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 · 2026-10-11
Before you start
Not confident with automotive wiring? Have a professional harness builder or tuner do it, or check your work before first power-up. A wiring mistake can damage the ECU, the engine or the car, or start a fire.
| Status | draft · not yet verified: nobody has reported building and running this harness |
|---|---|
| Open errors | 4: read the Findings page before cutting any wire |
| Size of the job | 61 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-T121-104 | ME221-C1-44 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W49 | OEM-T121-105 | ME221-C1-69 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W50 | OEM-T121-115 | ME221-C1-39 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W51 | OEM-T121-47 | ME221-C1-37 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W52 | OEM-T121-48 | ME221-C1-42 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W53 | OEM-T121-64 | ME221-C1-72 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W54 | OEM-T121-9 | 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-T121-60 | ME221-C1-21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W61 | 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 | — | W60 | — | 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-T121-47 | — | — | — |
| 38 | USB VBUS | — | — | — | — | — | — | — | — |
| 39 | LOW SIDE 6 | — | W50 | — | 0.5 | OEM-T121-115 | — | — | — |
| 4 | INJECTOR 2 | — | W34 | — | 0.5 | OEM-T121-89 | — | — | — |
| 41 | USB GROUND | — | — | — | — | — | — | — | — |
| 42 | LOW SIDE RELAY 12 | — | W52 | — | 0.5 | OEM-T121-48 | — | — | — |
| 43 | LOW SIDE RELAY 14 | — | W54 | — | 0.5 | OEM-T121-9 | — | — | — |
| 44 | LOW SIDE 4 | — | W48 | — | 0.5 | OEM-T121-104 | — | — | — |
| 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 | — | W61 | — | 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-T121-105 | — | — | — |
| 7 | DIG_IN 2 | — | — | — | — | — | — | — | — |
| 70 | Stepper 3 / B1 | — | — | — | — | — | — | — | — |
| 71 | Stepper 4 / B2 | — | — | — | — | — | — | — | — |
| 72 | LOW SIDE RELAY 13 | — | W53 | — | 0.5 | OEM-T121-64 | — | — | — |
| 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) | — | W48 | — | 0.5 | ME221-C1-44 | — | — | — |
| 105 | Diverter valve (N249) | — | W49 | — | 0.5 | ME221-C1-69 | — | — | — |
| 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) | — | W50 | — | 0.5 | ME221-C1-39 | — | — | — |
| 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 | — | — | — |
| 27 | MAF sensor supply (G70) | — | — | — | — | — | — | — | — |
| 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 | — | — | — |
| 43 | K-line diagnostics (OBD pin 7) | — | — | — | — | — | — | — | — |
| 47 | Check engine light (MIL) | — | W51 | — | 0.5 | ME221-C1-37 | — | — | — |
| 48 | EPC warning light | — | W52 | — | 0.5 | ME221-C1-42 | — | — | — |
| 5 | Wideband lambda heater (Z19) | — | W46 | — | 0.5 | ME221-C1-16 | — | — | — |
| 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 | — | — | — |
| 58 | CAN bus low | — | W61 | — | 0.5 | ME221-C1-51 | — | — | — |
| 60 | CAN bus high | — | W60 | — | 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) | — | W53 | — | 0.5 | ME221-C1-72 | — | — | — |
| 65 | Fuel pump relay control | — | W44 | — | 0.5 | ME221-C1-73 | — | — | — |
| 66 | Secondary-air pump relay (J299) | — | W45 | — | 0.5 | ME221-C1-12 | — | — | — |
| 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 | — | — | — |
| 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) | — | W54 | — | 0.5 | ME221-C1-43 | — | — | — |
| 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-C1-44 | LOW SIDE 4 | low_side_out | corroborated | |
| OEM-T121-105 | Diverter valve (N249) | low_side_out | ME221-C1-69 | LOW SIDE 5 | 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-C1-39 | LOW SIDE 6 | 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-T121-27 | MAF sensor supply (G70) | power_in | — | — | — | corroborated | |
| 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-T121-43 | K-line diagnostics (OBD pin 7) | serial | — | — | — | corroborated | |
| OEM-T121-47 | Check engine light (MIL) | low_side_out | ME221-C1-37 | LOW SIDE RELAY 11 | low_side_out | corroborated | |
| OEM-T121-48 | EPC warning light | low_side_out | ME221-C1-42 | LOW SIDE RELAY 12 | low_side_out | corroborated | |
| OEM-T121-5 | Wideband lambda heater (Z19) | low_side_out | ME221-C1-16 | LSU HEATER -VE | low_side_out | corroborated | |
| 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-T121-58 | 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 | ME221-C1-72 | LOW SIDE RELAY 13 | 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-T121-68 | 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-T121-82 | 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 | ME221-C1-43 | LOW SIDE RELAY 14 | 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-T121-104 | ME221-C1-44 | 0.5 | no route | Boost control solenoid (N75) | — | |
| W49 | OEM-T121-105 | ME221-C1-69 | 0.5 | no route | Diverter valve (N249) | — | |
| W50 | OEM-T121-115 | ME221-C1-39 | 0.5 | no route | VVT camshaft adjustment valve (N205) | — | |
| W51 | OEM-T121-47 | ME221-C1-37 | 0.5 | no route | Check engine light (MIL) | — | |
| W52 | OEM-T121-48 | ME221-C1-42 | 0.5 | no route | EPC warning light | — | |
| W53 | OEM-T121-64 | ME221-C1-72 | 0.5 | no route | EVAP canister valve (N80) | — | |
| W54 | OEM-T121-9 | ME221-C1-43 | 0.5 | no route | Secondary-air injection valve (N112) | — | |
| 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-T121-60 | ME221-C1-21 | 0.5 | no route | CAN bus high | — | |
| W61 | 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 (11)
| Severity | Code | Subject | Message |
|---|---|---|---|
| error | REQUIRED_UNMAPPED | OEM-T121-107 | Required OEM function "Knock sensor 2 (G66)" (knock_in) is not connected to the new ECU. |
| error | REQUIRED_UNMAPPED | OEM-T121-3 | Required OEM function "Ignition switch +12V (term 15)" (digital_in) is not connected to the new ECU. |
| 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 | 6 optional OEM pins are not mapped: OEM-T121-27 MAF sensor supply (G70); OEM-T121-43 K-line diagnostics (OBD pin 7); OEM-T121-52 Wideband lambda pump (G39); OEM-T121-68 Post-cat lambda signal (G130); OEM-T121-69 Post-cat lambda signal (G130); OEM-T121-71 Wideband lambda Nernst signal (G39) |
Accepted (1)
| Code | Subject | Reason | By |
|---|---|---|---|
| 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 - 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 2026-10-11. 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 3: Ignition switch +12V (term 15): 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 - 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 input; not needed - 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 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
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 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 | — | — | — |