Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Problem Symptoms Table

PROBLEM SYMPTOMS TABLE

HINT:

Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.
Inspect the fuses and relays related to this system before inspecting the suspected areas below.

Front Power Seat Control System (w/o Memory) (for Driver)

Symptom	Suspected Area	Link
All functions do not operate	Front power seat switch LH
All functions do not operate	Wire harness or connector	-
Only slide function does not operate	Front power seat switch LH
	Slide motor (Front seat adjuster assembly LH)
	Wire harness or connector	-
Only front vertical function does not operate	Front power seat switch LH
	Front vertical motor (Front seat adjuster assembly LH)
	Wire harness or connector	-
Only lifter function does not operate	Front power seat switch LH
	Lifter motor (Front seat adjuster assembly LH)
	Wire harness or connector	-
Only reclining function does not operate	Front power seat switch LH
	Reclining motor (Front seatback frame sub-assembly LH)
	Wire harness or connector	-
Only lumbar support adjustment function does not operate	Front lumbar power seat switch (driver seat)
	Front power seat switch LH
	Lumbar support adjuster assembly LH
	Wire harness or connector	-

Front Power Seat Control System (w/o Memory) (for Front Passenger)

Symptom	Suspected Area	Link
All functions do not operate	Front power seat switch RH
All functions do not operate	Wire harness or connector	-
Only slide function does not operate	Front power seat switch RH
	Slide motor (Front seat adjuster assembly RH)
	Wire harness or connector	-
Only front vertical function does not operate	Front power seat switch RH
	Front vertical motor (Front seat adjuster assembly RH)
	Wire harness or connector	-
Only lifter function does not operate	Front power seat switch RH
	Lifter motor (Front seat adjuster assembly RH)
	Wire harness or connector	-
Only reclining function does not operate	Front power seat switch RH
	Reclining motor (Front seatback frame sub-assembly RH)
	Wire harness or connector	-
Only lumbar support adjustment function does not operate	Front lumbar power seat switch (front passenger seat)
	Front power seat switch RH
	Lumbar support adjuster assembly RH
	Wire harness or connector	-
Only cushion length function does not operate*	Seat variable cushion switch RH
	Length motor (Front seat vertical adjuster assembly RH)
	Wire harness or connector	-

SYSTEM DIAGRAM Driver Seat Front Passenger Seat ...

Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual > Occupant Classification System: Front Occupant Classification Sensor LH Circuit Malfunction (B1780)
DESCRIPTION The front occupant classification sensor LH circuit consists of the occupant detection ECU and front occupant classification sensor LH. DTC B1780 is stored when a malfunction is detected in the front occupant classification sensor LH circuit. DTC No. Detection Item DTC Detection C ...

Lexus RX (RX 350L, RX450h) 2016-2025 Owners Manual > Steps to take in an emergency: If the hybrid system will not start
Reasons for the hybrid system not starting vary depending on the situation. Check the following and perform the appropriate procedure: The hybrid system will not start even though the correct starting procedure is being followed. One of the following may be the cause of the problem: Th ...

Lexus RX (RX 350L, RX450h) 2016-{YEAR} Owners Manual