VW Golf Mk4 1.8T 20v (AUM, Bosch ME7.5) DBW → Haltech Nexus S3 HT-213000 (auto)
VW Golf Mk4 1.8T 20v (AUM, Bosch ME7.5) DBW — Haltech — Nexus S3
Drawn by Michael Gnankou · Rev 0 · proposal · 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 | proposal · not yet verified: nobody has reported building and running this harness |
|---|---|
| Open errors | none |
| Size of the job | 64 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 | NEXUSS3-A-18 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W4 | SP-14V-1 | NEXUSS3-A-25 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W5 | OEM-T121-1 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W6 | OEM-T121-2 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W7 | SP-GND-1 | NEXUSS3-A-10 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | SP-GND-1 | NEXUSS3-A-11 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | OEM-T121-108 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | OEM-T121-29 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | OEM-T121-34 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | OEM-T121-36 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | OEM-T121-90 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | OEM-T121-91 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | SP-0V-1 | NEXUSS3-C-26 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | OEM-T121-72 | SP-5V1-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-T121-73 | SP-5V1-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-T121-83 | SP-5V1-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-T121-98 | SP-5V1-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-T121-99 | SP-5V1-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | SP-5V1-1 | NEXUSS3-C-25 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-T121-82 | NEXUSS3-C-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | SP-0V-1 | NEXUSS3-C-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-T121-86 | NEXUSS3-C-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | SP-0V-1 | NEXUSS3-C-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-T121-106 | NEXUSS3-C-23 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-T121-107 | NEXUSS3-C-24 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-T121-102 | NEXUSS3-A-27 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-T121-95 | NEXUSS3-A-28 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | OEM-T121-103 | NEXUSS3-A-29 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-T121-94 | NEXUSS3-A-30 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-T121-96 | NEXUSS3-A-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-T121-89 | NEXUSS3-A-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-T121-97 | NEXUSS3-A-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W35 | OEM-T121-88 | NEXUSS3-A-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W36 | OEM-T121-118 | NEXUSS3-A-20 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W37 | OEM-T121-117 | NEXUSS3-A-19 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W38 | OEM-T121-3 | NEXUSS3-A-13 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W39 | OEM-T121-53 | NEXUSS3-C-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W40 | OEM-T121-101 | NEXUSS3-C-11 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W41 | OEM-T121-33 | NEXUSS3-C-12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W42 | OEM-T121-84 | NEXUSS3-C-13 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W43 | OEM-T121-35 | NEXUSS3-C-14 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W44 | OEM-T121-92 | NEXUSS3-C-15 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W45 | OEM-T121-93 | NEXUSS3-C-16 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W46 | OEM-T121-65 | NEXUSS3-A-26 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W47 | OEM-T121-66 | NEXUSS3-A-9 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W48 | OEM-T121-5 | NEXUSS3-C-33 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W49 | OEM-T121-63 | NEXUSS3-A-12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W50 | OEM-T121-104 | NEXUSS3-A-14 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W51 | OEM-T121-105 | NEXUSS3-A-15 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W52 | OEM-T121-115 | NEXUSS3-A-16 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W53 | OEM-T121-47 | NEXUSS3-A-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W54 | OEM-T121-48 | NEXUSS3-A-5 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W55 | OEM-T121-64 | NEXUSS3-A-6 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W56 | OEM-T121-9 | NEXUSS3-A-7 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W57 | OEM-T121-51 | NEXUSS3-C-31 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W58 | OEM-T121-70 | NEXUSS3-C-32 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W59 | OEM-T121-68 | NEXUSS3-C-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W60 | OEM-T121-69 | NEXUSS3-C-18 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W61 | OEM-T121-85 | NEXUSS3-C-27 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W62 | OEM-T121-54 | NEXUSS3-C-5 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W63 | OEM-T121-60 | NEXUSS3-A-23 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W64 | OEM-T121-58 | NEXUSS3-A-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 | NEXUSS3-A-10 | NEXUSS3-A-18 | open (OL) | power ground must not touch +12 V supply | |
| 2 | NEXUSS3-A-10 | NEXUSS3-C-25 | open (OL) | power ground must not touch 5 V sensor reference | |
| 3 | NEXUSS3-A-18 | NEXUSS3-C-25 | open (OL) | +12 V supply must not touch 5 V sensor reference | |
| 4 | NEXUSS3-C-2 | NEXUSS3-A-18 | open (OL) | sensor ground must not touch +12 V supply | |
| 5 | NEXUSS3-C-2 | NEXUSS3-C-25 | 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
NEXUSS3-A
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Injector 1 | — | W32 | — | 0.5 | OEM-T121-96 | — | — | — |
| 10 | Battery ground | — | W7 | — | 0.85 | SP-GND-1 | — | — | — |
| 11 | Battery ground | — | W8 | — | 0.85 | SP-GND-1 | — | — | — |
| 12 | DPO 2 | — | W49 | — | 0.5 | OEM-T121-63 | — | — | — |
| 13 | Ignition switch input | — | W38 | — | 0.5 | OEM-T121-3 | — | — | — |
| 14 | DPO 3 | — | W50 | — | 0.5 | OEM-T121-104 | — | — | — |
| 15 | DPO 4 | — | W51 | — | 0.5 | OEM-T121-105 | — | — | — |
| 16 | DPO 5 | — | W52 | — | 0.5 | OEM-T121-115 | — | — | — |
| 17 | DPO 6 | — | W53 | — | 0.5 | OEM-T121-47 | — | — | — |
| 18 | +12V switched input | — | W3 | — | 0.85 | SP-14V-1 | — | — | — |
| 19 | HBO 1 | — | W37 | — | 0.5 | OEM-T121-117 | — | — | — |
| 2 | Injector 2 | — | W33 | — | 0.5 | OEM-T121-89 | — | — | — |
| 20 | HBO 2 | — | W36 | — | 0.5 | OEM-T121-118 | — | — | — |
| 21 | HBO 3 | — | — | — | — | — | — | — | — |
| 22 | HBO 4 | — | — | — | — | — | — | — | — |
| 23 | CAN 1 High | — | W63 | — | 0.5 | OEM-T121-60 | — | — | — |
| 24 | CAN 1 Low | — | W64 | — | 0.5 | OEM-T121-58 | — | — | — |
| 25 | +12V switched input | — | W4 | — | 0.85 | SP-14V-1 | — | — | — |
| 26 | ECR output | — | W46 | — | 0.5 | OEM-T121-65 | — | — | — |
| 27 | Ignition 1 | — | W28 | — | 0.5 | OEM-T121-102 | — | — | — |
| 28 | Ignition 2 | — | W29 | — | 0.5 | OEM-T121-95 | — | — | — |
| 29 | Ignition 3 | — | W30 | — | 0.5 | OEM-T121-103 | — | — | — |
| 3 | Injector 3 | — | W34 | — | 0.5 | OEM-T121-97 | — | — | — |
| 30 | Ignition 4 | — | W31 | — | 0.5 | OEM-T121-94 | — | — | — |
| 31 | Ignition 5 | — | — | — | — | — | — | — | — |
| 32 | Ignition 6 | — | — | — | — | — | — | — | — |
| 33 | Ignition 7 | — | — | — | — | — | — | — | — |
| 34 | Ignition 8 | — | — | — | — | — | — | — | — |
| 4 | Injector 4 | — | W35 | — | 0.5 | OEM-T121-88 | — | — | — |
| 5 | Injector 5 | — | W54 | — | 0.5 | OEM-T121-48 | — | — | — |
| 6 | Injector 6 | — | W55 | — | 0.5 | OEM-T121-64 | — | — | — |
| 7 | Injector 7 | — | W56 | — | 0.5 | OEM-T121-9 | — | — | — |
| 8 | Injector 8 | — | — | — | — | — | — | — | — |
| 9 | DPO 1 | — | W47 | — | 0.5 | OEM-T121-66 | — | — | — |
NEXUSS3-C
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Trigger + | — | W22 | — | 0.5 | OEM-T121-82 | — | — | — |
| 10 | AVI 1 | — | W39 | — | 0.5 | OEM-T121-53 | — | — | — |
| 11 | AVI 2 | — | W40 | — | 0.5 | OEM-T121-101 | — | — | — |
| 12 | AVI 3 | — | W41 | — | 0.5 | OEM-T121-33 | — | — | — |
| 13 | AVI 4 | — | W42 | — | 0.5 | OEM-T121-84 | — | — | — |
| 14 | AVI 5 | — | W43 | — | 0.5 | OEM-T121-35 | — | — | — |
| 15 | AVI 6 | — | W44 | — | 0.5 | OEM-T121-92 | — | — | — |
| 16 | AVI 7 | — | W45 | — | 0.5 | OEM-T121-93 | — | — | — |
| 17 | AVI 8 | — | W59 | — | 0.5 | OEM-T121-68 | — | — | — |
| 18 | AVI 9 | — | W60 | — | 0.5 | OEM-T121-69 | — | — | — |
| 19 | SPI 5 | — | — | — | — | — | — | — | — |
| 2 | Trigger - | — | W23 | — | 0.5 | SP-0V-1 | — | — | — |
| 20 | SPI 6 | — | — | — | — | — | — | — | — |
| 21 | CAN 2 High | — | — | — | — | — | — | — | — |
| 22 | CAN 2 Low | — | — | — | — | — | — | — | — |
| 23 | Knock 1 | — | W26 | — | 0.5 | OEM-T121-106 | — | — | — |
| 24 | Knock 2 | — | W27 | — | 0.5 | OEM-T121-107 | — | — | — |
| 25 | +5V | — | W21 | — | 0.5 | SP-5V1-1 | — | — | — |
| 26 | Signal ground | — | W15 | — | 0.5 | SP-0V-1 | — | — | — |
| 27 | AVI 10 | — | W61 | — | 0.5 | OEM-T121-85 | — | — | — |
| 28 | AVI 11 | — | — | — | — | — | — | — | — |
| 29 | WBI 1 Heater + | — | — | — | — | — | — | — | — |
| 3 | Home + | — | W24 | — | 0.5 | OEM-T121-86 | — | — | — |
| 30 | WBI 1 Input | — | — | — | — | — | — | — | — |
| 31 | WBI 1 Pump | — | W57 | — | 0.5 | OEM-T121-51 | — | — | — |
| 32 | WBI 1 Nernst | — | W58 | — | 0.5 | OEM-T121-70 | — | — | — |
| 33 | WBI 1 Heater - | — | W48 | — | 0.5 | OEM-T121-5 | — | — | — |
| 34 | WBI 1 Cal | — | — | — | — | — | — | — | — |
| 4 | Home - | — | W25 | — | 0.5 | SP-0V-1 | — | — | — |
| 5 | SPI 1 | — | W62 | — | 0.5 | OEM-T121-54 | — | — | — |
| 6 | SPI 2 | — | — | — | — | — | — | — | — |
| 7 | SPI 3 | — | — | — | — | — | — | — | — |
| 8 | SPI 4 | — | — | — | — | — | — | — | — |
| 9 | +8V | — | — | — | — | — | — | — | — |
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 | NEXUSS3-C-11 | — | — | — |
| 102 | Ignition coil 1 (N127) | — | W28 | — | 0.5 | NEXUSS3-A-27 | — | — | — |
| 103 | Ignition coil 3 (N158) | — | W30 | — | 0.5 | NEXUSS3-A-29 | — | — | — |
| 104 | Boost control solenoid (N75) | — | W50 | — | 0.5 | NEXUSS3-A-14 | — | — | — |
| 105 | Diverter valve (N249) | — | W51 | — | 0.5 | NEXUSS3-A-15 | — | — | — |
| 106 | Knock sensor 1 (G61) | — | W26 | — | 0.5 | NEXUSS3-C-23 | — | — | — |
| 107 | Knock sensor 2 (G66) | — | W27 | — | 0.5 | NEXUSS3-C-24 | — | — | — |
| 108 | Sensor ground | — | W9 | — | 0.5 | SP-0V-1 | — | — | — |
| 115 | VVT camshaft adjustment valve (N205) | — | W52 | — | 0.5 | NEXUSS3-A-16 | — | — | — |
| 117 | Throttle motor G186 (+) | — | W37 | — | 0.5 | NEXUSS3-A-19 | — | — | — |
| 118 | Throttle motor G186 (−) | — | W36 | — | 0.5 | NEXUSS3-A-20 | — | — | — |
| 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) | — | W10 | — | 0.5 | SP-0V-1 | — | — | — |
| 3 | Ignition switch +12V (term 15) | — | W38 | — | 0.5 | NEXUSS3-A-13 | — | — | — |
| 33 | Accelerator pedal position 1 (G79) | — | W41 | — | 0.5 | NEXUSS3-C-12 | — | — | — |
| 34 | Accelerator pedal position 1 ground (G79) | — | W11 | — | 0.5 | SP-0V-1 | — | — | — |
| 35 | Accelerator pedal position 2 (G185) | — | W43 | — | 0.5 | NEXUSS3-C-14 | — | — | — |
| 36 | Accelerator pedal position 2 ground (G185) | — | W12 | — | 0.5 | SP-0V-1 | — | — | — |
| 37 | Engine speed signal (tacho to cluster) | — | — | — | — | — | — | — | — |
| 43 | K-line diagnostics (OBD pin 7) | — | — | — | — | — | — | — | — |
| 47 | Check engine light (MIL) | — | W53 | — | 0.5 | NEXUSS3-A-17 | — | — | — |
| 48 | EPC warning light | — | W54 | — | 0.5 | NEXUSS3-A-5 | — | — | — |
| 5 | Wideband lambda heater (Z19) | — | W48 | — | 0.5 | NEXUSS3-C-33 | — | — | — |
| 51 | Wideband lambda pump (G39) | — | W57 | — | 0.5 | NEXUSS3-C-31 | — | — | — |
| 52 | Wideband lambda pump (G39) | — | — | — | — | — | — | — | — |
| 53 | MAF sensor signal (G70) | — | W39 | — | 0.5 | NEXUSS3-C-10 | — | — | — |
| 54 | Road speed signal (VSS) | — | W62 | — | 0.5 | NEXUSS3-C-5 | — | — | — |
| 58 | CAN bus low | — | W64 | — | 0.5 | NEXUSS3-A-24 | — | — | — |
| 60 | CAN bus high | — | W63 | — | 0.5 | NEXUSS3-A-23 | — | — | — |
| 62 | Battery constant +12V (term 30) | — | — | — | — | — | — | — | — |
| 63 | Post-cat lambda heater (Z29) | — | W49 | — | 0.5 | NEXUSS3-A-12 | — | — | — |
| 64 | EVAP canister valve (N80) | — | W55 | — | 0.5 | NEXUSS3-A-6 | — | — | — |
| 65 | Fuel pump relay control | — | W46 | — | 0.5 | NEXUSS3-A-26 | — | — | — |
| 66 | Secondary-air pump relay (J299) | — | W47 | — | 0.5 | NEXUSS3-A-9 | — | — | — |
| 68 | Post-cat lambda signal (G130) | — | W59 | — | 0.5 | NEXUSS3-C-17 | — | — | — |
| 69 | Post-cat lambda signal (G130) | — | W60 | — | 0.5 | NEXUSS3-C-18 | — | — | — |
| 70 | Wideband lambda Nernst signal (G39) | — | W58 | — | 0.5 | NEXUSS3-C-32 | — | — | — |
| 71 | Wideband lambda Nernst signal (G39) | — | — | — | — | — | — | — | — |
| 72 | Accelerator pedal position 1 5V supply (G79) | — | W16 | — | 0.5 | SP-5V1-1 | — | — | — |
| 73 | Accelerator pedal position 2 5V supply (G185) | — | W17 | — | 0.5 | SP-5V1-1 | — | — | — |
| 82 | Crank position sensor (G28) | — | W22 | — | 0.5 | NEXUSS3-C-1 | — | — | — |
| 83 | Throttle position sensor 5V supply (G187/G188) | — | W18 | — | 0.5 | SP-5V1-1 | — | — | — |
| 84 | Throttle position sensor 1 (G187) | — | W42 | — | 0.5 | NEXUSS3-C-13 | — | — | — |
| 85 | Intake air temperature (G42) | — | W61 | — | 0.5 | NEXUSS3-C-27 | — | — | — |
| 86 | Camshaft position sensor (G40) | — | W24 | — | 0.5 | NEXUSS3-C-3 | — | — | — |
| 88 | Injector 4 (N33) | — | W35 | — | 0.5 | NEXUSS3-A-4 | — | — | — |
| 89 | Injector 2 (N31) | — | W33 | — | 0.5 | NEXUSS3-A-2 | — | — | — |
| 9 | Secondary-air injection valve (N112) | — | W56 | — | 0.5 | NEXUSS3-A-7 | — | — | — |
| 90 | Crank position sensor ground (G28) | — | W13 | — | 0.5 | SP-0V-1 | — | — | — |
| 91 | Throttle position sensor ground (G187/G188) | — | W14 | — | 0.5 | SP-0V-1 | — | — | — |
| 92 | Throttle position sensor 2 (G188) | — | W44 | — | 0.5 | NEXUSS3-C-15 | — | — | — |
| 93 | Engine coolant temperature (G62) | — | W45 | — | 0.5 | NEXUSS3-C-16 | — | — | — |
| 94 | Ignition coil 4 (N163) | — | W31 | — | 0.5 | NEXUSS3-A-30 | — | — | — |
| 95 | Ignition coil 2 (N128) | — | W29 | — | 0.5 | NEXUSS3-A-28 | — | — | — |
| 96 | Injector 1 (N30) | — | W32 | — | 0.5 | NEXUSS3-A-1 | — | — | — |
| 97 | Injector 3 (N32) | — | W34 | — | 0.5 | NEXUSS3-A-3 | — | — | — |
| 98 | Cam + boost sensor 5V supply (G40/G31) | — | W19 | — | 0.5 | SP-5V1-1 | — | — | — |
| 99 | Knock sensor 5V supply (G61/G66) | — | W20 | — | 0.5 | SP-5V1-1 | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W9 | — | 0.5 | OEM-T121-108 | — | — | — |
| 1 | — | — | W10 | — | 0.5 | OEM-T121-29 | — | — | — |
| 1 | — | — | W11 | — | 0.5 | OEM-T121-34 | — | — | — |
| 1 | — | — | W12 | — | 0.5 | OEM-T121-36 | — | — | — |
| 1 | — | — | W13 | — | 0.5 | OEM-T121-90 | — | — | — |
| 1 | — | — | W14 | — | 0.5 | OEM-T121-91 | — | — | — |
| 1 | — | — | W15 | — | 0.5 | NEXUSS3-C-26 | — | — | — |
| 1 | — | — | W23 | — | 0.5 | NEXUSS3-C-2 | — | — | — |
| 1 | — | — | W25 | — | 0.5 | NEXUSS3-C-4 | — | — | — |
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 | NEXUSS3-A-18 | — | — | — |
| 1 | — | — | W4 | — | 0.85 | NEXUSS3-A-25 | — | — | — |
SP-5V1
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W16 | — | 0.5 | OEM-T121-72 | — | — | — |
| 1 | — | — | W17 | — | 0.5 | OEM-T121-73 | — | — | — |
| 1 | — | — | W18 | — | 0.5 | OEM-T121-83 | — | — | — |
| 1 | — | — | W19 | — | 0.5 | OEM-T121-98 | — | — | — |
| 1 | — | — | W20 | — | 0.5 | OEM-T121-99 | — | — | — |
| 1 | — | — | W21 | — | 0.5 | NEXUSS3-C-25 | — | — | — |
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 | NEXUSS3-A-10 | — | — | — |
| 1 | — | — | W8 | — | 0.85 | NEXUSS3-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 | NEXUSS3-A-10 + NEXUSS3-A-11 | Battery ground + Battery ground | ground | corroborated | |
| OEM-T121-101 | Boost pressure sensor (G31) | analog_in | NEXUSS3-C-11 | AVI 2 | analog_in | corroborated | |
| OEM-T121-102 | Ignition coil 1 (N127) | ignition_out | NEXUSS3-A-27 | Ignition 1 | ignition_out | corroborated | |
| OEM-T121-103 | Ignition coil 3 (N158) | ignition_out | NEXUSS3-A-29 | Ignition 3 | ignition_out | corroborated | |
| OEM-T121-104 | Boost control solenoid (N75) | low_side_out | NEXUSS3-A-14 | DPO 3 | low_side_out | corroborated | |
| OEM-T121-105 | Diverter valve (N249) | low_side_out | NEXUSS3-A-15 | DPO 4 | low_side_out | corroborated | |
| OEM-T121-106 | Knock sensor 1 (G61) | knock_in | NEXUSS3-C-23 | Knock 1 | knock_in | corroborated | |
| OEM-T121-107 | Knock sensor 2 (G66) | knock_in | NEXUSS3-C-24 | Knock 2 | knock_in | corroborated | |
| OEM-T121-108 | Sensor ground | sensor_ground | NEXUSS3-C-2 + NEXUSS3-C-26 + NEXUSS3-C-4 | Trigger - + Signal ground + Home - | sensor_ground + trigger_in | corroborated | |
| OEM-T121-115 | VVT camshaft adjustment valve (N205) | low_side_out | NEXUSS3-A-16 | DPO 5 | low_side_out | corroborated | |
| OEM-T121-117 | Throttle motor G186 (+) | hbridge_out | NEXUSS3-A-19 | HBO 1 | hbridge_out | corroborated | |
| OEM-T121-118 | Throttle motor G186 (−) | hbridge_out | NEXUSS3-A-20 | HBO 2 | hbridge_out | corroborated | |
| OEM-T121-121 | ECM + coil power (J271 relay feed) | power_in | NEXUSS3-A-18 + NEXUSS3-A-25 | +12V switched input + +12V switched input | power_in | corroborated | |
| OEM-T121-2 | ECU ground | ground | NEXUSS3-A-10 + NEXUSS3-A-11 | Battery ground + Battery ground | ground | corroborated | |
| OEM-T121-21 | ECM power (J271 relay feed) | power_in | NEXUSS3-A-18 + NEXUSS3-A-25 | +12V switched input + +12V switched input | power_in | corroborated | |
| OEM-T121-27 | MAF sensor supply (G70) | power_in | — | — | — | corroborated | |
| OEM-T121-29 | MAF sensor ground (G70) | sensor_ground | NEXUSS3-C-2 + NEXUSS3-C-26 + NEXUSS3-C-4 | Trigger - + Signal ground + Home - | sensor_ground + trigger_in | corroborated | |
| OEM-T121-3 | Ignition switch +12V (term 15) | digital_in | NEXUSS3-A-13 | Ignition switch input | digital_in | corroborated | |
| OEM-T121-33 | Accelerator pedal position 1 (G79) | analog_in | NEXUSS3-C-12 | AVI 3 | analog_in | corroborated | |
| OEM-T121-34 | Accelerator pedal position 1 ground (G79) | sensor_ground | NEXUSS3-C-2 + NEXUSS3-C-26 + NEXUSS3-C-4 | Trigger - + Signal ground + Home - | sensor_ground + trigger_in | corroborated | |
| OEM-T121-35 | Accelerator pedal position 2 (G185) | analog_in | NEXUSS3-C-14 | AVI 5 | analog_in | corroborated | |
| OEM-T121-36 | Accelerator pedal position 2 ground (G185) | sensor_ground | NEXUSS3-C-2 + NEXUSS3-C-26 + NEXUSS3-C-4 | Trigger - + Signal ground + Home - | sensor_ground + trigger_in | 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 | NEXUSS3-A-17 | DPO 6 | low_side_out | corroborated | |
| OEM-T121-48 | EPC warning light | low_side_out | NEXUSS3-A-5 | Injector 5 | injector_out | corroborated | |
| OEM-T121-5 | Wideband lambda heater (Z19) | low_side_out | NEXUSS3-C-33 | WBI 1 Heater - | low_side_out | corroborated | |
| OEM-T121-51 | Wideband lambda pump (G39) | wb_ip | NEXUSS3-C-31 | WBI 1 Pump | wb_ip | corroborated | |
| OEM-T121-52 | Wideband lambda pump (G39) | wb_ip | — | — | — | corroborated | |
| OEM-T121-53 | MAF sensor signal (G70) | analog_in | NEXUSS3-C-10 | AVI 1 | analog_in | corroborated | |
| OEM-T121-54 | Road speed signal (VSS) | digital_in | NEXUSS3-C-5 | SPI 1 | digital_in | corroborated | |
| OEM-T121-58 | CAN bus low | can_l | NEXUSS3-A-24 | CAN 1 Low | can_l | corroborated | |
| OEM-T121-60 | CAN bus high | can_h | NEXUSS3-A-23 | 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 | NEXUSS3-A-12 | DPO 2 | low_side_out | corroborated | |
| OEM-T121-64 | EVAP canister valve (N80) | low_side_out | NEXUSS3-A-6 | Injector 6 | injector_out | corroborated | |
| OEM-T121-65 | Fuel pump relay control | low_side_out | NEXUSS3-A-26 | ECR output | low_side_out | corroborated | |
| OEM-T121-66 | Secondary-air pump relay (J299) | low_side_out | NEXUSS3-A-9 | DPO 1 | low_side_out | corroborated | |
| OEM-T121-68 | Post-cat lambda signal (G130) | lambda_nb_in | NEXUSS3-C-17 | AVI 8 | analog_in | corroborated | |
| OEM-T121-69 | Post-cat lambda signal (G130) | lambda_nb_in | NEXUSS3-C-18 | AVI 9 | analog_in | corroborated | |
| OEM-T121-70 | Wideband lambda Nernst signal (G39) | wb_vs | NEXUSS3-C-32 | WBI 1 Nernst | 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 | NEXUSS3-C-25 | +5V | vref | corroborated | |
| OEM-T121-73 | Accelerator pedal position 2 5V supply (G185) | vref | NEXUSS3-C-25 | +5V | vref | corroborated | |
| OEM-T121-82 | Crank position sensor (G28) | trigger_in | NEXUSS3-C-1 | Trigger + | trigger_in | corroborated | |
| OEM-T121-83 | Throttle position sensor 5V supply (G187/G188) | vref | NEXUSS3-C-25 | +5V | vref | corroborated | |
| OEM-T121-84 | Throttle position sensor 1 (G187) | analog_in | NEXUSS3-C-13 | AVI 4 | analog_in | corroborated | |
| OEM-T121-85 | Intake air temperature (G42) | temp_in | NEXUSS3-C-27 | AVI 10 | analog_in | corroborated | |
| OEM-T121-86 | Camshaft position sensor (G40) | trigger_in | NEXUSS3-C-3 | Home + | trigger_in | corroborated | |
| OEM-T121-88 | Injector 4 (N33) | injector_out | NEXUSS3-A-4 | Injector 4 | injector_out | corroborated | |
| OEM-T121-89 | Injector 2 (N31) | injector_out | NEXUSS3-A-2 | Injector 2 | injector_out | corroborated | |
| OEM-T121-9 | Secondary-air injection valve (N112) | low_side_out | NEXUSS3-A-7 | Injector 7 | injector_out | corroborated | |
| OEM-T121-90 | Crank position sensor ground (G28) | sensor_ground | NEXUSS3-C-2 + NEXUSS3-C-26 + NEXUSS3-C-4 | Trigger - + Signal ground + Home - | sensor_ground + trigger_in | corroborated | |
| OEM-T121-91 | Throttle position sensor ground (G187/G188) | sensor_ground | NEXUSS3-C-2 + NEXUSS3-C-26 + NEXUSS3-C-4 | Trigger - + Signal ground + Home - | sensor_ground + trigger_in | corroborated | |
| OEM-T121-92 | Throttle position sensor 2 (G188) | analog_in | NEXUSS3-C-15 | AVI 6 | analog_in | corroborated | |
| OEM-T121-93 | Engine coolant temperature (G62) | temp_in | NEXUSS3-C-16 | AVI 7 | analog_in | corroborated | |
| OEM-T121-94 | Ignition coil 4 (N163) | ignition_out | NEXUSS3-A-30 | Ignition 4 | ignition_out | corroborated | |
| OEM-T121-95 | Ignition coil 2 (N128) | ignition_out | NEXUSS3-A-28 | Ignition 2 | ignition_out | corroborated | |
| OEM-T121-96 | Injector 1 (N30) | injector_out | NEXUSS3-A-1 | Injector 1 | injector_out | corroborated | |
| OEM-T121-97 | Injector 3 (N32) | injector_out | NEXUSS3-A-3 | Injector 3 | injector_out | corroborated | |
| OEM-T121-98 | Cam + boost sensor 5V supply (G40/G31) | vref | NEXUSS3-C-25 | +5V | vref | corroborated | |
| OEM-T121-99 | Knock sensor 5V supply (G61/G66) | vref | NEXUSS3-C-25 | +5V | 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 | NEXUSS3-A-18 | 0.85 | no route | +12V switched input | — | |
| W4 | SP-14V-1 | NEXUSS3-A-25 | 0.85 | no route | +12V switched input | — | |
| 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 | NEXUSS3-A-10 | 0.85 | no route | Battery ground | — | |
| W8 | SP-GND-1 | NEXUSS3-A-11 | 0.85 | no route | Battery ground | — | |
| W9 | OEM-T121-108 | SP-0V-1 | 0.5 | no route | Sensor ground | — | |
| W10 | OEM-T121-29 | SP-0V-1 | 0.5 | no route | MAF sensor ground (G70) | — | |
| W11 | OEM-T121-34 | SP-0V-1 | 0.5 | no route | Accelerator pedal position 1 ground (G79) | — | |
| W12 | OEM-T121-36 | SP-0V-1 | 0.5 | no route | Accelerator pedal position 2 ground (G185) | — | |
| W13 | OEM-T121-90 | SP-0V-1 | 0.5 | no route | Crank position sensor ground (G28) | — | |
| W14 | OEM-T121-91 | SP-0V-1 | 0.5 | no route | Throttle position sensor ground (G187/G188) | — | |
| W15 | SP-0V-1 | NEXUSS3-C-26 | 0.5 | no route | Signal ground | — | |
| W16 | OEM-T121-72 | SP-5V1-1 | 0.5 | no route | Accelerator pedal position 1 5V supply (G79) | — | |
| W17 | OEM-T121-73 | SP-5V1-1 | 0.5 | no route | Accelerator pedal position 2 5V supply (G185) | — | |
| W18 | OEM-T121-83 | SP-5V1-1 | 0.5 | no route | Throttle position sensor 5V supply (G187/G188) | — | |
| W19 | OEM-T121-98 | SP-5V1-1 | 0.5 | no route | Cam + boost sensor 5V supply (G40/G31) | — | |
| W20 | OEM-T121-99 | SP-5V1-1 | 0.5 | no route | Knock sensor 5V supply (G61/G66) | — | |
| W21 | SP-5V1-1 | NEXUSS3-C-25 | 0.5 | no route | +5V | — | |
| W22 | OEM-T121-82 | NEXUSS3-C-1 | 0.5 | no route | Crank position sensor (G28) | — | |
| W23 | SP-0V-1 | NEXUSS3-C-2 | 0.5 | no route | Trigger - | — | |
| W24 | OEM-T121-86 | NEXUSS3-C-3 | 0.5 | no route | Camshaft position sensor (G40) | — | |
| W25 | SP-0V-1 | NEXUSS3-C-4 | 0.5 | no route | Home - | — | |
| W26 | OEM-T121-106 | NEXUSS3-C-23 | 0.5 | no route | Knock sensor 1 (G61) | — | |
| W27 | OEM-T121-107 | NEXUSS3-C-24 | 0.5 | no route | Knock sensor 2 (G66) | — | |
| W28 | OEM-T121-102 | NEXUSS3-A-27 | 0.5 | no route | Ignition coil 1 (N127) | — | |
| W29 | OEM-T121-95 | NEXUSS3-A-28 | 0.5 | no route | Ignition coil 2 (N128) | — | |
| W30 | OEM-T121-103 | NEXUSS3-A-29 | 0.5 | no route | Ignition coil 3 (N158) | — | |
| W31 | OEM-T121-94 | NEXUSS3-A-30 | 0.5 | no route | Ignition coil 4 (N163) | — | |
| W32 | OEM-T121-96 | NEXUSS3-A-1 | 0.5 | no route | Injector 1 (N30) | — | |
| W33 | OEM-T121-89 | NEXUSS3-A-2 | 0.5 | no route | Injector 2 (N31) | — | |
| W34 | OEM-T121-97 | NEXUSS3-A-3 | 0.5 | no route | Injector 3 (N32) | — | |
| W35 | OEM-T121-88 | NEXUSS3-A-4 | 0.5 | no route | Injector 4 (N33) | — | |
| W36 | OEM-T121-118 | NEXUSS3-A-20 | 0.5 | no route | Throttle motor G186 (−) | — | |
| W37 | OEM-T121-117 | NEXUSS3-A-19 | 0.5 | no route | Throttle motor G186 (+) | — | |
| W38 | OEM-T121-3 | NEXUSS3-A-13 | 0.5 | no route | Ignition switch +12V (term 15) | — | |
| W39 | OEM-T121-53 | NEXUSS3-C-10 | 0.5 | no route | MAF sensor signal (G70) | — | |
| W40 | OEM-T121-101 | NEXUSS3-C-11 | 0.5 | no route | Boost pressure sensor (G31) | — | |
| W41 | OEM-T121-33 | NEXUSS3-C-12 | 0.5 | no route | Accelerator pedal position 1 (G79) | — | |
| W42 | OEM-T121-84 | NEXUSS3-C-13 | 0.5 | no route | Throttle position sensor 1 (G187) | — | |
| W43 | OEM-T121-35 | NEXUSS3-C-14 | 0.5 | no route | Accelerator pedal position 2 (G185) | — | |
| W44 | OEM-T121-92 | NEXUSS3-C-15 | 0.5 | no route | Throttle position sensor 2 (G188) | — | |
| W45 | OEM-T121-93 | NEXUSS3-C-16 | 0.5 | no route | Engine coolant temperature (G62) | — | |
| W46 | OEM-T121-65 | NEXUSS3-A-26 | 0.5 | no route | Fuel pump relay control | — | |
| W47 | OEM-T121-66 | NEXUSS3-A-9 | 0.5 | no route | Secondary-air pump relay (J299) | — | |
| W48 | OEM-T121-5 | NEXUSS3-C-33 | 0.5 | no route | Wideband lambda heater (Z19) | — | |
| W49 | OEM-T121-63 | NEXUSS3-A-12 | 0.5 | no route | Post-cat lambda heater (Z29) | — | |
| W50 | OEM-T121-104 | NEXUSS3-A-14 | 0.5 | no route | Boost control solenoid (N75) | — | |
| W51 | OEM-T121-105 | NEXUSS3-A-15 | 0.5 | no route | Diverter valve (N249) | — | |
| W52 | OEM-T121-115 | NEXUSS3-A-16 | 0.5 | no route | VVT camshaft adjustment valve (N205) | — | |
| W53 | OEM-T121-47 | NEXUSS3-A-17 | 0.5 | no route | Check engine light (MIL) | — | |
| W54 | OEM-T121-48 | NEXUSS3-A-5 | 0.5 | no route | EPC warning light | — | |
| W55 | OEM-T121-64 | NEXUSS3-A-6 | 0.5 | no route | EVAP canister valve (N80) | — | |
| W56 | OEM-T121-9 | NEXUSS3-A-7 | 0.5 | no route | Secondary-air injection valve (N112) | — | |
| W57 | OEM-T121-51 | NEXUSS3-C-31 | 0.5 | no route | Wideband lambda pump (G39) | — | |
| W58 | OEM-T121-70 | NEXUSS3-C-32 | 0.5 | no route | Wideband lambda Nernst signal (G39) | — | |
| W59 | OEM-T121-68 | NEXUSS3-C-17 | 0.5 | no route | Post-cat lambda signal (G130) | — | |
| W60 | OEM-T121-69 | NEXUSS3-C-18 | 0.5 | no route | Post-cat lambda signal (G130) | — | |
| W61 | OEM-T121-85 | NEXUSS3-C-27 | 0.5 | no route | Intake air temperature (G42) | — | |
| W62 | OEM-T121-54 | NEXUSS3-C-5 | 0.5 | no route | Road speed signal (VSS) | — | |
| W63 | OEM-T121-60 | NEXUSS3-A-23 | 0.5 | no route | CAN bus high | — | |
| W64 | OEM-T121-58 | NEXUSS3-A-24 | 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 (12)
| Severity | Code | Subject | Message |
|---|---|---|---|
| warn | DBW_MOTOR_CURRENT | NEXUSS3-A-19 | Cannot confirm Nexus S3 can drive the throttle motor: NEXUSS3-A-19 "HBO 1" is rated 8.0 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 | NEXUSS3-A-20 | Cannot confirm Nexus S3 can drive the throttle motor: NEXUSS3-A-20 "HBO 2" is rated 8.0 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 | NEXUSS3-C-25 + OEM-T121-72 + OEM-T121-73 + OEM-T121-83 + OEM-T121-98 + OEM-T121-99 + SP-5V1-1 | These 5 V supplies are separate in the stock car (OEM-T121-72 [pedal1], OEM-T121-73 [pedal2], OEM-T121-83 [tps], OEM-T121-98 [cam_boost], OEM-T121-99 [knock]) and here share one ECU 5 V (NEXUSS3-C-25). On a drive-by-wire car the OEM splits them so one short or fault can't corrupt both throttle/pedal tracks at once. Nexus S3 has 1 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 | NEXUSS3-A-26 | NEXUSS3-A-26 "ECR output" 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 | NEXUSS3-C-25 + OEM-T121-72 + OEM-T121-73 + OEM-T121-83 + OEM-T121-98 + OEM-T121-99 + SP-5V1-1 | Supplies meant to stay independent share one net: OEM-T121-72 [pedal1], OEM-T121-73 [pedal2], OEM-T121-83 [tps], OEM-T121-98 [cam_boost], 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 | NET_FAMILY | OEM-T121-29 ↔ NEXUSS3-C-2 | OEM-T121-29 "MAF sensor ground (G70)" [sensor_ground] is wired to NEXUSS3-C-2 "Trigger -" [trigger_in]. Trigger return tied to sensor/trigger ground: correct for single-ended trigger inputs. |
| info | NET_FAMILY | OEM-T121-48 ↔ NEXUSS3-A-5 | OEM-T121-48 "EPC warning light" [low_side_out] is wired to NEXUSS3-A-5 "Injector 5" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-T121-64 ↔ NEXUSS3-A-6 | OEM-T121-64 "EVAP canister valve (N80)" [low_side_out] is wired to NEXUSS3-A-6 "Injector 6" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-T121-85 ↔ NEXUSS3-C-27 | OEM-T121-85 "Intake air temperature (G42)" [temp_in] is wired to NEXUSS3-C-27 "AVI 10" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one. |
| info | NET_FAMILY | OEM-T121-9 ↔ NEXUSS3-A-7 | OEM-T121-9 "Secondary-air injection valve (N112)" [low_side_out] is wired to NEXUSS3-A-7 "Injector 7" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-T121-93 ↔ NEXUSS3-C-16 | OEM-T121-93 "Engine coolant temperature (G62)" [temp_in] is wired to NEXUSS3-C-16 "AVI 7" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one. |
| info | UNMAPPED | OEM | 5 optional OEM pins are not mapped: OEM-T121-27 MAF sensor supply (G70); OEM-T121-37 Engine speed signal (tacho to cluster); OEM-T121-43 K-line diagnostics (OBD pin 7); OEM-T121-52 Wideband lambda pump (G39); 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
Auto-mapped by auto_map() from the library pin data on 2026-10-11. Review every wire against both manuals before building. Not wired: - OEM-T121 62: Battery constant +12V (term 30): Haltech Nexus S3 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 Haltech Nexus S3 - OEM-T121 52: Wideband lambda pump (G39): no free wb_ip on Haltech Nexus S3 - OEM-T121 71: Wideband lambda Nernst signal (G39): no free wb_vs on Haltech Nexus S3 - OEM-T121 43: K-line diagnostics (OBD pin 7): no free k_line on Haltech Nexus S3 - 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 | Haltech: Nexus S3 Plug 'n' Play adapter QSG (Subaru WRX/STI ADM, HT-186300) — ECU Connector A & C pinout | https://www.haltech.com/product/ht-186300-nexus-s3-plug-n-play-adapter-harness/ | archive | 2026-10-05 | 3cab7cd337c2 |
| 4 | vendor_doc | Haltech: Nexus S3/S2 ECU Overview (QSG) — specifications | https://store.haltech.com/product/ht-213000-nexus-s3-ecu-only/ | archive | 2026-10-05 | 388299668207 |
| 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 | — | — | — |