Have you ever wondered why your customers buy the vehicles they do? Leaving our own prejudices against some vehicle brands aside for the moment, do you think our customers bought their current vehicles based purely on brand loyalty, or for other reasons, such as affordability, fitness for purpose, or because they perceive their chosen brand/model to be “a cut above the rest” in terms of quality and durability?
Have you also ever wondered why some customers switch vehicle brands, vowing never to own another “such and such” a vehicle again? Since there are neither simple nor right or wrong answers to any of these questions because we can’t always know the minds of our customers, we should perhaps consider these questions from our perspective as technicians. For instance, have you ever considered the possibility that there might be a link between our customers’ purchasing decisions and our continued employment in the car repair industry? There is indeed such a link, and in this article, we will take a closer look at how OEM manufacturers keep us employed, starting with saying that-
Before we get to specifics, we should state that it is not the intention of this article to either malign or promote any particular vehicle brand or manufacturer over any other. What follows are some findings from an extensive academic study of 345 vehicle recall campaigns during the period 2011/2012, and a subsequent effort to develop a system to classify both the causes and the effects of such recall campaigns purely for the purpose of statistical analysis. As a result, the details of the study are anonymous, and therefore, do not reference any particular OEM vehicle manufacturer or vehicle range/model.
Nonetheless, this writer has accumulated a vast collection of repair notes and diagnostic data spanning at least 25 years, and he is nothing if not meticulous about collating this data. Thus, when this academic study was released, this writer conducted his own research into the causes of vehicle recall campaigns as reported by, and to, the National Highway Traffic Safety Administration and the results of his research were somewhat surprising.
It turned out that even though the database maintained by the NHTSA (the primary source of the study data) only covers vehicles that are built and sold in the US domestic market, many of the study’s findings largely correlated with many pattern failures on a variety of vehicle brands and models that had passed through this writer’s workshop over many years. So why should this be surprising?
It is surprising because the pattern failures this writer had observed over many years occurred in and on vehicles that were built in markets outside of the US market. In practice, and based on this writer’s records and observations, this means that the causes of recall campaigns are not limited to geographical regions. It is also surprising because it seems that many OEM manufacturers fail to learn appropriate lessons from both their own and other manufacturers’ past mistakes as shown by the academic study that highlights multiple vehicle recalls for largely the same reasons across a variety of manufacturers.
The above is saying a lot, so let us look at some of the principal-
In the interests of fairness to vehicle manufacturers, it must be stated that a typical modern high-end vehicle can contain 20 000 or more individual components, all of which can interact in millions of different ways depending vehicle usage, driving style, and environmental factors. Therefore, ensuring that all components in all vehicles made by a particular manufacturer always work as designed, or always interact with other components as intended during the vehicle's useful life is an extremely challenging proposition.
However, since vehicle recalls are extremely expensive in terms of notification costs, parts/labour costs, possible legal liabilities, and lost sales, most manufacturers go to great lengths to ensure that the possibility of vehicle recalls are minimised. Nonetheless, according to the academic study cited above, the principal causes of vehicle recalls have largely remained the same over many years, and fall into several distinct categories or failure classes, so let us look at some figures from the cited study-
Note that the details reproduced here are taken from the study, and although only a few causes of vehicle recalls are listed here, these cases represent the highest number of vehicles recalled globally as the result of defective components during the study period-
|
Defective Component(s) |
Number of Affected vehicles |
|
Airbags/SRS systems |
3 069 306 |
|
Electrical system(s) |
5 014 387 |
|
Engine and engine cooling systems |
2 255 757 |
|
Vehicle speed control |
2 453 622 |
|
Power train |
2 660 439 |
|
Steering |
1 746 116 |
|
Suspension |
2 055 274 |
|
Exterior lighting |
2 487 802 |
Source: https://www.sciencedirect.com/science/article/pii/S0951832019311123
Limited space precludes the inclusion of a longer list, but we can put the above figures into some sort of perspective by saying that during 2004, manufacturers recalled a total of 30 806 508 vehicles globally, which was almost twice the number of vehicles (17 168 000) sold globally during the same year. Although defective components accounted for a significant percentage of the total number of recalls, other reasons for vehicles being recalled include aspects of vehicle design that failed to conform to one or more design and functionality standards set by regulatory bodies in different countries or jurisdictions.
So what does all or any of the above have to do with us as technicians? Simply this- in almost all cases, thousands of car owners make return visits to their chosen service providers (us, in this case) to resolve problems that originated during the design and development phases of their vehicles, and persisted through the testing phase without either being recognised or resolved by the vehicle manufacturer. Let us look at how some of these defects manifest in the real world by discussing some-
In practice, it can take several years for some types of design and/or manufacturing defects on vehicles to manifest. Moreover, even if faults do manifest, it can sometimes take several more years before a regulatory body recognises and/or acknowledges shortcomings or defects on a vehicle as a factory fault, but of course, recognising a fault or shortcoming on a vehicle does not necessarily translate into a vehicle recall. In practice, this means that we are sometimes required to diagnose/fix faults on vehicles with built-in faults that the manufacturer a) may not be aware of, and/or b), have not developed repair procedures for because the fault did not manifest during the vehicle’s development or testing phases.
Below are some examples of such faults, defects, and shortcomings, starting with-
All of us have struggled with reprogramming issues that appear to be un-resolvable at some point in our careers, and this writer had on several occasions returned vehicles to the manufacturer under warranty conditions precisely because of programming issues that could not be resolved.
We need not delve into the details of those cases here, but suffice to say that we often forget that the programming of even mid-sized modern vehicles can run to more than 10 million lines of code, which is about twice the amount of code a modern airliner requires to operate safely. Moreover, unlike an airliner, most of the code on a modern passenger vehicle is shared between two dozen or more microprocessors on a more or less permanent basis while the vehicle is in operation, so it is hardly surprising that things sometimes go awry.
As a practical matter though, most vehicle programming goes through several iterations before everything works as intended, but more importantly, the basic software architecture is often not compatible with patches, fixes, or updates that are developed and released during a vehicle’s production run. So what does this mean for us?
It means that when we replace or attempt to reprogram a defective control module or perform software updates, we could create (through no fault of our own), a situation where both "old" and "new" software configurations are established in the software architecture. The practical effects of such a condition usually include major incompatibilities between affected control modules, the disabling of some features and/or functionalities of some control modules, or more commonly, an inability to make patches, fixes, or updates "stick" to the overall programming of a problem vehicle.
Other common effects include changing or even removing minimum/maximum thresholds for systems like tyre pressure monitoring, engine cooling, and/or impact values for crash detection systems. The latter is rather serious, because it can prevent airbag deployment, or equally bad, trigger unrequested airbag deployments during normal vehicle operation.
Available data shows that during 2015, programming issues such as described here accounted for about 50% of vehicle recalls caused by software related failures of various electrical systems, exterior lighting, airbags, and systems/components relating to airbag operation.
Thus, given these insights, can you estimate how many hours you have spent during your professional life on trying to diagnose/repair issues that had nothing to do with your theoretical knowledge, diagnostic skills, or the quality/abilities of your diagnostic equipment?
This writer is willing to bet good money that many thousands of hours are lost globally due to built-in vehicle programming issues, but there are other, equally potentially serious causes of vehicle recalls that we deal with almost daily, such as-
These kinds of issues take many forms, and we have all dealt with them at some point even though we may not have realised that we were dealing with built-in defects at the time. Among many others, these include water and dust leaks, unsolvable rattles and squeaks, uneven tyre wear, peeling paint, and fasteners working themselves loose.
Unfortunately, limited space precludes a complete and/or exhaustive list of manufacturing and/or assembly defects, but we can do the next best thing, which is to look at a few of these causes that occurred during the 345 vehicle recalls that affected the highest number of vehicles during the study period (2011 to 2012) in some detail, starting with-
Water leaks
Adhesive application and poor sealing accounted for 84 out of the 345 vehicle recalls, with 78 of these cases reported by authorised installers/repairers of sunroofs- all reports being for the same defect. These 84 recalls affected 536 936 vehicles.
Improper fastening
Failing to tighten fasteners during assembly is the most common defect after poor sealing. The study cites 15 recalls caused by insufficient tightening, 13 recalls caused by fasteners not tightened to recommended specifications, and 2 recalls caused by fasteners coming undone because components were not seated, locked, or secured correctly.
It is worth noting that one vehicle recall was caused by improper tightening of rear suspension adjusting nuts, which caused excessive free play in control arms. In this particular instance that affected 780 585 vehicles, the excessive free play did not only cause uneven wear of the rear tyres, but also the failure of control arm bushings.
Surface processes
Although the study cites only 10 cases of vehicle recalls caused by surface issues, these 10 recalls affected 3 097 634 vehicles. These recalls addressed issues with inconsistent application of paint, over-application of paint and/or finishing coats, inconsistent and or insufficient paint thickness, or incorrect mixing of surface coatings.
Component damage during installation
Since almost any part or component can be damaged during installation, the study does not cite specific examples, but it does cite some interesting figures; for instance, 10 vehicle recalls caused by damaged components that affected 1 041 542 vehicles. Three more recalls were caused by damaged or improperly set jigs, tools, and fixtures, while 1 recall was caused by a poorly trained human installer, and yet another recall was caused by a malfunctioning assembly robot.
Regulatory oversights
While most vehicle recalls are caused by factors and issues at the individual vehicle manufacturer level, one particular vehicle recall caused by defective airbags manufactured by a single firm has affected several tens of millions of vehicles over several years. However, the exact reasons why and how major, and life-threatening defects in these airbags escaped the notice of both vehicle manufacturers and regulatory bodies the world over remain largely unexplained.
One other noteworthy example of a major vehicle recall campaign caused by regulatory oversights involves the emissions scandal involving some VAG-group vehicles, and although this recall did not involve life-and-limb defects, many technicians the world over spent many hours rectifying the problem on individual vehicles, which leaves us with this-
It would be fair to say that modern vehicles are marvels of design and engineering, and it has been said that the mere fact that they work at all is a sort of miracle, given the high number of parts they contain. However, despite the fact that the ISO and other organisations are actively involved in improving manufacturing and quality control processes in both vehicle assembly plants and parts supply chains, it is unlikely that it will ever be possible to develop vehicle design, manufacturing, testing, and assembly processes that will eliminate all or even most possible defects in new vehicles.
While we, as technicians, cannot do anything about built-in defects in new vehicles, it nevertheless behoves us to be aware of the fact that millions are vehicles are recalled every year, and in many cases, vehicles that are several years old are recalled. Of course, we can't use this as an excuse to get out of particularly difficult diagnostic challenges, but we can use this background knowledge to research these kinds of issues, which ultimately, allows us to serve our customers better.
