MAINTENANCE MATTERS

WORKING IN THE 21ST CENTURY SHOP
Tools and equipment necessary to service the modern motor coach

Model-year 2007 motor coaches will hit the streets with a dozen or more individual computers and electronic modules contained within their electrical system — a scary thought to many. Engine and transmission computers, ABS, HVAC, even the dashboard is a computer data-driven necessity.

So, whatever happened to the "good old days" when a screwdriver, some wrenches and a hammer were about all you needed to keep the wheels turning? Blame it on progress.

Operators wanted longer service intervals and less maintenance. More power but better mileage. More 'creature comforts' like air conditioning, kneeling, smoother ride, automatic transmissions and stereo. Then along came DVD players and now even laptop wireless accessibility for passengers.

And let's not forget the Department of Transportation, the EPA, OSHA and other regulatory agencies. A lot of the changes were for the better.

So why all of the electronics?
It's less expensive to manufacture, which means we can keep prices down for you. That front junction box with hundreds of single wire connections used to take a couple of days to assemble, but now it only takes a few hours to build. Think back to the mileage, smoke, oil and power loss on that engine if the overhead wasn't adjusted just right. And how long did it take to "run a rack"? Electronic fuel injection did away with all of that. Now we use computers and their related sensors. The feeler gauge became timing pins as engine design changed and improved. The test light became the "high impedance" multi meter. Plus, all of the different computers/modules onboard are communicating with each other on a common "party line" circuit that is behind the
multiplexing system.

This is really for the better, because now the once independent systems, each with their own sensors and individual wiring harnesses, are able to share information. This means fewer components doing the same jobs that each system needs. And communication is getting faster,
which means quicker, more accurate responses to changes in operating conditions. But alas, the more sophisticated the systems in our coaches are, the more sophisticated the test and diagnostic equipment.

Service Bulletin 2933 provides information on which diagnostic and equipment is needed for which operating systems. While many of us found it hard to accept the need for a fax machine in the office, or shop, today it's pretty hard to imagine doing business without it. Today's test equipment of choice is the laptop computer. The advantages of having a computer available for diagnostics is as far-reaching as the difference between a multi-meter is over the test light.

And so, the toolbox will have to adapt just like it always has. All of the mechanical basics of the internal combustion engine are still there. So we still need mechanics in the shop. But with the reality of the electronic age, we also need technicians. Lucky is the shop that has both, maybe even wearing the same uniform.

If your technicians need to brush up their diagnostic skills, MCI offers technician training classes. And, of course, MCI's technical support center is just a phone call away. Today's coaches may be more complicated, but it doesn't take a computer to see why they're so popular.

The FYI from MCI editorial staff values your feedback. Please e-mail any suggestions, comments, or ideas for future articles to fyi@mcicoach.com.