Lexus RX 350 4th generation was produced in 2016, 2017, 2018, 2019, 2020, 2021 and 2022 with the designation AL20. In this article, we will present a description of Lexus RX350 4th generation fuses and relays with fuse box diagrams, their locations and photos. We will show the fuses responsible for the cigarette lighter.
The fuse and relay assignment may vary from the one shown and depends on the year of manufacture, the level of electrical equipment and the region of delivery of your vehicle.
Passenger compartment
In the passenger compartment, the fuse and relay box is located under the instrument panel on the left side. To access the block, remove the protective cover.
Photo example
Check the assignment against your schematics on the unit cover.
Diagram
Assignment
- 5A METER – Instruments (instrument panel)
- 10A A-BAG – Airbags
- 10A STRG LOCK – Steering lock system
- 20A DOOR R/L – Rear left door
- 10A METER – Instruments (instrument cluster)
- 20A TI&TE – Steering column adjustments
- 7.5A DOOR BACK – Rear door
- 7.5A DOME – Interior Lighting
- 7.5A ODB – Diagnostic connector
- 7.5A FOG RR – Rear fog lights
- 7.5A BKUP LP – Rear reversing lamp
- 15A WIPER RR – Rear Wiper
- 20A WASHER – Washer
- 15A P/OUTLET – Cigarette lighter (socket)
- 20A DOOR R/R – Rear right door
- 10A TAIL – Parking light, number plate light
- 10A HAZ – Emergency signalling, turn signals
- 7.5A STOP – Stop signals
- 20A D/L – Daytime running lights.
A fuse located in a block under the bonnet is responsible for the operation of the auxiliary power supply socket (cigarette lighter) in the armrest.
Engine compartment
Under the bonnet in the engine compartment on the left hand side is the main fuse and relay box.
Photo
Diagram
Designation
| (S/HTR F/L) | Front seat heater |
| (S/HTR F/R) | Seat heater |
| (ECU-IG1 NO.7) | Engine control unit |
| (IG1-MAIN) | Protects several circuits |
| (INV) Power outlet | DC/AC inverter |
| (DOOR-DL) | Door double locking |
| (P/OUTLET) | Cigar lighter / power outlet |
| (S/ROOF NO.2) | Sunroof |
| (TOWING BRK) | Trailer brakes |
| (H-LP CLN) | Headlight cleaner |
| (PTC HTR NO.3) | Additional heater |
| (PTC HTR NO.2) | Additional heater |
| (P/SEAT R/R) | Power seats |
| (P/SEAT R/L) | Power seats |
| (PBD) | Power back door |
| (SPARE) | Spare fuse |
| (FAN) | Electric cooling fan |
| (PTC HTR NO.1) | Additional heater |
| (HTR) | Air conditioning system |
| (WIPER NO.2) | Wipers |
| (ALT) | Battery and charging system |
| (ST) | Starter system |
| (ABS NO.2) | Anti-lock braking system |
| (ABS NO.1) | Anti-lock braking system |
| (EPS) | Electric power steering |
| (WIPER NO.3) | Wipers |
| (ECU-IG1 NO.9) | Engine control unit |
| (FUEL PMP) | Fuel pump |
| (TOWING) | Trailer lights |
| (INJ) | Fuel injectors |
| (ETCS) | Electronic throttle control system |
| (S-HORN) | Horn / anti-theft deterrent |
| (H-LP LH) | Left-hand headlight |
| (HORN) | Horn |
| (H-LP RH) | Right-hand headlight |
| (STRG HTR) | Heated steering wheel |
| (ECU-IG1 NO.6) | Engine control unit |
| (RADIO NO.2) | Radio and audio system |
| (AMP) | Audio system |
| (H-LP LH-LO) | Left-hand headlight low beam |
| (H-LP RH-LO) | Right hand headlight low beam |
| (IG2-MAIN) | Protects several circuits |
| (IG2) | Protects several circuits |
| (P INJ) | Fuel injectors |
| (EFI-MAIN) | Multiport fuel injection system |
| RELAY | |
| (WIPER) | Wipers |
| (PTC HTR NO.1) | Additional heater |
| (IG1 – MAIN) | Protects several circuits |
| (H-LP RH) | Right-hand headlight |
| (S-HORN) | Horn / anti-theft deterrent |
| (ST) | Starter system |
| (H-LP CLN) | Headlight cleaner |
| (FUEL PMP) | Fuel pump |
| (H-LP LH) | Left-hand headlight |
| (HORN) | Horn |
| (FAN) | Electric cooling fan |
| (PTC HTR NO.3) | Additional heater |
| (INJ) | Fuel injectors |
In the luggage compartment, another high-capacity power fuse box is located on the plus terminal of the battery.
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