Lexus UX 250h

The most commonly reported UX 250h issue, shared with many Toyota/Lexus hybrids. The auxiliary 12V battery is undersized relative to the car's standby power draw from various electronic modules. Early software versions of the telematics module ('Phone Home') kept the system continuously active, accelerating drain. Lexus released software updates that improved the situation, but the fundamental draw remains higher than many competitors. In cold weather, the problem worsens. A trickle charger (CTEK MXS 5.0 or similar) is strongly recommended for owners who do not drive daily. Replacement 12V batteries cost €150-250 at an independent shop, €200-300 at a Lexus dealer. Some owners report needing replacement every 2-3 years.

Early 2019-2020 models are most affected. The infotainment system can freeze mid-use, go blank, or reboot spontaneously. Apple CarPlay and Bluetooth connectivity are commonly impacted. Lexus has released multiple software updates via TSBs (L-SB-0007-23, L-SB-0047-25) that address the majority of these issues. A dealer software update is typically free if the car is under Lexus Relax warranty, otherwise €100-200. In rare cases where the multimedia unit itself fails, replacement costs €300-400 including labor. Most instances resolve with a software update, making the actual cost zero for many owners.

The M20A-FXS uses Toyota's D-4S dual-injection system (direct + port injection), which reduces but does not eliminate carbon buildup on intake valves. Internal Toyota data from 2023 indicates roughly 8% of M20A-FXS engines over 80,000 km require valve cleaning. Urban hybrids that spend significant time in EV-only mode are most susceptible, as reduced fuel flow through the intake allows crankcase vapors and EGR gases to deposit carbon on the valves. Symptoms include rough idle, cold-start hesitation, and misfire codes (P0300-P0304). Walnut-shell blasting or chemical cleaning typically costs €400-600 at a specialist, up to €800 at a Lexus dealer. Regular highway driving and periodic higher-RPM use help reduce buildup.

Some owners report knocking or creaking sounds from the rear suspension, particularly when driving over speed bumps or uneven surfaces at low speed. The issue is traced to premature wear of rear stabilizer link bushings and, in some cases, worn rear shock absorber mounts. It is more commonly reported on the E-Four (AWD) variant, likely due to the additional weight of the rear electric motor. Lexus issued TSB L-SB-0030-19 addressing a rear suspension squeak. Replacing stabilizer links and bushings costs €200-350 at an independent garage, up to €500 at a dealer. While not a safety concern, the noise degrades ride comfort.

The M20A-FXS engine's coolant bypass valve can fail, triggering DTC P268111 or P268115 and an 'Engine Maintenance Required' message. Symptoms include loss of cabin heating and, in more advanced cases, visible coolant drip under the engine. Toyota released Customer Support Program CSP 24TE04 to address this issue on affected models, covering replacement at no cost for eligible vehicles. Outside of the CSP program, the valve and hose assembly costs €80-150 for the part, with labor running €120-350 depending on the shop. Check eligibility with a Lexus dealer using the VIN before paying out of pocket.

A known issue affecting some pre-2022 M20A-FXS engines. Corrosion develops inside the EGR cooler's heat exchanger, eventually allowing coolant to seep into the combustion chamber. The primary symptom is white smoke from the exhaust, especially during warm-up. If caught early, replacement of the EGR cooler resolves the issue. If ignored, coolant contamination of the engine oil can cause accelerated wear. The issue appears in a minority of affected-year cars, and 2022+ models have an updated EGR cooler design. Repair involves replacing the EGR cooler assembly, costing €600-900 at an independent specialist or up to €1,200 at a Lexus dealer.