Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Problem Symptoms Table
2010 Lexus RX 450h 3.5 BSECTION 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.
FRONT WIPER AND WASHER (W/O AUTO WIPER SYSTEM)
| Symptom | Suspected Area | See |
|---|---|---|
| Front wipers do not operate at all | Wiper ECU power source circuit | Refer to Wiper ECU Power Source Circuit |
| Front wiper motor circuit | Refer to Front Wiper Motor Circuit | |
| Windshield wiper switch assembly | Refer to \REMOVAL (TO 08/2009) | |
| Front wipers do not operate in LO | Front wiper motor circuit | Refer to Front Wiper Motor Circuit |
| Windshield wiper switch assembly | Refer to REMOVAL (TO 08/2009) | |
| Front wipers do not operate in HI | Front wiper motor circuit | Refer to Front Wiper Motor Circuit |
| Windshield wiper switch assembly | Refer to REMOVAL (TO 08/2009) | |
| Front washer motor does not operate | Washer motor circuit | Refer to Washer Motor Circuit |
| Windshield wiper switch assembly | Refer to REMOVAL (TO 08/2009) | |
| Washer fluid does not flow | Washer hose and nozzle | - |
| Front wipers do not operate when front washer switch is on | Front wiper motor circuit | Refer to Front Wiper Motor Circuit |
| Windshield wiper switch assembly | Refer to REMOVAL (TO 08/2009) | |
| When the front wiper switch is off, the wiper blades do not park or park in the wrong position | Front wiper arm installation position | Refer to INSTALLATION |
| Windshield wiper motor assembly | Refer to REMOVAL (TO 08/2009) |
FRONT WIPER AND WASHER (W/ AUTO WIPER SYSTEM)
| Symptom | Suspected Area | See |
|---|---|---|
| Front wipers do not operate at all | Wiper ECU power source circuit | Refer to Wiper ECU Power Source Circuit |
| Front wiper motor circuit | Refer to Front Wiper Motor Circuit | |
| Windshield wiper switch assembly | Refer to REMOVAL (TO 08/2009) | |
| Front wipers do not operate in AUTO | Rain sensor tape*1 | - |
| Rain sensor circuit | Refer to Rain Sensor Circuit | |
| Speed signal circuit | Refer to Speed Signal Circuit | |
| Front wiper motor circuit | Refer to Front Wiper Motor Circuit | |
| Windshield wiper switch assembly | Refer to REMOVAL (TO 08/2009) | |
| Front wipers do not operate in LO | Front wiper motor circuit | Refer to Front Wiper Motor Circuit |
| Windshield wiper switch assembly | Refer to REMOVAL (TO 08/2009) | |
| Front wipers do not operate in HI | Front wiper motor circuit | Refer to Front Wiper Motor Circuit |
| Windshield wiper switch assembly | Refer to REMOVAL (TO 08/2009) | |
| Front washer motor does not operate | Washer motor circuit | Refer to Washer Motor Circuit |
| Windshield wiper switch assembly | Refer to REMOVAL (TO 08/2009) | |
| Washer fluid does not flow | Washer hose and nozzle | - |
| Front wipers do not operate when front washer switch is on | Front wiper motor circuit | Refer to Front Wiper Motor Circuit |
| Windshield wiper switch assembly | Refer to REMOVAL (TO 08/2009) | |
| When the front wiper switch is off, the wiper blades do not park or park in the wrong position | Front wiper arm installation position | Refer to INSTALLATION |
| Windshield wiper motor assembly | Refer to REMOVAL (TO 08/2009) |
REAR WIPER AND WASHER
| Symptom | Suspected Area | See |
|---|---|---|
| Rear wiper does not operate at all | RR WIP fuse | - |
| Rear wiper motor assembly | Refer to INSPECTION | |
| Windshield wiper switch assembly | Refer to INSPECTION | |
| Harness or connector | - | |
| Rear wiper does not operate in LO or HI | Rear wiper motor assembly | Refer to INSPECTION |
| Windshield wiper switch assembly | Refer to INSPECTION | |
| Harness or connector | - | |
| Rear washer motor does not operate | RR WASH fuse | - |
| Rear washer motor assembly | Refer to INSPECTION | |
| Windshield wiper switch assembly | Refer to INSPECTION | |
| Harness or connector | - | |
| Washer fluid does not flow | Washer hose and nozzle | - |
| When the rear wiper switch is off, the wiper blade does not park or park in the wrong position | Rear wiper arm installation position | Refer to INSTALLATION |
| Rear wiper motor assembly | Refer to INSPECTION |
HEADLIGHT CLEANER SYSTEM
| Symptom | Suspected Area | See |
|---|---|---|
| Headlight cleaner system does not operate when the headlight cleaner switch is operated. | IG power source circuit | Refer to IG Power Source Circuit |
| Headlight cleaner switch circuit | Refer to Headlight Cleaner Switch Circuit | |
| Headlight cleaner motor and relay circuit | Refer to Headlight Cleaner Motor and Relay Circuit | |
| Headlight cleaner control relay | Refer to REMOVAL | |
| Headlight cleaner system does not operate when the front washer switch is operated*2. | IG power source circuit | Refer to IG Power Source Circuit |
| Headlight signal circuit | Refer to Headlight Signal Circuit | |
| Washer signal circuit | Refer to Washer Signal Circuit | |
| Headlight cleaner motor and relay circuit | Refer to Headlight Cleaner Motor and Relay Circuit | |
| Headlight cleaner control relay | Refer to REMOVAL |
WASHER FLUID LEVEL WARNING SYSTEM
| Symptom | Suspected Area | See |
|---|---|---|
| Washer fluid level warning system does not operate | Washer fluid level warning switch circuit | Refer to Washer Fluid Level Warning Switch Circuit |
| Combination meter assembly | Refer to REMOVAL (TO 8/2009) |
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.