Lexus Rx400h MOT Failures
An analysis of 54,438 real DVSA MOT tests on the Lexus Rx400h — what fails, how often, and how that compares to every other car on UK roads. Generations covered: XU30 (2005–2009).
Where the Lexus Rx400h fails its MOT
The single biggest MOT failure point on the Lexus Rx400h is parking brake efficiency less than 50% of the r... — this model is 8.8 times more likely to fail on this item than the average car on UK roads. That makes it worth watching for anyone buying or owning this model. Across 54,438 MOT tests, 0.38% of all Lexus Rx400h tests recorded this as a failure.
Brake failures on the MOT range from worn pads and discs (routine maintenance) to corroded brake lines and seized calipers (more serious). Check for any pulling under braking and listen for grinding.
Other notable weak points include parking brake efficiency below minimum requirement (8.6x the fleet average), anti-roll bar links worn (6.8x the fleet average), fuel pipe or hose damaged (26x the fleet average), and abs fault (7.5x the fleet average). These ratios compare the Lexus Rx400h's failure rate on each item against the national average for all cars tested — a ratio of 10x means this model fails ten times more often than a typical car.
The failures span 5 categories: Brakes, Suspension, Bodywork, Steering, Lights & Electrics. If you're inspecting a Lexus Rx400h before purchase, these are the areas to focus on — and if any have been flagged as advisories on a previous MOT, they're likely to become failures in the near future.
How failures change with mileage
The Lexus Rx400h's weak points shift as the car covers more miles. Understanding these patterns helps you know what to expect — and what to budget for — at each stage of ownership.
Under 60,000 miles
At this mileage, most failures are either design-related or caused by age rather than wear. Components like bushes and drop links may not have been replaced yet, and original-fit parts can deteriorate even on low-mileage cars that spend a lot of time sitting.
The standout failure at this mileage is suspension pin, bush or joint worn at 5.3x the fleet average.
60,000 to 100,000 miles
This is where routine wear items start to show up. Brake components, tyres, and exhaust parts have done serious work by this point. Cars that have been well serviced will show fewer of these failures — this mileage band is where good maintenance really separates the well-kept from the neglected.
For the Lexus Rx400h specifically, the DVSA data shows the most common failures at this mileage are abs fault (7.5x the average) and anti-roll bar links worn (6.8x). tyre valve seriously damaged or misaligned (5.0x) and tyre valve seriously damaged or misaligned also appear frequently.
Over 100,000 miles
High-mileage cars accumulate failures across multiple systems. The key question isn't whether things will need doing — they will — but whether the car has been maintained well enough to keep on top of them. Look for a consistent service history and recent MOT passes with minimal advisories.
For the Lexus Rx400h specifically, the DVSA data shows the most common failures at this mileage are fuel pipe or hose damaged (26x the average) and parking brake efficiency less than 50% of the r... (8.8x). parking brake efficiency below minimum requirement (6.9x) and suspension component damaged or corroded (6.4x) also appear frequently.
The shift from suspension pin, bush or joint worn at lower mileages to fuel pipe or hose damaged at higher mileages is typical — early failures tend to be design or factory-related, while high-mileage failures reflect accumulated mechanical wear. A car that's been well maintained will usually dodge the worst of both.
Known issues beyond the MOT
An MOT only tests roadworthiness at a single point in time — it won't catch developing faults, intermittent problems, or issues that haven't yet reached the failure threshold. These are the issues that Lexus Rx400h specialists and owners flag most frequently, drawn from manufacturer technical bulletins, workshop data, and verified owner reports.
Subframe mounting area corrosion Dangerous
The rear subframe mounting points on the RX400h are subject to accelerated corrosion that can compromise structural integrity. Affects XU30; typical independent garage repair cost is £800–£1,500.
Suspension component corrosion Major
The RX400h suffers from accelerated corrosion of suspension components including control arms, links, and mounting brackets. Affects XU30; typical independent garage repair cost is £300–£800.
Suspension bush wear Major
The RX400h experiences premature suspension bush and joint wear, with MOT failures occurring at 5.3 times the national average starting from 40,000 miles. Affects XU30; typical independent garage repair cost is £200–£600.
Parking brake efficiency failure Major
The RX400h parking brake system fails at exceptionally high rates, with MOT data showing efficiency failures at 8.6 times the national average on high-mileage examples. Affects XU30; typical independent garage repair cost is £250–£500.
For the complete picture — including repair costs across independent, specialist, and dealer garages — see the full Lexus Rx400h common problems breakdown.
What to check before buying a Lexus Rx400h
Based on the MOT failure data and known issues above, here's what to prioritise when inspecting a Lexus Rx400h:
Brakes — check for parking brake efficiency less than 50% of the r..., parking brake efficiency below minimum requirement. Suspension — check for anti-roll bar links worn, abs fault, suspension component damaged or corroded. Bodywork — check for fuel pipe or hose damaged.
Beyond the MOT items, ask specifically about subframe mounting area corrosion and suspension component corrosion. These won't show up on a standard MOT but can be expensive to fix — repairs start from £800. A specialist pre-purchase inspection is worth the investment on this model.
Always check the car's full MOT history for patterns — recurring advisories often become failures within 12 months. And verify the service history to confirm maintenance has been kept up to schedule. Enter any reg into our free car check to see the complete picture.
Looking at a specific Lexus Rx400h?
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Lexus Rx400h MOT FAQs
What are the most common MOT failures on a Lexus Rx400h?
Based on 54,438 DVSA MOT tests, the most common failure is parking brake efficiency less than 50% of the r... — at 9x the national fleet average. Other frequent failures include parking brake efficiency below minimum requirement and anti-roll bar links worn.
Is the Lexus Rx400h reliable based on MOT data?
The Lexus Rx400h has 12 MOT failure categories above the fleet average. Specialists also flag subframe mounting area corrosion as a concern. A pre-purchase inspection and service history check are recommended.
What MOT failures should I expect at high mileage?
Above 100,000 miles, the Lexus Rx400h most commonly fails on fuel pipe or hose damaged and parking brake efficiency less than 50% of the r.... Under 60,000 miles, the main issues are suspension pin, bush or joint worn.
How do I check a Lexus Rx400h's MOT history?
Enter the registration number into our free car check above. You'll see every MOT test result, advisories and failures, mileage readings, write-off status, and finance checks.
MOT failure data sourced from DVSA bulk test records via data.gov.uk. Ratios compare this model's failure rate against the national fleet average. Known issues sourced from manufacturer bulletins, specialist workshops, and verified owner reports.