Inside Toyota's U.S. Plants: Rain Booths, Weld Ultrasounds and Medical-Grade CT Scans
From rain booths to medical-grade CT scanners, Toyota lists five checks its U.S. plants run. They catch build flaws, not the software faults behind its latest recalls.
Toyota has detailed five quality checks it runs inside its U.S. factories, and the most striking thing about the list is how much medical equipment has ended up on the plant floor. The rundown, published October 26 for Manufacturing Month, spans vehicle plants in four states plus engine, casting, and battery sites, many of which appear on our Southern Auto Belt plant map.
None of the five checks is unique to Toyota. Together, though, they show where the company thinks defects are most likely to slip through: welds, seals, trim content, and the inside of aluminum castings.
Five checks, from the line to the foundry
Andon. Any team member on the assembly line can pull a cord or press a button when something looks wrong. Toyota says the call doesn't halt the line; it brings a team leader over to assess the problem while production keeps moving.
Ultrasound on welds. Where a standard chisel test can't reach, or where the steel is high-tensile, technicians check weld integrity with ultrasound. They use the same gel a clinic would use for a prenatal scan.
Water leak booth. At the assembly plants in Indiana, Kentucky, Mississippi, and Texas, every vehicle that enters the booth gets soaked by a simulated downpour. A team member then checks the cabin for any water that got in.
Camera vision system. Toyota Texas recently added an inspection station with eight cameras that verify 30 exterior specifications, covering the front and rear wheels, hood, side panels, and rear deck. According to the company, the system confirms 204 variations of model content.
CT scanning. Toyota Missouri and Toyota Tennessee use medical-grade CT machines on cast aluminum components. Unlike a flat X-ray image, the scan produces a 3D map, so team members can spot trapped air and other flaws hidden inside the metal.
Why Toyota is talking about quality now
The timing suits Toyota. Its owners ranked the brand first overall in the 2026 ACSI satisfaction study with a score of 83, taking the industry lead from Subaru, as we covered in September. The company is also building more here: in November 2025 it committed $912 million to hybrid production at five U.S. plants, including Troy, Missouri, and Jackson, Tennessee, as part of a plan for up to $10 billion in additional U.S. investment over five years, WEKU reported. Toyota employs about 50,000 people across 11 U.S. plants.
It has also been a heavy recall season. Toyota is recalling about 31,000 2026 RAV4 Plug-in Hybrids for a control-unit fault that can cut drive power, 8,521 electric C-HRs for a battery-software error, and 105,794 Land Cruisers for a fuel-line joint that can leak, a failure Toyota told NHTSA it hasn't yet explained.
That marks the limit of what plant checks can do. Leak booths, weld scans, and CT machines are built to catch assembly and casting defects before a vehicle ships. The RAV4 and C-HR campaigns are software problems, which no water booth or camera gantry will find.
Toyota's post also leaves out the numbers that would show how well the checks work: how often they flag a defect, and what share of vehicles gets pulled for rework. Earlier this month the company profiled the team that makes sure new models fit its paint shop, so more of these factory-floor stories are likely before Manufacturing Month ends.
