Lexus SC400 1992-97 (1UZ-FE non-VVTi) → DTAFast T4 (auto)
Lexus SC400 1992-97 (1UZ-FE non-VVTi) — DTAFast — T4
⚠ NOT CHECKED. Don't build from this.
Drawn by Michael Gnankou · Rev 0 · draft · 2026-10-11
Before you start
Not confident with automotive wiring? Have a professional harness builder or tuner do it, or check your work before first power-up. A wiring mistake can damage the ECU, the engine or the car, or start a fire.
| Status | draft · not yet verified: nobody has reported building and running this harness |
|---|---|
| Open errors | 2: read the Findings page before cutting any wire |
| Size of the job | 49 wires · 10 connectors · 2 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-A-12 | SP-14V-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W2 | OEM-A-13 | SP-14V-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W3 | SP-14V-1 | T4-C1-31 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W4 | OEM-B-26 | T4-C3-26 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W5 | OEM-A-22 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W6 | OEM-D-13 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W7 | OEM-D-26 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | SP-GND-1 | T4-C1-13 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | SP-GND-1 | T4-C1-14 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | OEM-A-18 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | OEM-C-15 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | OEM-C-16 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | SP-0V-1 | T4-C2-21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | SP-0V-1 | T4-C2-33 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | OEM-A-11 | T4-C2-24 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | OEM-C-8 | T4-C2-12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-C-7 | T4-C2-22 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-C-6 | T4-C2-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-C-5 | T4-C1-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-C-13 | T4-C1-18 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-D-12 | T4-C1-9 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-D-11 | T4-C1-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-D-24 | T4-C1-34 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-D-25 | T4-C1-25 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-A-4 | T4-C2-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-A-5 | T4-C2-7 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-B-4 | T4-C1-5 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-B-6 | T4-C1-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-B-7 | T4-C1-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | OEM-D-19 | T4-C3-9 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-D-20 | T4-C3-22 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-D-17 | T4-C3-23 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-D-8 | T4-C3-24 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-D-7 | T4-C3-25 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W35 | OEM-D-6 | T4-C3-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W36 | OEM-A-17 | T4-C2-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W37 | OEM-A-6 | T4-C2-5 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W38 | OEM-B-11 | T4-C2-6 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W39 | OEM-B-24 | T4-C2-19 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W40 | OEM-A-16 | T4-C2-25 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W41 | OEM-A-7 | T4-C2-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W42 | OEM-C-2 | T4-C2-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W43 | OEM-C-10 | T4-C2-14 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W44 | OEM-A-19 | T4-C2-15 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W45 | OEM-A-9 | T4-C3-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W46 | OEM-A-20 | T4-C3-18 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W47 | OEM-A-14 | T4-C2-34 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W48 | OEM-A-2 | T4-C2-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W49 | OEM-B-19 | T4-C2-16 | 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-C1-31 | T4-C1-13 | open (OL) | +12 V supply must not touch power ground | |
| 2 | T4-C1-31 | T4-C2-21 | open (OL) | +12 V supply must not touch sensor ground | |
| 3 | T4-C2-24 | T4-C1-13 | open (OL) | 5 V sensor reference must not touch power ground | |
| 4 | T4-C2-24 | T4-C2-21 | open (OL) | 5 V sensor reference must not touch sensor ground | |
| 5 | T4-C1-13 | T4-C3-26 | open (OL) | power ground must not touch +12 V supply | |
| 6 | T4-C2-21 | T4-C3-26 | open (OL) | sensor ground must not touch +12 V supply | |
| 7 | T4-C2-24 | T4-C1-31 | open (OL) | 5 V sensor reference 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 | Ignition switch (IGSW) | — | — | — | — | — | — | — | — |
| 11 | Sensor supply +5V (VC) | — | W15 | — | 0.5 | T4-C2-24 | — | — | — |
| 12 | EFI main relay (B+) | — | W1 | — | 0.85 | SP-14V-1 | — | — | — |
| 13 | EFI main relay (B1+) | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
| 14 | Neutral start switch (NSW) | — | W47 | — | 0.5 | T4-C2-34 | — | — | — |
| 16 | Intake air temperature (THA) | — | W40 | — | 0.5 | T4-C2-25 | — | — | — |
| 17 | O2 right front (OXR1) | — | W36 | — | 0.5 | T4-C2-1 | — | — | — |
| 18 | Sensor ground (E2) | — | W10 | — | 0.5 | SP-0V-1 | — | — | — |
| 19 | Vehicle speed (SPD) | — | W44 | — | 0.5 | T4-C2-15 | — | — | — |
| 2 | Starter signal (STA) | — | W48 | — | 0.5 | T4-C2-3 | — | — | — |
| 20 | Diagnostic test 2 (TE2) | — | W46 | — | 0.5 | T4-C3-18 | — | — | — |
| 22 | Power ground (E1) | — | W5 | — | 0.85 | SP-GND-1 | — | — | — |
| 4 | Throttle position (VTA1) | — | W25 | — | 0.5 | T4-C2-10 | — | — | — |
| 5 | Coolant temperature (THW) | — | W26 | — | 0.5 | T4-C2-7 | — | — | — |
| 6 | O2 left front (OXL1) | — | W37 | — | 0.5 | T4-C2-5 | — | — | — |
| 7 | EGR temperature sensor | — | W41 | — | 0.5 | T4-C2-17 | — | — | — |
| 8 | Knock/shield (KS) | — | — | — | — | — | — | — | — |
| 9 | Diagnostic test 1 (TE1) | — | W45 | — | 0.5 | T4-C3-17 | — | — | — |
OEM-B
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 11 | O2 right rear (OXR2) | — | W38 | — | 0.5 | T4-C2-6 | — | — | — |
| 19 | Stop light switch (BK) | — | W49 | — | 0.5 | T4-C2-16 | — | — | — |
| 20 | A/T kickdown switch (KD) | — | — | — | — | — | — | — | — |
| 23 | A/C request (AC) | — | — | — | — | — | — | — | — |
| 24 | O2 left rear (OXL2) | — | W39 | — | 0.5 | T4-C2-19 | — | — | — |
| 26 | Battery constant (BATT) | — | W4 | — | 0.85 | T4-C3-26 | — | — | — |
| 4 | EFI main relay control (MREL) | — | W27 | — | 0.5 | T4-C1-5 | — | — | — |
| 5 | Check-engine lamp (W) | — | — | — | — | — | — | — | — |
| 6 | Fuel pump relay (FPR) | — | W28 | — | 0.5 | T4-C1-4 | — | — | — |
| 7 | A/C clutch relay (ACMG) | — | W29 | — | 0.5 | T4-C1-3 | — | — | — |
| 8 | Fuel pump control (FC) | — | — | — | — | — | — | — | — |
OEM-C
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | TPS idle switch (IDL) | — | — | — | — | — | — | — | — |
| 10 | Igniter 2 feedback (IGF2) | — | W43 | — | 0.5 | T4-C2-14 | — | — | — |
| 11 | Knock sensor 2 (KNK2) | — | — | — | — | — | — | — | — |
| 12 | Check connector VF2 | — | — | — | — | — | — | — | — |
| 13 | Ignition 2 (IGT2) | — | W20 | — | 0.5 | T4-C1-18 | — | — | — |
| 15 | Cam sensor ground (G-) | — | W11 | — | 0.5 | SP-0V-1 | — | — | — |
| 16 | Crank sensor - (NE-) | — | W12 | — | 0.5 | SP-0V-1 | — | — | — |
| 2 | Igniter 1 feedback (IGF1) | — | W42 | — | 0.5 | T4-C2-4 | — | — | — |
| 3 | Knock sensor 1 (KNK1) | — | — | — | — | — | — | — | — |
| 4 | Check connector VF1 | — | — | — | — | — | — | — | — |
| 5 | Ignition 1 (IGT1) | — | W19 | — | 0.5 | T4-C1-10 | — | — | — |
| 6 | Cam sensor 2 + (G2+) | — | W18 | — | 0.5 | T4-C2-2 | — | — | — |
| 7 | Cam sensor 1 + (G1+) | — | W17 | — | 0.5 | T4-C2-22 | — | — | — |
| 8 | Crank sensor + (NE+) | — | W16 | — | 0.5 | T4-C2-12 | — | — | — |
OEM-D
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 11 | Injector 2&8 (#20) | — | W22 | — | 0.5 | T4-C1-17 | — | — | — |
| 12 | Injector 1&7 (#10) | — | W21 | — | 0.5 | T4-C1-9 | — | — | — |
| 13 | Power ground (E01) | — | W6 | — | 0.85 | SP-GND-1 | — | — | — |
| 17 | Cold start injector 1 (STJ1) | — | W32 | — | 0.5 | T4-C3-23 | — | — | — |
| 19 | O2 heater 2 (HT2) | — | W30 | — | 0.5 | T4-C3-9 | — | — | — |
| 20 | O2 heater 1 (HT1) | — | W31 | — | 0.5 | T4-C3-22 | — | — | — |
| 21 | EGR solenoid | — | — | — | — | — | — | — | — |
| 22 | Fuel pressure-up VSV (PR) | — | — | — | — | — | — | — | — |
| 24 | Injector 3&5 (#40) | — | W23 | — | 0.5 | T4-C1-34 | — | — | — |
| 25 | Injector 4&6 (#30) | — | W24 | — | 0.5 | T4-C1-25 | — | — | — |
| 26 | Power ground (E02) | — | W7 | — | 0.85 | SP-GND-1 | — | — | — |
| 4 | Cold start injector (STJ) | — | — | — | — | — | — | — | — |
| 5 | ISC stepper coil 4 (ISC4) | — | — | — | — | — | — | — | — |
| 6 | ISC stepper coil 3 (ISC3) | — | W35 | — | 0.5 | T4-C3-10 | — | — | — |
| 7 | ISC stepper coil 2 (ISC2) | — | W34 | — | 0.5 | T4-C3-25 | — | — | — |
| 8 | ISC stepper coil 1 (ISC1) | — | W33 | — | 0.5 | T4-C3-24 | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W10 | — | 0.5 | OEM-A-18 | — | — | — |
| 1 | — | — | W11 | — | 0.5 | OEM-C-15 | — | — | — |
| 1 | — | — | W12 | — | 0.5 | OEM-C-16 | — | — | — |
| 1 | — | — | W13 | — | 0.5 | T4-C2-21 | — | — | — |
| 1 | — | — | W14 | — | 0.5 | T4-C2-33 | — | — | — |
SP-14V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W1 | — | 0.85 | OEM-A-12 | — | — | — |
| 1 | — | — | W2 | — | 0.85 | OEM-A-13 | — | — | — |
| 1 | — | — | W3 | — | 0.85 | T4-C1-31 | — | — | — |
SP-GND
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W9 | — | 0.85 | T4-C1-14 | — | — | — |
| 1 | — | — | W5 | — | 0.85 | OEM-A-22 | — | — | — |
| 1 | — | — | W6 | — | 0.85 | OEM-D-13 | — | — | — |
| 1 | — | — | W7 | — | 0.85 | OEM-D-26 | — | — | — |
| 1 | — | — | W8 | — | 0.85 | T4-C1-13 | — | — | — |
T4-C1
Mating face
Wire side
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Coil 3 | — | — | — | — | — | — | — | — |
| 2 | — | — | — | — | — | — | — | — | — |
| 3 | PWM 3 | — | W29 | — | 0.5 | OEM-B-7 | — | — | — |
| 4 | PWM 2 | — | W28 | — | 0.5 | OEM-B-6 | — | — | — |
| 5 | PWM 1 | — | W27 | — | 0.5 | OEM-B-4 | — | — | — |
| 6 | — | — | — | — | — | — | — | — | — |
| 7 | — | — | — | — | — | — | — | — | — |
| 8 | — | — | — | — | — | — | — | — | — |
| 9 | Injector 1 | — | W21 | — | 0.5 | OEM-D-12 | — | — | — |
| 10 | Coil 1 | — | W19 | — | 0.5 | OEM-C-5 | — | — | — |
| 11 | — | — | — | — | — | — | — | — | — |
| 12 | — | — | — | — | — | — | — | — | — |
| 13 | Power Ground 1 | — | W8 | — | 0.85 | SP-GND-1 | — | — | — |
| 14 | Power Ground 2 | — | W9 | — | 0.85 | SP-GND-1 | — | — | — |
| 15 | — | — | — | — | — | — | — | — | — |
| 16 | — | — | — | — | — | — | — | — | — |
| 17 | Injector 2 | — | W22 | — | 0.5 | OEM-D-11 | — | — | — |
| 18 | Coil 2 | — | W20 | — | 0.5 | OEM-C-13 | — | — | — |
| 19 | — | — | — | — | — | — | — | — | — |
| 20 | — | — | — | — | — | — | — | — | — |
| 21 | — | — | — | — | — | — | — | — | — |
| 22 | — | — | — | — | — | — | — | — | — |
| 23 | — | — | — | — | — | — | — | — | — |
| 24 | — | — | — | — | — | — | — | — | — |
| 25 | Injector 4 | — | W24 | — | 0.5 | OEM-D-25 | — | — | — |
| 26 | Coil 4 | — | — | — | — | — | — | — | — |
| 27 | — | — | — | — | — | — | — | — | — |
| 28 | — | — | — | — | — | — | — | — | — |
| 29 | — | — | — | — | — | — | — | — | — |
| 30 | — | — | — | — | — | — | — | — | — |
| 31 | Ignition 12v In | — | W3 | — | 0.85 | SP-14V-1 | — | — | — |
| 32 | — | — | — | — | — | — | — | — | — |
| 33 | — | — | — | — | — | — | — | — | — |
| 34 | Injector 3 | — | W23 | — | 0.5 | OEM-D-24 | — | — | — |
T4-C2
Mating face
Wire side
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Analogue 2 | — | W36 | — | 0.5 | OEM-A-17 | — | — | — |
| 2 | Wheel 1 | — | W18 | — | 0.5 | OEM-C-6 | — | — | — |
| 3 | Analogue 10 | — | W48 | — | 0.5 | OEM-A-2 | — | — | — |
| 4 | Digital 1 | — | W42 | — | 0.5 | OEM-C-2 | — | — | — |
| 5 | Analogue 3 | — | W37 | — | 0.5 | OEM-A-6 | — | — | — |
| 6 | Analogue 4 | — | W38 | — | 0.5 | OEM-B-11 | — | — | — |
| 7 | Thermistor 1 | — | W26 | — | 0.5 | OEM-A-5 | — | — | — |
| 8 | — | — | — | — | — | — | — | — | — |
| 9 | 5v Output | — | — | — | — | — | — | — | — |
| 10 | Analogue 1 | — | W25 | — | 0.5 | OEM-A-4 | — | — | — |
| 11 | — | — | — | — | — | — | — | — | — |
| 12 | Crank | — | W16 | — | 0.5 | OEM-C-8 | — | — | — |
| 13 | — | — | — | — | — | — | — | — | — |
| 14 | Digital 4 | — | W43 | — | 0.5 | OEM-C-10 | — | — | — |
| 15 | Digital 5 | — | W44 | — | 0.5 | OEM-A-19 | — | — | — |
| 16 | Analogue 11 | — | W49 | — | 0.5 | OEM-B-19 | — | — | — |
| 17 | Thermistor 3 | — | W41 | — | 0.5 | OEM-A-7 | — | — | — |
| 18 | — | — | — | — | — | — | — | — | — |
| 19 | Analogue 6 | — | W39 | — | 0.5 | OEM-B-24 | — | — | — |
| 20 | — | — | — | — | — | — | — | — | — |
| 21 | Sensor Ground | — | W13 | — | 0.5 | SP-0V-1 | — | — | — |
| 22 | Cam 1 | — | W17 | — | 0.5 | OEM-C-7 | — | — | — |
| 23 | — | — | — | — | — | — | — | — | — |
| 24 | 5v Output | — | W15 | — | 0.5 | OEM-A-11 | — | — | — |
| 25 | Thermistor 2 | — | W40 | — | 0.5 | OEM-A-16 | — | — | — |
| 26 | CAN High | — | — | — | — | — | — | — | — |
| 27 | — | — | — | — | — | — | — | — | — |
| 28 | CAN Low | — | — | — | — | — | — | — | — |
| 29 | — | — | — | — | — | — | — | — | — |
| 30 | — | — | — | — | — | — | — | — | — |
| 31 | — | — | — | — | — | — | — | — | — |
| 32 | — | — | — | — | — | — | — | — | — |
| 33 | Sensor Ground | — | W14 | — | 0.5 | SP-0V-1 | — | — | — |
| 34 | Analogue 9 | — | W47 | — | 0.5 | OEM-A-14 | — | — | — |
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 | — | W30 | — | 0.5 | OEM-D-19 | — | — | — |
| 10 | PWM 8 | — | W35 | — | 0.5 | OEM-D-6 | — | — | — |
| 11 | Lambda 1 Trim Resistor | — | — | — | — | — | — | — | — |
| 12 | Lambda 1 Nernst Voltage | — | — | — | — | — | — | — | — |
| 13 | — | — | — | — | — | — | — | — | — |
| 14 | — | — | — | — | — | — | — | — | — |
| 15 | — | — | — | — | — | — | — | — | — |
| 16 | — | — | — | — | — | — | — | — | — |
| 17 | Analogue 7 | — | W45 | — | 0.5 | OEM-A-9 | — | — | — |
| 18 | Analogue 8 | — | W46 | — | 0.5 | OEM-A-20 | — | — | — |
| 19 | — | — | — | — | — | — | — | — | — |
| 20 | — | — | — | — | — | — | — | — | — |
| 21 | — | — | — | — | — | — | — | — | — |
| 22 | PWM 4 | — | W31 | — | 0.5 | OEM-D-20 | — | — | — |
| 23 | PWM 5 | — | W32 | — | 0.5 | OEM-D-17 | — | — | — |
| 24 | PWM 6 | — | W33 | — | 0.5 | OEM-D-8 | — | — | — |
| 25 | PWM 7 | — | W34 | — | 0.5 | OEM-D-7 | — | — | — |
| 26 | Permanent 12v | — | W4 | — | 0.85 | OEM-B-26 | — | — | — |
| 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 | Ignition switch (IGSW) | digital_in | — | — | — | single_source | |
| OEM-A-11 | Sensor supply +5V (VC) | vref | T4-C2-24 | 5v Output | vref | single_source | |
| OEM-A-12 | EFI main relay (B+) | power_in | T4-C1-31 | Ignition 12v In | power_in | single_source | |
| OEM-A-13 | EFI main relay (B1+) | power_in | T4-C1-31 | Ignition 12v In | power_in | single_source | |
| OEM-A-14 | Neutral start switch (NSW) | digital_in | T4-C2-34 | Analogue 9 | analog_in | single_source | |
| OEM-A-16 | Intake air temperature (THA) | temp_in | T4-C2-25 | Thermistor 2 | temp_in | single_source | |
| OEM-A-17 | O2 right front (OXR1) | lambda_nb_in | T4-C2-1 | Analogue 2 | analog_in | single_source | |
| OEM-A-18 | Sensor ground (E2) | sensor_ground | T4-C2-21 + T4-C2-33 | Sensor Ground + Sensor Ground | sensor_ground | single_source | |
| OEM-A-19 | Vehicle speed (SPD) | digital_in | T4-C2-15 | Digital 5 | digital_in | single_source | |
| OEM-A-2 | Starter signal (STA) | digital_in | T4-C2-3 | Analogue 10 | analog_in | single_source | |
| OEM-A-20 | Diagnostic test 2 (TE2) | digital_in | T4-C3-18 | Analogue 8 | analog_in | single_source | |
| OEM-A-22 | Power ground (E1) | ground | T4-C1-13 + T4-C1-14 | Power Ground 1 + Power Ground 2 | ground | single_source | |
| OEM-A-4 | Throttle position (VTA1) | analog_in | T4-C2-10 | Analogue 1 | analog_in | single_source | |
| OEM-A-5 | Coolant temperature (THW) | temp_in | T4-C2-7 | Thermistor 1 | temp_in | single_source | |
| OEM-A-6 | O2 left front (OXL1) | lambda_nb_in | T4-C2-5 | Analogue 3 | analog_in | single_source | |
| OEM-A-7 | EGR temperature sensor | temp_in | T4-C2-17 | Thermistor 3 | temp_in | single_source | |
| OEM-A-8 | Knock/shield (KS) | knock_in | — | — | — | single_source | |
| OEM-A-9 | Diagnostic test 1 (TE1) | digital_in | T4-C3-17 | Analogue 7 | analog_in | single_source | |
| OEM-B-11 | O2 right rear (OXR2) | lambda_nb_in | T4-C2-6 | Analogue 4 | analog_in | single_source | |
| OEM-B-19 | Stop light switch (BK) | digital_in | T4-C2-16 | Analogue 11 | analog_in | single_source | |
| OEM-B-20 | A/T kickdown switch (KD) | digital_in | — | — | — | single_source | |
| OEM-B-23 | A/C request (AC) | digital_in | — | — | — | single_source | |
| OEM-B-24 | O2 left rear (OXL2) | lambda_nb_in | T4-C2-19 | Analogue 6 | analog_in | single_source | |
| OEM-B-26 | Battery constant (BATT) | power_in | T4-C3-26 | Permanent 12v | power_in | single_source | |
| OEM-B-4 | EFI main relay control (MREL) | low_side_out | T4-C1-5 | PWM 1 | low_side_out | single_source | |
| OEM-B-5 | Check-engine lamp (W) | low_side_out | — | — | — | single_source | |
| OEM-B-6 | Fuel pump relay (FPR) | low_side_out | T4-C1-4 | PWM 2 | low_side_out | single_source | |
| OEM-B-7 | A/C clutch relay (ACMG) | low_side_out | T4-C1-3 | PWM 3 | low_side_out | single_source | |
| OEM-B-8 | Fuel pump control (FC) | low_side_out | — | — | — | single_source | |
| OEM-C-1 | TPS idle switch (IDL) | digital_in | — | — | — | single_source | |
| OEM-C-10 | Igniter 2 feedback (IGF2) | digital_in | T4-C2-14 | Digital 4 | digital_in | single_source | |
| OEM-C-11 | Knock sensor 2 (KNK2) | knock_in | — | — | — | single_source | |
| OEM-C-12 | Check connector VF2 | analog_out | — | — | — | single_source | |
| OEM-C-13 | Ignition 2 (IGT2) | ignition_out | T4-C1-18 | Coil 2 | ignition_out | single_source | |
| OEM-C-15 | Cam sensor ground (G-) | sensor_ground | T4-C2-21 + T4-C2-33 | Sensor Ground + Sensor Ground | sensor_ground | single_source | |
| OEM-C-16 | Crank sensor - (NE-) | sensor_ground | T4-C2-21 + T4-C2-33 | Sensor Ground + Sensor Ground | sensor_ground | single_source | |
| OEM-C-2 | Igniter 1 feedback (IGF1) | digital_in | T4-C2-4 | Digital 1 | digital_in | single_source | |
| OEM-C-3 | Knock sensor 1 (KNK1) | knock_in | — | — | — | single_source | |
| OEM-C-4 | Check connector VF1 | analog_out | — | — | — | single_source | |
| OEM-C-5 | Ignition 1 (IGT1) | ignition_out | T4-C1-10 | Coil 1 | ignition_out | single_source | |
| OEM-C-6 | Cam sensor 2 + (G2+) | trigger_in | T4-C2-2 | Wheel 1 | digital_in | single_source | |
| OEM-C-7 | Cam sensor 1 + (G1+) | trigger_in | T4-C2-22 | Cam 1 | trigger_in | single_source | |
| OEM-C-8 | Crank sensor + (NE+) | trigger_in | T4-C2-12 | Crank | trigger_in | single_source | |
| OEM-D-11 | Injector 2&8 (#20) | injector_out | T4-C1-17 | Injector 2 | injector_out | single_source | |
| OEM-D-12 | Injector 1&7 (#10) | injector_out | T4-C1-9 | Injector 1 | injector_out | single_source | |
| OEM-D-13 | Power ground (E01) | ground | T4-C1-13 + T4-C1-14 | Power Ground 1 + Power Ground 2 | ground | single_source | |
| OEM-D-17 | Cold start injector 1 (STJ1) | low_side_out | T4-C3-23 | PWM 5 | low_side_out | single_source | |
| OEM-D-19 | O2 heater 2 (HT2) | low_side_out | T4-C3-9 | Lambda 1 Heater Negative | low_side_out | single_source | |
| OEM-D-20 | O2 heater 1 (HT1) | low_side_out | T4-C3-22 | PWM 4 | low_side_out | single_source | |
| OEM-D-21 | EGR solenoid | low_side_out | — | — | — | single_source | |
| OEM-D-22 | Fuel pressure-up VSV (PR) | low_side_out | — | — | — | single_source | |
| OEM-D-24 | Injector 3&5 (#40) | injector_out | T4-C1-34 | Injector 3 | injector_out | single_source | |
| OEM-D-25 | Injector 4&6 (#30) | injector_out | T4-C1-25 | Injector 4 | injector_out | single_source | |
| OEM-D-26 | Power ground (E02) | ground | T4-C1-13 + T4-C1-14 | Power Ground 1 + Power Ground 2 | ground | single_source | |
| OEM-D-4 | Cold start injector (STJ) | low_side_out | — | — | — | single_source | |
| OEM-D-5 | ISC stepper coil 4 (ISC4) | low_side_out | — | — | — | single_source | |
| OEM-D-6 | ISC stepper coil 3 (ISC3) | low_side_out | T4-C3-10 | PWM 8 | low_side_out | single_source | |
| OEM-D-7 | ISC stepper coil 2 (ISC2) | low_side_out | T4-C3-25 | PWM 7 | low_side_out | single_source | |
| OEM-D-8 | ISC stepper coil 1 (ISC1) | low_side_out | T4-C3-24 | PWM 6 | low_side_out | single_source |
Cut list
| Wire | From | To | Gauge (mm²) | Colour | Length | Signal | Ident |
|---|---|---|---|---|---|---|---|
| W1 | OEM-A-12 | SP-14V-1 | 0.85 | no route | EFI main relay (B+) | — | |
| W2 | OEM-A-13 | SP-14V-1 | 0.85 | no route | EFI main relay (B1+) | — | |
| W3 | SP-14V-1 | T4-C1-31 | 0.85 | no route | Ignition 12v In | — | |
| W4 | OEM-B-26 | T4-C3-26 | 0.85 | no route | Battery constant (BATT) | — | |
| W5 | OEM-A-22 | SP-GND-1 | 0.85 | no route | Power ground (E1) | — | |
| W6 | OEM-D-13 | SP-GND-1 | 0.85 | no route | Power ground (E01) | — | |
| W7 | OEM-D-26 | SP-GND-1 | 0.85 | no route | Power ground (E02) | — | |
| W8 | SP-GND-1 | T4-C1-13 | 0.85 | no route | Power Ground 1 | — | |
| W9 | SP-GND-1 | T4-C1-14 | 0.85 | no route | Power Ground 2 | — | |
| W10 | OEM-A-18 | SP-0V-1 | 0.5 | no route | Sensor ground (E2) | — | |
| W11 | OEM-C-15 | SP-0V-1 | 0.5 | no route | Cam sensor ground (G-) | — | |
| W12 | OEM-C-16 | SP-0V-1 | 0.5 | no route | Crank sensor - (NE-) | — | |
| W13 | SP-0V-1 | T4-C2-21 | 0.5 | no route | Sensor Ground | — | |
| W14 | SP-0V-1 | T4-C2-33 | 0.5 | no route | Sensor Ground | — | |
| W15 | OEM-A-11 | T4-C2-24 | 0.5 | no route | Sensor supply +5V (VC) | — | |
| W16 | OEM-C-8 | T4-C2-12 | 0.5 | no route | Crank sensor + (NE+) | — | |
| W17 | OEM-C-7 | T4-C2-22 | 0.5 | no route | Cam sensor 1 + (G1+) | — | |
| W18 | OEM-C-6 | T4-C2-2 | 0.5 | no route | Cam sensor 2 + (G2+) | — | |
| W19 | OEM-C-5 | T4-C1-10 | 0.5 | no route | Ignition 1 (IGT1) | — | |
| W20 | OEM-C-13 | T4-C1-18 | 0.5 | no route | Ignition 2 (IGT2) | — | |
| W21 | OEM-D-12 | T4-C1-9 | 0.5 | no route | Injector 1&7 (#10) | — | |
| W22 | OEM-D-11 | T4-C1-17 | 0.5 | no route | Injector 2&8 (#20) | — | |
| W23 | OEM-D-24 | T4-C1-34 | 0.5 | no route | Injector 3&5 (#40) | — | |
| W24 | OEM-D-25 | T4-C1-25 | 0.5 | no route | Injector 4&6 (#30) | — | |
| W25 | OEM-A-4 | T4-C2-10 | 0.5 | no route | Throttle position (VTA1) | — | |
| W26 | OEM-A-5 | T4-C2-7 | 0.5 | no route | Coolant temperature (THW) | — | |
| W27 | OEM-B-4 | T4-C1-5 | 0.5 | no route | EFI main relay control (MREL) | — | |
| W28 | OEM-B-6 | T4-C1-4 | 0.5 | no route | Fuel pump relay (FPR) | — | |
| W29 | OEM-B-7 | T4-C1-3 | 0.5 | no route | A/C clutch relay (ACMG) | — | |
| W30 | OEM-D-19 | T4-C3-9 | 0.5 | no route | O2 heater 2 (HT2) | — | |
| W31 | OEM-D-20 | T4-C3-22 | 0.5 | no route | O2 heater 1 (HT1) | — | |
| W32 | OEM-D-17 | T4-C3-23 | 0.5 | no route | Cold start injector 1 (STJ1) | — | |
| W33 | OEM-D-8 | T4-C3-24 | 0.5 | no route | ISC stepper coil 1 (ISC1) | — | |
| W34 | OEM-D-7 | T4-C3-25 | 0.5 | no route | ISC stepper coil 2 (ISC2) | — | |
| W35 | OEM-D-6 | T4-C3-10 | 0.5 | no route | ISC stepper coil 3 (ISC3) | — | |
| W36 | OEM-A-17 | T4-C2-1 | 0.5 | no route | O2 right front (OXR1) | — | |
| W37 | OEM-A-6 | T4-C2-5 | 0.5 | no route | O2 left front (OXL1) | — | |
| W38 | OEM-B-11 | T4-C2-6 | 0.5 | no route | O2 right rear (OXR2) | — | |
| W39 | OEM-B-24 | T4-C2-19 | 0.5 | no route | O2 left rear (OXL2) | — | |
| W40 | OEM-A-16 | T4-C2-25 | 0.5 | no route | Intake air temperature (THA) | — | |
| W41 | OEM-A-7 | T4-C2-17 | 0.5 | no route | EGR temperature sensor | — | |
| W42 | OEM-C-2 | T4-C2-4 | 0.5 | no route | Igniter 1 feedback (IGF1) | — | |
| W43 | OEM-C-10 | T4-C2-14 | 0.5 | no route | Igniter 2 feedback (IGF2) | — | |
| W44 | OEM-A-19 | T4-C2-15 | 0.5 | no route | Vehicle speed (SPD) | — | |
| W45 | OEM-A-9 | T4-C3-17 | 0.5 | no route | Diagnostic test 1 (TE1) | — | |
| W46 | OEM-A-20 | T4-C3-18 | 0.5 | no route | Diagnostic test 2 (TE2) | — | |
| W47 | OEM-A-14 | T4-C2-34 | 0.5 | no route | Neutral start switch (NSW) | — | |
| W48 | OEM-A-2 | T4-C2-3 | 0.5 | no route | Starter signal (STA) | — | |
| W49 | OEM-B-19 | T4-C2-16 | 0.5 | no route | Stop light switch (BK) | — |
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) | 41.000 | ea |
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 |
|---|---|---|---|
| error | PHYS_REQUIRED_OPEN | T4-C3-27 | T4-C3-27 "Permanent 12v" is required but not wired. |
| error | REQUIRED_UNMAPPED | OEM-A-1 | Required OEM function "Ignition switch (IGSW)" (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. |
| warn | NET_FAMILY | OEM-A-14 ↔ T4-C2-34 | OEM-A-14 "Neutral start switch (NSW)" [digital_in] is wired to T4-C2-34 "Analogue 9" [analog_in]. Analog and digital on one net. A switch on an analog input works with a pull-up and a threshold; an analog sensor on a digital input loses its value. |
| warn | NET_FAMILY | OEM-A-2 ↔ T4-C2-3 | OEM-A-2 "Starter signal (STA)" [digital_in] is wired to T4-C2-3 "Analogue 10" [analog_in]. Analog and digital on one net. A switch on an analog input works with a pull-up and a threshold; an analog sensor on a digital input loses its value. |
| warn | NET_FAMILY | OEM-A-20 ↔ T4-C3-18 | OEM-A-20 "Diagnostic test 2 (TE2)" [digital_in] is wired to T4-C3-18 "Analogue 8" [analog_in]. Analog and digital on one net. A switch on an analog input works with a pull-up and a threshold; an analog sensor on a digital input loses its value. |
| warn | NET_FAMILY | OEM-A-9 ↔ T4-C3-17 | OEM-A-9 "Diagnostic test 1 (TE1)" [digital_in] is wired to T4-C3-17 "Analogue 7" [analog_in]. Analog and digital on one net. A switch on an analog input works with a pull-up and a threshold; an analog sensor on a digital input loses its value. |
| warn | NET_FAMILY | OEM-B-19 ↔ T4-C2-16 | OEM-B-19 "Stop light switch (BK)" [digital_in] is wired to T4-C2-16 "Analogue 11" [analog_in]. Analog and digital on one net. A switch on an analog input works with a pull-up and a threshold; an analog sensor on a digital input loses its value. |
| warn | NET_FAMILY | OEM-C-6 ↔ T4-C2-2 | OEM-C-6 "Cam sensor 2 + (G2+)" [trigger_in] is wired to T4-C2-2 "Wheel 1" [digital_in]. Hall-type cam/speed signals can use a digital input if it handles the frequency; VR signals cannot. |
| info | UNMAPPED | OEM | 14 optional OEM pins are not mapped: OEM-A-8 Knock/shield (KS); OEM-B-20 A/T kickdown switch (KD); OEM-B-23 A/C request (AC); OEM-B-5 Check-engine lamp (W); OEM-B-8 Fuel pump control (FC); OEM-C-1 TPS idle switch (IDL); OEM-C-11 Knock sensor 2 (KNK2); OEM-C-12 Check connector VF2; OEM-C-3 Knock sensor 1 (KNK1); OEM-C-4 Check connector VF1; OEM-D-21 EGR solenoid; OEM-D-22 Fuel pressure-up VSV (PR); OEM-D-4 Cold start injector (STJ); OEM-D-5 ISC stepper coil 4 (ISC4) |
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 1: Ignition switch (IGSW): 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-C 3: Knock sensor 1 (KNK1): no free knock input on DTAFast T4 - OEM-C 11: Knock sensor 2 (KNK2): no free knock input on DTAFast T4 - OEM-A 8: Knock/shield (KS): no free knock input on DTAFast T4 - OEM-D 5: ISC stepper coil 4 (ISC4): no free low_side/relay_control/heater_low_side/ls_hs/injector on DTAFast T4 - OEM-B 5: Check-engine lamp (W): no free low_side/relay_control/heater_low_side/ls_hs/injector on DTAFast T4 - OEM-B 8: Fuel pump control (FC): no free low_side/relay_control/heater_low_side/ls_hs/injector on DTAFast T4 - OEM-D 21: EGR solenoid: no free low_side/relay_control/heater_low_side/ls_hs/injector on DTAFast T4 - OEM-D 22: Fuel pressure-up VSV (PR): no free low_side/relay_control/heater_low_side/ls_hs/injector on DTAFast T4 - OEM-D 4: Cold start injector (STJ): no free low_side/relay_control/heater_low_side/ls_hs/injector on DTAFast T4 - OEM-B 20: A/T kickdown switch (KD): no free switch_in/frequency_in/analog_0_5 on DTAFast T4 - OEM-B 23: A/C request (AC): no free switch_in/frequency_in/analog_0_5 on DTAFast T4 - OEM-C 1: TPS idle switch (IDL): no free switch_in/frequency_in/analog_0_5 on DTAFast T4 - OEM-C 4: Check connector VF1: no free analog_out on DTAFast T4 - OEM-C 12: Check connector VF2: no free analog_out on DTAFast T4
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 | Lextreme: Adaptronic install for 1UZ-FE (Lexus LS400/SC400) — 4-plug A/B/C/D ECU pin table (1992 LS400) | https://www.lextreme.com/installation-of-an-adaptronic-ecu-for-a-lexus-ls400-sc400-1uzfe-engine/ | — | — | — |