Control module (ECM/PCM/BCM) failure on the 2005 Audi A6
Only 7 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 8 reports of control module (ECM/PCM/BCM) failure on the 2005 Audi A6, 7 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 3rd most-reported problem on this model year.
The whole distribution
| 10th | 25th | Median | 75th | 90th |
|---|---|---|---|---|
| — | — | 120,000 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
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 7 model years of this car. It shows up earliest on the 2003, at a median of 10,000 miles, and latest on the 2005 at 120,000 miles.
By volume the 2000 carries the most reports, with 13; the 2005 has 8. 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.
My ABS light, parking brake failure, and esp lights all came on at the same time while driving my 2005 audi a6 4.2 s-line model through a sudden snow storm in colorado. My ABS immediately failed and my brakes locked, causing me to lose control of my vehicle, and fortunately I avoided a crash (I was at low speeds). The quattro all wheel drive was also disabled at this time and I was unable to gain traction on the icy road. This could have been a devastating crash resulting in injuries if I had been going the speed limit that night. I immediately took my car in for service on 12/2/09 and was told I needed to have the ABS module replaced at a cost of around $1600. Why was this not a recalled part? According to the service tech at stammler audi in boulder, co it is a very common problem with the 2005 model year because it is the first year to have some new technology involved in the vehicle's driving systems. I am extremely upset that there is nothing I can do but pay out of pocket for a defective part, that audi also agrees with, just to drive safely on the roadways. *tr
My ABS light, parking brake failure, and esp lights all came on at the same time while driving my 2005 audi a6 4.2 s-line model through a sudden snow storm in colorado. My ABS immediately failed and my brakes locked, causing me to lose control of my vehicle, and fortunately I avoided a crash (I was at low speeds). The quattro all wheel drive was also disabled at this time and I was unable to gain traction on the icy road. This could have been a devastating crash resulting in injuries if I had been going the speed limit that night. I immediately took my car in for service on 12/2/09 and was told I needed to have the ABS module replaced at a cost of around $1600. Why was this not a recalled part? According to the service tech at stammler audi in boulder, co it is a very common problem with the 2005 model year because it is the first year to have some new technology involved in the vehicle's driving systems. I am extremely upset that there is nothing I can do but pay out of pocket for a defective part, that audi also agrees with, just to drive safely on the roadways. *tr
Very common problem - "ignition module defective" code at 190,000 miles. Temporary repair of the issue with dtc reset. Full logging of car data via obd-ii port reveals zero faults while car is running, and diagnostic traffic on the can bus at startup show zero faults. Once key is inserted in dash and turned to "accessory", module faults out without any traffic sent/received. Happens intermittently and dealership states this is a known problem. Dealership-only repair, per multiple audi service technicians, audi of america refuses to comply with massachusetts right to repair law by making available to independent repair shops, the necessary tools and equipment to access the immobilizer hardware. Dealer estimates/quotes range from $2100-$3700 to replace entire steering column with the attached and separable ignition module (accessible via 2 screws and 1 rivet). Dealerships refuse to replace/re-code only the ignition module, stating the entire steering column needs replaced. Multiple reports of the same issue with other c6 body audi a6 owners confirm the same details. Nothing is physically wrong with the ignition switch or module, and…
Also reported on the 2005 Audi A6
Airbag inflator rupture
Parking brake failure
Steering column or shaft failure
ABS module or sensor failure
Other electrical problem
Other visibility problem
How far this goes
This page is kept out of search results because 8 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 8 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 Audi A6?
Across 7 owner reports that included an odometer reading, half were filed by 120,000 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 2005 Audi A6?
8 reports have been filed with NHTSA, about 0.5 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