Control module (ECM/PCM/BCM) failure on the 2009 Hyundai Sonata
Only 5 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 control module (ecm/pcm/bcm) failure gets reported
There are 7 reports of control module (ECM/PCM/BCM) failure on the 2009 Hyundai Sonata, 5 with a mileage attached. That is too few to place the failure on the odometer with any confidence.
A part like this is normally expected to survive 92,000 miles. It is the 23rd most-reported problem on this model year.
The whole distribution
| 10th | 25th | Median | 75th | 90th |
|---|---|---|---|---|
| — | — | 90,250 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 $700–$3,000 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 17 model years of this car. It shows up earliest on the 2008, at a median of 5,000 miles, and latest on the 2011 at 117,500 miles.
By volume the 2011 carries the most reports, with 41; the 2009 has 7. 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.
Tl* the contact owns a 2009 hyundai sonata. The air bag warning light was illuminated on the instrument control panel, which indicated that the air bags were inoperative. The manufacturer and the dealer were notified, and the representatives concluded that the failure was a normal characteristic of the vehicle. The failure mileage was 6,000. The consumer stated his wife is 90bls and when she sat in the passenger seat, the air bag light remained on. Sometimes, the light will go off. Updated 10/29/09
I noticed a shuddering at 90,250 miles, while traveling during the winter at around 30-45 MPH, but was very intermittent, and would go away. Then on 10/9/2013 at 102,515 miles, from park, the transmission would not engage into reverse or drive. I could hear the transmission shift, but it was not disengaging from park. Per hyundai service technician, the transmission was "junk" and would need to be replaced. I contacted hyundai corporate, during which time I was informed they didn't have my information in their system and that in fact there were 2 recalls that they failed to notify me of, and was told that if I allowed the hyundai service to do the repair right then, that I would be eligible for their policy reimbursement. One of the recalls was an ECM and tcm software update in which symptoms were improper clutching and de-clutching of gears when accelerating and decelerating. That shift quality over time caused undo stress on the gearing causing my failure. The repair was made, I then had to pay upfront, and a week later they've denied my policy reimbursement claim due to fluid being the cause of failure. I then provided them…
I noticed a shuddering at 90,250 miles, while traveling during the winter at around 30-45 MPH, but was very intermittent, and would go away. Then on 10/9/2013 at 102,515 miles, from park, the transmission would not engage into reverse or drive. I could hear the transmission shift, but it was not disengaging from park. Per hyundai service technician, the transmission was "junk" and would need to be replaced. I contacted hyundai corporate, during which time I was informed they didn't have my information in their system and that in fact there were 2 recalls that they failed to notify me of, and was told that if I allowed the hyundai service to do the repair right then, that I would be eligible for their policy reimbursement. One of the recalls was an ECM and tcm software update in which symptoms were improper clutching and de-clutching of gears when accelerating and decelerating. That shift quality over time caused undo stress on the gearing causing my failure. The repair was made, I then had to pay upfront, and a week later they've denied my policy reimbursement claim due to fluid being the cause of failure. I then provided them…
Also reported on the 2009 Hyundai Sonata
Other brake problem
Other body or interior problem
Other engine problem
Other electrical problem
Other driver assistance problem
Other powertrain problem
How far this goes
This page is kept out of search results because 7 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 7 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 control module (ecm/pcm/bcm) failure happen on the 2009 Hyundai Sonata?
Across 5 owner reports that included an odometer reading, half were filed by 90,000 miles. A quarter were filed before — and a quarter after —. These are the mileages owners reported when they complained, not a prediction for any individual car.
How common is control module (ecm/pcm/bcm) failure on the 2009 Hyundai Sonata?
7 reports have been filed with NHTSA, about 0.2 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