VW Corrado VR6 12v (AAA) Motronic M2.9 OBD1 → DTAFast T4 (auto)
VW Corrado VR6 12v (AAA) Motronic M2.9 OBD1 — DTAFast — T4
⚠ NOT CHECKED. Don't build from this.
Drawn by Michael Gnankou · Rev 0 · draft · 2026-10-12
Before you start
Not confident with automotive wiring? Have a professional harness builder or tuner do it, or check your work before first power-up. A wiring mistake can damage the ECU, the engine or the car, or start a fire.
| Status | draft · not yet verified: nobody has reported building and running this harness |
|---|---|
| Open errors | 5: read the Findings page before cutting any wire |
| Size of the job | 44 wires · 7 connectors · 2 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 | T4-C1-31 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W3 | OEM-A-54 | T4-C3-26 | 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 | T4-C1-13 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | SP-GND-1 | T4-C1-14 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | OEM-A-16 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | OEM-A-33 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | OEM-A-67 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | SP-0V-1 | T4-C2-21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | SP-0V-1 | T4-C2-33 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | OEM-A-41 | T4-C2-24 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-A-68 | T4-C2-12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-A-44 | T4-C2-22 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-A-8 | T4-C1-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-A-60 | T4-C1-18 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-A-52 | T4-C1-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-A-24 | T4-C1-9 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-A-3 | T4-C1-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-A-26 | T4-C1-34 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-A-4 | T4-C1-25 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-A-25 | T4-C1-9 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-A-2 | T4-C1-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-A-17 | T4-C2-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-A-40 | T4-C2-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | OEM-A-14 | T4-C2-7 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-A-49 | T4-C1-5 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-A-6 | T4-C1-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-A-9 | T4-C1-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-A-27 | T4-C3-22 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W35 | OEM-A-31 | T4-C3-23 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W36 | OEM-A-5 | T4-C3-24 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W37 | OEM-A-53 | T4-C3-25 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W38 | OEM-A-22 | T4-C3-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W39 | OEM-A-20 | T4-C2-5 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W40 | OEM-A-15 | T4-C2-25 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W41 | OEM-A-36 | T4-C2-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W42 | OEM-A-65 | T4-C2-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W43 | OEM-A-37 | T4-C2-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W44 | OEM-A-39 | T4-C2-14 | 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 | T4-C1-13 | T4-C1-31 | open (OL) | power ground must not touch +12 V supply | |
| 2 | T4-C1-13 | T4-C2-24 | open (OL) | power ground must not touch 5 V sensor reference | |
| 3 | T4-C1-13 | T4-C3-26 | open (OL) | power ground must not touch +12 V supply | |
| 4 | T4-C1-31 | T4-C2-24 | open (OL) | +12 V supply must not touch 5 V sensor reference | |
| 5 | T4-C2-21 | T4-C1-31 | open (OL) | sensor ground must not touch +12 V supply | |
| 6 | T4-C2-21 | T4-C2-24 | open (OL) | sensor ground must not touch 5 V sensor reference | |
| 7 | T4-C2-21 | T4-C3-26 | open (OL) | sensor ground must not touch +12 V supply | |
| 8 | T4-C2-24 | T4-C3-26 | open (OL) | 5 V sensor reference must not touch +12 V supply |
If any reading doesn't match, stop and get help before powering up.
Revisions
| Rev | Label | By | Date |
|---|---|---|---|
| No revisions yet. | |||
Schematic
Connectors
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) | — | W30 | — | 0.5 | T4-C2-7 | — | — | — |
| 15 | EGR temperature sensor | — | W40 | — | 0.5 | T4-C2-25 | — | — | — |
| 16 | MAF ground | — | W11 | — | 0.5 | SP-0V-1 | — | — | — |
| 17 | MAF signal | — | W28 | — | 0.5 | T4-C2-10 | — | — | — |
| 2 | Injector 6 (cyl 6) | — | W27 | — | 0.5 | T4-C1-17 | — | — | — |
| 20 | O2 sensor 1 (primary) | — | W39 | — | 0.5 | T4-C2-5 | — | — | — |
| 21 | Diagnostic L-line | — | — | — | — | — | — | — | — |
| 22 | Tachometer output | — | W38 | — | 0.5 | T4-C3-10 | — | — | — |
| 23 | ECU main power (from engine-electronics relay) | — | W1 | — | 0.85 | SP-14V-1 | — | — | — |
| 24 | Injector 1 (cyl 1) | — | W22 | — | 0.5 | T4-C1-9 | — | — | — |
| 25 | Injector 5 (cyl 5) | — | W26 | — | 0.5 | T4-C1-9 | — | — | — |
| 26 | Injector 3 (cyl 3) | — | W24 | — | 0.5 | T4-C1-34 | — | — | — |
| 27 | Idle air control valve | — | W34 | — | 0.5 | T4-C3-22 | — | — | — |
| 3 | Injector 2 (cyl 2) | — | W23 | — | 0.5 | T4-C1-17 | — | — | — |
| 31 | EVAP canister purge valve | — | W35 | — | 0.5 | T4-C3-23 | — | — | — |
| 33 | Sensor ground bus | — | W12 | — | 0.5 | SP-0V-1 | — | — | — |
| 34 | Knock sensor 1 | — | — | — | — | — | — | — | — |
| 36 | Intake air temperature (IAT) | — | W41 | — | 0.5 | T4-C2-17 | — | — | — |
| 37 | A/C compressor switch | — | W43 | — | 0.5 | T4-C2-4 | — | — | — |
| 38 | Ignition switch (run/start) | — | — | — | — | — | — | — | — |
| 39 | A/C switch (cabin) | — | W44 | — | 0.5 | T4-C2-14 | — | — | — |
| 4 | Injector 4 (cyl 4) | — | W25 | — | 0.5 | T4-C1-25 | — | — | — |
| 40 | Throttle position sensor 1 | — | W29 | — | 0.5 | T4-C2-1 | — | — | — |
| 41 | TPS power (+5V) | — | W16 | — | 0.5 | T4-C2-24 | — | — | — |
| 43 | Diagnostic K-line | — | — | — | — | — | — | — | — |
| 44 | Camshaft position sensor (G40) | — | W18 | — | 0.5 | T4-C2-22 | — | — | — |
| 49 | Secondary air injection relay control | — | W31 | — | 0.5 | T4-C1-5 | — | — | — |
| 5 | Check engine light (MIL) | — | W36 | — | 0.5 | T4-C3-24 | — | — | — |
| 51 | MFA fuel-consumption signal | — | — | — | — | — | — | — | — |
| 52 | Ignition coil 4 (coil pack pin 4) | — | W21 | — | 0.5 | T4-C1-1 | — | — | — |
| 53 | Idle air control valve (2nd) | — | W37 | — | 0.5 | T4-C3-25 | — | — | — |
| 54 | Battery constant (+12V) | — | W3 | — | 0.85 | T4-C3-26 | — | — | — |
| 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 | — | W32 | — | 0.5 | T4-C1-4 | — | — | — |
| 60 | Ignition coil 3 (coil pack pin 3) | — | W20 | — | 0.5 | T4-C1-18 | — | — | — |
| 65 | Vehicle speed sensor (VSS) | — | W42 | — | 0.5 | T4-C2-2 | — | — | — |
| 67 | Crank sensor return (VR-) | — | W13 | — | 0.5 | SP-0V-1 | — | — | — |
| 68 | Crank position sensor (G28, VR+) | — | W17 | — | 0.5 | T4-C2-12 | — | — | — |
| 7 | Ground (E-2) | — | W8 | — | 0.85 | SP-GND-1 | — | — | — |
| 8 | Ignition coil 2 (coil pack pin 2) | — | W19 | — | 0.5 | T4-C1-10 | — | — | — |
| 9 | Engine electronics relay control | — | W33 | — | 0.5 | T4-C1-3 | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W11 | — | 0.5 | OEM-A-16 | — | — | — |
| 1 | — | — | W12 | — | 0.5 | OEM-A-33 | — | — | — |
| 1 | — | — | W13 | — | 0.5 | OEM-A-67 | — | — | — |
| 1 | — | — | W14 | — | 0.5 | T4-C2-21 | — | — | — |
| 1 | — | — | W15 | — | 0.5 | T4-C2-33 | — | — | — |
SP-14V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W1 | — | 0.85 | OEM-A-23 | — | — | — |
| 1 | — | — | W2 | — | 0.85 | T4-C1-31 | — | — | — |
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 | T4-C1-13 | — | — | — |
| 1 | — | — | W10 | — | 0.85 | T4-C1-14 | — | — | — |
T4-C1
Mating face
Wire side
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Coil 3 | — | W21 | — | 0.5 | OEM-A-52 | — | — | — |
| 2 | — | — | — | — | — | — | — | — | — |
| 3 | PWM 3 | — | W33 | — | 0.5 | OEM-A-9 | — | — | — |
| 4 | PWM 2 | — | W32 | — | 0.5 | OEM-A-6 | — | — | — |
| 5 | PWM 1 | — | W31 | — | 0.5 | OEM-A-49 | — | — | — |
| 6 | — | — | — | — | — | — | — | — | — |
| 7 | — | — | — | — | — | — | — | — | — |
| 8 | — | — | — | — | — | — | — | — | — |
| 9 | Injector 1 | — | W26 | — | 0.5 | OEM-A-25 | — | — | — |
| 9 | Injector 1 | — | W22 | — | 0.5 | OEM-A-24 | — | — | — |
| 10 | Coil 1 | — | W19 | — | 0.5 | OEM-A-8 | — | — | — |
| 11 | — | — | — | — | — | — | — | — | — |
| 12 | — | — | — | — | — | — | — | — | — |
| 13 | Power Ground 1 | — | W9 | — | 0.85 | SP-GND-1 | — | — | — |
| 14 | Power Ground 2 | — | W10 | — | 0.85 | SP-GND-1 | — | — | — |
| 15 | — | — | — | — | — | — | — | — | — |
| 16 | — | — | — | — | — | — | — | — | — |
| 17 | Injector 2 | — | W23 | — | 0.5 | OEM-A-3 | — | — | — |
| 17 | Injector 2 | — | W27 | — | 0.5 | OEM-A-2 | — | — | — |
| 18 | Coil 2 | — | W20 | — | 0.5 | OEM-A-60 | — | — | — |
| 19 | — | — | — | — | — | — | — | — | — |
| 20 | — | — | — | — | — | — | — | — | — |
| 21 | — | — | — | — | — | — | — | — | — |
| 22 | — | — | — | — | — | — | — | — | — |
| 23 | — | — | — | — | — | — | — | — | — |
| 24 | — | — | — | — | — | — | — | — | — |
| 25 | Injector 4 | — | W25 | — | 0.5 | OEM-A-4 | — | — | — |
| 26 | Coil 4 | — | — | — | — | — | — | — | — |
| 27 | — | — | — | — | — | — | — | — | — |
| 28 | — | — | — | — | — | — | — | — | — |
| 29 | — | — | — | — | — | — | — | — | — |
| 30 | — | — | — | — | — | — | — | — | — |
| 31 | Ignition 12v In | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
| 32 | — | — | — | — | — | — | — | — | — |
| 33 | — | — | — | — | — | — | — | — | — |
| 34 | Injector 3 | — | W24 | — | 0.5 | OEM-A-26 | — | — | — |
T4-C2
Mating face
Wire side
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Analogue 2 | — | W29 | — | 0.5 | OEM-A-40 | — | — | — |
| 2 | Wheel 1 | — | W42 | — | 0.5 | OEM-A-65 | — | — | — |
| 3 | Analogue 10 | — | — | — | — | — | — | — | — |
| 4 | Digital 1 | — | W43 | — | 0.5 | OEM-A-37 | — | — | — |
| 5 | Analogue 3 | — | W39 | — | 0.5 | OEM-A-20 | — | — | — |
| 6 | Analogue 4 | — | — | — | — | — | — | — | — |
| 7 | Thermistor 1 | — | W30 | — | 0.5 | OEM-A-14 | — | — | — |
| 8 | — | — | — | — | — | — | — | — | — |
| 9 | 5v Output | — | — | — | — | — | — | — | — |
| 10 | Analogue 1 | — | W28 | — | 0.5 | OEM-A-17 | — | — | — |
| 11 | — | — | — | — | — | — | — | — | — |
| 12 | Crank | — | W17 | — | 0.5 | OEM-A-68 | — | — | — |
| 13 | — | — | — | — | — | — | — | — | — |
| 14 | Digital 4 | — | W44 | — | 0.5 | OEM-A-39 | — | — | — |
| 15 | Digital 5 | — | — | — | — | — | — | — | — |
| 16 | Analogue 11 | — | — | — | — | — | — | — | — |
| 17 | Thermistor 3 | — | W41 | — | 0.5 | OEM-A-36 | — | — | — |
| 18 | — | — | — | — | — | — | — | — | — |
| 19 | Analogue 6 | — | — | — | — | — | — | — | — |
| 20 | — | — | — | — | — | — | — | — | — |
| 21 | Sensor Ground | — | W14 | — | 0.5 | SP-0V-1 | — | — | — |
| 22 | Cam 1 | — | W18 | — | 0.5 | OEM-A-44 | — | — | — |
| 23 | — | — | — | — | — | — | — | — | — |
| 24 | 5v Output | — | W16 | — | 0.5 | OEM-A-41 | — | — | — |
| 25 | Thermistor 2 | — | W40 | — | 0.5 | OEM-A-15 | — | — | — |
| 26 | CAN High | — | — | — | — | — | — | — | — |
| 27 | — | — | — | — | — | — | — | — | — |
| 28 | CAN Low | — | — | — | — | — | — | — | — |
| 29 | — | — | — | — | — | — | — | — | — |
| 30 | — | — | — | — | — | — | — | — | — |
| 31 | — | — | — | — | — | — | — | — | — |
| 32 | — | — | — | — | — | — | — | — | — |
| 33 | Sensor Ground | — | W15 | — | 0.5 | SP-0V-1 | — | — | — |
| 34 | Analogue 9 | — | — | — | — | — | — | — | — |
T4-C3
Mating face
Wire side
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | — | — | — | — | — | — | — |
| 2 | — | — | — | — | — | — | — | — | — |
| 3 | — | — | — | — | — | — | — | — | — |
| 4 | — | — | — | — | — | — | — | — | — |
| 5 | — | — | — | — | — | — | — | — | — |
| 6 | — | — | — | — | — | — | — | — | — |
| 7 | Lambda 1 Pump Current | — | — | — | — | — | — | — | — |
| 8 | Lambda 1 VGND | — | — | — | — | — | — | — | — |
| 9 | Lambda 1 Heater Negative | — | — | — | — | — | — | — | — |
| 10 | PWM 8 | — | W38 | — | 0.5 | OEM-A-22 | — | — | — |
| 11 | Lambda 1 Trim Resistor | — | — | — | — | — | — | — | — |
| 12 | Lambda 1 Nernst Voltage | — | — | — | — | — | — | — | — |
| 13 | — | — | — | — | — | — | — | — | — |
| 14 | — | — | — | — | — | — | — | — | — |
| 15 | — | — | — | — | — | — | — | — | — |
| 16 | — | — | — | — | — | — | — | — | — |
| 17 | Analogue 7 | — | — | — | — | — | — | — | — |
| 18 | Analogue 8 | — | — | — | — | — | — | — | — |
| 19 | — | — | — | — | — | — | — | — | — |
| 20 | — | — | — | — | — | — | — | — | — |
| 21 | — | — | — | — | — | — | — | — | — |
| 22 | PWM 4 | — | W34 | — | 0.5 | OEM-A-27 | — | — | — |
| 23 | PWM 5 | — | W35 | — | 0.5 | OEM-A-31 | — | — | — |
| 24 | PWM 6 | — | W36 | — | 0.5 | OEM-A-5 | — | — | — |
| 25 | PWM 7 | — | W37 | — | 0.5 | OEM-A-53 | — | — | — |
| 26 | Permanent 12v | — | W3 | — | 0.85 | OEM-A-54 | — | — | — |
| 27 | Permanent 12v | — | — | — | — | — | — | — | — |
| 28 | — | — | — | — | — | — | — | — | — |
| 29 | — | — | — | — | — | — | — | — | — |
| 30 | — | — | — | — | — | — | — | — | — |
| 31 | — | — | — | — | — | — | — | — | — |
| 32 | — | — | — | — | — | — | — | — | — |
| 33 | — | — | — | — | — | — | — | — | — |
| 34 | — | — | — | — | — | — | — | — | — |
Pin map
| OEM point | OEM function | OEM family | Target point | Target function | Target family | Wire colour | Evidence |
|---|---|---|---|---|---|---|---|
| OEM-A-1 | Ground (E-1) | ground | T4-C1-13 + T4-C1-14 | Power Ground 1 + Power Ground 2 | ground | single_source | |
| OEM-A-10 | Ground (OBD1 EGR enable) | ground | T4-C1-13 + T4-C1-14 | Power Ground 1 + Power Ground 2 | ground | single_source | |
| OEM-A-14 | Coolant temperature (CLT) | temp_in | T4-C2-7 | Thermistor 1 | temp_in | single_source | |
| OEM-A-15 | EGR temperature sensor | temp_in | T4-C2-25 | Thermistor 2 | temp_in | single_source | |
| OEM-A-16 | MAF ground | sensor_ground | T4-C2-21 + T4-C2-33 | Sensor Ground + Sensor Ground | sensor_ground | single_source | |
| OEM-A-17 | MAF signal | analog_in | T4-C2-10 | Analogue 1 | analog_in | single_source | |
| OEM-A-2 | Injector 6 (cyl 6) | injector_out | T4-C1-17 | Injector 2 | injector_out | single_source | |
| OEM-A-20 | O2 sensor 1 (primary) | lambda_nb_in | T4-C2-5 | Analogue 3 | analog_in | single_source | |
| OEM-A-21 | Diagnostic L-line | serial | — | — | — | single_source | |
| OEM-A-22 | Tachometer output | tacho_out | T4-C3-10 | PWM 8 | low_side_out | single_source | |
| OEM-A-23 | ECU main power (from engine-electronics relay) | power_in | T4-C1-31 | Ignition 12v In | power_in | single_source | |
| OEM-A-24 | Injector 1 (cyl 1) | injector_out | T4-C1-9 | Injector 1 | injector_out | single_source | |
| OEM-A-25 | Injector 5 (cyl 5) | injector_out | T4-C1-9 | Injector 1 | injector_out | single_source | |
| OEM-A-26 | Injector 3 (cyl 3) | injector_out | T4-C1-34 | Injector 3 | injector_out | single_source | |
| OEM-A-27 | Idle air control valve | low_side_out | T4-C3-22 | PWM 4 | low_side_out | single_source | |
| OEM-A-3 | Injector 2 (cyl 2) | injector_out | T4-C1-17 | Injector 2 | injector_out | single_source | |
| OEM-A-31 | EVAP canister purge valve | low_side_out | T4-C3-23 | PWM 5 | low_side_out | single_source | |
| OEM-A-33 | Sensor ground bus | sensor_ground | T4-C2-21 + T4-C2-33 | Sensor Ground + Sensor Ground | sensor_ground | single_source | |
| OEM-A-34 | Knock sensor 1 | knock_in | — | — | — | single_source | |
| OEM-A-36 | Intake air temperature (IAT) | temp_in | T4-C2-17 | Thermistor 3 | temp_in | single_source | |
| OEM-A-37 | A/C compressor switch | digital_in | T4-C2-4 | Digital 1 | digital_in | single_source | |
| OEM-A-38 | Ignition switch (run/start) | digital_in | — | — | — | single_source | |
| OEM-A-39 | A/C switch (cabin) | digital_in | T4-C2-14 | Digital 4 | digital_in | single_source | |
| OEM-A-4 | Injector 4 (cyl 4) | injector_out | T4-C1-25 | Injector 4 | injector_out | single_source | |
| OEM-A-40 | Throttle position sensor 1 | analog_in | T4-C2-1 | Analogue 2 | analog_in | single_source | |
| OEM-A-41 | TPS power (+5V) | vref | T4-C2-24 | 5v Output | vref | single_source | |
| OEM-A-43 | Diagnostic K-line | serial | — | — | — | single_source | |
| OEM-A-44 | Camshaft position sensor (G40) | trigger_in | T4-C2-22 | Cam 1 | trigger_in | single_source | |
| OEM-A-49 | Secondary air injection relay control | low_side_out | T4-C1-5 | PWM 1 | low_side_out | single_source | |
| OEM-A-5 | Check engine light (MIL) | low_side_out | T4-C3-24 | PWM 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 | T4-C1-1 | Coil 3 | ignition_out | single_source | |
| OEM-A-53 | Idle air control valve (2nd) | low_side_out | T4-C3-25 | PWM 7 | low_side_out | single_source | |
| OEM-A-54 | Battery constant (+12V) | power_in | T4-C3-26 | Permanent 12v | power_in | single_source | |
| OEM-A-55 | Ground (E-3) | ground | T4-C1-13 + T4-C1-14 | Power Ground 1 + Power Ground 2 | ground | single_source | |
| OEM-A-56 | Ground (E-4) | ground | T4-C1-13 + T4-C1-14 | Power Ground 1 + Power Ground 2 | 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 | T4-C1-4 | PWM 2 | low_side_out | single_source | |
| OEM-A-60 | Ignition coil 3 (coil pack pin 3) | ignition_out | T4-C1-18 | Coil 2 | ignition_out | single_source | |
| OEM-A-65 | Vehicle speed sensor (VSS) | digital_in | T4-C2-2 | Wheel 1 | digital_in | single_source | |
| OEM-A-67 | Crank sensor return (VR-) | sensor_ground | T4-C2-21 + T4-C2-33 | Sensor Ground + Sensor Ground | sensor_ground | single_source | |
| OEM-A-68 | Crank position sensor (G28, VR+) | trigger_in | T4-C2-12 | Crank | trigger_in | single_source | |
| OEM-A-7 | Ground (E-2) | ground | T4-C1-13 + T4-C1-14 | Power Ground 1 + Power Ground 2 | ground | single_source | |
| OEM-A-8 | Ignition coil 2 (coil pack pin 2) | ignition_out | T4-C1-10 | Coil 1 | ignition_out | single_source | |
| OEM-A-9 | Engine electronics relay control | low_side_out | T4-C1-3 | PWM 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 | T4-C1-31 | 0.85 | no route | Ignition 12v In | — | |
| W3 | OEM-A-54 | T4-C3-26 | 0.85 | no route | Battery constant (+12V) | — | |
| 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 | T4-C1-13 | 0.85 | no route | Power Ground 1 | — | |
| W10 | SP-GND-1 | T4-C1-14 | 0.85 | no route | Power Ground 2 | — | |
| W11 | OEM-A-16 | SP-0V-1 | 0.5 | no route | MAF ground | — | |
| W12 | OEM-A-33 | SP-0V-1 | 0.5 | no route | Sensor ground bus | — | |
| W13 | OEM-A-67 | SP-0V-1 | 0.5 | no route | Crank sensor return (VR-) | — | |
| W14 | SP-0V-1 | T4-C2-21 | 0.5 | no route | Sensor Ground | — | |
| W15 | SP-0V-1 | T4-C2-33 | 0.5 | no route | Sensor Ground | — | |
| W16 | OEM-A-41 | T4-C2-24 | 0.5 | no route | TPS power (+5V) | — | |
| W17 | OEM-A-68 | T4-C2-12 | 0.5 | no route | Crank position sensor (G28, VR+) | — | |
| W18 | OEM-A-44 | T4-C2-22 | 0.5 | no route | Camshaft position sensor (G40) | — | |
| W19 | OEM-A-8 | T4-C1-10 | 0.5 | no route | Ignition coil 2 (coil pack pin 2) | — | |
| W20 | OEM-A-60 | T4-C1-18 | 0.5 | no route | Ignition coil 3 (coil pack pin 3) | — | |
| W21 | OEM-A-52 | T4-C1-1 | 0.5 | no route | Ignition coil 4 (coil pack pin 4) | — | |
| W22 | OEM-A-24 | T4-C1-9 | 0.5 | no route | Injector 1 (cyl 1) | — | |
| W23 | OEM-A-3 | T4-C1-17 | 0.5 | no route | Injector 2 (cyl 2) | — | |
| W24 | OEM-A-26 | T4-C1-34 | 0.5 | no route | Injector 3 (cyl 3) | — | |
| W25 | OEM-A-4 | T4-C1-25 | 0.5 | no route | Injector 4 (cyl 4) | — | |
| W26 | OEM-A-25 | T4-C1-9 | 0.5 | no route | Injector 5 (cyl 5) | — | |
| W27 | OEM-A-2 | T4-C1-17 | 0.5 | no route | Injector 6 (cyl 6) | — | |
| W28 | OEM-A-17 | T4-C2-10 | 0.5 | no route | MAF signal | — | |
| W29 | OEM-A-40 | T4-C2-1 | 0.5 | no route | Throttle position sensor 1 | — | |
| W30 | OEM-A-14 | T4-C2-7 | 0.5 | no route | Coolant temperature (CLT) | — | |
| W31 | OEM-A-49 | T4-C1-5 | 0.5 | no route | Secondary air injection relay control | — | |
| W32 | OEM-A-6 | T4-C1-4 | 0.5 | no route | Fuel pump relay control | — | |
| W33 | OEM-A-9 | T4-C1-3 | 0.5 | no route | Engine electronics relay control | — | |
| W34 | OEM-A-27 | T4-C3-22 | 0.5 | no route | Idle air control valve | — | |
| W35 | OEM-A-31 | T4-C3-23 | 0.5 | no route | EVAP canister purge valve | — | |
| W36 | OEM-A-5 | T4-C3-24 | 0.5 | no route | Check engine light (MIL) | — | |
| W37 | OEM-A-53 | T4-C3-25 | 0.5 | no route | Idle air control valve (2nd) | — | |
| W38 | OEM-A-22 | T4-C3-10 | 0.5 | no route | Tachometer output | — | |
| W39 | OEM-A-20 | T4-C2-5 | 0.5 | no route | O2 sensor 1 (primary) | — | |
| W40 | OEM-A-15 | T4-C2-25 | 0.5 | no route | EGR temperature sensor | — | |
| W41 | OEM-A-36 | T4-C2-17 | 0.5 | no route | Intake air temperature (IAT) | — | |
| W42 | OEM-A-65 | T4-C2-2 | 0.5 | no route | Vehicle speed sensor (VSS) | — | |
| W43 | OEM-A-37 | T4-C2-4 | 0.5 | no route | A/C compressor switch | — | |
| W44 | OEM-A-39 | T4-C2-14 | 0.5 | no route | A/C switch (cabin) | — |
Bill of materials
| Category | Part number | Manufacturer | Description | Qty | Unit |
|---|---|---|---|---|---|
| connector | 4-1437290-0 | TE | Superseal 1.0 34-way plug, Key 1 | 3.000 | ea |
| terminal | 3-1447221-4 | TE | Superseal 1.0 socket terminal, 20 AWG (0.5 sq mm) | 33.000 | ea |
ECU setup sheet
| Role | Engine ref | Engine signal | Sensor | ECU point | ECU function | ECU class | Setup flag |
|---|---|---|---|---|---|---|---|
| No configured channels. | |||||||
Findings
Open (10)
| Severity | Code | Subject | Message |
|---|---|---|---|
| error | NET_MERGED | OEM-A-2 + OEM-A-3 + T4-C1-17 | 2 different OEM functions share one net: OEM-A-2 Injector 6 (cyl 6); OEM-A-3 Injector 2 (cyl 2) |
| error | NET_MERGED | OEM-A-24 + OEM-A-25 + T4-C1-9 | 2 different OEM functions share one net: OEM-A-24 Injector 1 (cyl 1); OEM-A-25 Injector 5 (cyl 5) |
| error | PHYS_REQUIRED_OPEN | T4-C3-27 | T4-C3-27 "Permanent 12v" is required but not wired. |
| error | REQUIRED_UNMAPPED | OEM-A-34 | Required OEM function "Knock sensor 1" (knock_in) is not connected to the new ECU. |
| error | REQUIRED_UNMAPPED | OEM-A-38 | Required OEM function "Ignition switch (run/start)" (digital_in) is not connected to the new ECU. |
| warn | DATASET_GAP | T4 C1 | 20 of 34 cavities on T4 C1 have no pin data (2,6,7,8,11,12,15,16,19,20,21,22,23,24,27,28,29,30,32,33). Anything there is invisible to these checks. |
| warn | DATASET_GAP | T4 C2 | 11 of 34 cavities on T4 C2 have no pin data (8,11,13,18,20,23,27,29,30,31,32). Anything there is invisible to these checks. |
| warn | DATASET_GAP | T4 C3 | 20 of 34 cavities on T4 C3 have no pin data (1,2,3,4,5,6,13,14,15,16,19,20,21,28,29,30,31,32,33,34). Anything there is invisible to these checks. |
| info | NET_FAMILY | OEM-A-22 ↔ T4-C3-10 | OEM-A-22 "Tachometer output" [tacho_out] is wired to T4-C3-10 "PWM 8" [low_side_out]. Tacho as a low-side output: check the tach needs a pull-up. |
| info | UNMAPPED | OEM | 4 optional OEM pins are not mapped: OEM-A-21 Diagnostic L-line; OEM-A-43 Diagnostic K-line; OEM-A-51 MFA fuel-consumption signal; OEM-A-59 Mass airflow sensor (5th terminal) |
Accepted (0)
| Code | Subject | Reason | By |
|---|
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 34: Knock sensor 1: no free knock input on DTAFast T4 - 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); DTAFast T4 has no dedicated key-on input - T4-C3 27: Permanent 12v: required by DTAFast T4 but no stock pin feeds it; wire by hand Not wired: - OEM-A 51: MFA fuel-consumption signal: no free tacho/frequency_out/low_side/ls_hs on DTAFast T4 - OEM-A 21: Diagnostic L-line: no free k_line on DTAFast T4 - OEM-A 43: Diagnostic K-line: no free k_line on DTAFast T4 - 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 | DTAFast T4 ECU wiring diagram | https://cdn.shopify.com/s/files/1/0848/7508/4108/files/T4_Wiring_Diagram.pdf?v=1789413067 | — | — | — |
| 2 | community_copy | a2resource: VR6/ABA Motronic M2.9 (OBD1) engine control unit pinout | http://www.a2resource.com/electrical/management/motronicvr6aba.html | — | — | — |