Own a Lexus UX 300H in the Phoenix area? EZ Swap LLC repairs and maintains the Lexus UX 300H for model years 2025 to 2026. Our shop at 9050 N 9th St handles everything from routine service to diagnostics and major repairs.
To help UX 300H owners know what to watch for, we reviewed public records from the National Highway Traffic Safety Administration (NHTSA). For these model years NHTSA has 2 owner complaints on file for the UX 300H and 0 safety recall campaigns. The most-reported problem areas are vehicle speed control (2), power train (1), fuel/propulsion system (1).
Most-Reported Lexus UX 300H Problems
These problem areas come up most often in NHTSA owner complaints for the UX 300H (all model years combined). Complaint counts reflect reports filed, not the share of vehicles affected, so popular and older models naturally have more.
| Problem area (NHTSA component) | Complaints | Share | |
|---|---|---|---|
| Vehicle Speed Control | 2 | 100% | |
| Power Train | 1 | 50% | |
| Fuel/Propulsion System | 1 | 50% | |
| Forward Collision Avoidance | 1 | 50% | |
| Service Brakes | 1 | 50% |
Vehicle Speed Control
2 of the 2 complaints (100%) mention vehicle speed control (throttle and cruise control). Speed control complaints involve the throttle, cruise control and related sensors. We scan for stored codes and test the throttle system and sensors to find the actual cause instead of guessing. See our check engine light diagnostics and auto repair pages.
Power Train
1 of the 2 complaints (50%) mention the powertrain. Powertrain complaints can range from rough shifting to loss of drive. We road test, scan for stored codes and inspect fluids before recommending any repair. See our auto repair page.
Fuel/Propulsion System
1 of the 2 complaints (50%) mention the fuel system. Fuel system problems can cause stalling, hard starts and poor mileage. We test fuel delivery and related sensors to find the real cause. See our no-start diagnostics and check engine light diagnostics pages.
Lexus UX 300H Check Engine Codes
NHTSA owner complaints rarely cite specific trouble codes for the UX 300H, so we do not have a model-specific ranking to show. These are the check engine codes we see most often on vehicles in Phoenix heat, and any of them can show up on a Lexus.
| Code | What it means |
|---|---|
| P0420 | Catalyst efficiency below threshold (bank 1) Often a worn catalytic converter, but failing oxygen sensors or exhaust leaks can set it too. Can cause an emissions test failure. |
| P0300 | Random or multiple cylinder misfire Worn spark plugs, failing ignition coils, fuel or vacuum problems. Do not ignore a flashing check engine light. |
| P0171 | System too lean (bank 1) Often a vacuum leak, dirty MAF sensor, weak fuel delivery or a failing oxygen sensor. |
| P0455 | EVAP system large leak Missing or loose gas cap, or a disconnected or cracked vapor hose. |
| P0128 | Coolant temperature below thermostat regulating temperature Usually a thermostat stuck open. Fix it to restore efficiency and cabin heat. |
| P0442 | EVAP system small leak Loose or worn gas cap, cracked hose or purge or vent valve. |
| P0301 | Cylinder 1 misfire Commonly a bad spark plug or ignition coil on that cylinder. |
| P0401 | EGR flow insufficient Clogged EGR passages or a stuck EGR valve. |
Got a check engine light on your UX 300H? A code is a clue, not a diagnosis, so we scan it and test the system before replacing anything. See our check engine light diagnostics.
Serious Incident Reports
Of the NHTSA complaints on file for the UX 300H, 1 involved a crash. These numbers are drawn from self-reported complaints and are not verified findings. If your vehicle has an open recall, get it repaired promptly.
Keeping a Lexus UX 300H Reliable in Phoenix
Arizona heat is the hardest test a Lexus will face. Batteries, belts, hoses, tires and engine oil all wear faster here, and a UX 300H that spends its life in stop-and-go Valley traffic needs maintenance earlier than the owner's manual's normal schedule suggests.
Our recommendation for UX 300H owners: follow the severe-service schedule, test the battery before every summer, inspect brakes and tires twice a year, and have any warning light diagnosed instead of ignored. If you are shopping for a used Lexus UX 300H, a pre-purchase inspection shows what the paperwork does not.
Lexus UX 300H Services at EZ Swap LLC
Get the details on our Phoenix Lexus UX 300H repair service, or choose a service below.
Lexus UX 300H FAQ
What are the most common problems with the Lexus UX 300H?
Based on NHTSA owner complaints, the most-reported problem areas for the Lexus UX 300H are vehicle speed control (2), power train (1), fuel/propulsion system (1). Complaint counts reflect reports filed, not the share of vehicles affected.
Which UX 300H model years have the most complaints?
The UX 300H model years with the most NHTSA complaints on file are 2025. Older years have had longer to collect reports, so inspect any specific vehicle before buying.
What check engine codes are common on the Lexus UX 300H?
NHTSA complaints rarely cite specific codes for the Lexus UX 300H. On Phoenix vehicles in general, we see P0420, P0300 misfires, P0171 lean conditions and EVAP leaks such as P0455 and P0442 most often. Bring yours in and we will scan and test it.
Does the Lexus UX 300H have any safety recalls?
NHTSA lists 0 recall campaigns for the Lexus UX 300H across model years 2025 to 2026. Each recall applies only to certain vehicles, so enter your VIN at nhtsa.gov/recalls to see if yours is affected.
Do you repair the Lexus UX 300H in Phoenix?
Yes. EZ Swap LLC repairs and maintains Lexus vehicles including the UX 300H, at 9050 N 9th St in Phoenix. Call or text (602) 246-9063 for an appointment.
Is a pre-purchase inspection worth it for a used Lexus UX 300H?
Yes. An inspection checks the engine, transmission, brakes, suspension, A/C and electrical system, and scans for stored codes, so you know the real condition before you buy.
How often should I service my Lexus UX 300H in Phoenix?
Follow the severe-service schedule in your owner's manual, since heat and stop-and-go driving count as severe use. Test the battery before summer and inspect brakes and tires regularly.
More Lexus Models We Service
Source: public complaint and recall records from the National Highway Traffic Safety Administration (nhtsa.gov). Counts reflect reports filed and do not predict the condition of any individual vehicle.