The Lexus RX is a mid-size luxury crossover SUV produced by Japanese automaker Toyota since 1998. In 2015, Lexus unveiled the fourth-generation model at the New York International Auto Show. It is powered by a 3.5-liter V6 engine producing 300 hp, paired with an eight-speed automatic transmission. This guide provides detailed fuse box diagrams and relay assignments for the Lexus RX 350 (fourth generation; chassis code AL20 / GGL25) covering the 2016, 2017, 2018, 2019, 2020, 2021, and 2022 model years.
Below you will find the locations, photos, and circuit layouts for the power distribution centers. Fuses critical to components such as the “Cigarette Lighter” (Power Outlet) and “Fuel Pump” are bolded for quick reference.
Engine Compartment Fuse Box
The main underhood fuse box is located on the left side of the engine compartment.
Fuse box cover removal and access.
| Diagram | |
|---|---|
|
|
| Designation | Relay Circuit / Component |
| FAN | Electric radiator cooling fan |
| FUEL PMP | Fuel pump relay |
| H-LP CLN | Headlight washer system |
| H-LP LH | Left headlight assembly |
| H-LP RH | Right headlight assembly |
| HORN | Horn |
| IG1 – MAIN | Ignition system (IG1 main relay) |
| INJ | Fuel injectors |
| PTC HTR NO.1 | PTC auxiliary heater No. 1 |
| PTC HTR NO.3 | PTC auxiliary heater No. 3 |
| S-HORN | Security horn / Anti-theft system |
| ST | Starter relay |
| WIPER | Windshield wipers |
| Designation | Fuse Circuit / Component Protected |
| ABS 1 | Anti-lock Braking System (ABS) / Vehicle Stability Control (VSC) |
| ABS 2 | Anti-lock Braking System (ABS) / Vehicle Stability Control (VSC) |
| ALT | Alternator / Charging system |
| AMP | Audio amplifier system |
| DOOR-DL | Door lock control / Deadlock system |
| ECU-IG1 №6 | Engine Control Unit (ECU) / Ignition circuit |
| ECU-IG1 №7 | Engine Control Unit (ECU) / Ignition circuit |
| ECU-IG1 №9 | Engine Control Unit (ECU) / Ignition circuit |
| EFI-MAIN | Electronic Fuel Injection (EFI) main system |
| EPS | Electric Power Steering |
| ETCS | Electronic Throttle Control System |
| FAN | Radiator cooling fan motor |
| FUEL PMP | Fuel pump fuse |
| H-LP CLN | Headlight washer pump motor |
| H-LP LH | Left headlight assembly |
| H-LP LH-LO | Left low-beam headlight |
| H-LP RH | Right headlight assembly |
| HORN | Horn |
| HTR | Climate control / HVAC blower motor |
| IG1-MAIN | Primary ignition supply circuit 1 |
| IG2 | Ignition supply circuit 2 |
| IG2-MAIN | Primary ignition supply circuit 2 |
| INJ | Fuel injection system |
| INV Power outlet | DC/AC power inverter module |
| P INJ | Port fuel injectors |
| P/OUTLET | Power outlet / Cigarette lighter socket |
| P/SEAT R/L | Rear left power seat switch |
| P/SEAT R/R | Rear right power seat switch |
| PBD | Power Back Door (Power tailgate opener) |
| PTC HTR NO.1 | PTC auxiliary heater element 1 |
| PTC HTR NO.2 | PTC auxiliary heater element 2 |
| PTC HTR NO.3 | PTC auxiliary heater element 3 |
| RADIO NO.2 | Audio system receiver / Head unit |
| S/HTR F/L | Front left seat heater switch |
| S/HTR F/R | Front right seat heater switch |
| S/ROOF NO.2 | Power sunroof / Moonroof |
| S-HORN | Security horn / Anti-theft alarm system |
| SPARE | Spare fuse slot |
| ST | Starter motor solenoid |
| STRG HTR | Heated steering wheel element |
| TOWING BRK | Electric trailer brake controller |
| TOWING | Trailer wiring harness / Tailgate lamps |
| WIPER NO.2 | Windshield wiper motor circuit 2 |
| WIPER NO.3 | Windshield wiper motor circuit 3 |
| H-LP RH-LO | Right low-beam headlight |
Passenger Compartment Fuse Box
The interior fuse box is located underneath the instrument panel on the driver's side.
Fuse panel access location.
| Diagram | |
|---|---|
|
|
| Designation | Circuit Protected / Rating |
| A-BAG | Supplemental Restraint System (Airbag ECU) — 10A |
| BKUP LP | Backup / Reverse lamps — 7.5A |
| D/L | Door lock actuators — 20A |
| DOME | Interior dome / Courtesy illumination — 7.5A |
| DOOR BACK | Power back door / Trunk latch module — 7.5A |
| DOOR R/L | Rear left power window / Lock module — 20A |
| DOOR R/R | Rear right power window / Lock module — 20A |
| FOG RR | Rear fog lamps — 7.5A |
| HAZ | Hazard warning flasher / Turn signal indicators — 10A |
| METER | Instrument cluster display — 10A |
| METER-IG2 | Instrument cluster ignition feed — 5A |
| ODB | On-Board Diagnostics (OBD-II port) — 7.5A |
| P/OUTLET | Cigarette lighter / 12V DC accessory outlet — 15A |
| STOP | Stop / Brake lamps — 7.5A |
| STRG LOCK | Electric steering column lock system — 10A |
| TAIL | Tail lamps, side marker lamps, license plate lamps — 10A |
| TI&TE | Power tilt and telescopic steering column — 20A |
| WASHER | Windshield washer fluid pump — 20A |
| WIPER RR | Rear window wiper motor — 15A |