VW Golf Mk4 1.8T 20v (AUM, Bosch ME7.5) DBW → MoTeC M800 universal (auto)
VW Golf Mk4 1.8T 20v (AUM, Bosch ME7.5) DBW — MoTeC — M800
⚠ 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 | 61 wires · 8 connectors · 3 part lines |
| Tools | Crimp and extraction tools for each terminal family (see Connectors) · wire strippers · multimeter · heat gun + heat-shrink |
| Terminals | 3-1447221-4 |
| 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 | M800-A-26 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W4 | OEM-T121-1 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W5 | OEM-T121-2 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W6 | SP-GND-1 | M800-A-10 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W7 | SP-GND-1 | M800-A-11 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | OEM-T121-108 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | OEM-T121-29 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | OEM-T121-34 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | OEM-T121-36 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | OEM-T121-90 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | OEM-T121-91 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | SP-0V-1 | M800-B-14 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | SP-0V-1 | M800-B-15 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | SP-0V-1 | M800-B-16 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-T121-72 | SP-5V1-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-T121-83 | SP-5V1-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-T121-99 | SP-5V1-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | SP-5V1-1 | M800-A-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-T121-73 | SP-5V2-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-T121-98 | SP-5V2-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | SP-5V2-1 | M800-A-9 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-T121-82 | M800-B-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-T121-86 | M800-B-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-T121-102 | M800-A-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-T121-95 | M800-A-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-T121-103 | M800-A-5 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-T121-94 | M800-A-6 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | OEM-T121-96 | M800-A-19 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-T121-89 | M800-A-20 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-T121-97 | M800-A-21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-T121-88 | M800-A-22 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-T121-53 | M800-A-14 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W35 | OEM-T121-101 | M800-A-15 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W36 | OEM-T121-33 | M800-A-16 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W37 | OEM-T121-84 | M800-A-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W38 | OEM-T121-35 | M800-A-25 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W39 | OEM-T121-92 | M800-B-20 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W40 | OEM-T121-93 | M800-B-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W41 | OEM-T121-65 | M800-A-18 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W42 | OEM-T121-66 | M800-A-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W43 | OEM-T121-5 | M800-A-23 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W44 | OEM-T121-63 | M800-A-24 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W45 | OEM-T121-104 | M800-A-31 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W46 | OEM-T121-105 | M800-A-32 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W47 | OEM-T121-115 | M800-A-33 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W48 | OEM-T121-47 | M800-A-34 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W49 | OEM-T121-48 | M800-A-27 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W50 | OEM-T121-64 | M800-A-28 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W51 | OEM-T121-9 | M800-A-29 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W52 | OEM-T121-51 | M800-B-26 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W53 | OEM-T121-52 | M800-B-13 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W54 | OEM-T121-70 | M800-B-25 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W55 | OEM-T121-71 | M800-B-12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W56 | OEM-T121-68 | M800-B-21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W57 | OEM-T121-69 | M800-B-22 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W58 | OEM-T121-85 | M800-B-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W59 | OEM-T121-54 | M800-B-8 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W60 | OEM-T121-60 | M800-B-23 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W61 | OEM-T121-58 | M800-B-24 | 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 | M800-A-10 | M800-A-2 | open (OL) | power ground must not touch 5 V sensor reference | |
| 2 | M800-A-10 | M800-A-26 | open (OL) | power ground must not touch +12 V supply | |
| 3 | M800-A-10 | M800-A-9 | open (OL) | power ground must not touch 5 V sensor reference | |
| 4 | M800-A-26 | M800-A-2 | open (OL) | +12 V supply must not touch 5 V sensor reference | |
| 5 | M800-A-26 | M800-A-9 | open (OL) | +12 V supply must not touch 5 V sensor reference | |
| 6 | M800-B-14 | M800-A-2 | open (OL) | sensor ground must not touch 5 V sensor reference | |
| 7 | M800-B-14 | M800-A-26 | open (OL) | sensor ground must not touch +12 V supply | |
| 8 | M800-B-14 | M800-A-9 | 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
M800-A
Mating face
Wire side
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | AUX2 | — | W42 | — | 0.5 | OEM-T121-66 | — | — | — |
| 2 | 5V Engine Sensor Supply | — | W20 | — | 0.5 | SP-5V1-1 | — | — | — |
| 3 | IGN1 | — | W26 | — | 0.5 | OEM-T121-102 | — | — | — |
| 4 | IGN2 | — | W27 | — | 0.5 | OEM-T121-95 | — | — | — |
| 5 | IGN3 | — | W28 | — | 0.5 | OEM-T121-103 | — | — | — |
| 6 | IGN4 | — | W29 | — | 0.5 | OEM-T121-94 | — | — | — |
| 7 | IGN5 | — | — | — | — | — | — | — | — |
| 8 | IGN6 | — | — | — | — | — | — | — | — |
| 9 | 5V Auxiliary Sensor Supply | — | W23 | — | 0.5 | SP-5V2-1 | — | — | — |
| 10 | GND Battery Negative | — | W6 | — | 0.85 | SP-GND-1 | — | — | — |
| 11 | GND Battery Negative | — | W7 | — | 0.85 | SP-GND-1 | — | — | — |
| 12 | 8V Engine Sensor Supply | — | — | — | — | — | — | — | — |
| 13 | 8V Auxiliary Sensor and CAN Supply | — | — | — | — | — | — | — | — |
| 14 | AV1 | — | W34 | — | 0.5 | OEM-T121-53 | — | — | — |
| 15 | Analog Voltage Input 2 | — | W35 | — | 0.5 | OEM-T121-101 | — | — | — |
| 16 | Analog Voltage Input 3 | — | W36 | — | 0.5 | OEM-T121-33 | — | — | — |
| 17 | Analog Voltage Input 4 | — | W37 | — | 0.5 | OEM-T121-84 | — | — | — |
| 18 | AUX1 | — | W41 | — | 0.5 | OEM-T121-65 | — | — | — |
| 19 | INJ1 | — | W30 | — | 0.5 | OEM-T121-96 | — | — | — |
| 20 | INJ2 | — | W31 | — | 0.5 | OEM-T121-89 | — | — | — |
| 21 | INJ3 | — | W32 | — | 0.5 | OEM-T121-97 | — | — | — |
| 22 | INJ4 | — | W33 | — | 0.5 | OEM-T121-88 | — | — | — |
| 23 | AUX3 | — | W43 | — | 0.5 | OEM-T121-5 | — | — | — |
| 24 | AUX4 | — | W44 | — | 0.5 | OEM-T121-63 | — | — | — |
| 25 | Analog Voltage Input 5 | — | W38 | — | 0.5 | OEM-T121-35 | — | — | — |
| 26 | VBAT Battery Positive | — | W3 | — | 0.85 | SP-14V-1 | — | — | — |
| 27 | INJ5 | — | W49 | — | 0.5 | OEM-T121-48 | — | — | — |
| 28 | INJ6 | — | W50 | — | 0.5 | OEM-T121-64 | — | — | — |
| 29 | INJ7 | — | W51 | — | 0.5 | OEM-T121-9 | — | — | — |
| 30 | INJ8 | — | — | — | — | — | — | — | — |
| 31 | AUX5 | — | W45 | — | 0.5 | OEM-T121-104 | — | — | — |
| 32 | AUX6 | — | W46 | — | 0.5 | OEM-T121-105 | — | — | — |
| 33 | AUX7 | — | W47 | — | 0.5 | OEM-T121-115 | — | — | — |
| 34 | AUX8 | — | W48 | — | 0.5 | OEM-T121-47 | — | — | — |
M800-B
Mating face
Wire side
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Crank Reference Timing Input | — | W24 | — | 0.5 | OEM-T121-82 | — | — | — |
| 2 | Cam Sync Timing Input | — | W25 | — | 0.5 | OEM-T121-86 | — | — | — |
| 3 | Analog Temperature Input 1 | — | W40 | — | 0.5 | OEM-T121-93 | — | — | — |
| 4 | Analog Temperature Input 2 | — | W58 | — | 0.5 | OEM-T121-85 | — | — | — |
| 5 | Analog Temperature Input 3 | — | — | — | — | — | — | — | — |
| 6 | Analog Temperature Input 4 | — | — | — | — | — | — | — | — |
| 7 | Analog Temperature Input 5 | — | — | — | — | — | — | — | — |
| 8 | Digital Input 1 | — | W59 | — | 0.5 | OEM-T121-54 | — | — | — |
| 9 | Digital Input 2 | — | — | — | — | — | — | — | — |
| 10 | Digital Input 3 | — | — | — | — | — | — | — | — |
| 11 | Digital Input 4 | — | — | — | — | — | — | — | — |
| 12 | Lambda2 Sense Voltage | — | W55 | — | 0.5 | OEM-T121-71 | — | — | — |
| 13 | Lambda2 Pump Current | — | W53 | — | 0.5 | OEM-T121-52 | — | — | — |
| 14 | 0V Comms Reference | — | W14 | — | 0.5 | SP-0V-1 | — | — | — |
| 15 | 0V Auxiliary Sensor Supply | — | W15 | — | 0.5 | SP-0V-1 | — | — | — |
| 16 | 0V Engine Sensor Supply | — | W16 | — | 0.5 | SP-0V-1 | — | — | — |
| 17 | RS232 Transmit Data | — | — | — | — | — | — | — | — |
| 18 | RS232 Receive Data | — | — | — | — | — | — | — | — |
| 19 | Analog Temperature Input 6 | — | — | — | — | — | — | — | — |
| 20 | Analog Voltage Input 6 | — | W39 | — | 0.5 | OEM-T121-92 | — | — | — |
| 21 | AV7 | — | W56 | — | 0.5 | OEM-T121-68 | — | — | — |
| 22 | AV8 | — | W57 | — | 0.5 | OEM-T121-69 | — | — | — |
| 23 | CAN Bus High | — | W60 | — | 0.5 | OEM-T121-60 | — | — | — |
| 24 | CAN Bus Low | — | W61 | — | 0.5 | OEM-T121-58 | — | — | — |
| 25 | Lambda1 Sense Voltage | — | W54 | — | 0.5 | OEM-T121-70 | — | — | — |
| 26 | Lambda1 Pump Current | — | W52 | — | 0.5 | OEM-T121-51 | — | — | — |
OEM-T121
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | ECU ground | — | W4 | — | 0.85 | SP-GND-1 | — | — | — |
| 101 | Boost pressure sensor (G31) | — | W35 | — | 0.5 | M800-A-15 | — | — | — |
| 102 | Ignition coil 1 (N127) | — | W26 | — | 0.5 | M800-A-3 | — | — | — |
| 103 | Ignition coil 3 (N158) | — | W28 | — | 0.5 | M800-A-5 | — | — | — |
| 104 | Boost control solenoid (N75) | — | W45 | — | 0.5 | M800-A-31 | — | — | — |
| 105 | Diverter valve (N249) | — | W46 | — | 0.5 | M800-A-32 | — | — | — |
| 106 | Knock sensor 1 (G61) | — | — | — | — | — | — | — | — |
| 107 | Knock sensor 2 (G66) | — | — | — | — | — | — | — | — |
| 108 | Sensor ground | — | W8 | — | 0.5 | SP-0V-1 | — | — | — |
| 115 | VVT camshaft adjustment valve (N205) | — | W47 | — | 0.5 | M800-A-33 | — | — | — |
| 117 | Throttle motor G186 (+) | — | — | — | — | — | — | — | — |
| 118 | Throttle motor G186 (−) | — | — | — | — | — | — | — | — |
| 121 | ECM + coil power (J271 relay feed) | — | W1 | — | 0.85 | SP-14V-1 | — | — | — |
| 2 | ECU ground | — | W5 | — | 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) | — | W9 | — | 0.5 | SP-0V-1 | — | — | — |
| 3 | Ignition switch +12V (term 15) | — | — | — | — | — | — | — | — |
| 33 | Accelerator pedal position 1 (G79) | — | W36 | — | 0.5 | M800-A-16 | — | — | — |
| 34 | Accelerator pedal position 1 ground (G79) | — | W10 | — | 0.5 | SP-0V-1 | — | — | — |
| 35 | Accelerator pedal position 2 (G185) | — | W38 | — | 0.5 | M800-A-25 | — | — | — |
| 36 | Accelerator pedal position 2 ground (G185) | — | W11 | — | 0.5 | SP-0V-1 | — | — | — |
| 37 | Engine speed signal (tacho to cluster) | — | — | — | — | — | — | — | — |
| 43 | K-line diagnostics (OBD pin 7) | — | — | — | — | — | — | — | — |
| 47 | Check engine light (MIL) | — | W48 | — | 0.5 | M800-A-34 | — | — | — |
| 48 | EPC warning light | — | W49 | — | 0.5 | M800-A-27 | — | — | — |
| 5 | Wideband lambda heater (Z19) | — | W43 | — | 0.5 | M800-A-23 | — | — | — |
| 51 | Wideband lambda pump (G39) | — | W52 | — | 0.5 | M800-B-26 | — | — | — |
| 52 | Wideband lambda pump (G39) | — | W53 | — | 0.5 | M800-B-13 | — | — | — |
| 53 | MAF sensor signal (G70) | — | W34 | — | 0.5 | M800-A-14 | — | — | — |
| 54 | Road speed signal (VSS) | — | W59 | — | 0.5 | M800-B-8 | — | — | — |
| 58 | CAN bus low | — | W61 | — | 0.5 | M800-B-24 | — | — | — |
| 60 | CAN bus high | — | W60 | — | 0.5 | M800-B-23 | — | — | — |
| 62 | Battery constant +12V (term 30) | — | — | — | — | — | — | — | — |
| 63 | Post-cat lambda heater (Z29) | — | W44 | — | 0.5 | M800-A-24 | — | — | — |
| 64 | EVAP canister valve (N80) | — | W50 | — | 0.5 | M800-A-28 | — | — | — |
| 65 | Fuel pump relay control | — | W41 | — | 0.5 | M800-A-18 | — | — | — |
| 66 | Secondary-air pump relay (J299) | — | W42 | — | 0.5 | M800-A-1 | — | — | — |
| 68 | Post-cat lambda signal (G130) | — | W56 | — | 0.5 | M800-B-21 | — | — | — |
| 69 | Post-cat lambda signal (G130) | — | W57 | — | 0.5 | M800-B-22 | — | — | — |
| 70 | Wideband lambda Nernst signal (G39) | — | W54 | — | 0.5 | M800-B-25 | — | — | — |
| 71 | Wideband lambda Nernst signal (G39) | — | W55 | — | 0.5 | M800-B-12 | — | — | — |
| 72 | Accelerator pedal position 1 5V supply (G79) | — | W17 | — | 0.5 | SP-5V1-1 | — | — | — |
| 73 | Accelerator pedal position 2 5V supply (G185) | — | W21 | — | 0.5 | SP-5V2-1 | — | — | — |
| 82 | Crank position sensor (G28) | — | W24 | — | 0.5 | M800-B-1 | — | — | — |
| 83 | Throttle position sensor 5V supply (G187/G188) | — | W18 | — | 0.5 | SP-5V1-1 | — | — | — |
| 84 | Throttle position sensor 1 (G187) | — | W37 | — | 0.5 | M800-A-17 | — | — | — |
| 85 | Intake air temperature (G42) | — | W58 | — | 0.5 | M800-B-4 | — | — | — |
| 86 | Camshaft position sensor (G40) | — | W25 | — | 0.5 | M800-B-2 | — | — | — |
| 88 | Injector 4 (N33) | — | W33 | — | 0.5 | M800-A-22 | — | — | — |
| 89 | Injector 2 (N31) | — | W31 | — | 0.5 | M800-A-20 | — | — | — |
| 9 | Secondary-air injection valve (N112) | — | W51 | — | 0.5 | M800-A-29 | — | — | — |
| 90 | Crank position sensor ground (G28) | — | W12 | — | 0.5 | SP-0V-1 | — | — | — |
| 91 | Throttle position sensor ground (G187/G188) | — | W13 | — | 0.5 | SP-0V-1 | — | — | — |
| 92 | Throttle position sensor 2 (G188) | — | W39 | — | 0.5 | M800-B-20 | — | — | — |
| 93 | Engine coolant temperature (G62) | — | W40 | — | 0.5 | M800-B-3 | — | — | — |
| 94 | Ignition coil 4 (N163) | — | W29 | — | 0.5 | M800-A-6 | — | — | — |
| 95 | Ignition coil 2 (N128) | — | W27 | — | 0.5 | M800-A-4 | — | — | — |
| 96 | Injector 1 (N30) | — | W30 | — | 0.5 | M800-A-19 | — | — | — |
| 97 | Injector 3 (N32) | — | W32 | — | 0.5 | M800-A-21 | — | — | — |
| 98 | Cam + boost sensor 5V supply (G40/G31) | — | W22 | — | 0.5 | SP-5V2-1 | — | — | — |
| 99 | Knock sensor 5V supply (G61/G66) | — | W19 | — | 0.5 | SP-5V1-1 | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W8 | — | 0.5 | OEM-T121-108 | — | — | — |
| 1 | — | — | W9 | — | 0.5 | OEM-T121-29 | — | — | — |
| 1 | — | — | W10 | — | 0.5 | OEM-T121-34 | — | — | — |
| 1 | — | — | W11 | — | 0.5 | OEM-T121-36 | — | — | — |
| 1 | — | — | W12 | — | 0.5 | OEM-T121-90 | — | — | — |
| 1 | — | — | W13 | — | 0.5 | OEM-T121-91 | — | — | — |
| 1 | — | — | W14 | — | 0.5 | M800-B-14 | — | — | — |
| 1 | — | — | W15 | — | 0.5 | M800-B-15 | — | — | — |
| 1 | — | — | W16 | — | 0.5 | M800-B-16 | — | — | — |
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 | M800-A-26 | — | — | — |
SP-5V1
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W17 | — | 0.5 | OEM-T121-72 | — | — | — |
| 1 | — | — | W18 | — | 0.5 | OEM-T121-83 | — | — | — |
| 1 | — | — | W19 | — | 0.5 | OEM-T121-99 | — | — | — |
| 1 | — | — | W20 | — | 0.5 | M800-A-2 | — | — | — |
SP-5V2
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W21 | — | 0.5 | OEM-T121-73 | — | — | — |
| 1 | — | — | W22 | — | 0.5 | OEM-T121-98 | — | — | — |
| 1 | — | — | W23 | — | 0.5 | M800-A-9 | — | — | — |
SP-GND
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W4 | — | 0.85 | OEM-T121-1 | — | — | — |
| 1 | — | — | W5 | — | 0.85 | OEM-T121-2 | — | — | — |
| 1 | — | — | W6 | — | 0.85 | M800-A-10 | — | — | — |
| 1 | — | — | W7 | — | 0.85 | M800-A-11 | — | — | — |
Pin map
| OEM point | OEM function | OEM family | Target point | Target function | Target family | Wire colour | Evidence |
|---|---|---|---|---|---|---|---|
| OEM-T121-1 | ECU ground | ground | M800-A-10 + M800-A-11 | GND Battery Negative + GND Battery Negative | ground | corroborated | |
| OEM-T121-101 | Boost pressure sensor (G31) | analog_in | M800-A-15 | Analog Voltage Input 2 | analog_in | corroborated | |
| OEM-T121-102 | Ignition coil 1 (N127) | ignition_out | M800-A-3 | IGN1 | ignition_out | corroborated | |
| OEM-T121-103 | Ignition coil 3 (N158) | ignition_out | M800-A-5 | IGN3 | ignition_out | corroborated | |
| OEM-T121-104 | Boost control solenoid (N75) | low_side_out | M800-A-31 | AUX5 | switch_out | corroborated | |
| OEM-T121-105 | Diverter valve (N249) | low_side_out | M800-A-32 | AUX6 | switch_out | corroborated | |
| OEM-T121-106 | Knock sensor 1 (G61) | knock_in | — | — | — | corroborated | |
| OEM-T121-107 | Knock sensor 2 (G66) | knock_in | — | — | — | corroborated | |
| OEM-T121-108 | Sensor ground | sensor_ground | M800-B-14 + M800-B-15 + M800-B-16 | 0V Comms Reference + 0V Auxiliary Sensor Supply + 0V Engine Sensor Supply | sensor_ground | corroborated | |
| OEM-T121-115 | VVT camshaft adjustment valve (N205) | low_side_out | M800-A-33 | AUX7 | switch_out | corroborated | |
| OEM-T121-117 | Throttle motor G186 (+) | hbridge_out | — | — | — | corroborated | |
| OEM-T121-118 | Throttle motor G186 (−) | hbridge_out | — | — | — | corroborated | |
| OEM-T121-121 | ECM + coil power (J271 relay feed) | power_in | M800-A-26 | VBAT Battery Positive | power_in | corroborated | |
| OEM-T121-2 | ECU ground | ground | M800-A-10 + M800-A-11 | GND Battery Negative + GND Battery Negative | ground | corroborated | |
| OEM-T121-21 | ECM power (J271 relay feed) | power_in | M800-A-26 | VBAT Battery Positive | power_in | corroborated | |
| OEM-T121-27 | MAF sensor supply (G70) | power_in | — | — | — | corroborated | |
| OEM-T121-29 | MAF sensor ground (G70) | sensor_ground | M800-B-14 + M800-B-15 + M800-B-16 | 0V Comms Reference + 0V Auxiliary Sensor Supply + 0V Engine Sensor Supply | sensor_ground | corroborated | |
| OEM-T121-3 | Ignition switch +12V (term 15) | digital_in | — | — | — | corroborated | |
| OEM-T121-33 | Accelerator pedal position 1 (G79) | analog_in | M800-A-16 | Analog Voltage Input 3 | analog_in | corroborated | |
| OEM-T121-34 | Accelerator pedal position 1 ground (G79) | sensor_ground | M800-B-14 + M800-B-15 + M800-B-16 | 0V Comms Reference + 0V Auxiliary Sensor Supply + 0V Engine Sensor Supply | sensor_ground | corroborated | |
| OEM-T121-35 | Accelerator pedal position 2 (G185) | analog_in | M800-A-25 | Analog Voltage Input 5 | analog_in | corroborated | |
| OEM-T121-36 | Accelerator pedal position 2 ground (G185) | sensor_ground | M800-B-14 + M800-B-15 + M800-B-16 | 0V Comms Reference + 0V Auxiliary Sensor Supply + 0V Engine Sensor Supply | sensor_ground | corroborated | |
| OEM-T121-37 | Engine speed signal (tacho to cluster) | tacho_out | — | — | — | corroborated | |
| OEM-T121-43 | K-line diagnostics (OBD pin 7) | serial | — | — | — | corroborated | |
| OEM-T121-47 | Check engine light (MIL) | low_side_out | M800-A-34 | AUX8 | switch_out | corroborated | |
| OEM-T121-48 | EPC warning light | low_side_out | M800-A-27 | INJ5 | injector_out | corroborated | |
| OEM-T121-5 | Wideband lambda heater (Z19) | low_side_out | M800-A-23 | AUX3 | switch_out | corroborated | |
| OEM-T121-51 | Wideband lambda pump (G39) | wb_ip | M800-B-26 | Lambda1 Pump Current | wb_ip | corroborated | |
| OEM-T121-52 | Wideband lambda pump (G39) | wb_ip | M800-B-13 | Lambda2 Pump Current | wb_ip | corroborated | |
| OEM-T121-53 | MAF sensor signal (G70) | analog_in | M800-A-14 | AV1 | analog_in | corroborated | |
| OEM-T121-54 | Road speed signal (VSS) | digital_in | M800-B-8 | Digital Input 1 | digital_in | corroborated | |
| OEM-T121-58 | CAN bus low | can_l | M800-B-24 | CAN Bus Low | can_l | corroborated | |
| OEM-T121-60 | CAN bus high | can_h | M800-B-23 | CAN Bus 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 | M800-A-24 | AUX4 | switch_out | corroborated | |
| OEM-T121-64 | EVAP canister valve (N80) | low_side_out | M800-A-28 | INJ6 | injector_out | corroborated | |
| OEM-T121-65 | Fuel pump relay control | low_side_out | M800-A-18 | AUX1 | switch_out | corroborated | |
| OEM-T121-66 | Secondary-air pump relay (J299) | low_side_out | M800-A-1 | AUX2 | switch_out | corroborated | |
| OEM-T121-68 | Post-cat lambda signal (G130) | lambda_nb_in | M800-B-21 | AV7 | analog_in | corroborated | |
| OEM-T121-69 | Post-cat lambda signal (G130) | lambda_nb_in | M800-B-22 | AV8 | analog_in | corroborated | |
| OEM-T121-70 | Wideband lambda Nernst signal (G39) | wb_vs | M800-B-25 | Lambda1 Sense Voltage | wb_vs | corroborated | |
| OEM-T121-71 | Wideband lambda Nernst signal (G39) | wb_vs | M800-B-12 | Lambda2 Sense Voltage | wb_vs | corroborated | |
| OEM-T121-72 | Accelerator pedal position 1 5V supply (G79) | vref | M800-A-2 | 5V Engine Sensor Supply | vref | corroborated | |
| OEM-T121-73 | Accelerator pedal position 2 5V supply (G185) | vref | M800-A-9 | 5V Auxiliary Sensor Supply | vref | corroborated | |
| OEM-T121-82 | Crank position sensor (G28) | trigger_in | M800-B-1 | Crank Reference Timing Input | trigger_in | corroborated | |
| OEM-T121-83 | Throttle position sensor 5V supply (G187/G188) | vref | M800-A-2 | 5V Engine Sensor Supply | vref | corroborated | |
| OEM-T121-84 | Throttle position sensor 1 (G187) | analog_in | M800-A-17 | Analog Voltage Input 4 | analog_in | corroborated | |
| OEM-T121-85 | Intake air temperature (G42) | temp_in | M800-B-4 | Analog Temperature Input 2 | temp_in | corroborated | |
| OEM-T121-86 | Camshaft position sensor (G40) | trigger_in | M800-B-2 | Cam Sync Timing Input | trigger_in | corroborated | |
| OEM-T121-88 | Injector 4 (N33) | injector_out | M800-A-22 | INJ4 | injector_out | corroborated | |
| OEM-T121-89 | Injector 2 (N31) | injector_out | M800-A-20 | INJ2 | injector_out | corroborated | |
| OEM-T121-9 | Secondary-air injection valve (N112) | low_side_out | M800-A-29 | INJ7 | injector_out | corroborated | |
| OEM-T121-90 | Crank position sensor ground (G28) | sensor_ground | M800-B-14 + M800-B-15 + M800-B-16 | 0V Comms Reference + 0V Auxiliary Sensor Supply + 0V Engine Sensor Supply | sensor_ground | corroborated | |
| OEM-T121-91 | Throttle position sensor ground (G187/G188) | sensor_ground | M800-B-14 + M800-B-15 + M800-B-16 | 0V Comms Reference + 0V Auxiliary Sensor Supply + 0V Engine Sensor Supply | sensor_ground | corroborated | |
| OEM-T121-92 | Throttle position sensor 2 (G188) | analog_in | M800-B-20 | Analog Voltage Input 6 | analog_in | corroborated | |
| OEM-T121-93 | Engine coolant temperature (G62) | temp_in | M800-B-3 | Analog Temperature Input 1 | temp_in | corroborated | |
| OEM-T121-94 | Ignition coil 4 (N163) | ignition_out | M800-A-6 | IGN4 | ignition_out | corroborated | |
| OEM-T121-95 | Ignition coil 2 (N128) | ignition_out | M800-A-4 | IGN2 | ignition_out | corroborated | |
| OEM-T121-96 | Injector 1 (N30) | injector_out | M800-A-19 | INJ1 | injector_out | corroborated | |
| OEM-T121-97 | Injector 3 (N32) | injector_out | M800-A-21 | INJ3 | injector_out | corroborated | |
| OEM-T121-98 | Cam + boost sensor 5V supply (G40/G31) | vref | M800-A-9 | 5V Auxiliary Sensor Supply | vref | corroborated | |
| OEM-T121-99 | Knock sensor 5V supply (G61/G66) | vref | M800-A-2 | 5V Engine Sensor Supply | 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 | M800-A-26 | 0.85 | no route | VBAT Battery Positive | — | |
| W4 | OEM-T121-1 | SP-GND-1 | 0.85 | no route | ECU ground | — | |
| W5 | OEM-T121-2 | SP-GND-1 | 0.85 | no route | ECU ground | — | |
| W6 | SP-GND-1 | M800-A-10 | 0.85 | no route | GND Battery Negative | — | |
| W7 | SP-GND-1 | M800-A-11 | 0.85 | no route | GND Battery Negative | — | |
| W8 | OEM-T121-108 | SP-0V-1 | 0.5 | no route | Sensor ground | — | |
| W9 | OEM-T121-29 | SP-0V-1 | 0.5 | no route | MAF sensor ground (G70) | — | |
| W10 | OEM-T121-34 | SP-0V-1 | 0.5 | no route | Accelerator pedal position 1 ground (G79) | — | |
| W11 | OEM-T121-36 | SP-0V-1 | 0.5 | no route | Accelerator pedal position 2 ground (G185) | — | |
| W12 | OEM-T121-90 | SP-0V-1 | 0.5 | no route | Crank position sensor ground (G28) | — | |
| W13 | OEM-T121-91 | SP-0V-1 | 0.5 | no route | Throttle position sensor ground (G187/G188) | — | |
| W14 | SP-0V-1 | M800-B-14 | 0.5 | no route | 0V Comms Reference | — | |
| W15 | SP-0V-1 | M800-B-15 | 0.5 | no route | 0V Auxiliary Sensor Supply | — | |
| W16 | SP-0V-1 | M800-B-16 | 0.5 | no route | 0V Engine Sensor Supply | — | |
| W17 | OEM-T121-72 | SP-5V1-1 | 0.5 | no route | Accelerator pedal position 1 5V supply (G79) | — | |
| W18 | OEM-T121-83 | SP-5V1-1 | 0.5 | no route | Throttle position sensor 5V supply (G187/G188) | — | |
| W19 | OEM-T121-99 | SP-5V1-1 | 0.5 | no route | Knock sensor 5V supply (G61/G66) | — | |
| W20 | SP-5V1-1 | M800-A-2 | 0.5 | no route | 5V Engine Sensor Supply | — | |
| W21 | OEM-T121-73 | SP-5V2-1 | 0.5 | no route | Accelerator pedal position 2 5V supply (G185) | — | |
| W22 | OEM-T121-98 | SP-5V2-1 | 0.5 | no route | Cam + boost sensor 5V supply (G40/G31) | — | |
| W23 | SP-5V2-1 | M800-A-9 | 0.5 | no route | 5V Auxiliary Sensor Supply | — | |
| W24 | OEM-T121-82 | M800-B-1 | 0.5 | no route | Crank position sensor (G28) | — | |
| W25 | OEM-T121-86 | M800-B-2 | 0.5 | no route | Camshaft position sensor (G40) | — | |
| W26 | OEM-T121-102 | M800-A-3 | 0.5 | no route | Ignition coil 1 (N127) | — | |
| W27 | OEM-T121-95 | M800-A-4 | 0.5 | no route | Ignition coil 2 (N128) | — | |
| W28 | OEM-T121-103 | M800-A-5 | 0.5 | no route | Ignition coil 3 (N158) | — | |
| W29 | OEM-T121-94 | M800-A-6 | 0.5 | no route | Ignition coil 4 (N163) | — | |
| W30 | OEM-T121-96 | M800-A-19 | 0.5 | no route | Injector 1 (N30) | — | |
| W31 | OEM-T121-89 | M800-A-20 | 0.5 | no route | Injector 2 (N31) | — | |
| W32 | OEM-T121-97 | M800-A-21 | 0.5 | no route | Injector 3 (N32) | — | |
| W33 | OEM-T121-88 | M800-A-22 | 0.5 | no route | Injector 4 (N33) | — | |
| W34 | OEM-T121-53 | M800-A-14 | 0.5 | no route | MAF sensor signal (G70) | — | |
| W35 | OEM-T121-101 | M800-A-15 | 0.5 | no route | Boost pressure sensor (G31) | — | |
| W36 | OEM-T121-33 | M800-A-16 | 0.5 | no route | Accelerator pedal position 1 (G79) | — | |
| W37 | OEM-T121-84 | M800-A-17 | 0.5 | no route | Throttle position sensor 1 (G187) | — | |
| W38 | OEM-T121-35 | M800-A-25 | 0.5 | no route | Accelerator pedal position 2 (G185) | — | |
| W39 | OEM-T121-92 | M800-B-20 | 0.5 | no route | Throttle position sensor 2 (G188) | — | |
| W40 | OEM-T121-93 | M800-B-3 | 0.5 | no route | Engine coolant temperature (G62) | — | |
| W41 | OEM-T121-65 | M800-A-18 | 0.5 | no route | Fuel pump relay control | — | |
| W42 | OEM-T121-66 | M800-A-1 | 0.5 | no route | Secondary-air pump relay (J299) | — | |
| W43 | OEM-T121-5 | M800-A-23 | 0.5 | no route | Wideband lambda heater (Z19) | — | |
| W44 | OEM-T121-63 | M800-A-24 | 0.5 | no route | Post-cat lambda heater (Z29) | — | |
| W45 | OEM-T121-104 | M800-A-31 | 0.5 | no route | Boost control solenoid (N75) | — | |
| W46 | OEM-T121-105 | M800-A-32 | 0.5 | no route | Diverter valve (N249) | — | |
| W47 | OEM-T121-115 | M800-A-33 | 0.5 | no route | VVT camshaft adjustment valve (N205) | — | |
| W48 | OEM-T121-47 | M800-A-34 | 0.5 | no route | Check engine light (MIL) | — | |
| W49 | OEM-T121-48 | M800-A-27 | 0.5 | no route | EPC warning light | — | |
| W50 | OEM-T121-64 | M800-A-28 | 0.5 | no route | EVAP canister valve (N80) | — | |
| W51 | OEM-T121-9 | M800-A-29 | 0.5 | no route | Secondary-air injection valve (N112) | — | |
| W52 | OEM-T121-51 | M800-B-26 | 0.5 | no route | Wideband lambda pump (G39) | — | |
| W53 | OEM-T121-52 | M800-B-13 | 0.5 | no route | Wideband lambda pump (G39) | — | |
| W54 | OEM-T121-70 | M800-B-25 | 0.5 | no route | Wideband lambda Nernst signal (G39) | — | |
| W55 | OEM-T121-71 | M800-B-12 | 0.5 | no route | Wideband lambda Nernst signal (G39) | — | |
| W56 | OEM-T121-68 | M800-B-21 | 0.5 | no route | Post-cat lambda signal (G130) | — | |
| W57 | OEM-T121-69 | M800-B-22 | 0.5 | no route | Post-cat lambda signal (G130) | — | |
| W58 | OEM-T121-85 | M800-B-4 | 0.5 | no route | Intake air temperature (G42) | — | |
| W59 | OEM-T121-54 | M800-B-8 | 0.5 | no route | Road speed signal (VSS) | — | |
| W60 | OEM-T121-60 | M800-B-23 | 0.5 | no route | CAN bus high | — | |
| W61 | OEM-T121-58 | M800-B-24 | 0.5 | no route | CAN bus low | — |
Bill of materials
| Category | Part number | Manufacturer | Description | Qty | Unit |
|---|---|---|---|---|---|
| connector | 3-1437290-7 | TE | Superseal 1.0 26-way plug | 1.000 | ea |
| connector | 4-1437290-0 | TE | Superseal 1.0 34-way plug, Key 1 | 1.000 | ea |
| terminal | 3-1447221-4 | TE | Superseal 1.0 socket terminal, 20 AWG (0.5 sq mm) | 46.000 | ea |
ECU setup sheet
| Role | Engine ref | Engine signal | Sensor | ECU point | ECU function | ECU class | Setup flag |
|---|---|---|---|---|---|---|---|
| No configured channels. | |||||||
Findings
Open (23)
| Severity | Code | Subject | Message |
|---|---|---|---|
| error | REQUIRED_UNMAPPED | OEM-T121-106 | Required OEM function "Knock sensor 1 (G61)" (knock_in) is not connected to the new ECU. |
| 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-T121-117 | Required OEM function "Throttle motor G186 (+)" (hbridge_out) is not connected to the new ECU. |
| error | REQUIRED_UNMAPPED | OEM-T121-118 | Required OEM function "Throttle motor G186 (−)" (hbridge_out) 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. |
| warn | DBW_SHARED_5V | M800-A-2 + OEM-T121-72 + OEM-T121-83 + OEM-T121-99 + SP-5V1-1 | These 5 V supplies are separate in the stock car (OEM-T121-72 [pedal1], OEM-T121-83 [tps], OEM-T121-99 [knock]) and here share one ECU 5 V (M800-A-2). On a drive-by-wire car the OEM splits them so one short or fault can't corrupt both throttle/pedal tracks at once. M800 has 2 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 | M800-A-9 + OEM-T121-73 + OEM-T121-98 + SP-5V2-1 | These 5 V supplies are separate in the stock car (OEM-T121-73 [pedal2], OEM-T121-98 [cam_boost]) and here share one ECU 5 V (M800-A-9). On a drive-by-wire car the OEM splits them so one short or fault can't corrupt both throttle/pedal tracks at once. M800 has 2 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 | LOAD_UNKNOWN | M800-A-1 | M800-A-1 "AUX2" drives OEM-T121-66 Secondary-air pump relay (J299) (load 0.2 A) but its current rating is unknown. Check the ECU manual. |
| warn | LOAD_UNKNOWN | M800-A-18 | M800-A-18 "AUX1" drives OEM-T121-65 Fuel pump relay control (load 0.2 A) but its current rating is unknown. Check the ECU manual. |
| warn | SUPPLY_GROUP | M800-A-2 + OEM-T121-72 + OEM-T121-83 + OEM-T121-99 + SP-5V1-1 | Supplies meant to stay independent share one net: OEM-T121-72 [pedal1], OEM-T121-83 [tps], 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. |
| warn | SUPPLY_GROUP | M800-A-9 + OEM-T121-73 + OEM-T121-98 + SP-5V2-1 | Supplies meant to stay independent share one net: OEM-T121-73 [pedal2], 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. |
| info | NET_FAMILY | OEM-T121-104 ↔ M800-A-31 | OEM-T121-104 "Boost control solenoid (N75)" [low_side_out] is wired to M800-A-31 "AUX5" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-T121-105 ↔ M800-A-32 | OEM-T121-105 "Diverter valve (N249)" [low_side_out] is wired to M800-A-32 "AUX6" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-T121-115 ↔ M800-A-33 | OEM-T121-115 "VVT camshaft adjustment valve (N205)" [low_side_out] is wired to M800-A-33 "AUX7" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-T121-47 ↔ M800-A-34 | OEM-T121-47 "Check engine light (MIL)" [low_side_out] is wired to M800-A-34 "AUX8" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-T121-48 ↔ M800-A-27 | OEM-T121-48 "EPC warning light" [low_side_out] is wired to M800-A-27 "INJ5" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-T121-5 ↔ M800-A-23 | OEM-T121-5 "Wideband lambda heater (Z19)" [low_side_out] is wired to M800-A-23 "AUX3" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-T121-63 ↔ M800-A-24 | OEM-T121-63 "Post-cat lambda heater (Z29)" [low_side_out] is wired to M800-A-24 "AUX4" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-T121-64 ↔ M800-A-28 | OEM-T121-64 "EVAP canister valve (N80)" [low_side_out] is wired to M800-A-28 "INJ6" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-T121-65 ↔ M800-A-18 | OEM-T121-65 "Fuel pump relay control" [low_side_out] is wired to M800-A-18 "AUX1" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-T121-66 ↔ M800-A-1 | OEM-T121-66 "Secondary-air pump relay (J299)" [low_side_out] is wired to M800-A-1 "AUX2" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-T121-9 ↔ M800-A-29 | OEM-T121-9 "Secondary-air injection valve (N112)" [low_side_out] is wired to M800-A-29 "INJ7" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | UNMAPPED | OEM | 3 optional OEM pins are not mapped: OEM-T121-27 MAF sensor supply (G70); OEM-T121-37 Engine speed signal (tacho to cluster); OEM-T121-43 K-line diagnostics (OBD pin 7) |
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
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 106: Knock sensor 1 (G61): no free knock input on MoTeC M800 - OEM-T121 107: Knock sensor 2 (G66): no free knock input on MoTeC M800 - OEM-T121 117: Throttle motor G186 (+): needs a paired H-bridge on MoTeC M800 - OEM-T121 118: Throttle motor G186 (−): needs a paired H-bridge on MoTeC M800 - 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); MoTeC M800 has no dedicated key-on input Not wired: - OEM-T121 62: Battery constant +12V (term 30): MoTeC M800 has no battery-constant input; not needed - OEM-T121 37: Engine speed signal (tacho to cluster): no free tacho/frequency_out/low_side/ls_hs on MoTeC M800 - OEM-T121 43: K-line diagnostics (OBD pin 7): no free k_line on MoTeC M800 - 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 | MoTeC M400/M600/M800/M880 Manual — Appendix L: Pin list by Function | https://starracecars.com/wp-content/uploads/resources/M400_M600_M800_M880_Manual_A5.pdf | archive | 2026-10-05 | b69bb8ffb674 |
| 4 | vendor_doc | MoTeC M800 OEM WRX56 Installation | https://motec.com.au | archive | 2026-10-05 | 2ca4be92bb65 |
| 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 | — | — | — |