Control module (ECM/PCM/BCM) failure on the 2005 Hyundai Elantra
When control module (ecm/pcm/bcm) failure gets reported
Owners of the 2005 Hyundai Elantra report control module (ECM/PCM/BCM) failure at a median of 20,000 miles. A quarter of the reports come in before 1,800 miles and a quarter after 45,000 miles, from 8 reports that carried an odometer reading.
A part like this is normally expected to survive 92,000 miles. It is the 4th most-reported problem on this model year.
The mileage distribution
The reported range runs from 800 miles at the tenth percentile to 50,000 miles at the ninetieth, a spread of 49,494 miles across the middle 80% of reports.
Reports bunched into a band this tight usually mean the component has a life of its own: it goes at roughly the same mileage regardless of who owns it.
63% of the dated reports were filed under 36,000 miles.
The whole distribution
| 10th | 25th | Median | 75th | 90th |
|---|---|---|---|---|
| 806 miles | 1,750 miles | 19,930 miles | 44,000 miles | 50,300 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 12 model years of this car. It shows up earliest on the 2017, at a median of 2 miles, and latest on the 2009 at 100,000 miles.
By volume the 2004 carries the most reports, with 36; the 2005 has 10. 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.
Passenger's air bag light came on intermittently stayed on. Passenger's weight requirement for the seat was specified in the manual, however, the light would not go off. Consumer took the vehicle to the dealer. The dealer found a recall on the air bag software. Per the recall the technician reprogrammed the air bag sensor and the light went off. Consumer was concerned because he was not notified of a recall for this problem .*ak *bf *nm
The passenger side airbag off indicator light comes on sporadically in our new 2005 hyundai elantra when people are sitting in the seat. My wife weighs in excess on 190 pounds and the light came on at least 5 times during a trip of 124 miles in early march and has come on once or twice during trips of 26 miles to the grocery store. We tooke the car to the dealer and they did not do anything since they could not duplicate the problem.
Dt*: the contact stated the frontal airbag sensor works improperly. The airbag off light illuminated while an adult of 120 lbs. Was setting in the seat. The sensor illuminated for up to six minutes then turn off. The problem occurred at a variety of speeds. Every time the vehicle was inspected by the dealership the sensor was reset. The problem continued to occur. There was a recall, NHTSA # 05v395000, regarding the airbags. The recall was because the sensors identified a child as an adult were as in this case the problem is reversed.
Also reported on the 2005 Hyundai Elantra
Airbag warning light or occupant sensor fault
Airbag failed to deploy in a crash
Other speed control problem
Other body or interior problem
Other brake problem
Control arm, ball joint or bushing failure
How far this goes
Complaints are voluntary, so 10 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 2005 Hyundai Elantra?
Across 8 owner reports that included an odometer reading, half were filed by 20,000 miles. A quarter were filed before 1,800 miles and a quarter after 45,000 miles. 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 2005 Hyundai Elantra?
10 reports have been filed with NHTSA, about 0.1 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