Diagnostic Dilemmas: Changes In Our Diagnostic Outlook

Diagnostic Dilemmas: Changes In Our Diagnostic Outlook

Everybody likes to read about a Diagnostic Dilemma that has been solved to everybody's satisfaction. But this month I have an unsolved Diagnostic Dilemma that is more about customers than cars. This particular dilemma involves a 2005 Ford Crown Victoria with headlamps that randomly lose power during night driving.

Everybody likes to read about a Diagnostic Dilemma that has been solved to everybody’s satisfaction. But this month I have an unsolved Diagnostic Dilemma that is more about customers than cars. This particular dilemma involves a 2005 Ford Crown Victoria with headlamps that randomly lose power during night driving. According to its 80-year-old owner, a flick of the dimmer switch will reactivate the headlamps for several days, weeks or perhaps a month. Based on a prior experience he had with intermittent headlamps on a 1978 Ford LTD, the Crown Victoria’s owner requested our local Ford dealership replace the light switch, which, of course, didn’t solve the problem.

Because the two lighting technologies are completely different, the customer arrived at a false conclusion. As I explained to him, a headlamp switch on a 1978 Ford LTD is mechanical device containing a circuit breaker that’s designed to momentarily interrupt current to the headlamps if the lamp wiring circuit shorts to ground. The headlamps will blink off, but they will come back on. In contrast, his 2005 Crown Victoria uses a fuse box to protect the lighting circuits and a module to control the lighting system. The lights blinking off and on probably, according to my experience, has more to do with the lighting module than with a faulty lighting switch.

I also explained that the diagnosis might be complicated by his vehicle being equipped with the optional automatic dimmer and daytime driving light modules.

At this point, I was fairly ­certain that I was talking way over my octogenarian ­customer’s head, but hope springs eternal. When I checked the light module for diagnostic trouble codes, I found five trouble codes addressing different parts of the system, including the newly installed light switch. I hate to use the word “assume,” but to make sense of the codes, I had to assume that most of these codes were stored when the dealer tech replaced the light switch. If it were me, I would have cleared all codes after replacing the switch. But, since this wasn’t the case, I spent an hour running the headlamps, checking for loose fuses, and doing a wiggle test on the light module and failing to duplicate the problem.

So, with my suspicions and experiences pointing at the lighting module, I’m faced at this point with making an educated guess on the cause of the intermittent loss of light complaint. Since the owner is living on a fixed income, I recommended clearing the codes and driving the vehicle until the lights again failed. At least then I would have some valid codes to work with.

But, I actually had two Diagnostic Dilemmas, the first being technical and the second being clearly communicating with the customer. Given a realistic approach, the technical part I can deal with. But the customer communications part began to give me trouble. After I patiently explained the situation, this retiree seemed to understand that replacing suspect parts would be expensive and with no guarantee of success.

When I called back a week later, he told me that he had driven the car on a 300-mile trip with no headlamp failures and I haven’t heard to the contrary since. I had to ask myself if the customer had any confidence whatsoever in my technical know-how. Is a repair possible in this circumstance? Probably only if my customer drives at night, which might not be the case.

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Our Aging Vehicle Fleet

Because we work on different types of vehicles in different situations, most of us in automotive diagnostics become the products of our experiences. With that said, let me expound for a bit on the changes that might be affecting our future diagnostic outlook. While I’m certain that diagnostic techs working in rust-belt areas don’t have this problem, in my end of the world we have very little rust and, as long as it’s economically feasible to continue repairing a vehicle, many vehicle owners seem to be choosing that option. In fact, after the economy crashed in 2008, many in our rural mountain area actually began rehabilitating some of the “golden oldies” parked in their back yards. On some days, I’ve been using my old 60-pin Ford break out box more than I’ve been using my scan tools. But, the diagnostic reality is that electronic parts are becoming less available for many of these vehicles and I believe more will find their way to the scrap yard due to major electronics failures than due to ­conventional mechanical failures.

When I first began working as a gas pump attendant in the late 1950s, engines would last only about 70,000 miles on average before developing a burned exhaust valve or a knocking connecting rod bearing. Even worse, the interior upholstery would last only about half that long. Back in that day, it wasn’t hard to find a five-year-old vehicle rusting away in a salvage yard simply because it was worn out and its technology had become obsolete. But now, the average age of our national vehicle fleet is pushing 11 years, with much of this longevity being attributed to better engines and powertrains and far more durable exterior paint and interior appointments. So, given some decent maintenance, it’s not unusual for a modern vehicle to last well over 250,000 miles and 10 years of age. While much of the maintenance needs on older vehicles disappear into the DIY market, most owners still need the services of a trained diagnostic technician to deal with the vehicle’s electronic failures. Given the aging of our national vehicle fleet, we’re probably going to see an interesting mix of new and old coming through our shop doors.

Thanks to more vehicle recalls and more information available through various technical hotlines, I’m also seeing fewer pattern failures among out-of-warranty vehicles. Other ­pattern failures have simply disappeared due to better fuels and oils. For example, most veteran techs have repaired the sticking fuel injector poppet valves on the late 1990s 5.7L Chevy Vortec truck engines. As you may recall, a stuck poppet valve would result in a cylinder misfire. A reformulation of our gasoline and conversion of the poppet valve systems to conventional fuel injectors has since eliminated this once troublesome problem. As a matter of fact, I’m seeing no contaminated fuel or fuel-quality problems whatsoever in our current market. I couldn’t say that 10 years ago.

Leaking fuel pressure regulators were very common on this early 2000 Chevy Vortec truck engine. Thanks to better replacement parts, I haven't seen a similar failure in the past several years.

On the other hand, I’m seeing more problems caused by the lack of familiarity with older systems. Case in point, I had a client ask me about the cause of a minor, but irritating, no-code surging complaint at low engine speeds and light throttle applications on his 1996 5.7L Chevy Vortec. At 140,000 miles, I recommended replacing the original spark plugs, wires, distributor cap and rotor just to eliminate the possibility of secondary ignition problems. Since the problem remained, I next recommended re-synchronizing the distributor cam sensor, which was ­running at about -7°, due to timing chain wear. While -7° cam synch normally wouldn’t cause any problems, it might aggravate a minor lean-fuel condition brought on by dirty fuel injectors. Re-synching the cam sensor did remedy the complaint. Here again, this vehicle is now 17 years old and we’re diagnosing a non-pattern failure that is related more to age and mileage than to any particular design or component failure.

Our Modern Vehicle Fleet

Although some technicians believe that hybrid, electric and alternative fuel vehicles are more a fad than technical reality, I believe quite to the contrary. During the early 1990s, I covered much of the technology that various auto manufacturers were racing at Colorado’s famous Pikes Peak hill climb. Even then, at least one major petroleum company was doing developmental work on propane and natural gas-­powered vehicles. One auto manufacturer had even set a new class record with a battery-powered compact pickup truck.

The fact is, much of the development work on all hybrid, electric and alternative fuel vehicles is at least several decades old. Two of the world’s largest motor companies are heavily invested in producing hybrid and electric vehicles and now we’re beginning to see hybrid technology adapted to conventional platforms in the form of idle/stop technology.

Some OEMs are handling this deluge of technical information by certifying their technicians to be “service-ready” to repair specific platforms like hybrids and electrics. Their objective, of course, is to have their technicians trained to a high level of service readiness when the new generation of vehicles appears on a show room floor. Thanks to longer manufacturer warranty and extended warranty periods, the aftermarket lags about three to four years behind dealerships on the types of maintenance and repairs we see coming into our service bays. So, although service readiness isn’t currently seen as a major requirement in the aftermarket, we do need service-ready training before we attempt to do major repairs on revolutionary designs like hybrid, electric, idle-stop and alternative fuel technologies.

The current deluge of the “service-ready” knowledge needed to diagnose and repair hybrid, electric and alternative fuel vehicles is of such breadth and depth that it’s difficult to teach on a piecemeal basis. The breadth and depth of knowledge has also increased to the point that it’s becoming more difficult to present live training in a classroom situation. A second current reality is that many trainers need at least two-dozen paying students to form a class. And, last, any service-ready training must be sequential and in order of ascending difficulty, which are two qualities that aftermarket training has struggled to provide. Since very little aftermarket training meets service-ready standards, we’re beginning to have a dialog about how our training might trend away from generalized live instruction to more self-directed, on-line learning.

We’re also beginning to discuss why Career Technical Education (CTE) must change its role in educating future technicians. To illustrate, the current task-based system works more effectively at acquiring factual knowledge than it does at promoting the understanding of that knowledge. For example, solving the low-beam lighting problem on the above 2005 Ford Crown Victoria requires far more critical and logical thinking skills (understanding) than it does hands-on repair skills. The least critical hands-on skills are knowing how to replace a lighting module or light bulb, whereas the most critical hands-on skills are knowing how to acquire data by using a professional multimeter and scan tool. But logical and critical thinking skills are also needed to understand how the light switch, light module, automatic dimming module and daytime driving light module interact with each other to operate the exterior lighting system and what type of diagnostic strategy might be required to verify and diagnose the customer’s complaint. Without logical and critical thinking skills (understanding), the hands-on skills become useless in the modern world of auto repair.

Tooling and Equipment

The rubber really hits the road for independent shops when it’s time to update their diagnostic tooling. I’m sure that many of us have bought “leading-edge” tooling only to see it gather dust in the real-world environment of a production shop. As a result, many of us are approaching the topic of OE tooling with caution. But let’s keep in mind that in the near future, more vehicle operating systems will be “drive-by-wire” and will be operated by modules that will need to be initialized or programmed when they are replaced. While various J-2534 reprogramming tools are designed to re-flash or program powertrain control modules (PCMs) for exhaust emissions repairs, many aren’t as adept at re-flashing modules that control the various operating systems in the vehicle.

On the other hand, it’s impractical for the average independent shop to maintain a dozen or more OE scan tools and their software updates and database subscriptions to support what inevitably turns out to be a modest volume of initialization and reprogramming service work relative to that investment. Unless we’re speaking of a large, high-volume or multiple outlet shop, it’s also impractical to expect the most adept technician to gain enough training and technical proficiency to profitably repair each of the 1,000-plus vehicle platforms being sold on the domestic ­market each year.

Of course, this leads us to the topic of specialization. The most profitable independent repair shops in recent years are the ones that focus their operations on specific services or vehicle platforms. The math is pretty simple: A Subaru technician needs only one scan tool, one information system, one set of special tools and one relatively short learning curve to produce eight hours of billable labor. In contrast, the general repair technician needs the same tooling in multiples of 12 or more to bill an equal number of hours. While specialization isn’t possible in all market and economic bases, the narrowing of a shop’s service focus is not only possible, but will become a major requirement for economic survival in the near future.


Cost Of Owning Operating Vehicle In U.S. Increases Nearly 2%

AAA has released the results of its annual ‘Your Driving Costs‘ study, revealing a 1.96% increase in the cost to own and operate a sedan in the U.S. The average cost rose 1.17 cents to 60.8 cents per mile, or $9,122 per year, based upon 15,000 miles of annual driving.

“Many factors go into the cost calculation of owning and operating a vehicle,” said John Nielsen, AAA director of automotive engineering and repair. “This year, changes in maintenance, fuel and insurance costs resulted in the increase to just over 60 cents a mile.”

The costs associated with maintaining a vehicle had the single largest percentage increase from 2012 to 2013, growing by 11.26% to 4.97 cents per mile on average for sedan owners. AAA’s estimates are based upon the cost to maintain a vehicle and perform needed repairs for five years and 75,000 miles including labor expenses, replacement part prices and the purchase of an extended warranty policy. Driving the increase in maintenance costs are significant increases in labor and part costs for some models and a major increase in the price of extended warranty ­policies due to high loss ratios by underwriters.

Source: AAA


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