IsItAGoodCar
Reliability Guide

Common Problems with the
2021 Lexus UX

Lexus introduced the UX 300e, the brand's first-ever fully electric vehicle. While it offered legendary Lexus refinement, its relatively small battery and CHAdeMO charging port limited its appeal for long journeys.

What changed for 2021

  • •Launch of the UX 300e, Lexus's first fully electric vehicle.
  • •Minor trim updates across the hybrid range.

Common MOT watch-outs

  • !Wear on suspension components due to the increased weight of the EV battery.
  • !Minor software glitches.
5
Known Issues
0
Serious
2
Moderate
3
Minor

All Known Issues

12V Battery Drain

ModerateElectrics & Electronics

The most common complaint on UX owner forums; the 12V battery is small and can be drained by the car's connected systems.

Est. Repair Cost: £150–£200
Warning Signs:

Weak cranking, "Check Hybrid System" warning caused by low voltage, Keyless entry not working

What to Inspect:
  • Ask if the 12V battery has been replaced with a higher-capacity aftermarket unit (e.g. Yuasa)
Verified by IsItAGoodCar Research Team

12V Auxiliary Battery Drain

ModerateElectrics & Electronics

The UX's small 12V auxiliary battery can be drained by the car's connected systems and telematics, particularly on cars used for short urban trips or left parked for extended periods. A flat 12V battery prevents the car from entering READY mode and triggers false hybrid system warnings.

Est. Repair Cost: £150–£200
Warning Signs:

Weak cranking or slow startup, Check Hybrid System warning caused by low voltage, Keyless entry not working

What to Inspect:
  • Ask if the 12V battery has been replaced with a higher-capacity unit
  • Check the battery age and replacement history
  • Test voltage after the car has been parked for 24 hours
Verified by IsItAGoodCar Research TeamUpdated

Excessive Road Noise (Run-Flats)

MinorSuspension & Chassis

Models on 18-inch wheels with run-flat tyres can suffer from significant road roar on coarse UK motorways.

Est. Repair Cost: £600 (Set of non-run-flat tyres)
Warning Signs:

Loud humming from tyres, Harsh ride over expansion joints

What to Inspect:
  • Check tyre tread and brand
  • Listen for road noise at 60mph+
Verified by IsItAGoodCar Research Team

Excessive Road Noise from Run-Flat Tyres

MinorSuspension & Chassis

UX models fitted with 18-inch run-flat tyres can suffer from significant road roar on coarse UK motorways. The stiff sidewalls transmit more tyre noise into the cabin, and the ride can feel harsh over expansion joints and potholes.

Est. Repair Cost: £600 (set of non-run-flat tyres)
Warning Signs:

Loud humming from the tyres at cruising speeds, Harsh ride over expansion joints, Increased cabin noise on motorway surfaces

What to Inspect:
  • Check the tyre tread depth and brand
  • Listen for road noise at 60mph and above
  • Compare ride quality on different road surfaces
Verified by IsItAGoodCar Research TeamUpdated

Touchpad Infotainment Controller Frustration (Pre-2023)

MinorInterior & Trim

Pre-2023 UX models use Lexus's touchpad Remote Touch controller rather than a touchscreen. The pad is fiddly and unintuitive to use while driving, with laggy cursor response and multiple steps required for simple actions. The 2023 update introduced a touchscreen, so early cars are affected.

Est. Repair Cost: £200–£700
Warning Signs:

Cursor jumps or fails to register on the touchpad, Menu navigation is slow and unintuitive, Inputs are difficult to make while driving

What to Inspect:
  • Test the touchpad controller for lag and unresponsiveness
  • Navigate several menus quickly during the test drive
  • Confirm whether the car is pre- or post-2023 touchscreen update
Verified by IsItAGoodCar Research TeamUpdated

Buying Tips for 2021 Lexus UX

  • On the UX 300e, be aware that it uses the older CHAdeMO rapid charging standard, which is becoming less common on newer public chargers.
  • Check the electric-only range estimation, as the UX 300e's real-world range is relatively modest.
20202022
Check a 2021 Lexus UX by Registration