Unclassified problem on the 1999 Toyota 4RUNNER
2 crashes 1 fire 2 injuries 5 of the 21 reports for this failure mention a crash, a fire, an injury or a death. Those are the owner's words on the complaint form, not a verified finding, and one report can mention more than one.
Only 14 reports for this mode came with an odometer reading, which is too few for percentiles to mean anything. The page is here because someone linked to it; treat the figures as anecdotes, and see the full report for this year instead.
When unclassified problem gets reported
Owners of the 1999 Toyota 4RUNNER report unclassified problem at a median of 195,000 miles. A quarter of the reports come in before 160,000 miles and a quarter after 220,000 miles, from 14 reports that carried an odometer reading.
It is the 30th most-reported problem on this model year.
The mileage distribution
The reported range runs from 125,000 miles at the tenth percentile to 240,000 miles at the ninetieth, a spread of 114,100 miles across the middle 80% of reports.
A spread this wide points at use rather than design. Towing, climate, service history and city mileage all move a failure like this, so the median is a weak guide to any individual car.
0% of the dated reports were filed under 36,000 miles.
The whole distribution
| 10th | 25th | Median | 75th | 90th |
|---|---|---|---|---|
| 126,900 miles | 160,000 miles | 193,206 miles | 217,817 miles | 241,000 miles |
Read the 10th percentile as “one report in ten arrived this early”. Exact figures are shown in this table because it is the table of record; everywhere else on the site they are rounded to the precision the sample can carry.
What a percentile can and cannot tell you here
These five numbers describe the readings owners gave, in order. The median is the middle one: half the reports arrived below it. The 10th and 90th are the edges of the bulk of the distribution, and the distance between them is the part worth reading. A tight spread — say 70,000 to 95,000 miles — points at something that wears out on a schedule, and the schedule is knowable. A wide one, 20,000 to 190,000, points at a fault that hits some cars and never troubles others, which means the mileage on the listing in front of you tells you very little about your odds.
What these figures are not is a survival curve. Every reading here comes from a car whose owner filed a complaint, so the sample contains only failures: it cannot say what share of the fleet made it past 150,000 miles untouched, because those owners had nothing to report. Nor is the mileage the moment of failure — it is the odometer reading as recalled at the time of filing, which may be weeks later and is sometimes rounded to the nearest ten thousand by the person typing it.
Percentiles are shown at all only once 8 readings exist for the vehicle and mode. Below that the middle of a handful of numbers is noise wearing a decimal point, so the figures are withheld rather than dressed up.
What happens, and what it costs
Of these reports, 2 a crash, 1 a fire and 2 an injury are mentioned. Owners write their own complaints and the agency does not verify them, so read this as what the reports say happened rather than as a confirmed count.
The same failure on other years
The same failure is reported on 25 model years of this car. It shows up earliest on the 2022, at a median of 200 miles, and latest on the 1997 at 225,000 miles.
By volume the 2004 carries the most reports, with 87; the 1999 has 21. A mode that appears across most years of a model is usually a design choice rather than a bad batch.
If one year stands out to the left, that is the year to avoid; if the whole line sits at a similar mileage, this is wear rather than a defect in one production run.
Tick median reported mileage Solid middle half of reports Faint 10th to 90th percentile Colour how bad the failure is when it happens
What owners wrote
Verbatim from NHTSA complaint narratives, trimmed for length. The mileage is the one the owner gave.
Air bags failed to deploy on feb. 10, 2010 following a serious front end crash (30-50 MPH) of our 1999 toyota 4 runner. As a result wife was hospitalized for 2 days with concussion, sprained neck and ptss.california highway patrol responded. Report taken. *tr
604i was driving on the highway and out of no where a loud beeping started, along with flashing "loss of traction" icon and then all of the sudden the brakes engaged and a loud grinding sound began which slammed myself and my children forward. It slammed us so hard it brought my speed down from 65 MPH to 40 MPH, and I was unable to accelerate or control the speed. To avoid hitting another vehicle I had to swerve, and began pushing the brake to try to slow the SUV, while it was still grinding so loud. I practically was standing with both feet in the brakes to stop it. The dealer ship said it was a faulty yaw rate sensor.
I bought my 1999 4runner less than a year and a half ago at 150,000 miles on it. My sister was driving it on the highway going 60-70 MPH and suddenly the car started swerving left so she immediately got off and went to our mechanic who then told us that my frame is completely cracked, he said that I could not drive my car home and that the frame was too rusted so there was nothing I could do so its totaled. I barely got to 200,000 miles and had it for such a short amount of time. Not to mention the fact that the car could have flipped at any second my mechanic said "one more bump and it would have flipped". I am 19 years old and a nanny so I constantly have kids in my car, we could have been extremely hurt or died!! I called toyota but they have no recall and cant do anything about it so now I have to buy a new car. Disappointing to say at the least, I was under the impression that toyota's lasted for an extremely long amount of time.
Also reported on the 1999 Toyota 4RUNNER
Other body or interior problem
Rust or structural corrosion
Control arm, ball joint or bushing failure
Other suspension problem
Fuel gauge or level sensor failure
Differential or transfer case failure
How far this goes
This page is kept out of search results because 21 reports is not enough to publish percentiles from. It stays reachable because somebody looking at this exact car would rather see the reports than be told there are none.
Complaints are voluntary, so 21 is a floor and not a count of affected cars. Mileages are typed in by owners and cluster on round numbers. And the mode itself is assigned by software reading the complaint text, which is reliable in bulk and fallible one report at a time.
Questions this page answers
At what mileage does unclassified problem happen on the 1999 Toyota 4RUNNER?
Across 14 owner reports that included an odometer reading, half were filed by 195,000 miles. A quarter were filed before 160,000 miles and a quarter after 220,000 miles. These are the mileages owners reported when they complained, not a prediction for any individual car.
How common is unclassified problem on the 1999 Toyota 4RUNNER?
21 reports have been filed with NHTSA, about 121 per 1,000 vehicles. Complaints are voluntary, so this is a floor rather than a count of affected cars.
What this is and is not. These are the mileages at which owners chose to complain to a federal agency, which is not the same as the mileage at which the part fails on every car. It skews toward failures that happened outside warranty, cost real money, or frightened someone. It is still the only public dataset that carries failure mileage at all, and the shape of a few hundred readings is informative even when a single one is not. Methodology · JSON · this failure on other cars
Source Owner complaints and recall records published by the US National Highway Traffic Safety Administration, model years 1996–2027 Figures rebuilt Published by AtWhatMileage How every figure is computed