The fourth-generation Lexus ES 300 sedan delivered enhanced luxury, adopting numerous premium features from the flagship LS model. Introduced in 2001 under the XV30 chassis designation, the restyled model featured prominent headlight clusters and expanded exterior dimensions. The vehicle's wheelbase was increased from 2,670 mm to 2,720 mm, alongside increases in overall length and width, significantly enhancing interior cabin roominess. Consequently, the fourth-generation ES became the best-selling luxury sedan in the United States while enjoying strong demand in international markets, including the Middle East. Under the hood, the 2001–2006 Lexus ES 300 is powered by the 3.0-liter 1MZ-FE V6 engine carried over from the previous generation.
Electrical power circuits in this vehicle are protected by a system of fuses, fusible links, and relays. These components are housed in distribution blocks (junction blocks) located in both the engine compartment and the passenger cabin. This guide details the fuse box diagrams, relay layouts, and circuit assignments for the fourth-generation Lexus ES 300 / ES 330 (chassis codes MCV30 / MCV31) covering model years 2001, 2002, 2003, 2004, 2005, and 2006.
Engine Compartment
Component Locations: 1. Fuse Block / Junction Block, 2. Left Headlight ECU, 3. ABS Relay Box, 5. Right Headlight ECU, 5. Vehicle Stability Control (VSC) ECU
Component location overview.
| Diagram | ||
|---|---|---|
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| No. | Circuit Description / Protected Components | Rating (A) |
| 1 | Fuses: “DEF”, “PWR NO.1”, “PWR NO.2”, “PWR NO.3”, “PWR NO.4”, “STOP”, “DOOR NO.2”, “OBD”, “PWR SEAT”, “FUEL OPEN”, “FOG”, “AMP”, “PANEL”, “TAIL”, “AM1”, “CIG”, “POWER POINT”, “RAD NO.2”, “ECU-ACC”, “GAUGE1”, “GAUGE2”, “ECU-IG”, “WIPER”, “WASHER”, “HTR (10 A)”, “SEAT HTR”, “SUN-SHADE” | 120 |
| 2 | 2002–2003 : Anti-lock Braking System (ABS), Vehicle Stability Control (VSC), Traction Control (TRAC), Brake Assist System (BA); fuses: “RDI FAN”, “ABS No. 2”, “ABS No. 3”, “CDS”, “HTR (50 A)”, “ADJ PDL” | 60 |
| 2003–2006 : Anti-lock Braking System (ABS), Vehicle Stability Control (VSC), Traction Control (TRAC), Brake Assist System (BA); fuses: “RDI FAN”, “ABS No. 2”, “ABS No. 3”, “CDS”, “HTR (50 A)”, “ADJ PDL” | 50 | |
| 3 | Left low-beam headlight, front fog lights | 15 |
| 4 | Right low-beam headlight | 15 |
| 5 | Daytime Running Lights (DRL) | 5 |
| 6 | Air conditioning system | 10 |
| 7 | - | - |
| 8 | - | - |
| 9 | - | - |
| 10 | Fuses: “HEAD LH LWR”, “HEAD RH LWR”, “HEAD LH UPR”, “HEAD RH UPR”, “DRL” | 40 |
| 11 | ABS, VSC, Traction Control (TRAC), Brake Assist System | 40 |
| 12 | Radiator cooling fan | 30 |
| 13 | 30 | |
| 14 | Air conditioning system | 50 |
| 15 | Electronic Throttle Control System (ETCS) | 30 |
| 16 | 2002–2003 : ABS, VSC, Traction Control (TRAC), Brake Assist System | 40 |
| 2003–2006 : ABS, VSC, Traction Control (TRAC), Brake Assist System | 30 | |
| 17 | Starting system; fuses: “IGN”, “IG2” | 30 |
| 18 | Left high-beam headlight | 10 |
| 19 | Right high-beam headlight | 10 |
| 20 | Starting system | 5 |
| 21 | Cellular telephone system | 5 |
| 22 | Charging system | 5 |
| 23 | Starting system | 15 |
| 24 | Multiport Fuel Injection (MFI) / Sequential Multiport Fuel Injection (SFI) system, SRS airbag system, cruise control, seat belt pretensioners | 10 |
| 25 | Body ECU (central door locking) | 25 |
| 26 | Sequential Multiport Fuel Injection (SFI) system | 20 |
| 27 | Horns | 10 |
| 28 | Fuses: “ECU-B”, “RAD NO.1”, “DOME” | 30 |
| 29 | Sequential Multiport Fuel Injection (SFI) system | 25 |
| 30 | - | - |
| 31 | Sequential Multiport Fuel Injection (SFI) system | 10 |
| 32 | Anti-theft alarm system | 15 |
| Relays | ||
| R1 | - | |
| R2 | - | |
| R3 | Daytime Running Lights (DRL) Relay No. 2 | |
| R4 | Daytime Running Lights (DRL) Relay No. 3 | |
| R5 | Radiator Cooling Fan Relay No. 2 | |
| R6 | Daytime Running Lights (DRL) Relay No. 4 | |
| R7 | - | |
| R8 | Radiator Cooling Fan Relay No. 3 | |
| R9 | A/C Compressor Magnetic Clutch Relay | |
| R10 | Air-Fuel Ratio (A/F) Sensor Relay | |
| R11 | Heater Blower / A/C Relay | |
| R12 | Starter Relay | |
| R13 | Headlight Relay | |
| R14 | Radiator Cooling Fan Relay No. 1 | |
| R15 | Fuel Pump Relay (Circuit Opening Relay / C-OPN) | |
| R16 | Horn Relay | |
| R17 | Electronic Fuel Injection (EFI) Main Relay | |
| ABS Relay Box (No. 3 in Location Diagram) | ||
|---|---|---|
|
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| No. | Circuit Description | Rating (A) |
| 1 | ABS, VSC, Traction Control (TRAC), Brake Assist System | 7.5 |
| Relays | ||
| R1 | ABS Solenoid / Pump Relays | |
| R2 | ||
Passenger Compartment
Component Locations: 1. Fuse Block, 2. Body ECU, 3. Adaptive Suspension (AVS) ECU, 4. Transponder Key Amplifier, 5. Air Conditioning ECU, 6. Navigation / Audio Head Unit, 7. Anti-Theft ECU, 8. Audio Amplifier (except Mark Levinson), 9. Skid Control ECU, 10. Engine Control Module (ECM / ECU), 11. Junction Block, 12. Outer Mirror Memory ECU, 13. Headlight Leveling ECU, 14. Shift Lock Control ECU, 15. SRS Airbag Sensor Assembly, 16. Wiper Relay, 17. Turn Signal Flasher Relay
Component location overview.
Fuse box panel access example.
| Diagram | ||
|---|---|---|
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| No. | Circuit Description / Protected Components | Rating (A) |
| 1 | Body ECU (central door locking, anti-theft system, automatic headlight system, daytime running lights, automatic door locks, exterior lighting), air conditioning system, adaptive suspension, seat memory system | 10 |
| 2 | Ignition key cylinder light, interior lights, footwell lights, door courtesy lights, luggage compartment light, clock, ambient temperature sensor, multi-information display, vanity mirror lights, garage door opener ECU | 7.5 |
| 3 | Cigarette Lighter (Lexus ES 300 / ES 330) | 15 |
| 4 | Power outer mirrors, seat memory system, multi-information display | 5 |
| 5 | Audio head unit, navigation system | 10 |
| 6 | Auxiliary power outlet | 15 |
| 7 | Audio head unit, navigation system | 20 |
| 8 | Instrument cluster, clock, ambient temperature sensor, multi-information display, shift lock control system | 10 |
| 9 | SRS airbag system, power windows, ABS, adaptive suspension, seat memory system | 10 |
| 10 | Windshield wipers | 25 |
| 11 | Air conditioning system | 10 |
| 12 | Outside rearview mirror defoggers | 10 |
| 13 | Starting system | 5 |
| 14 | Front fog lights | 15 |
| 15 | Power rear sunshade | 15 |
| 16 | Inside rearview mirror, compass, backup (reverse) lights, automatic headlight system, automatic headlight leveling system, cruise control, seat belt warning light | 10 |
| 17 | Glove box light, center console box light, clock, ambient temperature sensor, instrument panel illumination, instrument cluster, multi-information display | 10 |
| 18 | Parking lights, license plate lights | 10 |
| 19 | Rear left power window | 20 |
| 20 | Front right power window, central door locking system | 20 |
| 21 | Diagnostic connector (OBD-II / DLC3) | 7.5 |
| 22 | Seat heaters and seat ventilation system | 20 |
| 23 | Windshield washer | 15 |
| 24 | Radiator cooling fan | 10 |
| 25 | Stop lights (brake lights), high-mounted stop light | 15 |
| 26 | Fuel filler door opener | 5 |
| 27 | Body ECU (central door locking) | 25 |
| 28 | Audio amplifier | 25 |
| 29 | Rear right power window | 20 |
| 30 | Power seats | 30 |
| 31 | Front left power window, central door locking system, power moonroof | 30 |
| 32 | Rear window defogger | 40 |
| Relays | ||
| R1 | Front fog light relay | |
| R2 | Parking light relay | |
| R3 | Accessory (ACC) relay | |
| R4 | Rear window defogger relay | |
| R5 | Ignition (IG1) relay | |
| R6 | - | |
Body Electrical Components
Component Locations: 1. Junction Box, 2. Power Moonroof ECU, 3. Front Passenger Door ECU, 4. Rear Right Door ECU, 5. Power Rear Sunshade Relay, 6. Audio Amplifier (Mark Levinson), 7. Navigation ECU, 8. Cellular Telephone ECU, 9. Lamp Failure Sensor Unit, 10. Rear Left Door ECU, 11. Front Driver Door ECU