Lexus LS400 1989-97 (1UZ-FE non-VVTi) → AMP EFI MS3Pro Mini (auto)
Lexus LS400 1989-97 (1UZ-FE non-VVTi) — AMP EFI — MS3Pro Mini
⚠ 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 | 1: read the Findings page before cutting any wire |
| Size of the job | 38 wires · 8 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-A-12 | SP-14V-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W2 | OEM-A-13 | SP-14V-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W3 | SP-14V-1 | MS3PROMINI-A-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W4 | OEM-A-22 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W5 | OEM-D-13 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W6 | OEM-D-26 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W7 | SP-GND-1 | MS3PROMINI-A-22 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | SP-GND-1 | MS3PROMINI-A-23 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | OEM-A-18 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | OEM-C-15 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | OEM-C-16 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | SP-0V-1 | MS3PROMINI-A-21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | OEM-A-11 | MS3PROMINI-A-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | OEM-C-8 | MS3PROMINI-A-30 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | OEM-C-7 | MS3PROMINI-A-32 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | OEM-C-6 | MS3PROMINI-A-33 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-C-5 | MS3PROMINI-A-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-C-13 | MS3PROMINI-A-18 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-D-12 | MS3PROMINI-A-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-D-11 | MS3PROMINI-A-11 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-D-24 | MS3PROMINI-A-12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-D-25 | MS3PROMINI-A-5 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-A-4 | MS3PROMINI-A-28 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-A-5 | MS3PROMINI-A-26 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-B-4 | MS3PROMINI-A-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-B-6 | MS3PROMINI-A-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-B-7 | MS3PROMINI-A-6 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-D-19 | MS3PROMINI-A-7 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-D-20 | MS3PROMINI-A-8 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | OEM-D-17 | MS3PROMINI-A-9 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-A-17 | MS3PROMINI-A-13 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-A-6 | MS3PROMINI-A-14 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-B-11 | MS3PROMINI-A-15 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-B-24 | MS3PROMINI-A-16 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W35 | OEM-A-16 | MS3PROMINI-A-27 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W36 | OEM-C-2 | MS3PROMINI-A-34 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W37 | OEM-C-10 | MS3PROMINI-A-35 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W38 | OEM-A-19 | MS3PROMINI-A-29 | 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 | MS3PROMINI-A-1 | MS3PROMINI-A-21 | open (OL) | +12 V supply must not touch sensor ground | |
| 2 | MS3PROMINI-A-1 | MS3PROMINI-A-22 | open (OL) | +12 V supply must not touch power ground | |
| 3 | MS3PROMINI-A-2 | MS3PROMINI-A-21 | open (OL) | 5 V sensor reference must not touch sensor ground | |
| 4 | MS3PROMINI-A-2 | MS3PROMINI-A-22 | open (OL) | 5 V sensor reference must not touch power ground | |
| 5 | MS3PROMINI-A-2 | MS3PROMINI-A-1 | 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
MS3PROMINI-A
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | 12V+ switched power in | — | W3 | — | 0.85 | SP-14V-1 | — | — | — |
| 10 | Injector out F | — | W19 | — | 0.5 | OEM-D-12 | — | — | — |
| 11 | Injector out G | — | W20 | — | 0.5 | OEM-D-11 | — | — | — |
| 12 | Injector out H | — | W21 | — | 0.5 | OEM-D-24 | — | — | — |
| 13 | Analog in 1 | — | W31 | — | 0.5 | OEM-A-17 | — | — | — |
| 14 | Analog in 2 | — | W32 | — | 0.5 | OEM-A-6 | — | — | — |
| 15 | Analog in 3 | — | W33 | — | 0.5 | OEM-B-11 | — | — | — |
| 16 | Analog in 4 | — | W34 | — | 0.5 | OEM-B-24 | — | — | — |
| 17 | Spark out A | — | W17 | — | 0.5 | OEM-C-5 | — | — | — |
| 18 | Spark out B | — | W18 | — | 0.5 | OEM-C-13 | — | — | — |
| 19 | Spark out C | — | — | — | — | — | — | — | — |
| 2 | +5V VREF out | — | W13 | — | 0.5 | OEM-A-11 | — | — | — |
| 20 | Spark out D | — | — | — | — | — | — | — | — |
| 21 | Sensor ground | — | W12 | — | 0.5 | SP-0V-1 | — | — | — |
| 22 | Power ground | — | W7 | — | 0.85 | SP-GND-1 | — | — | — |
| 23 | Power ground | — | W8 | — | 0.85 | SP-GND-1 | — | — | — |
| 24 | CAN Low | — | — | — | — | — | — | — | — |
| 25 | CAN High | — | — | — | — | — | — | — | — |
| 26 | CLT in | — | W24 | — | 0.5 | OEM-A-5 | — | — | — |
| 27 | IAT in | — | W35 | — | 0.5 | OEM-A-16 | — | — | — |
| 28 | TPS in | — | W23 | — | 0.5 | OEM-A-4 | — | — | — |
| 29 | Digital switched in 1 / Flex fuel | — | W38 | — | 0.5 | OEM-A-19 | — | — | — |
| 3 | PWM out 1 / Idle | — | W26 | — | 0.5 | OEM-B-6 | — | — | — |
| 30 | CKP+ | — | W14 | — | 0.5 | OEM-C-8 | — | — | — |
| 31 | CKP- | — | — | — | — | — | — | — | — |
| 32 | CMP+ | — | W15 | — | 0.5 | OEM-C-7 | — | — | — |
| 33 | CMP- | — | W16 | — | 0.5 | OEM-C-6 | — | — | — |
| 34 | Digital frequency in 1 (Hall) | — | W36 | — | 0.5 | OEM-C-2 | — | — | — |
| 35 | Digital frequency in 2 (Hall) | — | W37 | — | 0.5 | OEM-C-10 | — | — | — |
| 4 | Fuel pump out | — | W25 | — | 0.5 | OEM-B-4 | — | — | — |
| 5 | Injector out A | — | W22 | — | 0.5 | OEM-D-25 | — | — | — |
| 6 | Injector out B | — | W27 | — | 0.5 | OEM-B-7 | — | — | — |
| 7 | Injector out C | — | W28 | — | 0.5 | OEM-D-19 | — | — | — |
| 8 | Injector out D | — | W29 | — | 0.5 | OEM-D-20 | — | — | — |
| 9 | Injector out E | — | W30 | — | 0.5 | OEM-D-17 | — | — | — |
OEM-A
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Ignition switch (IGSW) | — | — | — | — | — | — | — | — |
| 11 | Sensor supply +5V (VC) | — | W13 | — | 0.5 | MS3PROMINI-A-2 | — | — | — |
| 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) | — | — | — | — | — | — | — | — |
| 16 | Intake air temperature (THA) | — | W35 | — | 0.5 | MS3PROMINI-A-27 | — | — | — |
| 17 | O2 right front (OXR1) | — | W31 | — | 0.5 | MS3PROMINI-A-13 | — | — | — |
| 18 | Sensor ground (E2) | — | W9 | — | 0.5 | SP-0V-1 | — | — | — |
| 19 | Vehicle speed (SPD) | — | W38 | — | 0.5 | MS3PROMINI-A-29 | — | — | — |
| 2 | Starter signal (STA) | — | — | — | — | — | — | — | — |
| 20 | Diagnostic test 2 (TE2) | — | — | — | — | — | — | — | — |
| 22 | Power ground (E1) | — | W4 | — | 0.85 | SP-GND-1 | — | — | — |
| 4 | Throttle position (VTA1) | — | W23 | — | 0.5 | MS3PROMINI-A-28 | — | — | — |
| 5 | Coolant temperature (THW) | — | W24 | — | 0.5 | MS3PROMINI-A-26 | — | — | — |
| 6 | O2 left front (OXL1) | — | W32 | — | 0.5 | MS3PROMINI-A-14 | — | — | — |
| 7 | EGR temperature sensor | — | — | — | — | — | — | — | — |
| 8 | Knock/shield (KS) | — | — | — | — | — | — | — | — |
| 9 | Diagnostic test 1 (TE1) | — | — | — | — | — | — | — | — |
OEM-B
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 11 | O2 right rear (OXR2) | — | W33 | — | 0.5 | MS3PROMINI-A-15 | — | — | — |
| 19 | Stop light switch (BK) | — | — | — | — | — | — | — | — |
| 20 | A/T kickdown switch (KD) | — | — | — | — | — | — | — | — |
| 23 | A/C request (AC) | — | — | — | — | — | — | — | — |
| 24 | O2 left rear (OXL2) | — | W34 | — | 0.5 | MS3PROMINI-A-16 | — | — | — |
| 26 | Battery constant (BATT) | — | — | — | — | — | — | — | — |
| 4 | EFI main relay control (MREL) | — | W25 | — | 0.5 | MS3PROMINI-A-4 | — | — | — |
| 5 | Check-engine lamp (W) | — | — | — | — | — | — | — | — |
| 6 | Fuel pump relay (FPR) | — | W26 | — | 0.5 | MS3PROMINI-A-3 | — | — | — |
| 7 | A/C clutch relay (ACMG) | — | W27 | — | 0.5 | MS3PROMINI-A-6 | — | — | — |
| 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) | — | W37 | — | 0.5 | MS3PROMINI-A-35 | — | — | — |
| 11 | Knock sensor 2 (KNK2) | — | — | — | — | — | — | — | — |
| 12 | Check connector VF2 | — | — | — | — | — | — | — | — |
| 13 | Ignition 2 (IGT2) | — | W18 | — | 0.5 | MS3PROMINI-A-18 | — | — | — |
| 15 | Cam sensor ground (G-) | — | W10 | — | 0.5 | SP-0V-1 | — | — | — |
| 16 | Crank sensor - (NE-) | — | W11 | — | 0.5 | SP-0V-1 | — | — | — |
| 2 | Igniter 1 feedback (IGF1) | — | W36 | — | 0.5 | MS3PROMINI-A-34 | — | — | — |
| 3 | Knock sensor 1 (KNK1) | — | — | — | — | — | — | — | — |
| 4 | Check connector VF1 | — | — | — | — | — | — | — | — |
| 5 | Ignition 1 (IGT1) | — | W17 | — | 0.5 | MS3PROMINI-A-17 | — | — | — |
| 6 | Cam sensor 2 + (G2+) | — | W16 | — | 0.5 | MS3PROMINI-A-33 | — | — | — |
| 7 | Cam sensor 1 + (G1+) | — | W15 | — | 0.5 | MS3PROMINI-A-32 | — | — | — |
| 8 | Crank sensor + (NE+) | — | W14 | — | 0.5 | MS3PROMINI-A-30 | — | — | — |
OEM-D
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 11 | Injector 2&8 (#20) | — | W20 | — | 0.5 | MS3PROMINI-A-11 | — | — | — |
| 12 | Injector 1&7 (#10) | — | W19 | — | 0.5 | MS3PROMINI-A-10 | — | — | — |
| 13 | Power ground (E01) | — | W5 | — | 0.85 | SP-GND-1 | — | — | — |
| 17 | Cold start injector 1 (STJ1) | — | W30 | — | 0.5 | MS3PROMINI-A-9 | — | — | — |
| 19 | O2 heater 2 (HT2) | — | W28 | — | 0.5 | MS3PROMINI-A-7 | — | — | — |
| 20 | O2 heater 1 (HT1) | — | W29 | — | 0.5 | MS3PROMINI-A-8 | — | — | — |
| 21 | EGR solenoid | — | — | — | — | — | — | — | — |
| 22 | Fuel pressure-up VSV (PR) | — | — | — | — | — | — | — | — |
| 24 | Injector 3&5 (#40) | — | W21 | — | 0.5 | MS3PROMINI-A-12 | — | — | — |
| 25 | Injector 4&6 (#30) | — | W22 | — | 0.5 | MS3PROMINI-A-5 | — | — | — |
| 26 | Power ground (E02) | — | W6 | — | 0.85 | SP-GND-1 | — | — | — |
| 4 | Cold start injector (STJ) | — | — | — | — | — | — | — | — |
| 5 | ISC stepper coil 4 (ISC4) | — | — | — | — | — | — | — | — |
| 6 | ISC stepper coil 3 (ISC3) | — | — | — | — | — | — | — | — |
| 7 | ISC stepper coil 2 (ISC2) | — | — | — | — | — | — | — | — |
| 8 | ISC stepper coil 1 (ISC1) | — | — | — | — | — | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W9 | — | 0.5 | OEM-A-18 | — | — | — |
| 1 | — | — | W10 | — | 0.5 | OEM-C-15 | — | — | — |
| 1 | — | — | W11 | — | 0.5 | OEM-C-16 | — | — | — |
| 1 | — | — | W12 | — | 0.5 | MS3PROMINI-A-21 | — | — | — |
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 | MS3PROMINI-A-1 | — | — | — |
SP-GND
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W4 | — | 0.85 | OEM-A-22 | — | — | — |
| 1 | — | — | W5 | — | 0.85 | OEM-D-13 | — | — | — |
| 1 | — | — | W6 | — | 0.85 | OEM-D-26 | — | — | — |
| 1 | — | — | W7 | — | 0.85 | MS3PROMINI-A-22 | — | — | — |
| 1 | — | — | W8 | — | 0.85 | MS3PROMINI-A-23 | — | — | — |
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 | MS3PROMINI-A-2 | +5V VREF out | vref | single_source | |
| OEM-A-12 | EFI main relay (B+) | power_in | MS3PROMINI-A-1 | 12V+ switched power in | power_in | single_source | |
| OEM-A-13 | EFI main relay (B1+) | power_in | MS3PROMINI-A-1 | 12V+ switched power in | power_in | single_source | |
| OEM-A-14 | Neutral start switch (NSW) | digital_in | — | — | — | single_source | |
| OEM-A-16 | Intake air temperature (THA) | temp_in | MS3PROMINI-A-27 | IAT in | temp_in | single_source | |
| OEM-A-17 | O2 right front (OXR1) | lambda_nb_in | MS3PROMINI-A-13 | Analog in 1 | analog_in | single_source | |
| OEM-A-18 | Sensor ground (E2) | sensor_ground | MS3PROMINI-A-21 | Sensor ground | sensor_ground | single_source | |
| OEM-A-19 | Vehicle speed (SPD) | digital_in | MS3PROMINI-A-29 | Digital switched in 1 / Flex fuel | digital_in | single_source | |
| OEM-A-2 | Starter signal (STA) | digital_in | — | — | — | single_source | |
| OEM-A-20 | Diagnostic test 2 (TE2) | digital_in | — | — | — | single_source | |
| OEM-A-22 | Power ground (E1) | ground | MS3PROMINI-A-22 + MS3PROMINI-A-23 | Power ground + Power ground | ground | single_source | |
| OEM-A-4 | Throttle position (VTA1) | analog_in | MS3PROMINI-A-28 | TPS in | analog_in | single_source | |
| OEM-A-5 | Coolant temperature (THW) | temp_in | MS3PROMINI-A-26 | CLT in | temp_in | single_source | |
| OEM-A-6 | O2 left front (OXL1) | lambda_nb_in | MS3PROMINI-A-14 | Analog in 2 | analog_in | single_source | |
| OEM-A-7 | EGR temperature sensor | temp_in | — | — | — | single_source | |
| OEM-A-8 | Knock/shield (KS) | knock_in | — | — | — | single_source | |
| OEM-A-9 | Diagnostic test 1 (TE1) | digital_in | — | — | — | single_source | |
| OEM-B-11 | O2 right rear (OXR2) | lambda_nb_in | MS3PROMINI-A-15 | Analog in 3 | analog_in | single_source | |
| OEM-B-19 | Stop light switch (BK) | digital_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 | MS3PROMINI-A-16 | Analog in 4 | analog_in | single_source | |
| OEM-B-26 | Battery constant (BATT) | power_in | — | — | — | single_source | |
| OEM-B-4 | EFI main relay control (MREL) | low_side_out | MS3PROMINI-A-4 | Fuel pump out | 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 | MS3PROMINI-A-3 | PWM out 1 / Idle | low_side_out | single_source | |
| OEM-B-7 | A/C clutch relay (ACMG) | low_side_out | MS3PROMINI-A-6 | Injector out B | injector_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 | MS3PROMINI-A-35 | Digital frequency in 2 (Hall) | 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 | MS3PROMINI-A-18 | Spark out B | ignition_out | single_source | |
| OEM-C-15 | Cam sensor ground (G-) | sensor_ground | MS3PROMINI-A-21 | Sensor ground | sensor_ground | single_source | |
| OEM-C-16 | Crank sensor - (NE-) | sensor_ground | MS3PROMINI-A-21 | Sensor ground | sensor_ground | single_source | |
| OEM-C-2 | Igniter 1 feedback (IGF1) | digital_in | MS3PROMINI-A-34 | Digital frequency in 1 (Hall) | 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 | MS3PROMINI-A-17 | Spark out A | ignition_out | single_source | |
| OEM-C-6 | Cam sensor 2 + (G2+) | trigger_in | MS3PROMINI-A-33 | CMP- | trigger_in | single_source | |
| OEM-C-7 | Cam sensor 1 + (G1+) | trigger_in | MS3PROMINI-A-32 | CMP+ | trigger_in | single_source | |
| OEM-C-8 | Crank sensor + (NE+) | trigger_in | MS3PROMINI-A-30 | CKP+ | trigger_in | single_source | |
| OEM-D-11 | Injector 2&8 (#20) | injector_out | MS3PROMINI-A-11 | Injector out G | injector_out | single_source | |
| OEM-D-12 | Injector 1&7 (#10) | injector_out | MS3PROMINI-A-10 | Injector out F | injector_out | single_source | |
| OEM-D-13 | Power ground (E01) | ground | MS3PROMINI-A-22 + MS3PROMINI-A-23 | Power ground + Power ground | ground | single_source | |
| OEM-D-17 | Cold start injector 1 (STJ1) | low_side_out | MS3PROMINI-A-9 | Injector out E | injector_out | single_source | |
| OEM-D-19 | O2 heater 2 (HT2) | low_side_out | MS3PROMINI-A-7 | Injector out C | injector_out | single_source | |
| OEM-D-20 | O2 heater 1 (HT1) | low_side_out | MS3PROMINI-A-8 | Injector out D | injector_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 | MS3PROMINI-A-12 | Injector out H | injector_out | single_source | |
| OEM-D-25 | Injector 4&6 (#30) | injector_out | MS3PROMINI-A-5 | Injector out A | injector_out | single_source | |
| OEM-D-26 | Power ground (E02) | ground | MS3PROMINI-A-22 + MS3PROMINI-A-23 | Power ground + Power ground | 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 | — | — | — | single_source | |
| OEM-D-7 | ISC stepper coil 2 (ISC2) | low_side_out | — | — | — | single_source | |
| OEM-D-8 | ISC stepper coil 1 (ISC1) | 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 | MS3PROMINI-A-1 | 0.85 | no route | 12V+ switched power in | — | |
| W4 | OEM-A-22 | SP-GND-1 | 0.85 | no route | Power ground (E1) | — | |
| W5 | OEM-D-13 | SP-GND-1 | 0.85 | no route | Power ground (E01) | — | |
| W6 | OEM-D-26 | SP-GND-1 | 0.85 | no route | Power ground (E02) | — | |
| W7 | SP-GND-1 | MS3PROMINI-A-22 | 0.85 | no route | Power ground | — | |
| W8 | SP-GND-1 | MS3PROMINI-A-23 | 0.85 | no route | Power ground | — | |
| W9 | OEM-A-18 | SP-0V-1 | 0.5 | no route | Sensor ground (E2) | — | |
| W10 | OEM-C-15 | SP-0V-1 | 0.5 | no route | Cam sensor ground (G-) | — | |
| W11 | OEM-C-16 | SP-0V-1 | 0.5 | no route | Crank sensor - (NE-) | — | |
| W12 | SP-0V-1 | MS3PROMINI-A-21 | 0.5 | no route | Sensor ground | — | |
| W13 | OEM-A-11 | MS3PROMINI-A-2 | 0.5 | no route | Sensor supply +5V (VC) | — | |
| W14 | OEM-C-8 | MS3PROMINI-A-30 | 0.5 | no route | Crank sensor + (NE+) | — | |
| W15 | OEM-C-7 | MS3PROMINI-A-32 | 0.5 | no route | Cam sensor 1 + (G1+) | — | |
| W16 | OEM-C-6 | MS3PROMINI-A-33 | 0.5 | no route | Cam sensor 2 + (G2+) | — | |
| W17 | OEM-C-5 | MS3PROMINI-A-17 | 0.5 | no route | Ignition 1 (IGT1) | — | |
| W18 | OEM-C-13 | MS3PROMINI-A-18 | 0.5 | no route | Ignition 2 (IGT2) | — | |
| W19 | OEM-D-12 | MS3PROMINI-A-10 | 0.5 | no route | Injector 1&7 (#10) | — | |
| W20 | OEM-D-11 | MS3PROMINI-A-11 | 0.5 | no route | Injector 2&8 (#20) | — | |
| W21 | OEM-D-24 | MS3PROMINI-A-12 | 0.5 | no route | Injector 3&5 (#40) | — | |
| W22 | OEM-D-25 | MS3PROMINI-A-5 | 0.5 | no route | Injector 4&6 (#30) | — | |
| W23 | OEM-A-4 | MS3PROMINI-A-28 | 0.5 | no route | Throttle position (VTA1) | — | |
| W24 | OEM-A-5 | MS3PROMINI-A-26 | 0.5 | no route | Coolant temperature (THW) | — | |
| W25 | OEM-B-4 | MS3PROMINI-A-4 | 0.5 | no route | EFI main relay control (MREL) | — | |
| W26 | OEM-B-6 | MS3PROMINI-A-3 | 0.5 | no route | Fuel pump relay (FPR) | — | |
| W27 | OEM-B-7 | MS3PROMINI-A-6 | 0.5 | no route | A/C clutch relay (ACMG) | — | |
| W28 | OEM-D-19 | MS3PROMINI-A-7 | 0.5 | no route | O2 heater 2 (HT2) | — | |
| W29 | OEM-D-20 | MS3PROMINI-A-8 | 0.5 | no route | O2 heater 1 (HT1) | — | |
| W30 | OEM-D-17 | MS3PROMINI-A-9 | 0.5 | no route | Cold start injector 1 (STJ1) | — | |
| W31 | OEM-A-17 | MS3PROMINI-A-13 | 0.5 | no route | O2 right front (OXR1) | — | |
| W32 | OEM-A-6 | MS3PROMINI-A-14 | 0.5 | no route | O2 left front (OXL1) | — | |
| W33 | OEM-B-11 | MS3PROMINI-A-15 | 0.5 | no route | O2 right rear (OXR2) | — | |
| W34 | OEM-B-24 | MS3PROMINI-A-16 | 0.5 | no route | O2 left rear (OXL2) | — | |
| W35 | OEM-A-16 | MS3PROMINI-A-27 | 0.5 | no route | Intake air temperature (THA) | — | |
| W36 | OEM-C-2 | MS3PROMINI-A-34 | 0.5 | no route | Igniter 1 feedback (IGF1) | — | |
| W37 | OEM-C-10 | MS3PROMINI-A-35 | 0.5 | no route | Igniter 2 feedback (IGF2) | — | |
| W38 | OEM-A-19 | MS3PROMINI-A-29 | 0.5 | no route | Vehicle speed (SPD) | — |
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 (6)
| Severity | Code | Subject | Message |
|---|---|---|---|
| error | REQUIRED_UNMAPPED | OEM-A-1 | Required OEM function "Ignition switch (IGSW)" (digital_in) is not connected to the new ECU. |
| info | NET_FAMILY | OEM-B-7 ↔ MS3PROMINI-A-6 | OEM-B-7 "A/C clutch relay (ACMG)" [low_side_out] is wired to MS3PROMINI-A-6 "Injector out B" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-D-17 ↔ MS3PROMINI-A-9 | OEM-D-17 "Cold start injector 1 (STJ1)" [low_side_out] is wired to MS3PROMINI-A-9 "Injector out E" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-D-19 ↔ MS3PROMINI-A-7 | OEM-D-19 "O2 heater 2 (HT2)" [low_side_out] is wired to MS3PROMINI-A-7 "Injector out C" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-D-20 ↔ MS3PROMINI-A-8 | OEM-D-20 "O2 heater 1 (HT1)" [low_side_out] is wired to MS3PROMINI-A-8 "Injector out D" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | UNMAPPED | OEM | 23 optional OEM pins are not mapped: OEM-A-14 Neutral start switch (NSW); OEM-A-2 Starter signal (STA); OEM-A-20 Diagnostic test 2 (TE2); OEM-A-7 EGR temperature sensor; OEM-A-8 Knock/shield (KS); OEM-A-9 Diagnostic test 1 (TE1); OEM-B-19 Stop light switch (BK); 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); OEM-D-6 ISC stepper coil 3 (ISC3); OEM-D-7 ISC stepper coil 2 (ISC2); OEM-D-8 ISC stepper coil 1 (ISC1) |
Accepted (1)
| Code | Subject | Reason | By |
|---|---|---|---|
| REQUIRED_UNMAPPED | OEM-B-26 | 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-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); AMP EFI MS3Pro Mini has no dedicated key-on input Not wired: - OEM-B 26: Battery constant (BATT): AMP EFI MS3Pro Mini has no battery-constant input; not needed - OEM-C 3: Knock sensor 1 (KNK1): no free knock input on AMP EFI MS3Pro Mini - OEM-C 11: Knock sensor 2 (KNK2): no free knock input on AMP EFI MS3Pro Mini - OEM-A 8: Knock/shield (KS): no free knock input on AMP EFI MS3Pro Mini - OEM-D 8: ISC stepper coil 1 (ISC1): no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI MS3Pro Mini - OEM-D 7: ISC stepper coil 2 (ISC2): no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI MS3Pro Mini - OEM-D 6: ISC stepper coil 3 (ISC3): no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI MS3Pro Mini - OEM-D 5: ISC stepper coil 4 (ISC4): no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI MS3Pro Mini - OEM-B 5: Check-engine lamp (W): no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI MS3Pro Mini - OEM-B 8: Fuel pump control (FC): no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI MS3Pro Mini - OEM-D 21: EGR solenoid: no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI MS3Pro Mini - OEM-D 22: Fuel pressure-up VSV (PR): no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI MS3Pro Mini - OEM-D 4: Cold start injector (STJ): no free low_side/relay_control/heater_low_side/ls_hs/injector on AMP EFI MS3Pro Mini - OEM-A 7: EGR temperature sensor: no free thermistor/analog_0_5 on AMP EFI MS3Pro Mini - OEM-A 9: Diagnostic test 1 (TE1): no free switch_in/frequency_in/analog_0_5 on AMP EFI MS3Pro Mini - OEM-A 20: Diagnostic test 2 (TE2): no free switch_in/frequency_in/analog_0_5 on AMP EFI MS3Pro Mini - OEM-A 14: Neutral start switch (NSW): no free switch_in/frequency_in/analog_0_5 on AMP EFI MS3Pro Mini - OEM-A 2: Starter signal (STA): no free switch_in/frequency_in/analog_0_5 on AMP EFI MS3Pro Mini - OEM-B 19: Stop light switch (BK): no free switch_in/frequency_in/analog_0_5 on AMP EFI MS3Pro Mini - OEM-B 20: A/T kickdown switch (KD): no free switch_in/frequency_in/analog_0_5 on AMP EFI MS3Pro Mini - OEM-B 23: A/C request (AC): no free switch_in/frequency_in/analog_0_5 on AMP EFI MS3Pro Mini - OEM-C 1: TPS idle switch (IDL): no free switch_in/frequency_in/analog_0_5 on AMP EFI MS3Pro Mini - OEM-C 4: Check connector VF1: no free analog_out on AMP EFI MS3Pro Mini - OEM-C 12: Check connector VF2: no free analog_out on AMP EFI MS3Pro Mini
Sources
| Reliability | Kind | Title | URL | Archive | Captured | SHA-256 |
|---|---|---|---|---|---|---|
| 4 | vendor_doc | AMP EFI: MS3Pro Mini manual (fw 1.6.1) pinout & output ratings | https://cdn.shopify.com/s/files/1/0960/0014/7754/files/MS3Pro_User_Manual_Firmware_1.6.1_Mini.pdf?v=1760643335 | archive | 2026-10-05 | bed7d8ae8408 |
| 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/ | — | — | — |