Compared to the outgoing LS 400 model, the new LS 430 sedan, introduced in 2000, was redesigned by nearly 90 percent across all components. The vehicle’s exterior styling became more expressive and distinct from the segment benchmark, the Mercedes-Benz S-Class. Although overall body length remained the same, the vehicle was taller, with an extended wheelbase and a shortened rear overhang. The chassis was tuned for tighter, more responsive handling. The new engine displacement was increased from 4.0 to 4.3 liters, delivering significantly higher torque while meeting the most stringent European emissions standards.
This article details the fuse and relay box diagrams for third-generation Lexus LS 430 (chassis code UCF30) models produced from 2000 through 2006.
Engine Compartment
Component Locations : 1. Fuse Block No. 1, 2. Relay Block No. 1, 3. Engine and Transmission Control Module (ECM/TCM), 4. Left Headlight ECU, 5. Headlight Washer Relay, 6. Cooling Fan ECU, 7. Right Headlight ECU, 8. Fuse Block No. 2, 9. 2003–2006 : ABS Control Module, 10. Relay Block No. 2
| Engine Compartment Main Fuse Block Specifications (#1 in Diagram) | ||
|---|---|---|
Example shown. |
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Fuse box diagram. |
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| No. | Protected Circuit / Function | Rating (A) |
| 1 | Right Headlight (Low Beam) | 15 |
| 2 | Left Headlight (Low Beam) | 15 |
| 3 | Sequential Multiport Fuel Injection (SFI) / Engine Control System | 7.5 |
| 4 | 7.5 | |
| 5 | 10 | |
| 6 | 7.5 | |
| 7 |
|
7.5 |
| 8 | Air Conditioning System (A/C) | 7.5 |
| 9 | Windshield Wipers | 30 |
| 10 | Front Fog Lights | 15 |
| 11 | Windshield Washers | 20 |
| 12 | Parking Lights, Tail Lights | 7.5 |
| 13 | Headlight Washers | 30 |
| 14 | 2000–2003 : Sequential Multiport Fuel Injection (SFI) system | 30 |
| 2003–2006 : Sequential Multiport Fuel Injection (SFI) system | 25 | |
| 2004–2006 : Sequential Multiport Fuel Injection (SFI) system | 20 | |
| 15 | Horns | 10 |
| 16 | Sequential Multiport Fuel Injection (SFI) system | 10 |
| 17 | Headlights (High Beam) | 20 |
| Relays | ||
| R1 | Ignition System (IG1) | |
| R2 | Circuit Opening / Fuel Pump (C/OPN) | |
| R3 | Fuel Pump (F/PMP) | |
| R4 | Ignition System (IG2) | |
| R5 | A/C Compressor Magnetic Clutch (A/C COMP) | |
| R6 | Engine Control Module (EFI MAIN) | |
| R7 | Headlights (HEAD LP) | |
| Engine Compartment Secondary Fuse Block Specifications (#8 in Diagram) | ||
|---|---|---|
General view. |
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Diagram. |
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| No. | Protected Circuit / Function | Rating (A) |
| 1 | 2000–2003: Fuses: “RR SEAT RH”, “RR SEAT LH”, “S/ROOF”, “AMP”, “RR IG”, “RR ECU-B”, “PP/SEAT”, “RR S/HTR”, “RR S/SHADE”, “RR A/C”, “RR ACC”, “FUEL OPN”, “LCE LP”, parking lights, brake lights | 50 |
| 2003–2006: 200 W Cooling Fan, Fuses: “RR SEAT RH”, “RR SEAT LH”, “S/ROOF”, “AMP”, “RR IG”, “RR ECU-B”, “PP/SEAT”, “RR S/HTR”, “RR S/SHADE”, “RR A/C”, “RR ACC”, “FUEL OPN”, “LCE LP”, parking lights, brake lights | ||
| 2 | 2000–2003: Anti-lock Brake System (ABS) | 40 |
| 2003–2006: Anti-lock Brake System (ABS) | 50 | |
| 3 | Climate Control Blower / Heater | 50 |
| 4 | 2000–2003: Anti-lock Brake System (ABS) | 40 |
| 2003–2006: Anti-lock Brake System (ABS) | 30 | |
| 5 | Rear Window Defogger | 40 |
| 6 | Electronically Controlled Air Suspension | 40 |
| 7 | 2000–2003: Anti-lock Brake System (ABS) | 50 |
| 2003–2006: 100 W Cooling Fan | ||
| 8 | Fuses: “FR FOG”, “TAIL”, “WASHER”, “FR IG”, “WIP”, “H-LP CRN”, “A/C IG” | 60 |
| 9 | 200 W Cooling Fan | 80 |
| 2003–2006: 100 W Fan, Fuses: “RR SEAT RH”, “RR SEAT LH”, “S/ROOF”, “AMP”, “RR IG”, “RR ECU-B”, “PP/SEAT”, “RR S/HTR”, “RR S/SHADE”, “RR A/C”, “RR ACC”, “FUEL OPN”, “LCE LP”, parking lights, brake lights | 60 | |
| 10 | Fuses: “TI & TE”, “DP/SEAT”, “A/C”, “OBD”, “STOP”, “AM1”, “MPX-IG”, “ABS-IG”, “GAUGE”, “AIRSUS”, “DS/HTR”, “SECURITY”, “PANEL”, “DB/ANC”, “POWER OUTLET”, “D-CIG”, “D RR-IG”, “D-ACC” | 80 |
| 11 | Alternator / Generator | 140 |
| 12 | Fuses: “RR DOOR RH”, “RR DOOR LH”, “D DOOR”, “H-LP LVL”, “P DOOR”, “PS/HTR”, “P-IG”, “P-ACC”, “PB/ANC”, “P-CIG”, “TEL”, “P RR-IG” | 80 |
| 13 | Fuses: “RADIO NO.1”, “AM2”, “HAZ”, “STR LOCK” | 30 |
| 14 | Starting System | 30 |
| 15 | Fuses: “DOME”, “MPX-B1”, “MPX-B3” | 20 |
| 16 | Charging System | 5 |
| 17 | Spare Fuses | - |
| 18 | - | |
| 19 | - | |
| 20 | - | |
| Relays | ||
| R1 | Starter Relay | |
| R2 | Air Suspension Relay (AIR SUS) | |
| R3 | Cooling Fan Relay (FAN) | |
| Relay Box No. 1 (#2 in Diagram) | |
|---|---|
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| No. | Function / Component |
| R1 | Rear Window Defogger Relay |
| R2 | Unused |
| Relay Box No. 2 (#10 in Diagram Above) | |
|---|---|
|
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| No. | Protected Circuit / Function |
| 1 | 2000–2003: ABS System (7.5 A) |
| R1 | Unused |
| R2 | ABS Pump Motor Relay (ABS MTR) |
| R3 | ABS Solenoid Relay (ABS SOL) |
Passenger Compartment
Component Locations : 1. Driver-side Fuse Box, 2. 2000–2003 : ABS Control Module – 2003–2006 : Air Suspension ECU, 3. Gateway ECU, 4. Tilt & Telescopic Steering Column ECU, 5. Steering Lock Control Module, 6. Transponder Key ECU, 7. Theft Deterrent ECU, 8. Air Conditioning ECU, 9. 2003–2006 : Progressive Power Steering (PPS) ECU, 10. 2004–2006 : Radar Cruise Control / Distance Control ECU, 11. 2003–2006 : Adaptive Front-lighting System (AFS) ECU, 12. 2000–2003 : Automatic Headlight Leveling ECU, 13. 2000–2003: Air Suspension ECU, 14. Passenger-side Junction Box, 15. Shift Lock ECU, 16. SRS Airbag ECU, 17. Transponder Key Amplifier
General view of the junction box.
| Driver-Side Fuse Box Specifications (#1 in Diagram) | ||
|---|---|---|
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| No. | Protected Circuit / Function | Rating (A) |
| 1 | Right-hand drive : Audio and Navigation Systems | 7.5 |
| 2 | Power Tilt and Telescopic Steering Column | 20 |
| 3 | Right-hand drive : Audio System | 30 |
| 4 | Instrument panel illumination, center console illumination, vanity mirror lights, glove box light, air suspension, turn signals, clock, shift lock, power rear sunshade, Intuitive Parking Assist, climate-controlled rear seats, multi-display, audio system, Vehicle Stability Control (VSC), cigarette lighter , power outer mirrors, fuel filler door release, Adaptive Front-lighting System (AFS) | 7.5 |
| 5 | - | - |
| 6 | Power Driver’s Seat | 30 |
| 7 | - | - |
| 8 | Instrument Cluster, Shift Lock System, Intuitive Parking Assist | 7.5 |
| 9 | Power tilt/telescopic steering column, power door locks, power seats, engine immobilizer | 7.5 |
| 10 | Climate-Controlled / Ventilated Driver’s Seat | 15 |
| 11 | Air Suspension System | 20 |
| 12 | Shift Lock System, Theft Deterrent System | 7.5 |
| 13 | Auxiliary Power Outlet | 15 |
| 14 | Lexus LS 430 Rear Cigarette Lighter Fuse | 15 |
| 15 | Diagnostic Connector (DLC3 / OBD-II) | 7.5 |
| 16 | Starting System | 7.5 |
| 17 | ABS, Vehicle Stability Control (VSC) | 7.5 |
| 18 | Seat Belt Pre-tensioners | 5 |
| 19 | Theft Deterrent System | 7.5 |
| 20 | Air Conditioning System | 7.5 |
| 21 | Brake Lights (Stop Lights) | 5 |
| 22 | Climate-Controlled / Ventilated Seats | 10 |
| Relays | ||
| R1 | Accessory Relay (D-ACC) | |
| R2 | Ignition Relay (D-IG1) | |
| Passenger-Side Fuse Box Specifications (#14 in Diagram) | ||
|---|---|---|
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| No. | Protected Circuit / Function | Rating (A) |
| 1 | 2000–2003: SRS Airbags, engine immobilizer, electric steering lock | 7.5 |
| 2003–2006: SRS Airbags, engine immobilizer, electric steering lock | 30 | |
| 2 | Alarm / Security System | 15 |
| 3 | Steering Column Lock | 7.5 |
| 4 | 2000–2003: Multi-display | 7.5 |
| 2003–2006: SRS Airbags, engine immobilizer, electric steering lock, starting system, fuses: “STA”, “IG2” | 7.5 | |
| 5 | Power door locks, engine immobilizer, steering column lock, power seats | 7.5 |
| 6 | Power tilt/telescopic steering, headlight switch, windshield wipers and washers, turn signals | 7.5 |
| 7 | Interior lights, ignition cylinder light, clock, instrument cluster, vanity mirror lights, door courtesy lights | 10 |
| 8 | Instrument cluster, Vehicle Stability Control (VSC), interior illumination, fuse: “TEL” | 7.5 |
| 9 | Climate-Controlled / Ventilated Seats | 10 |
| 10 | 2000–2003: Automatic Headlight Leveling | 5 |
| 2003–2006: Automatic Headlight Leveling, Adaptive Front-lighting System (AFS) | 7.5 | |
| 11 | Rain sensor, air conditioning, power moonroof, multi-display, clock | 7.5 |
| 12 | Heated and Ventilated Front Passenger Seat | 15 |
| 13 | Air conditioning, audio unit, clock, multi-display, interior illumination | 7.5 |
| 14 | Lexus LS 430 Front Cigarette Lighter Fuse | 15 |
| 15 | - | - |
| 16 | Audio / Cassette Player | 7.5 |
| 17 | 2000–2003 : Power Moonroof | 25 |
| 2003–2006: Left-hand drive : Rear door control modules (door locks, power windows, courtesy lights, power door closers) | 20 | |
| 18 | Front passenger door ECU (door lock, power mirror, mirror heater, power door closer, courtesy light, power window) | 25 |
| 19 | Left-hand drive : Audio and Navigation Systems | 7.5 |
| 20 | Seat Belt Pre-tensioners | 5 |
| 21 | 2000–2003: Left-hand drive : Audio System | 30 |
| 2000–2003: Right-hand drive : Power Passenger Seat | 30 | |
| 2003–2006: Left-hand drive : Rear Right Door ECU (door lock, power window, courtesy light, power door closer) | 20 | |
| 2003–2006: Right-hand drive : Rear Right Door ECU (door lock, power window, courtesy light, power door closer) | 20 | |
| 22 | Driver door ECU (door lock, power mirror, mirror heater, power door closer, courtesy light, power window) | 25 |
| Relays | ||
| R1 | Accessory Relay (P-ACC) | |
| R2 | Ignition Relay (P-IG1) | |
Luggage Compartment
Component Locations : 1. Moonroof ECU, 2. Left-hand drive : Front Passenger Door ECU; Right-hand drive : Driver Door ECU, 3. Rear Right Door ECU, 4. Stereo Component Amplifier, 5. 2003–2006: Rearview Camera ECU, 6. 2003–2006: Rear Air Conditioning ECU, 7. Radio Tuner Module, 8. Navigation ECU, 9. Power Rear Sunshade Relay, 10. 2000–2004 : Cellular Telephone ECU – 2004–2006 : Seat Belt Pre-crash ECU, 11. Fuse Box, 12. Intuitive Parking Assist ECU, 13. Rear Left Door ECU, 14. Left-hand drive : Driver Door ECU – Right-hand drive: Front Passenger Door ECU, 15. Luggage Compartment Junction Box
| Trunk Fuse Box Specifications (#11 in Diagram) | ||
|---|---|---|
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| No. | Protected Circuit / Function | Rating (A) |
| 1 | Intuitive Parking Assist, air suspension, theft deterrent system, cellular telephone | 7.5 |
| 2 | Audio system tuner, cellular telephone | 7.5 |
| 3 | Rear A/C control ECU, theft deterrent system, trunk lighting, climate-controlled rear seats | 7.5 |
| 4 | Unused | - |
| 5 | Rear A/C control ECU, air purifier | 7.5 |
| 6 | 2000–2003 : Heated rear seats | 20 |
| 2003–2006 : Climate-controlled (heated/ventilated) rear seats | 30 | |
| 7 | Power rear sunshade | 15 |
| 8 | License plate lights | 7.5 |
| 9 | 2000–2003 : Rear Right Door ECU (door lock, power window, courtesy light, power door closer) | 20 |
| 2003–2006 : Power moonroof | 30 | |
| 10 | Fuel filler door release, trunk lid release and power closer | 10 |
| 11 | 2000–2003 : Rear Left Door ECU (door lock, power window, courtesy light, power door closer) | 20 |
| 2003–2006: Left-hand drive : Stereo component amplifier | 30 | |
| 2003–2006: Right-hand drive : Power passenger seat | 30 | |
| 12 | Left-hand drive : Power passenger seat | 30 |
| 13 | Rear seat control electronics | 30 |
| 14 | 30 | |
| Relays | ||
| R1 | Accessory Relay | |
| R2 | Ignition Relay | |
| R2 | Power Rear Sunshade Relay | |