch pedal switch (F36) | — | — | — | — | — | — | — | — |
| 40 | A/C signal | — | — | — | — | — | — | — | — |
| 41 | A/C signal | — | — | — | — | — | — | — | — |
| 43 | K-line diagnostics (OBD pin 7) | — | — | — | — | — | — | — | — |
| 47 | Check engine light (MIL) | — | W54 | — | 0.5 | ME221-C1-43 | — | — | — |
| 48 | EPC warning light | — | — | — | — | — | — | — | — |
| 49 | Power steering pressure switch (F88) | — | — | — | — | — | — | — | — |
| 5 | Wideband lambda heater (Z19) | — | W46 | — | 0.5 | ME221-C1-16 | — | — | — |
| 50 | Power steering pressure switch supply (F88) | — | — | — | — | — | — | — | — |
| 51 | Wideband lambda pump (G39) | — | W56 | — | 0.5 | ME221-C1-50 | — | — | — |
| 52 | Wideband lambda pump (G39) | — | — | — | — | — | — | — | — |
| 53 | MAF sensor signal (G70) | — | W39 | — | 0.5 | ME221-C1-26 | — | — | — |
| 54 | Road speed signal (VSS) | — | W59 | — | 0.5 | ME221-C1-6 | — | — | — |
| 55 | Brake pedal switch (F) | — | — | — | — | — | — | — | — |
| 56 | Brake pedal switch (F) | — | — | — | — | — | — | — | — |
| 57 | Cruise control switch (E45) | — | — | — | — | — | — | — | — |
| 58 | CAN bus low | — | W62 | — | 0.5 | ME221-C1-51 | — | — | — |
| 60 | CAN bus high | — | W61 | — | 0.5 | ME221-C1-21 | — | — | — |
| 62 | Battery constant +12V (term 30) | — | — | — | — | — | — | — | — |
| 63 | Post-cat lambda heater (Z29) | — | W47 | — | 0.5 | ME221-C1-74 | — | — | — |
| 64 | EVAP canister valve (N80) | — | — | — | — | — | — | — | — |
| 65 | Fuel pump relay control | — | W44 | — | 0.5 | ME221-C1-73 | — | — | — |
| 66 | Secondary-air pump relay (J299) | — | W45 | — | 0.5 | ME221-C1-12 | — | — | — |
| 67 | Crash sensor signal | — | — | — | — | — | — | — | — |
| 68 | Post-cat lambda signal (G130) | — | — | — | — | — | — | — | — |
| 69 | Post-cat lambda signal (G130) | — | — | — | — | — | — | — | — |
| 70 | Wideband lambda Nernst signal (G39) | — | W57 | — | 0.5 | ME221-C1-19 | — | — | — |
| 71 | Wideband lambda Nernst signal (G39) | — | — | — | — | — | — | — | — |
| 72 | Accelerator pedal position 1 5V supply (G79) | — | W19 | — | 0.5 | SP-5V1-1 | — | — | — |
| 73 | Accelerator pedal position 2 5V supply (G185) | — | W22 | — | 0.5 | SP-5V2-1 | — | — | — |
| 75 | Cruise control switch (E45) | — | — | — | — | — | — | — | — |
| 76 | Cruise control switch (E45) | — | — | — | — | — | — | — | — |
| 80 | V144 Evap Diagnostic Pump (Pin 1) | — | W49 | — | 0.5 | ME221-C1-69 | — | — | — |
| 82 | Crank position sensor (G28) | — | W26 | — | 0.5 | ME221-C1-80 | — | — | — |
| 83 | Throttle position sensor 5V supply (G187/G188) | — | W25 | — | 0.5 | ME221-C1-76 | — | — | — |
| 84 | Throttle position sensor 1 (G187) | — | W42 | — | 0.5 | ME221-C1-18 | — | — | — |
| 85 | Intake air temperature (G42) | — | W58 | — | 0.5 | ME221-C1-57 | — | — | — |
| 86 | Camshaft position sensor (G40) | — | W27 | — | 0.5 | ME221-C1-22 | — | — | — |
| 88 | Injector 4 (N33) | — | W36 | — | 0.5 | ME221-C1-3 | — | — | — |
| 89 | Injector 2 (N31) | — | W34 | — | 0.5 | ME221-C1-4 | — | — | — |
| 9 | Secondary-air injection valve (N112) | — | — | — | — | — | — | — | — |
| 90 | Crank position sensor ground (G28) | — | W15 | — | 0.5 | SP-0V-1 | — | — | — |
| 91 | Throttle position sensor ground (G187/G188) | — | W16 | — | 0.5 | SP-0V-1 | — | — | — |
| 92 | Throttle position sensor 2 (G188) | — | — | — | — | — | — | — | — |
| 93 | Engine coolant temperature (G62) | — | W43 | — | 0.5 | ME221-C1-86 | — | — | — |
| 94 | Ignition coil 4 (N163) | — | W32 | — | 0.5 | ME221-C1-1 | — | — | — |
| 95 | Ignition coil 2 (N128) | — | W30 | — | 0.5 | ME221-C1-31 | — | — | — |
| 96 | Injector 1 (N30) | — | W33 | — | 0.5 | ME221-C1-63 | — | — | — |
| 97 | Injector 3 (N32) | — | W35 | — | 0.5 | ME221-C1-33 | — | — | — |
| 98 | Cam + boost sensor 5V supply (G40/G31) | — | W20 | — | 0.5 | SP-5V1-1 | — | — | — |
| 99 | Knock sensor 5V supply (G61/G66) | — | W23 | — | 0.5 | SP-5V2-1 | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W11 | — | 0.5 | OEM-T121-108 | — | — | — |
| 1 | — | — | W12 | — | 0.5 | OEM-T121-29 | — | — | — |
| 1 | — | — | W13 | — | 0.5 | OEM-T121-34 | — | — | — |
| 1 | — | — | W14 | — | 0.5 | OEM-T121-36 | — | — | — |
| 1 | — | — | W15 | — | 0.5 | OEM-T121-90 | — | — | — |
| 1 | — | — | W16 | — | 0.5 | OEM-T121-91 | — | — | — |
| 1 | — | — | W17 | — | 0.5 | ME221-C1-52 | — | — | — |
| 1 | — | — | W18 | — | 0.5 | ME221-C1-84 | — | — | — |
SP-14V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W1 | — | 0.85 | OEM-T121-121 | — | — | — |
| 1 | — | — | W2 | — | 0.85 | OEM-T121-21 | — | — | — |
| 1 | — | — | W3 | — | 0.85 | ME221-C1-15 | — | — | — |
| 1 | — | — | W4 | — | 0.85 | ME221-C1-64 | — | — | — |
SP-5V1
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W19 | — | 0.5 | OEM-T121-72 | — | — | — |
| 1 | — | — | W20 | — | 0.5 | OEM-T121-98 | — | — | — |
| 1 | — | — | W21 | — | 0.5 | ME221-C1-45 | — | — | — |
SP-5V2
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W22 | — | 0.5 | OEM-T121-73 | — | — | — |
| 1 | — | — | W23 | — | 0.5 | OEM-T121-99 | — | — | — |
| 1 | — | — | W24 | — | 0.5 | ME221-C1-46 | — | — | — |
SP-GND
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W5 | — | 0.85 | OEM-T121-1 | — | — | — |
| 1 | — | — | W6 | — | 0.85 | OEM-T121-2 | — | — | — |
| 1 | — | — | W7 | — | 0.85 | ME221-C1-10 | — | — | — |
| 1 | — | — | W8 | — | 0.85 | ME221-C1-61 | — | — | — |
| 1 | — | — | W9 | — | 0.85 | ME221-C1-89 | — | — | — |
| 1 | — | — | W10 | — | 0.85 | ME221-C1-90 | — | — | — |
Pin map
| OEM point | OEM function | OEM family | Target point | Target function | Target family | Wire colour | Evidence |
|---|---|---|---|---|---|---|---|
| OEM-T121-1 | ECU ground | ground | ME221-C1-10 + ME221-C1-61 + ME221-C1-89 + ME221-C1-90 | GROUND CHASSIS + GROUND + GROUND + GROUND | ground | corroborated | |
| OEM-T121-101 | Boost pressure sensor (G31) | analog_in | ME221-C1-56 | ANA VOLT 2 | analog_in | corroborated | |
| OEM-T121-102 | Ignition coil 1 (N127) | ignition_out | ME221-C1-32 | COIL 1 | ignition_out | corroborated | |
| OEM-T121-103 | Ignition coil 3 (N158) | ignition_out | ME221-C1-2 | COIL 3 | ignition_out | corroborated | |
| OEM-T121-104 | Boost control solenoid (N75) | low_side_out | ME221-C1-39 | LOW SIDE 6 | low_side_out | corroborated | |
| OEM-T121-105 | Diverter valve (N249) | low_side_out | ME221-C1-37 | LOW SIDE RELAY 11 | low_side_out | corroborated | |
| OEM-T121-106 | Knock sensor 1 (G61) | knock_in | ME221-C1-53 | KNOCK 1 SIGNAL | knock_in | corroborated | |
| OEM-T121-107 | Knock sensor 2 (G66) | knock_in | — | — | — | corroborated | |
| OEM-T121-108 | Sensor ground | sensor_ground | ME221-C1-52 + ME221-C1-84 | SENSORS GROUND + Sensor Ground | sensor_ground | corroborated | |
| OEM-T121-115 | VVT camshaft adjustment valve (N205) | low_side_out | ME221-C1-42 | LOW SIDE RELAY 12 | low_side_out | corroborated | |
| OEM-T121-117 | Throttle motor G186 (+) | hbridge_out | ME221-C1-67 | Stepper 1 / A1 | hbridge_out | corroborated | |
| OEM-T121-118 | Throttle motor G186 (−) | hbridge_out | ME221-C1-68 | Stepper 2 / A2 | hbridge_out | corroborated | |
| OEM-T121-121 | ECM + coil power (J271 relay feed) | power_in | ME221-C1-15 + ME221-C1-64 | IGN +12V + VBAT | power_in | corroborated | |
| OEM-T121-2 | ECU ground | ground | ME221-C1-10 + ME221-C1-61 + ME221-C1-89 + ME221-C1-90 | GROUND CHASSIS + GROUND + GROUND + GROUND | ground | corroborated | |
| OEM-T121-21 | ECM power (J271 relay feed) | power_in | ME221-C1-15 + ME221-C1-64 | IGN +12V + VBAT | power_in | corroborated | |
| OEM-T121-22 | Brake vacuum pump (V192) | low_side_out | ME221-C1-72 | LOW SIDE RELAY 13 | low_side_out | single_source | |
| OEM-T121-25 | V144 Evaporative diagnostic pump (Pin 2) | low_side_out | ME221-C1-44 | LOW SIDE 4 | low_side_out | corroborated | |
| OEM-T121-27 | MAF sensor supply (G70) | power_in | — | — | — | corroborated | |
| OEM-T121-28 | Alternator DF terminal (charge warning) | digital_in | ME221-C1-7 | DIG_IN 2 | digital_in | single_source | |
| OEM-T121-29 | MAF sensor ground (G70) | sensor_ground | ME221-C1-52 + ME221-C1-84 | SENSORS GROUND + Sensor Ground | sensor_ground | corroborated | |
| OEM-T121-3 | Ignition switch +12V (term 15) | digital_in | — | — | — | corroborated | |
| OEM-T121-33 | Accelerator pedal position 1 (G79) | analog_in | ME221-C1-17 | ANA VOLT 3 | analog_in | corroborated | |
| OEM-T121-34 | Accelerator pedal position 1 ground (G79) | sensor_ground | ME221-C1-52 + ME221-C1-84 | SENSORS GROUND + Sensor Ground | sensor_ground | corroborated | |
| OEM-T121-35 | Accelerator pedal position 2 (G185) | analog_in | — | — | — | corroborated | |
| OEM-T121-36 | Accelerator pedal position 2 ground (G185) | sensor_ground | ME221-C1-52 + ME221-C1-84 | SENSORS GROUND + Sensor Ground | sensor_ground | corroborated | |
| OEM-T121-37 | Engine speed signal (tacho to cluster) | tacho_out | ME221-C1-79 | TACHOMETER | tacho_out | corroborated | |
| OEM-T121-38 | Cruise control switch (E45) | digital_in | — | — | — | single_source | |
| OEM-T121-39 | Clutch pedal switch (F36) | digital_in | — | — | — | single_source | |
| OEM-T121-40 | A/C signal | digital_in | — | — | — | single_source | |
| OEM-T121-41 | A/C signal | digital_in | — | — | — | single_source | |
| OEM-T121-43 | K-line diagnostics (OBD pin 7) | serial | — | — | — | corroborated | |
| OEM-T121-47 | Check engine light (MIL) | low_side_out | ME221-C1-43 | LOW SIDE RELAY 14 | low_side_out | corroborated | |
| OEM-T121-48 | EPC warning light | low_side_out | — | — | — | corroborated | |
| OEM-T121-49 | Power steering pressure switch (F88) | digital_in | — | — | — | single_source | |
| OEM-T121-5 | Wideband lambda heater (Z19) | low_side_out | ME221-C1-16 | LSU HEATER -VE | low_side_out | corroborated | |
| OEM-T121-50 | Power steering pressure switch supply (F88) | power_in | — | — | — | single_source | |
| OEM-T121-51 | Wideband lambda pump (G39) | wb_ip | ME221-C1-50 | LSU IP | wb_ip | corroborated | |
| OEM-T121-52 | Wideband lambda pump (G39) | wb_ip | — | — | — | corroborated | |
| OEM-T121-53 | MAF sensor signal (G70) | analog_in | ME221-C1-26 | ANA VOLT 1 | analog_in | corroborated | |
| OEM-T121-54 | Road speed signal (VSS) | digital_in | ME221-C1-6 | DIG_IN 1 | digital_in | corroborated | |
| OEM-T121-55 | Brake pedal switch (F) | digital_in | — | — | — | single_source | |
| OEM-T121-56 | Brake pedal switch (F) | digital_in | — | — | — | single_source | |
| OEM-T121-57 | Cruise control switch (E45) | digital_in | — | — | — | single_source | |
| OEM-T121-58 | CAN bus low | can_l | ME221-C1-51 | CAN 1 LOW | can_l | corroborated | |
| OEM-T121-60 | CAN bus high | can_h | ME221-C1-21 | CAN 1 HIGH | can_h | corroborated | |
| OEM-T121-62 | Battery constant +12V (term 30) | power_in | — | — | — | corroborated | |
| OEM-T121-63 | Post-cat lambda heater (Z29) | low_side_out | ME221-C1-74 | LOW SIDE 3 | low_side_out | corroborated | |
| OEM-T121-64 | EVAP canister valve (N80) | low_side_out | — | — | — | corroborated | |
| OEM-T121-65 | Fuel pump relay control | low_side_out | ME221-C1-73 | LOW SIDE 1 | low_side_out | corroborated | |
| OEM-T121-66 | Secondary-air pump relay (J299) | low_side_out | ME221-C1-12 | LOW SIDE 2 | low_side_out | corroborated | |
| OEM-T121-67 | Crash sensor signal | digital_in | — | — | — | single_source | |
| OEM-T121-68 | Post-cat lambda signal (G130) | lambda_nb_in | — | — | — | corroborated | |
| OEM-T121-69 | Post-cat lambda signal (G130) | lambda_nb_in | — | — | — | corroborated | |
| OEM-T121-70 | Wideband lambda Nernst signal (G39) | wb_vs | ME221-C1-19 | LSU UN | wb_vs | corroborated | |
| OEM-T121-71 | Wideband lambda Nernst signal (G39) | wb_vs | — | — | — | corroborated | |
| OEM-T121-72 | Accelerator pedal position 1 5V supply (G79) | vref | ME221-C1-45 | 5V REF | vref | corroborated | |
| OEM-T121-73 | Accelerator pedal position 2 5V supply (G185) | vref | ME221-C1-46 | 5V REF | vref | corroborated | |
| OEM-T121-75 | Cruise control switch (E45) | digital_in | — | — | — | single_source | |
| OEM-T121-76 | Cruise control switch (E45) | digital_in | — | — | — | single_source | |
| OEM-T121-80 | V144 Evap Diagnostic Pump (Pin 1) | low_side_out | ME221-C1-69 | LOW SIDE 5 | low_side_out | corroborated | |
| OEM-T121-82 | Crank position sensor (G28) | trigger_in | ME221-C1-80 | CRANK VR+ | trigger_in | corroborated | |
| OEM-T121-83 | Throttle position sensor 5V supply (G187/G188) | vref | ME221-C1-76 | 5V REF | vref | corroborated | |
| OEM-T121-84 | Throttle position sensor 1 (G187) | analog_in | ME221-C1-18 | ANA VOLT 4 | analog_in | corroborated | |
| OEM-T121-85 | Intake air temperature (G42) | temp_in | ME221-C1-57 | ANA TEMP 2 | temp_in | corroborated | |
| OEM-T121-86 | Camshaft position sensor (G40) | trigger_in | ME221-C1-22 | CAM A VR+ | trigger_in | corroborated | |
| OEM-T121-88 | Injector 4 (N33) | injector_out | ME221-C1-3 | INJECTOR 4 | injector_out | corroborated | |
| OEM-T121-89 | Injector 2 (N31) | injector_out | ME221-C1-4 | INJECTOR 2 | injector_out | corroborated | |
| OEM-T121-9 | Secondary-air injection valve (N112) | low_side_out | — | — | — | corroborated | |
| OEM-T121-90 | Crank position sensor ground (G28) | sensor_ground | ME221-C1-52 + ME221-C1-84 | SENSORS GROUND + Sensor Ground | sensor_ground | corroborated | |
| OEM-T121-91 | Throttle position sensor ground (G187/G188) | sensor_ground | ME221-C1-52 + ME221-C1-84 | SENSORS GROUND + Sensor Ground | sensor_ground | corroborated | |
| OEM-T121-92 | Throttle position sensor 2 (G188) | analog_in | — | — | — | corroborated | |
| OEM-T121-93 | Engine coolant temperature (G62) | temp_in | ME221-C1-86 | ANA TEMP 1 | temp_in | corroborated | |
| OEM-T121-94 | Ignition coil 4 (N163) | ignition_out | ME221-C1-1 | COIL 4 | ignition_out | corroborated | |
| OEM-T121-95 | Ignition coil 2 (N128) | ignition_out | ME221-C1-31 | COIL 2 | ignition_out | corroborated | |
| OEM-T121-96 | Injector 1 (N30) | injector_out | ME221-C1-63 | INJECTOR 1 | injector_out | corroborated | |
| OEM-T121-97 | Injector 3 (N32) | injector_out | ME221-C1-33 | INJECTOR 3 | injector_out | corroborated | |
| OEM-T121-98 | Cam + boost sensor 5V supply (G40/G31) | vref | ME221-C1-45 | 5V REF | vref | corroborated | |
| OEM-T121-99 | Knock sensor 5V supply (G61/G66) | vref | ME221-C1-46 | 5V REF | vref | corroborated |
Cut list
| Wire | From | To | Gauge (mm²) | Colour | Length | Signal | Ident |
|---|---|---|---|---|---|---|---|
| W1 | OEM-T121-121 | SP-14V-1 | 0.85 | no route | ECM + coil power (J271 relay feed) | — | |
| W2 | OEM-T121-21 | SP-14V-1 | 0.85 | no route | ECM power (J271 relay feed) | — | |
| W3 | SP-14V-1 | ME221-C1-15 | 0.85 | no route | IGN +12V | — | |
| W4 | SP-14V-1 | ME221-C1-64 | 0.85 | no route | VBAT | — | |
| W5 | OEM-T121-1 | SP-GND-1 | 0.85 | no route | ECU ground | — | |
| W6 | OEM-T121-2 | SP-GND-1 | 0.85 | no route | ECU ground | — | |
| W7 | SP-GND-1 | ME221-C1-10 | 0.85 | no route | GROUND CHASSIS | — | |
| W8 | SP-GND-1 | ME221-C1-61 | 0.85 | no route | GROUND | — | |
| W9 | SP-GND-1 | ME221-C1-89 | 0.85 | no route | GROUND | — | |
| W10 | SP-GND-1 | ME221-C1-90 | 0.85 | no route | GROUND | — | |
| W11 | OEM-T121-108 | SP-0V-1 | 0.5 | no route | Sensor ground | — | |
| W12 | OEM-T121-29 | SP-0V-1 | 0.5 | no route | MAF sensor ground (G70) | — | |
| W13 | OEM-T121-34 | SP-0V-1 | 0.5 | no route | Accelerator pedal position 1 ground (G79) | — | |
| W14 | OEM-T121-36 | SP-0V-1 | 0.5 | no route | Accelerator pedal position 2 ground (G185) | — | |
| W15 | OEM-T121-90 | SP-0V-1 | 0.5 | no route | Crank position sensor ground (G28) | — | |
| W16 | OEM-T121-91 | SP-0V-1 | 0.5 | no route | Throttle position sensor ground (G187/G188) | — | |
| W17 | SP-0V-1 | ME221-C1-52 | 0.5 | no route | SENSORS GROUND | — | |
| W18 | SP-0V-1 | ME221-C1-84 | 0.5 | no route | Sensor Ground | — | |
| W19 | OEM-T121-72 | SP-5V1-1 | 0.5 | no route | Accelerator pedal position 1 5V supply (G79) | — | |
| W20 | OEM-T121-98 | SP-5V1-1 | 0.5 | no route | Cam + boost sensor 5V supply (G40/G31) | — | |
| W21 | SP-5V1-1 | ME221-C1-45 | 0.5 | no route | 5V REF | — | |
| W22 | OEM-T121-73 | SP-5V2-1 | 0.5 | no route | Accelerator pedal position 2 5V supply (G185) | — | |
| W23 | OEM-T121-99 | SP-5V2-1 | 0.5 | no route | Knock sensor 5V supply (G61/G66) | — | |
| W24 | SP-5V2-1 | ME221-C1-46 | 0.5 | no route | 5V REF | — | |
| W25 | OEM-T121-83 | ME221-C1-76 | 0.5 | no route | Throttle position sensor 5V supply (G187/G188) | — | |
| W26 | OEM-T121-82 | ME221-C1-80 | 0.5 | no route | Crank position sensor (G28) | — | |
| W27 | OEM-T121-86 | ME221-C1-22 | 0.5 | no route | Camshaft position sensor (G40) | — | |
| W28 | OEM-T121-106 | ME221-C1-53 | 0.5 | no route | Knock sensor 1 (G61) | — | |
| W29 | OEM-T121-102 | ME221-C1-32 | 0.5 | no route | Ignition coil 1 (N127) | — | |
| W30 | OEM-T121-95 | ME221-C1-31 | 0.5 | no route | Ignition coil 2 (N128) | — | |
| W31 | OEM-T121-103 | ME221-C1-2 | 0.5 | no route | Ignition coil 3 (N158) | — | |
| W32 | OEM-T121-94 | ME221-C1-1 | 0.5 | no route | Ignition coil 4 (N163) | — | |
| W33 | OEM-T121-96 | ME221-C1-63 | 0.5 | no route | Injector 1 (N30) | — | |
| W34 | OEM-T121-89 | ME221-C1-4 | 0.5 | no route | Injector 2 (N31) | — | |
| W35 | OEM-T121-97 | ME221-C1-33 | 0.5 | no route | Injector 3 (N32) | — | |
| W36 | OEM-T121-88 | ME221-C1-3 | 0.5 | no route | Injector 4 (N33) | — | |
| W37 | OEM-T121-118 | ME221-C1-68 | 0.5 | no route | Throttle motor G186 (−) | — | |
| W38 | OEM-T121-117 | ME221-C1-67 | 0.5 | no route | Throttle motor G186 (+) | — | |
| W39 | OEM-T121-53 | ME221-C1-26 | 0.5 | no route | MAF sensor signal (G70) | — | |
| W40 | OEM-T121-101 | ME221-C1-56 | 0.5 | no route | Boost pressure sensor (G31) | — | |
| W41 | OEM-T121-33 | ME221-C1-17 | 0.5 | no route | Accelerator pedal position 1 (G79) | — | |
| W42 | OEM-T121-84 | ME221-C1-18 | 0.5 | no route | Throttle position sensor 1 (G187) | — | |
| W43 | OEM-T121-93 | ME221-C1-86 | 0.5 | no route | Engine coolant temperature (G62) | — | |
| W44 | OEM-T121-65 | ME221-C1-73 | 0.5 | no route | Fuel pump relay control | — | |
| W45 | OEM-T121-66 | ME221-C1-12 | 0.5 | no route | Secondary-air pump relay (J299) | — | |
| W46 | OEM-T121-5 | ME221-C1-16 | 0.5 | no route | Wideband lambda heater (Z19) | — | |
| W47 | OEM-T121-63 | ME221-C1-74 | 0.5 | no route | Post-cat lambda heater (Z29) | — | |
| W48 | OEM-T121-25 | ME221-C1-44 | 0.5 | no route | V144 Evaporative diagnostic pump (Pin 2) | — | |
| W49 | OEM-T121-80 | ME221-C1-69 | 0.5 | no route | V144 Evap Diagnostic Pump (Pin 1) | — | |
| W50 | OEM-T121-104 | ME221-C1-39 | 0.5 | no route | Boost control solenoid (N75) | — | |
| W51 | OEM-T121-105 | ME221-C1-37 | 0.5 | no route | Diverter valve (N249) | — | |
| W52 | OEM-T121-115 | ME221-C1-42 | 0.5 | no route | VVT camshaft adjustment valve (N205) | — | |
| W53 | OEM-T121-22 | ME221-C1-72 | 0.5 | no route | Brake vacuum pump (V192) | — | |
| W54 | OEM-T121-47 | ME221-C1-43 | 0.5 | no route | Check engine light (MIL) | — | |
| W55 | OEM-T121-37 | ME221-C1-79 | 0.5 | no route | Engine speed signal (tacho to cluster) | — | |
| W56 | OEM-T121-51 | ME221-C1-50 | 0.5 | no route | Wideband lambda pump (G39) | — | |
| W57 | OEM-T121-70 | ME221-C1-19 | 0.5 | no route | Wideband lambda Nernst signal (G39) | — | |
| W58 | OEM-T121-85 | ME221-C1-57 | 0.5 | no route | Intake air temperature (G42) | — | |
| W59 | OEM-T121-54 | ME221-C1-6 | 0.5 | no route | Road speed signal (VSS) | — | |
| W60 | OEM-T121-28 | ME221-C1-7 | 0.5 | no route | Alternator DF terminal (charge warning) | — | |
| W61 | OEM-T121-60 | ME221-C1-21 | 0.5 | no route | CAN bus high | — | |
| W62 | OEM-T121-58 | ME221-C1-51 | 0.5 | no route | CAN bus low | — |
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 (9)
| Severity | Code | Subject | Message |
|---|---|---|---|
| error | REQUIRED_UNMAPPED | OEM-T121-35 | Required OEM function "Accelerator pedal position 2 (G185)" (analog_in) is not connected to the new ECU. |
| error | REQUIRED_UNMAPPED | OEM-T121-92 | Required OEM function "Throttle position sensor 2 (G188)" (analog_in) is not connected to the new ECU. |
| warn | DBW_MOTOR_CURRENT | ME221-C1-67 | Cannot confirm ME221 can drive the throttle motor: ME221-C1-67 "Stepper 1 / A1" is rated 0.5 A peak, but the motor stall current at OEM-T121-117 is unknown. Add the motor's peak current from a source, or measure the motor resistance: peak ≈ 14 V ÷ R (Hondata measured 4.9 A for a Civic Si body, 10.4 A for a ZDX body; holding current is about 1 A). |
| warn | DBW_MOTOR_CURRENT | ME221-C1-68 | Cannot confirm ME221 can drive the throttle motor: ME221-C1-68 "Stepper 2 / A2" is rated 0.5 A peak, but the motor stall current at OEM-T121-118 is unknown. Add the motor's peak current from a source, or measure the motor resistance: peak ≈ 14 V ÷ R (Hondata measured 4.9 A for a Civic Si body, 10.4 A for a ZDX body; holding current is about 1 A). |
| warn | DBW_SHARED_5V | ME221-C1-45 + OEM-T121-72 + OEM-T121-98 + SP-5V1-1 | These 5 V supplies are separate in the stock car (OEM-T121-72 [pedal1], OEM-T121-98 [cam_boost]) and here share one ECU 5 V (ME221-C1-45). On a drive-by-wire car the OEM splits them so one short or fault can't corrupt both throttle/pedal tracks at once. ME221 has 3 5 V sensor supply pin(s). All are in use, so decide: accept the shared supply (and rely on the ECU's DBW fault checks), or add a separate regulated 5 V for the sub tracks. |
| warn | DBW_SHARED_5V | ME221-C1-46 + OEM-T121-73 + OEM-T121-99 + SP-5V2-1 | These 5 V supplies are separate in the stock car (OEM-T121-73 [pedal2], OEM-T121-99 [knock]) and here share one ECU 5 V (ME221-C1-46). On a drive-by-wire car the OEM splits them so one short or fault can't corrupt both throttle/pedal tracks at once. ME221 has 3 5 V sensor supply pin(s). All are in use, so decide: accept the shared supply (and rely on the ECU's DBW fault checks), or add a separate regulated 5 V for the sub tracks. |
| warn | SUPPLY_GROUP | ME221-C1-45 + OEM-T121-72 + OEM-T121-98 + SP-5V1-1 | Supplies meant to stay independent share one net: OEM-T121-72 [pedal1], OEM-T121-98 [cam_boost]. The new ECU has no free 5 V reference, so they share one: normal on a standalone, but a short on any of these sensors drops them all. |
| warn | SUPPLY_GROUP | ME221-C1-46 + OEM-T121-73 + OEM-T121-99 + SP-5V2-1 | Supplies meant to stay independent share one net: OEM-T121-73 [pedal2], OEM-T121-99 [knock]. The new ECU has no free 5 V reference, so they share one: normal on a standalone, but a short on any of these sensors drops them all. |
| info | UNMAPPED | OEM | 21 optional OEM pins are not mapped: OEM-T121-27 MAF sensor supply (G70); OEM-T121-38 Cruise control switch (E45); OEM-T121-39 Clutch pedal switch (F36); OEM-T121-40 A/C signal; OEM-T121-41 A/C signal; OEM-T121-43 K-line diagnostics (OBD pin 7); OEM-T121-48 EPC warning light; OEM-T121-49 Power steering pressure switch (F88); OEM-T121-50 Power steering pressure switch supply (F88); OEM-T121-52 Wideband lambda pump (G39); OEM-T121-55 Brake pedal switch (F); OEM-T121-56 Brake pedal switch (F); OEM-T121-57 Cruise control switch (E45); OEM-T121-64 EVAP canister valve (N80); OEM-T121-67 Crash sensor signal; OEM-T121-68 Post-cat lambda signal (G130); OEM-T121-69 Post-cat lambda signal (G130); OEM-T121-71 Wideband lambda Nernst signal (G39); OEM-T121-75 Cruise control switch (E45); OEM-T121-76 Cruise control switch (E45); OEM-T121-9 Secondary-air injection valve (N112) |
Accepted (2)
| Code | Subject | Reason | By |
|---|---|---|---|
| REQUIRED_UNMAPPED | OEM-T121-107 | Knock input count is a documented capability limit: this ECU has a single knock input and it is already used by the engine's other stock knock sensor, so this extra sensor cannot be wired. | mapping-proposal |
| REQUIRED_UNMAPPED | OEM-T121-62 | Battery-constant (memory) feed of the stock ECU: the new ECU has no such input, so it is not needed. | mapping-proposal |
Notes
Fit check: needs add-on. Resolve these before building: - No drive-by-wire; needs a cable-throttle conversion or an external DBW controller - Only one knock input on this ECU; the stock engine has more knock sensors than it can read — the extra stock sensor cannot be wired - This car has VW/Audi Immobilizer (delete/bypass for standalone) immobilizer; needs a delete/bypass Auto-mapped by auto_map() from the library pin data on 2026-10-23. Review every wire against both manuals before building. Open items: - OEM-T121 107: Knock sensor 2 (G66): no free knock input on Motorsport Electronics ME221 - OEM-T121 35: Accelerator pedal position 2 (G185): no free tps/analog_0_5 on Motorsport Electronics ME221 - OEM-T121 92: Throttle position sensor 2 (G188): no free tps/analog_0_5 on Motorsport Electronics ME221 Not wired: - OEM-T121 62: Battery constant +12V (term 30): Motorsport Electronics ME221 has no battery-constant memory input; not needed - OEM-T121 3: Ignition switch +12V (term 15): key-on 12 V sense — handled by the chassis (it energises the main relay); not needed on this harness - OEM-T121 48: EPC warning light: no free low_side/relay_control/heater_low_side/ls_hs/injector on Motorsport Electronics ME221 - OEM-T121 64: EVAP canister valve (N80): no free low_side/relay_control/heater_low_side/ls_hs/injector on Motorsport Electronics ME221 - OEM-T121 9: Secondary-air injection valve (N112): no free low_side/relay_control/heater_low_side/ls_hs/injector on Motorsport Electronics ME221 - OEM-T121 52: Wideband lambda pump (G39): no free wb_ip on Motorsport Electronics ME221 - OEM-T121 71: Wideband lambda Nernst signal (G39): no free wb_vs on Motorsport Electronics ME221 - OEM-T121 68: Post-cat lambda signal (G130): no free o2_narrowband/analog_0_5 on Motorsport Electronics ME221 - OEM-T121 69: Post-cat lambda signal (G130): no free o2_narrowband/analog_0_5 on Motorsport Electronics ME221 - OEM-T121 38: Cruise control switch (E45): no free switch_in/frequency_in/analog_0_5 on Motorsport Electronics ME221 - OEM-T121 39: Clutch pedal switch (F36): no free switch_in/frequency_in/analog_0_5 on Motorsport Electronics ME221 - OEM-T121 40: A/C signal: no free switch_in/frequency_in/analog_0_5 on Motorsport Electronics ME221 - OEM-T121 41: A/C signal: no free switch_in/frequency_in/analog_0_5 on Motorsport Electronics ME221 - OEM-T121 49: Power steering pressure switch (F88): no free switch_in/frequency_in/analog_0_5 on Motorsport Electronics ME221 - OEM-T121 55: Brake pedal switch (F): no free switch_in/frequency_in/analog_0_5 on Motorsport Electronics ME221 - OEM-T121 56: Brake pedal switch (F): no free switch_in/frequency_in/analog_0_5 on Motorsport Electronics ME221 - OEM-T121 57: Cruise control switch (E45): no free switch_in/frequency_in/analog_0_5 on Motorsport Electronics ME221 - OEM-T121 67: Crash sensor signal: no free switch_in/frequency_in/analog_0_5 on Motorsport Electronics ME221 - OEM-T121 75: Cruise control switch (E45): no free switch_in/frequency_in/analog_0_5 on Motorsport Electronics ME221 - OEM-T121 76: Cruise control switch (E45): no free switch_in/frequency_in/analog_0_5 on Motorsport Electronics ME221 - OEM-T121 43: K-line diagnostics (OBD pin 7): no free k_line on Motorsport Electronics ME221 - OEM-T121 27: MAF sensor supply (G70): no rule for class sensor_supply_in; wire by hand - OEM-T121 50: Power steering pressure switch supply (F88): no rule for class sensor_supply_in; 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 | — | — | — |
| 3 | community_copy | NefMoto: ME7.5 1.8t Golf AWP ECU wiring breakdown (Bentley-derived) | https://nefariousmotorsports.com/forum/index.php?topic=18710.0 | — | — | — |
| 3 | community_copy | NefMoto: ME7.5 ECU bench-flashing power/ground pins | http://nefmoto.com/wiki/index.php?title=ECU_Bench_Flashing | — | — | — |
| 3 | community_copy | vwressources: Bosch Motronic ME7.5 (AMK/ARY/AUQ/ARX/AUM) T121 pinout | https://www.vwressources.planethoster.world/me75_pinout.html | — | — | — |