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Lexus SC400 1992-97 (1UZ-FE non-VVTi) → Emtron SL4 (auto)

Lexus SC400 1992-97 (1UZ-FE non-VVTi) — Emtron — SL4
⚠ 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.

Statusdraft · not yet verified: nobody has reported building and running this harness
Open errors1: read the Findings page before cutting any wire
Size of the job52 wires · 9 connectors · 3 part lines
ToolsCrimp and extraction tools for each terminal family (see Connectors) · wire strippers · multimeter · heat gun + heat-shrink
Terminals3-1447221-4
Order of work1. 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.

WireFromToGaugeColourCutLabelCrimp ACrimp BPin APin BContinuity
W1OEM-A-12SP-14V-10.85☐☐☐☐☐☐☐
W2OEM-A-13SP-14V-10.85☐☐☐☐☐☐☐
W3SP-14V-1SL4-A-340.85☐☐☐☐☐☐☐
W4SP-14V-1SL4-B-10.85☐☐☐☐☐☐☐
W5OEM-A-22SP-GND-10.85☐☐☐☐☐☐☐
W6OEM-D-13SP-GND-10.85☐☐☐☐☐☐☐
W7OEM-D-26SP-GND-10.85☐☐☐☐☐☐☐
W8SP-GND-1SL4-B-180.85☐☐☐☐☐☐☐
W9SP-GND-1SL4-B-260.85☐☐☐☐☐☐☐
W10OEM-A-18SP-0V-10.5☐☐☐☐☐☐☐
W11OEM-C-15SP-0V-10.5☐☐☐☐☐☐☐
W12OEM-C-16SP-0V-10.5☐☐☐☐☐☐☐
W13SP-0V-1SL4-B-100.5☐☐☐☐☐☐☐
W14OEM-A-11SL4-B-20.5☐☐☐☐☐☐☐
W15OEM-C-8SL4-B-50.5☐☐☐☐☐☐☐
W16SP-0V-1SL4-B-60.5☐☐☐☐☐☐☐
W17OEM-C-7SL4-B-70.5☐☐☐☐☐☐☐
W18SP-0V-1SL4-B-80.5☐☐☐☐☐☐☐
W19OEM-C-3SL4-B-160.5☐☐☐☐☐☐☐
W20OEM-C-11SL4-B-240.5☐☐☐☐☐☐☐
W21OEM-C-5SL4-A-260.5☐☐☐☐☐☐☐
W22OEM-C-13SL4-A-270.5☐☐☐☐☐☐☐
W23OEM-D-12SL4-A-10.5☐☐☐☐☐☐☐
W24OEM-D-11SL4-A-20.5☐☐☐☐☐☐☐
W25OEM-D-24SL4-A-30.5☐☐☐☐☐☐☐
W26OEM-D-25SL4-A-40.5☐☐☐☐☐☐☐
W27OEM-A-1SL4-B-40.5☐☐☐☐☐☐☐
W28OEM-A-4SL4-B-110.5☐☐☐☐☐☐☐
W29OEM-A-5SL4-B-120.5☐☐☐☐☐☐☐
W30OEM-B-4SL4-B-30.5☐☐☐☐☐☐☐
W31OEM-B-6SL4-A-140.5☐☐☐☐☐☐☐
W32OEM-B-7SL4-A-150.5☐☐☐☐☐☐☐
W33OEM-D-19SL4-A-160.5☐☐☐☐☐☐☐
W34OEM-D-20SL4-A-170.5☐☐☐☐☐☐☐
W35OEM-D-17SL4-A-100.5☐☐☐☐☐☐☐
W36OEM-D-8SL4-A-110.5☐☐☐☐☐☐☐
W37OEM-D-7SL4-A-120.5☐☐☐☐☐☐☐
W38OEM-D-6SL4-A-130.5☐☐☐☐☐☐☐
W39OEM-A-17SL4-B-130.5☐☐☐☐☐☐☐
W40OEM-A-6SL4-B-140.5☐☐☐☐☐☐☐
W41OEM-B-11SL4-B-150.5☐☐☐☐☐☐☐
W42OEM-B-24SL4-B-190.5☐☐☐☐☐☐☐
W43OEM-A-16SL4-B-200.5☐☐☐☐☐☐☐
W44OEM-A-7SL4-B-210.5☐☐☐☐☐☐☐
W45OEM-C-2SL4-A-200.5☐☐☐☐☐☐☐
W46OEM-C-10SL4-A-210.5☐☐☐☐☐☐☐
W47OEM-A-19SL4-A-220.5☐☐☐☐☐☐☐
W48OEM-A-9SL4-A-230.5☐☐☐☐☐☐☐
W49OEM-A-20SL4-A-240.5☐☐☐☐☐☐☐
W50OEM-A-14SL4-A-250.5☐☐☐☐☐☐☐
W51OEM-A-2SL4-B-220.5☐☐☐☐☐☐☐
W52OEM-B-19SL4-B-230.5☐☐☐☐☐☐☐

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 AProbe BExpectWhyReading
1SL4-A-34SL4-B-10open (OL)+12 V supply must not touch sensor ground
2SL4-A-34SL4-B-18open (OL)+12 V supply must not touch power ground
3SL4-B-2SL4-B-10open (OL)5 V sensor reference must not touch sensor ground
4SL4-B-2SL4-B-18open (OL)5 V sensor reference must not touch power ground
5SL4-B-2SL4-A-34open (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

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Schematic

OEM-AOEM-BOEM-COEM-DSL4-ASL4-BSP-0VSP-14VSP-GND

Connectors

OEM-A

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1Ignition switch (IGSW)—W27—0.5SL4-B-4———
11Sensor supply +5V (VC)—W14—0.5SL4-B-2———
12EFI main relay (B+)—W1—0.85SP-14V-1———
13EFI main relay (B1+)—W2—0.85SP-14V-1———
14Neutral start switch (NSW)—W50—0.5SL4-A-25———
16Intake air temperature (THA)—W43—0.5SL4-B-20———
17O2 right front (OXR1)—W39—0.5SL4-B-13———
18Sensor ground (E2)—W10—0.5SP-0V-1———
19Vehicle speed (SPD)—W47—0.5SL4-A-22———
2Starter signal (STA)—W51—0.5SL4-B-22———
20Diagnostic test 2 (TE2)—W49—0.5SL4-A-24———
22Power ground (E1)—W5—0.85SP-GND-1———
4Throttle position (VTA1)—W28—0.5SL4-B-11———
5Coolant temperature (THW)—W29—0.5SL4-B-12———
6O2 left front (OXL1)—W40—0.5SL4-B-14———
7EGR temperature sensor—W44—0.5SL4-B-21———
8Knock/shield (KS)————————
9Diagnostic test 1 (TE1)—W48—0.5SL4-A-23———

OEM-B

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
11O2 right rear (OXR2)—W41—0.5SL4-B-15———
19Stop light switch (BK)—W52—0.5SL4-B-23———
20A/T kickdown switch (KD)————————
23A/C request (AC)————————
24O2 left rear (OXL2)—W42—0.5SL4-B-19———
26Battery constant (BATT)————————
4EFI main relay control (MREL)—W30—0.5SL4-B-3———
5Check-engine lamp (W)————————
6Fuel pump relay (FPR)—W31—0.5SL4-A-14———
7A/C clutch relay (ACMG)—W32—0.5SL4-A-15———
8Fuel pump control (FC)————————

OEM-C

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1TPS idle switch (IDL)————————
10Igniter 2 feedback (IGF2)—W46—0.5SL4-A-21———
11Knock sensor 2 (KNK2)—W20—0.5SL4-B-24———
12Check connector VF2————————
13Ignition 2 (IGT2)—W22—0.5SL4-A-27———
15Cam sensor ground (G-)—W11—0.5SP-0V-1———
16Crank sensor - (NE-)—W12—0.5SP-0V-1———
2Igniter 1 feedback (IGF1)—W45—0.5SL4-A-20———
3Knock sensor 1 (KNK1)—W19—0.5SL4-B-16———
4Check connector VF1————————
5Ignition 1 (IGT1)—W21—0.5SL4-A-26———
6Cam sensor 2 + (G2+)————————
7Cam sensor 1 + (G1+)—W17—0.5SL4-B-7———
8Crank sensor + (NE+)—W15—0.5SL4-B-5———

OEM-D

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
11Injector 2&8 (#20)—W24—0.5SL4-A-2———
12Injector 1&7 (#10)—W23—0.5SL4-A-1———
13Power ground (E01)—W6—0.85SP-GND-1———
17Cold start injector 1 (STJ1)—W35—0.5SL4-A-10———
19O2 heater 2 (HT2)—W33—0.5SL4-A-16———
20O2 heater 1 (HT1)—W34—0.5SL4-A-17———
21EGR solenoid————————
22Fuel pressure-up VSV (PR)————————
24Injector 3&5 (#40)—W25—0.5SL4-A-3———
25Injector 4&6 (#30)—W26—0.5SL4-A-4———
26Power ground (E02)—W7—0.85SP-GND-1———
4Cold start injector (STJ)————————
5ISC stepper coil 4 (ISC4)————————
6ISC stepper coil 3 (ISC3)—W38—0.5SL4-A-13———
7ISC stepper coil 2 (ISC2)—W37—0.5SL4-A-12———
8ISC stepper coil 1 (ISC1)—W36—0.5SL4-A-11———

SL4-A

Mating face
SL4-A-1 · Injection channel 11SL4-A-2 · Injection channel 22SL4-A-3 · Injection channel 33SL4-A-4 · Injection channel 44SL4-A-5 · NC5SL4-A-6 · NC6SL4-A-7 · NC7SL4-A-8 · NC8SL4-A-9 · Sensor supply 8V9SL4-A-10 · Auxiliary output 110SL4-A-11 · Auxiliary output 211SL4-A-12 · Auxiliary output 312SL4-A-13 · Auxiliary output 413SL4-A-14 · Auxiliary output 514SL4-A-15 · Auxiliary output 615SL4-A-16 · Auxiliary output 716SL4-A-17 · Auxiliary output 817SL4-A-18 · Auxiliary output 918SL4-A-19 · Auxiliary output 1019SL4-A-20 · Digital input 120SL4-A-21 · Digital input 221SL4-A-22 · Digital input 322SL4-A-23 · Digital input 423SL4-A-24 · Digital input 524SL4-A-25 · Digital input 625SL4-A-26 · Ignition channel 126SL4-A-27 · Ignition channel 227SL4-A-28 · Ignition channel 328SL4-A-29 · Ignition channel 429SL4-A-30 · NC30SL4-A-31 · NC31SL4-A-32 · NC32SL4-A-33 · NC33SL4-A-34 · Aux 9–10 14V supply34
Wire side
SL4-A-1 · Injection channel 11SL4-A-2 · Injection channel 22SL4-A-3 · Injection channel 33SL4-A-4 · Injection channel 44SL4-A-5 · NC5SL4-A-6 · NC6SL4-A-7 · NC7SL4-A-8 · NC8SL4-A-9 · Sensor supply 8V9SL4-A-10 · Auxiliary output 110SL4-A-11 · Auxiliary output 211SL4-A-12 · Auxiliary output 312SL4-A-13 · Auxiliary output 413SL4-A-14 · Auxiliary output 514SL4-A-15 · Auxiliary output 615SL4-A-16 · Auxiliary output 716SL4-A-17 · Auxiliary output 817SL4-A-18 · Auxiliary output 918SL4-A-19 · Auxiliary output 1019SL4-A-20 · Digital input 120SL4-A-21 · Digital input 221SL4-A-22 · Digital input 322SL4-A-23 · Digital input 423SL4-A-24 · Digital input 524SL4-A-25 · Digital input 625SL4-A-26 · Ignition channel 126SL4-A-27 · Ignition channel 227SL4-A-28 · Ignition channel 328SL4-A-29 · Ignition channel 429SL4-A-30 · NC30SL4-A-31 · NC31SL4-A-32 · NC32SL4-A-33 · NC33SL4-A-34 · Aux 9–10 14V supply34
CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1Injection channel 1—W23—0.5OEM-D-12———
2Injection channel 2—W24—0.5OEM-D-11———
3Injection channel 3—W25—0.5OEM-D-24———
4Injection channel 4—W26—0.5OEM-D-25———
5NC————————
6NC————————
7NC————————
8NC————————
9Sensor supply 8V————————
10Auxiliary output 1—W35—0.5OEM-D-17———
11Auxiliary output 2—W36—0.5OEM-D-8———
12Auxiliary output 3—W37—0.5OEM-D-7———
13Auxiliary output 4—W38—0.5OEM-D-6———
14Auxiliary output 5—W31—0.5OEM-B-6———
15Auxiliary output 6—W32—0.5OEM-B-7———
16Auxiliary output 7—W33—0.5OEM-D-19———
17Auxiliary output 8—W34—0.5OEM-D-20———
18Auxiliary output 9————————
19Auxiliary output 10————————
20Digital input 1—W45—0.5OEM-C-2———
21Digital input 2—W46—0.5OEM-C-10———
22Digital input 3—W47—0.5OEM-A-19———
23Digital input 4—W48—0.5OEM-A-9———
24Digital input 5—W49—0.5OEM-A-20———
25Digital input 6—W50—0.5OEM-A-14———
26Ignition channel 1—W21—0.5OEM-C-5———
27Ignition channel 2—W22—0.5OEM-C-13———
28Ignition channel 3————————
29Ignition channel 4————————
30NC————————
31NC————————
32NC————————
33NC————————
34Aux 9–10 14V supply—W3—0.85SP-14V-1———

SL4-B

Mating face
SL4-B-1 · ECU 14V supply1SL4-B-2 · Sensor supply Vref1 5.0V2SL4-B-3 · EFI relay output (low side, 200 mA)3SL4-B-4 · Ignition switch input4SL4-B-5 · Crank index sensor +5SL4-B-6 · Crank index sensor −6SL4-B-7 · Sync sensor +7SL4-B-8 · Sync sensor −8SL4-B-9 · Shield (crank/sync/knock)9SL4-B-10 · Analog sensor 0V reference10SL4-B-11 · Analog input 111SL4-B-12 · Analog input 212SL4-B-13 · Analog input 313SL4-B-14 · Analog input 414SL4-B-15 · Analog input 515SL4-B-16 · Knock 1 +16SL4-B-17 · Knock 1 −17SL4-B-18 · ECU ground18SL4-B-19 · Analog input 619SL4-B-20 · Analog input 7 (switchable 1k pull-up)20SL4-B-21 · Analog input 8 (switchable 1k pull-up)21SL4-B-22 · Analog input 9 (switchable 1k pull-up)22SL4-B-23 · Analog input 10 (switchable 1k pull-up)23SL4-B-24 · Knock 2 +24SL4-B-25 · Knock 2 −25SL4-B-26 · ECU ground26SL4-B-27 · CAN 1 H27SL4-B-28 · CAN 1 L28SL4-B-29 · NC29SL4-B-30 · NC30SL4-B-31 · Ethernet Tx +31SL4-B-32 · Ethernet Tx −32SL4-B-33 · Ethernet Rx +33SL4-B-34 · Ethernet Rx −34
Wire side
SL4-B-1 · ECU 14V supply1SL4-B-2 · Sensor supply Vref1 5.0V2SL4-B-3 · EFI relay output (low side, 200 mA)3SL4-B-4 · Ignition switch input4SL4-B-5 · Crank index sensor +5SL4-B-6 · Crank index sensor −6SL4-B-7 · Sync sensor +7SL4-B-8 · Sync sensor −8SL4-B-9 · Shield (crank/sync/knock)9SL4-B-10 · Analog sensor 0V reference10SL4-B-11 · Analog input 111SL4-B-12 · Analog input 212SL4-B-13 · Analog input 313SL4-B-14 · Analog input 414SL4-B-15 · Analog input 515SL4-B-16 · Knock 1 +16SL4-B-17 · Knock 1 −17SL4-B-18 · ECU ground18SL4-B-19 · Analog input 619SL4-B-20 · Analog input 7 (switchable 1k pull-up)20SL4-B-21 · Analog input 8 (switchable 1k pull-up)21SL4-B-22 · Analog input 9 (switchable 1k pull-up)22SL4-B-23 · Analog input 10 (switchable 1k pull-up)23SL4-B-24 · Knock 2 +24SL4-B-25 · Knock 2 −25SL4-B-26 · ECU ground26SL4-B-27 · CAN 1 H27SL4-B-28 · CAN 1 L28SL4-B-29 · NC29SL4-B-30 · NC30SL4-B-31 · Ethernet Tx +31SL4-B-32 · Ethernet Tx −32SL4-B-33 · Ethernet Rx +33SL4-B-34 · Ethernet Rx −34
CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1ECU 14V supply—W4—0.85SP-14V-1———
2Sensor supply Vref1 5.0V—W14—0.5OEM-A-11———
3EFI relay output (low side, 200 mA)—W30—0.5OEM-B-4———
4Ignition switch input—W27—0.5OEM-A-1———
5Crank index sensor +—W15—0.5OEM-C-8———
6Crank index sensor −—W16—0.5SP-0V-1———
7Sync sensor +—W17—0.5OEM-C-7———
8Sync sensor −—W18—0.5SP-0V-1———
9Shield (crank/sync/knock)————————
10Analog sensor 0V reference—W13—0.5SP-0V-1———
11Analog input 1—W28—0.5OEM-A-4———
12Analog input 2—W29—0.5OEM-A-5———
13Analog input 3—W39—0.5OEM-A-17———
14Analog input 4—W40—0.5OEM-A-6———
15Analog input 5—W41—0.5OEM-B-11———
16Knock 1 +—W19—0.5OEM-C-3———
17Knock 1 −————————
18ECU ground—W8—0.85SP-GND-1———
19Analog input 6—W42—0.5OEM-B-24———
20Analog input 7 (switchable 1k pull-up)—W43—0.5OEM-A-16———
21Analog input 8 (switchable 1k pull-up)—W44—0.5OEM-A-7———
22Analog input 9 (switchable 1k pull-up)—W51—0.5OEM-A-2———
23Analog input 10 (switchable 1k pull-up)—W52—0.5OEM-B-19———
24Knock 2 +—W20—0.5OEM-C-11———
25Knock 2 −————————
26ECU ground—W9—0.85SP-GND-1———
27CAN 1 H————————
28CAN 1 L————————
29NC————————
30NC————————
31Ethernet Tx +————————
32Ethernet Tx −————————
33Ethernet Rx +————————
34Ethernet Rx −————————

SP-0V

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W10—0.5OEM-A-18———
1——W11—0.5OEM-C-15———
1——W12—0.5OEM-C-16———
1——W13—0.5SL4-B-10———
1——W16—0.5SL4-B-6———
1——W18—0.5SL4-B-8———

SP-14V

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W1—0.85OEM-A-12———
1——W2—0.85OEM-A-13———
1——W3—0.85SL4-A-34———
1——W4—0.85SL4-B-1———

SP-GND

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W5—0.85OEM-A-22———
1——W6—0.85OEM-D-13———
1——W7—0.85OEM-D-26———
1——W8—0.85SL4-B-18———
1——W9—0.85SL4-B-26———

Pin map

OEM pointOEM functionOEM familyTarget pointTarget functionTarget familyWire colourEvidence
OEM-A-1Ignition switch (IGSW)digital_inSL4-B-4Ignition switch inputdigital_insingle_source
OEM-A-11Sensor supply +5V (VC)vrefSL4-B-2Sensor supply Vref1 5.0Vvrefsingle_source
OEM-A-12EFI main relay (B+)power_inSL4-A-34 + SL4-B-1Aux 9–10 14V supply + ECU 14V supplypower_insingle_source
OEM-A-13EFI main relay (B1+)power_inSL4-A-34 + SL4-B-1Aux 9–10 14V supply + ECU 14V supplypower_insingle_source
OEM-A-14Neutral start switch (NSW)digital_inSL4-A-25Digital input 6digital_insingle_source
OEM-A-16Intake air temperature (THA)temp_inSL4-B-20Analog input 7 (switchable 1k pull-up)analog_insingle_source
OEM-A-17O2 right front (OXR1)lambda_nb_inSL4-B-13Analog input 3analog_insingle_source
OEM-A-18Sensor ground (E2)sensor_groundSL4-B-10 + SL4-B-6 + SL4-B-8Analog sensor 0V reference + Crank index sensor − + Sync sensor −sensor_ground + trigger_insingle_source
OEM-A-19Vehicle speed (SPD)digital_inSL4-A-22Digital input 3digital_insingle_source
OEM-A-2Starter signal (STA)digital_inSL4-B-22Analog input 9 (switchable 1k pull-up)analog_insingle_source
OEM-A-20Diagnostic test 2 (TE2)digital_inSL4-A-24Digital input 5digital_insingle_source
OEM-A-22Power ground (E1)groundSL4-B-18 + SL4-B-26ECU ground + ECU groundgroundsingle_source
OEM-A-4Throttle position (VTA1)analog_inSL4-B-11Analog input 1analog_insingle_source
OEM-A-5Coolant temperature (THW)temp_inSL4-B-12Analog input 2analog_insingle_source
OEM-A-6O2 left front (OXL1)lambda_nb_inSL4-B-14Analog input 4analog_insingle_source
OEM-A-7EGR temperature sensortemp_inSL4-B-21Analog input 8 (switchable 1k pull-up)analog_insingle_source
OEM-A-8Knock/shield (KS)knock_in———single_source
OEM-A-9Diagnostic test 1 (TE1)digital_inSL4-A-23Digital input 4digital_insingle_source
OEM-B-11O2 right rear (OXR2)lambda_nb_inSL4-B-15Analog input 5analog_insingle_source
OEM-B-19Stop light switch (BK)digital_inSL4-B-23Analog input 10 (switchable 1k pull-up)analog_insingle_source
OEM-B-20A/T kickdown switch (KD)digital_in———single_source
OEM-B-23A/C request (AC)digital_in———single_source
OEM-B-24O2 left rear (OXL2)lambda_nb_inSL4-B-19Analog input 6analog_insingle_source
OEM-B-26Battery constant (BATT)power_in———single_source
OEM-B-4EFI main relay control (MREL)low_side_outSL4-B-3EFI relay output (low side, 200 mA)low_side_outsingle_source
OEM-B-5Check-engine lamp (W)low_side_out———single_source
OEM-B-6Fuel pump relay (FPR)low_side_outSL4-A-14Auxiliary output 5switch_outsingle_source
OEM-B-7A/C clutch relay (ACMG)low_side_outSL4-A-15Auxiliary output 6switch_outsingle_source
OEM-B-8Fuel pump control (FC)low_side_out———single_source
OEM-C-1TPS idle switch (IDL)digital_in———single_source
OEM-C-10Igniter 2 feedback (IGF2)digital_inSL4-A-21Digital input 2digital_insingle_source
OEM-C-11Knock sensor 2 (KNK2)knock_inSL4-B-24Knock 2 +knock_insingle_source
OEM-C-12Check connector VF2analog_out———single_source
OEM-C-13Ignition 2 (IGT2)ignition_outSL4-A-27Ignition channel 2ignition_outsingle_source
OEM-C-15Cam sensor ground (G-)sensor_groundSL4-B-10 + SL4-B-6 + SL4-B-8Analog sensor 0V reference + Crank index sensor − + Sync sensor −sensor_ground + trigger_insingle_source
OEM-C-16Crank sensor - (NE-)sensor_groundSL4-B-10 + SL4-B-6 + SL4-B-8Analog sensor 0V reference + Crank index sensor − + Sync sensor −sensor_ground + trigger_insingle_source
OEM-C-2Igniter 1 feedback (IGF1)digital_inSL4-A-20Digital input 1digital_insingle_source
OEM-C-3Knock sensor 1 (KNK1)knock_inSL4-B-16Knock 1 +knock_insingle_source
OEM-C-4Check connector VF1analog_out———single_source
OEM-C-5Ignition 1 (IGT1)ignition_outSL4-A-26Ignition channel 1ignition_outsingle_source
OEM-C-6Cam sensor 2 + (G2+)trigger_in———single_source
OEM-C-7Cam sensor 1 + (G1+)trigger_inSL4-B-7Sync sensor +trigger_insingle_source
OEM-C-8Crank sensor + (NE+)trigger_inSL4-B-5Crank index sensor +trigger_insingle_source
OEM-D-11Injector 2&8 (#20)injector_outSL4-A-2Injection channel 2injector_outsingle_source
OEM-D-12Injector 1&7 (#10)injector_outSL4-A-1Injection channel 1injector_outsingle_source
OEM-D-13Power ground (E01)groundSL4-B-18 + SL4-B-26ECU ground + ECU groundgroundsingle_source
OEM-D-17Cold start injector 1 (STJ1)low_side_outSL4-A-10Auxiliary output 1switch_outsingle_source
OEM-D-19O2 heater 2 (HT2)low_side_outSL4-A-16Auxiliary output 7switch_outsingle_source
OEM-D-20O2 heater 1 (HT1)low_side_outSL4-A-17Auxiliary output 8switch_outsingle_source
OEM-D-21EGR solenoidlow_side_out———single_source
OEM-D-22Fuel pressure-up VSV (PR)low_side_out———single_source
OEM-D-24Injector 3&5 (#40)injector_outSL4-A-3Injection channel 3injector_outsingle_source
OEM-D-25Injector 4&6 (#30)injector_outSL4-A-4Injection channel 4injector_outsingle_source
OEM-D-26Power ground (E02)groundSL4-B-18 + SL4-B-26ECU ground + ECU groundgroundsingle_source
OEM-D-4Cold start injector (STJ)low_side_out———single_source
OEM-D-5ISC stepper coil 4 (ISC4)low_side_out———single_source
OEM-D-6ISC stepper coil 3 (ISC3)low_side_outSL4-A-13Auxiliary output 4switch_outsingle_source
OEM-D-7ISC stepper coil 2 (ISC2)low_side_outSL4-A-12Auxiliary output 3switch_outsingle_source
OEM-D-8ISC stepper coil 1 (ISC1)low_side_outSL4-A-11Auxiliary output 2switch_outsingle_source

Cut list

WireFromToGauge (mm²)ColourLengthSignalIdent
W1OEM-A-12SP-14V-10.85no routeEFI main relay (B+)—
W2OEM-A-13SP-14V-10.85no routeEFI main relay (B1+)—
W3SP-14V-1SL4-A-340.85no routeAux 9–10 14V supply—
W4SP-14V-1SL4-B-10.85no routeECU 14V supply—
W5OEM-A-22SP-GND-10.85no routePower ground (E1)—
W6OEM-D-13SP-GND-10.85no routePower ground (E01)—
W7OEM-D-26SP-GND-10.85no routePower ground (E02)—
W8SP-GND-1SL4-B-180.85no routeECU ground—
W9SP-GND-1SL4-B-260.85no routeECU ground—
W10OEM-A-18SP-0V-10.5no routeSensor ground (E2)—
W11OEM-C-15SP-0V-10.5no routeCam sensor ground (G-)—
W12OEM-C-16SP-0V-10.5no routeCrank sensor - (NE-)—
W13SP-0V-1SL4-B-100.5no routeAnalog sensor 0V reference—
W14OEM-A-11SL4-B-20.5no routeSensor supply +5V (VC)—
W15OEM-C-8SL4-B-50.5no routeCrank sensor + (NE+)—
W16SP-0V-1SL4-B-60.5no routeCrank index sensor −—
W17OEM-C-7SL4-B-70.5no routeCam sensor 1 + (G1+)—
W18SP-0V-1SL4-B-80.5no routeSync sensor −—
W19OEM-C-3SL4-B-160.5no routeKnock sensor 1 (KNK1)—
W20OEM-C-11SL4-B-240.5no routeKnock sensor 2 (KNK2)—
W21OEM-C-5SL4-A-260.5no routeIgnition 1 (IGT1)—
W22OEM-C-13SL4-A-270.5no routeIgnition 2 (IGT2)—
W23OEM-D-12SL4-A-10.5no routeInjector 1&7 (#10)—
W24OEM-D-11SL4-A-20.5no routeInjector 2&8 (#20)—
W25OEM-D-24SL4-A-30.5no routeInjector 3&5 (#40)—
W26OEM-D-25SL4-A-40.5no routeInjector 4&6 (#30)—
W27OEM-A-1SL4-B-40.5no routeIgnition switch (IGSW)—
W28OEM-A-4SL4-B-110.5no routeThrottle position (VTA1)—
W29OEM-A-5SL4-B-120.5no routeCoolant temperature (THW)—
W30OEM-B-4SL4-B-30.5no routeEFI main relay control (MREL)—
W31OEM-B-6SL4-A-140.5no routeFuel pump relay (FPR)—
W32OEM-B-7SL4-A-150.5no routeA/C clutch relay (ACMG)—
W33OEM-D-19SL4-A-160.5no routeO2 heater 2 (HT2)—
W34OEM-D-20SL4-A-170.5no routeO2 heater 1 (HT1)—
W35OEM-D-17SL4-A-100.5no routeCold start injector 1 (STJ1)—
W36OEM-D-8SL4-A-110.5no routeISC stepper coil 1 (ISC1)—
W37OEM-D-7SL4-A-120.5no routeISC stepper coil 2 (ISC2)—
W38OEM-D-6SL4-A-130.5no routeISC stepper coil 3 (ISC3)—
W39OEM-A-17SL4-B-130.5no routeO2 right front (OXR1)—
W40OEM-A-6SL4-B-140.5no routeO2 left front (OXL1)—
W41OEM-B-11SL4-B-150.5no routeO2 right rear (OXR2)—
W42OEM-B-24SL4-B-190.5no routeO2 left rear (OXL2)—
W43OEM-A-16SL4-B-200.5no routeIntake air temperature (THA)—
W44OEM-A-7SL4-B-210.5no routeEGR temperature sensor—
W45OEM-C-2SL4-A-200.5no routeIgniter 1 feedback (IGF1)—
W46OEM-C-10SL4-A-210.5no routeIgniter 2 feedback (IGF2)—
W47OEM-A-19SL4-A-220.5no routeVehicle speed (SPD)—
W48OEM-A-9SL4-A-230.5no routeDiagnostic test 1 (TE1)—
W49OEM-A-20SL4-A-240.5no routeDiagnostic test 2 (TE2)—
W50OEM-A-14SL4-A-250.5no routeNeutral start switch (NSW)—
W51OEM-A-2SL4-B-220.5no routeStarter signal (STA)—
W52OEM-B-19SL4-B-230.5no routeStop light switch (BK)—

Bill of materials

CategoryPart numberManufacturerDescriptionQtyUnit
connector4-1437290-0TESuperseal 1.0 34-way plug, Key 11.000ea
connector4-1437290-1TESuperseal 1.0 34-way plug, Key 21.000ea
terminal3-1447221-4TESuperseal 1.0 socket terminal, 20 AWG (0.5 sq mm)44.000ea

ECU setup sheet

RoleEngine refEngine signalSensorECU pointECU functionECU classSetup flag
No configured channels.

Findings

Open (16)

SeverityCodeSubjectMessage
errorREQUIRED_UNMAPPEDOEM-C-6Required OEM function "Cam sensor 2 + (G2+)" (trigger_in) is not connected to the new ECU.
warnNET_FAMILYOEM-A-2 ↔ SL4-B-22OEM-A-2 "Starter signal (STA)" [digital_in] is wired to SL4-B-22 "Analog input 9 (switchable 1k pull-up)" [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.
warnNET_FAMILYOEM-B-19 ↔ SL4-B-23OEM-B-19 "Stop light switch (BK)" [digital_in] is wired to SL4-B-23 "Analog input 10 (switchable 1k pull-up)" [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.
infoNET_FAMILYOEM-A-16 ↔ SL4-B-20OEM-A-16 "Intake air temperature (THA)" [temp_in] is wired to SL4-B-20 "Analog input 7 (switchable 1k pull-up)" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one.
infoNET_FAMILYOEM-A-5 ↔ SL4-B-12OEM-A-5 "Coolant temperature (THW)" [temp_in] is wired to SL4-B-12 "Analog input 2" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one.
infoNET_FAMILYOEM-A-7 ↔ SL4-B-21OEM-A-7 "EGR temperature sensor" [temp_in] is wired to SL4-B-21 "Analog input 8 (switchable 1k pull-up)" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one.
infoNET_FAMILYOEM-B-6 ↔ SL4-A-14OEM-B-6 "Fuel pump relay (FPR)" [low_side_out] is wired to SL4-A-14 "Auxiliary output 5" [switch_out]. Configure this output as low side.
infoNET_FAMILYOEM-B-7 ↔ SL4-A-15OEM-B-7 "A/C clutch relay (ACMG)" [low_side_out] is wired to SL4-A-15 "Auxiliary output 6" [switch_out]. Configure this output as low side.
infoNET_FAMILYOEM-C-16 ↔ SL4-B-6OEM-C-16 "Crank sensor - (NE-)" [sensor_ground] is wired to SL4-B-6 "Crank index sensor −" [trigger_in]. Trigger return tied to sensor/trigger ground: correct for single-ended trigger inputs.
infoNET_FAMILYOEM-D-17 ↔ SL4-A-10OEM-D-17 "Cold start injector 1 (STJ1)" [low_side_out] is wired to SL4-A-10 "Auxiliary output 1" [switch_out]. Configure this output as low side.
infoNET_FAMILYOEM-D-19 ↔ SL4-A-16OEM-D-19 "O2 heater 2 (HT2)" [low_side_out] is wired to SL4-A-16 "Auxiliary output 7" [switch_out]. Configure this output as low side.
infoNET_FAMILYOEM-D-20 ↔ SL4-A-17OEM-D-20 "O2 heater 1 (HT1)" [low_side_out] is wired to SL4-A-17 "Auxiliary output 8" [switch_out]. Configure this output as low side.
infoNET_FAMILYOEM-D-6 ↔ SL4-A-13OEM-D-6 "ISC stepper coil 3 (ISC3)" [low_side_out] is wired to SL4-A-13 "Auxiliary output 4" [switch_out]. Configure this output as low side.
infoNET_FAMILYOEM-D-7 ↔ SL4-A-12OEM-D-7 "ISC stepper coil 2 (ISC2)" [low_side_out] is wired to SL4-A-12 "Auxiliary output 3" [switch_out]. Configure this output as low side.
infoNET_FAMILYOEM-D-8 ↔ SL4-A-11OEM-D-8 "ISC stepper coil 1 (ISC1)" [low_side_out] is wired to SL4-A-11 "Auxiliary output 2" [switch_out]. Configure this output as low side.
infoUNMAPPEDOEM12 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-12 Check connector VF2; 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 (1)

CodeSubjectReasonBy
REQUIRED_UNMAPPEDOEM-B-26Battery-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-C 6: Cam sensor 2 + (G2+): no free cam_vr/cam_hall/frequency_in input on Emtron SL4 Not wired: - OEM-B 26: Battery constant (BATT): Emtron SL4 has no battery-constant input; not needed - SL4-B 17: Knock 1 − left open: the stock knock sensor has one ECU wire; check the ECU manual for single-wire knock sensors - SL4-B 25: Knock 2 − left open: the stock knock sensor has one ECU wire; check the ECU manual for single-wire knock sensors - OEM-A 8: Knock/shield (KS): no free knock input on Emtron SL4 - OEM-D 5: ISC stepper coil 4 (ISC4): no free low_side/relay_control/heater_low_side/ls_hs/injector on Emtron SL4 - OEM-B 5: Check-engine lamp (W): no free low_side/relay_control/heater_low_side/ls_hs/injector on Emtron SL4 - OEM-B 8: Fuel pump control (FC): no free low_side/relay_control/heater_low_side/ls_hs/injector on Emtron SL4 - OEM-D 21: EGR solenoid: no free low_side/relay_control/heater_low_side/ls_hs/injector on Emtron SL4 - OEM-D 22: Fuel pressure-up VSV (PR): no free low_side/relay_control/heater_low_side/ls_hs/injector on Emtron SL4 - OEM-D 4: Cold start injector (STJ): no free low_side/relay_control/heater_low_side/ls_hs/injector on Emtron SL4 - OEM-B 20: A/T kickdown switch (KD): no free switch_in/frequency_in/analog_0_5 on Emtron SL4 - OEM-B 23: A/C request (AC): no free switch_in/frequency_in/analog_0_5 on Emtron SL4 - OEM-C 1: TPS idle switch (IDL): no free switch_in/frequency_in/analog_0_5 on Emtron SL4 - OEM-C 4: Check connector VF1: no free analog_out on Emtron SL4 - OEM-C 12: Check connector VF2: no free analog_out on Emtron SL4

Sources

ReliabilityKindTitleURLArchiveCapturedSHA-256
4vendor_docEmtron SL4/SL6/SL8 ECU datasheetshttps://docs.emtronaustralia.com.au/engine-management/datasheets/index.htmlarchive2026-10-051e22846cec94
4vendor_docEmtron SL4/SL6/SL8 pinout pageshttps://docs.emtronaustralia.com.au/engine-management/wiring/index.htmlarchive2026-10-05e52b3da9996a
2community_copyLextreme: 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/———