Other driver assistance problem on the 2009 Hyundai Sonata
When other driver assistance problem gets reported
Owners of the 2009 Hyundai Sonata report other driver assistance problem at a median of 95,000 miles. A quarter of the reports come in before 67,500 miles and a quarter after 122,500 miles, from 33 reports that carried an odometer reading.
A part like this is normally expected to survive 45,000 miles. It is the 5th most-reported problem on this model year.
The mileage distribution
The reported range runs from 50,000 miles at the tenth percentile to 157,500 miles at the ninetieth, a spread of 107,180 miles across the middle 80% of reports.
When the reports scatter this far, the mileage is telling you about how these cars were driven more than about the part itself.
3% of the dated reports were filed under 36,000 miles.
The whole distribution
| 10th | 25th | Median | 75th | 90th |
|---|---|---|---|---|
| 51,220 miles | 67,000 miles | 95,000 miles | 123,000 miles | 158,400 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
Putting it right typically runs $250–$1,800 at an independent US shop. That range is an editorial estimate held in this site's failure-mode catalogue, not a figure from NHTSA, and it is a repair cost rather than a diagnosis cost.
The same failure on other years
The same failure is reported on 16 model years of this car. It shows up earliest on the 2024, at a median of 100 miles, and latest on the 2019 at 125,000 miles.
By volume the 2007 carries the most reports, with 40; the 2009 has 37. 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.
I was driving the sonata when all of a sudden the car lost its force and wouldn't move. While stuck in the middle of the street I was pushing the gas peddle but the car would not go. The esc off light came on, and the check engine light as well. I powered the car off and turned it back on but the car still did not have a lot of force, but enough to get to a nearby parking lot. I left the car off in a parking lot for about 5 min and turned it back on. The esc light turned off, but not the check engine. There have been similar problems where its a switch in the brake peddle but that should not make the entire car shut off. I took it to my dealership since I just bought the car 2 weeks ago and now I'm waiting for diagnostics to come back. *tr
While driving home, I braked to turn into my neighborhood and was almost rear ended. My friend whom was following me stated that my rear brakes did not come on when I brake. I attempted to park my vehicle and I could not put the car into park but only neutral, nor could I shut off the vehicle. The key would not turn to shut off the vehicle. I had drive the car to a friends garage, place the car into neutral, detach the battery in order to have the vehicle shut off. *tr
While driving the check engine light and esc light comes on and it's like the gas is shut off but doesn't die. This has happened several times over the past 9 months and it really hasn't been an issue because normally you can shut the car off and turn it back on and it's fine but the other day I was on a major hwy in the middle lane and it shut down. Luckily I was able to make it to the shoulder otherwise I would have stalled in the middle lane causing an accident. *tr
Also reported on the 2009 Hyundai Sonata
Other brake problem
Other body or interior problem
Other engine problem
Other electrical problem
Other powertrain problem
Premature brake pad or rotor wear
How far this goes
Complaints are voluntary, so 37 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 other driver assistance problem happen on the 2009 Hyundai Sonata?
Across 33 owner reports that included an odometer reading, half were filed by 95,000 miles. A quarter were filed before 67,500 miles and a quarter after 122,500 miles. These are the mileages owners reported when they complained, not a prediction for any individual car.
How common is other driver assistance problem on the 2009 Hyundai Sonata?
37 reports have been filed with NHTSA, about 1.0 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