Diagnostics can be deceptively simple. A light may just flash a semaphore-like code, but it will be going to something far more sophisticated, requiring proprietary tools, lots of computing power, and a work-shirt full of certification patches to know how to use them.

Yet at a time when the average highway tractor has more computing power onboard than an Apollo-vintage lunar module, troubleshooting engines and other electronically controlled components is still something of a crapshoot. The problem is at the start of the process, with the truck driver describing a clunk or a thud to a bemused, confused mechanic, and ending with a bill that’s over the moon because it took longer to find the problem than it should have.

Imagine, instead, the driver plugging a cell phone into his truck’s J1587/1939 diagnostic port when something goes amiss. It reads and compiles an array of fault codes and performance data on the ECM, dials a phone number, and posts the data to a web page so the mechanic can see what that clunk or thud looks like in graphic detail.

It’s coming to a truck near you, and soon, says the mobile diagnostics group at Eaton Corp.

Eaton hit the streets last year with a versatile and affordable ($700 US) handheld diagnostic scan tool and data logger and now wants to expand into remote diagnostics. In July, the company inked a deal with VTTi, a Tustin, Calif., software developer that made its mark by figuring out how to use a cellular phone to tap into the microprocessors that control hot tubs and then relay that information to someone who knows what to do with it.

Like your truck, a hot tub has a computer that monitors its operation. When something goes awry it can be an expensive fix, a lot of times because of a trial-and-error repair strategy.

Instead of guessing why the spa jets won’t fire up or the filtration system is on the fritz, now your local pool guy can plug one end of a cable into his phone and the other end into the hot tub’s electronic controller. A little Java-based application on the phone reads the fault codes, makes a call, and populates a web page with clear, concise diagnostic information. An engineer back at the plant can go online, troubleshoot the problem, and then call the pool guy on the phone and walk him through a repair on the spot.

Eaton says its work with VTTi should result in a product by the end of the year.

The collaboration between VTTi and Eaton illustrates some important points about the direction of heavy-truck diagnostic tools.

First, unless you’re a professional technician going to work every day in a shop, some of the hardware you can use to read engine, brake, transmission and power-line-carrier (PLC) diagnostic data may already be in your briefcase or on your hip. Second, it’s not enough to simply collect and see information on the ECM. To make the most of it, you’ll want to share it over the Internet or across a wireless network.

Third, diagnostics for heavy-trucks face new standards being driven by — who else — environmental regulators. The U.S. Environmental Protection Agency says heavy-duty trucks eventually will need onboard emission diagnostics similar to the OBD II systems you see in passenger cars. The EPA says fault data must be easily extracted and available to generic service tools using a standard connector.

HANDHELDS

That’s not necessarily a bad thing. With onboard electronics evolving so rapidly, most OEMs have figured out that it’s a drag financially for them (and their customers) to have to create a new, dedicated diagnostic tool and the software to run it every time they issue a next-generation product.

The groundbreaker in this regard was Cummins, which four years ago dropped its proprietary scan tool in favor of QuickCheck, a cost-effective software package and J1587/1939 connector that runs on a personal digital assistant (PDA). Most run either the Palm or Microsoft Windows Mobile 2003 operating system.

For truck owners and fleet managers, QuickCheck — now in its third iteration — showed that while a PDA may lack the resources to manage complex diagnostic tasks, it has plenty of memory and processing power to tap into a J1587/1939 diagnostic port and let you stand toe to toe with the computers that manage your truck’s engine, transmission, brakes, and other electronically controlled systems.

Today, even NEXIQ, maker of the Pro-Link scan tools favored by so many heavy-duty technicians, sells Palm-based software and a set of cables that are compatible with just about any ECM that supports generic SAE J1587/1708 messaging.

NOTEBOOKS

PDAs are designed to easily hook up and offload information to a PC or laptop, but the PC as a diagnostic tool has its drawbacks. The shop floor is not a friendly environment for office-grade PCs, which get buggy if they’re jostled around too much. Also, the term “hard drive crash” takes on new meaning when your computer slips and hits the shop floor.

Companies like Panasonic and Xplore Technologies make hardened notebook PCs for on-the-go computing in extreme environments, but they’re expensive. And IBM has developed a motion sensor for its ThinkPad notebooks that temporarily parks the hard drive’s read/write head when it detects a fall. The whole process takes less than 500 milliseconds. Your data is another story. And a shocking one if it can’t be recovered.

WIRELESS

The shift away from proprietary diagnostic hardware and software to a PDA-style handheld, notebook PC, or even a cell phone is making it easier for truck equipment manufacturers to focus on simpler, more intuitive diagnostics while letting someone else keep up with all the latest developments in hardware.

A lot of that development involves wireless communication over a wireless local area network (LAN). Wireless LANs are showing up everywhere: in the home, the office, and “hot spots” like Starbucks coffee stores, hotels, and airport departure lounges. The most common wireless LAN protocol is called 802.11b (better known as Wi-Fi); it’s cheap, easy to deploy, and has a range of 200 to 1,000 feet. More and more PDAs have Wi-Fi capability built in or a slot that can accept an expansion card.

In an office, installing a wireless LAN yields lightweight returns. In a shop, though, it means you don’t have to physically plug into every vehicle in order to read trip data or fault codes. And that’s huge.

Consider Mack Trucks’ InfoMax Wireless, launched last year. It puts each truck’s onboard computer and trip recorder onto a wireless LAN so you can extract data quickly and easily without a physical connection when the truck is within range of Mack’s wireless router.

If a truck drops out of wireless range before an upload is complete, the system simply catches it next time around. Information can flow the other way, too: you can change parameters for as many as 127 trucks simultaneously with a single keystroke.

Truly, it’s technology that keeps you moving.